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  • 1.
    Abbott, Benjamin
    et al.
    Univ Rennes 1, OSUR, CNRS, ECOBIO,UMR 6553, Rennes, France.
    Baranov, Viktor
    Leibniz Inst Freshwater Ecol & Inland Fisheries, Berlin, Germany.
    Mendoza-Lera, Clara
    Ctr LyonVilleurbanne, UR MALY, Irstea, F-69616 Villeurbanne, France.
    Nikolakopoulou, Myrto
    Naturalea, Barcelona, Spain.
    Harjung, Astrid
    Univ Barcelona, E-08007 Barcelona, Spain.
    Kolbe, Tamara
    Univ Rennes 1, CNRS, OSURGeosci Rennes, UMR 6118, F-35014 Rennes, France.
    Balasubramanian, Mukundh
    BioSistemika Ltd, Ljubljana, Slovenia.
    Vaessen, Timothy N
    CEAB CSIC, Girona, Spain.
    Ciocca, Francesco
    Silixa, Elstree, England.
    Campeau, Audrey
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Wallin, Marcus
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Romeijn, Paul
    Univ Birmingham, Sch Geog Earth & Environm Sci, Birmingham B15 2TT, W Midlands, England.
    Antonelli, Marta
    LIST, Esch Sur Alzette, Luxembourg.
    Goncalves, José
    Natl Inst Biol, Ljubljana, Slovenia.
    Datry, Thibault
    Ctr LyonVilleurbanne, UR MALY, Irstea, F-69616 Villeurbanne, France.
    Laverman, Anniet
    Univ Rennes 1, OSUR, CNRS, ECOBIO,UMR 6553, Rennes, France.
    de Dreuzý, Jean-Raynald
    Univ Rennes 1, CNRS, OSURGeosci Rennes, UMR 6118, F-35014 Rennes, France.
    David, Hannah M.
    Univ Birmingham, Sch Geog Earth & Environm Sci, Birmingham B15 2TT, W Midlands, England.
    Krause, Stefan
    Univ Birmingham, Sch Geog Earth & Environm Sci, Birmingham B15 2TT, W Midlands, England.
    Oldham, Carolyn
    Univ Western Australia, Civil Environm & Min Engn, Perth, WA, Australia.
    Pinay, Gilles
    Univ Rennes 1, OSUR, CNRS, ECOBIO,UMR 6553, Rennes, France.
    Using multi-tracer inference to move beyond single-catchment ecohydrology2016In: Earth-Science Reviews, ISSN 0012-8252, E-ISSN 1872-6828, Vol. 160, p. 19-42Article in journal (Refereed)
    Abstract [en]

    Protecting or restoring aquatic ecosystems in the face of growing anthropogenic pressures requires an understanding of hydrological and biogeochemical functioning across multiple spatial and temporal scales. Recent technological and methodological advances have vastly increased the number and diversity of hydrological, biogeochemical, and ecological tracers available, providing potentially powerful tools to improve understanding of fundamental problems in ecohydrology, notably: 1. Identifying spatially explicit flowpaths, 2. Quantifying water residence time, and 3. Quantifying and localizing biogeochemical transformation. In this review, we synthesize the history of hydrological and biogeochemical theory, summarize modem tracer methods, and discuss how improved understanding of flowpath, residence time, and biogeochemical transformation can help ecohydrology move beyond description of site-specific heterogeneity. We focus on using multiple tracers with contrasting characteristics (crossing proxies) to infer ecosystem functioning across multiple scales. Specifically, we present how crossed proxies could test recent ecohydrological theory, combining the concepts of hotspots and hot moments with the Damkohler number in what we call the HotDam framework.

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  • 2.
    Abbott, Benjamin W.
    et al.
    Univ Rennes 1, OSUR, CNRS, UMR ECOBIO 6553, F-35014 Rennes, France.;Univ Alaska Fairbanks, Inst Arctic Biol, Fairbanks, AK USA.;Univ Alaska Fairbanks, Dept Biology& Wildlife, Fairbanks, AK USA..
    Jones, Jeremy B.
    Univ Alaska Fairbanks, Inst Arctic Biol, Fairbanks, AK USA.;Univ Alaska Fairbanks, Dept Biology& Wildlife, Fairbanks, AK USA..
    Schuur, Edward A. G.
    No Arizona Univ, Ctr Ecosyst Sci & Soc, Flagstaff, AZ 86011 USA..
    Chapin, F. Stuart, III
    Univ Alaska Fairbanks, Inst Arctic Biol, Fairbanks, AK USA.;Univ Alaska Fairbanks, Dept Biology& Wildlife, Fairbanks, AK USA..
    Bowden, William B.
    Univ Vermont, Rubenstein Sch Environm & Nat Resources, Burlington, VT 05405 USA..
    Bret-Harte, M. Syndonia
    Univ Alaska Fairbanks, Inst Arctic Biol, Fairbanks, AK USA.;Univ Alaska Fairbanks, Dept Biology& Wildlife, Fairbanks, AK USA..
    Epstein, Howard E.
    Univ Virginia, Dept Environm Sci, Charlottesville, VA 22903 USA..
    Flannigan, Michael D.
    Univ Alberta, Dept Renewable Resources, Edmonton, AB T6G 2M7, Canada..
    Harms, Tamara K.
    Univ Alaska Fairbanks, Inst Arctic Biol, Fairbanks, AK USA.;Univ Alaska Fairbanks, Dept Biology& Wildlife, Fairbanks, AK USA..
    Hollingsworth, Teresa N.
    Univ Alaska Fairbanks, PNW Res Stn, USDA Forest Serv, Fairbanks, AK USA..
    Mack, Michelle C.
    No Arizona Univ, Ctr Ecosyst Sci & Soc, Flagstaff, AZ 86011 USA..
    McGuire, A. David
    Univ Alaska Fairbanks, Alaska Cooperat Fish & Wildlife Res Unit, US Geol Survey, Anchorage, AK USA..
    Natali, Susan M.
    Woods Hole Res Ctr, Woods Hole, MA USA..
    Rocha, Adrian V.
    Univ Notre Dame, Dept Biol Sci, Notre Dame, IN 46556 USA.;Univ Notre Dame, Environm Change Initiat, Notre Dame, IN 46556 USA..
    Tank, Suzanne E.
    Univ Alberta, Dept Biol Sci, Edmonton, AB T6G 2M7, Canada..
    Turetsky, Merritt R.
    Univ Guelph, Dept Integrat Biol, Guelph, ON N1G 2W1, Canada..
    Vonk, Jorien E.
    Vrije Univ Amsterdam, Dept Earth Sci, Amsterdam, Netherlands..
    Wickland, Kimberly P.
    US Geol Survey, Natl Res Program, Boulder, CO USA..
    Aiken, George R.
    US Geol Survey, Natl Res Program, Boulder, CO USA..
    Alexander, Heather D.
    Mississippi State Univ, Forest & Wildlife Res Ctr, Mississippi State, MS 39762 USA..
    Amon, Rainer M. W.
    Texas A&M Univ, Galveston, TX USA..
    Benscoter, Brian W.
    Florida Atlantic Univ, Boca Raton, FL 33431 USA..
    Bergeron, Yves
    Univ Quebec Abitibi Temiscamingue, Forest Res Inst, Rouyn Noranda, PQ, Canada..
    Bishop, Kevin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. wedish Univ Agr Sci, Dept Aquat Sci & Assessment, S-90183 Umea, Sweden..
    Blarquez, Olivier
    Univ Montreal, Dept Geog, Montreal, PQ H3C 3J7, Canada..
    Bond-Lamberty, Ben
    Pacific NW Natl Lab, Richland, WA 99352 USA..
    Breen, Amy L.
    Univ Alaska Fairbanks, Int Arctic Res Ctr, Scenarios Network Alaska & Arctic Planning, Fairbanks, AK USA..
    Buffam, Ishi
    Univ Cincinnati, Cincinnati, OH 45221 USA..
    Cai, Yihua
    Xiamen Univ, State Key Lab Marine Environm Sci, Xiamen, Peoples R China..
    Carcaillet, Christopher
    Ecole Prat Hautes Etud, UMR5023, CNRS Lyon 1, Lyon, France..
    Carey, Sean K.
    McMaster Univ, Hamilton, ON L8S 4L8, Canada..
    Chen, Jing M.
    Univ Toronto, Toronto, ON M5S 1A1, Canada..
    Chen, Han Y. H.
    Lakehead Univ, Fac Nat Resources Management, Thunder Bay, ON P7B 5E1, Canada..
    Christensen, Torben R.
    Lund Univ, Arctic Res Ctr, S-22100 Lund, Sweden.;Aarhus Univ, DK-8000 Aarhus C, Denmark..
    Cooper, Lee W.
    Univ Maryland, Ctr Environm Sci, Bethesda, MD USA..
    Cornelissen, J. Hans C.
    Vrije Univ Amsterdam, Syst Ecol, Amsterdam, Netherlands..
    de Groot, William J.
    Nat Resources Canada, Canadian Forest Serv, Toronto, ON, Canada..
    DeLuca, Thomas H.
    Univ Washington, Sch Environm & Forest Sci, Seattle, WA 98195 USA..
    Dorrepaal, Ellen
    Umea Univ, Dept Ecol & Environm Sci, Climate Impacts Res Ctr, S-90187 Umea, Sweden..
    Fetcher, Ned
    Wilkes Univ, Inst Environm Sci & Sustainabil, Wilkes Barre, PA 18766 USA..
    Finlay, Jacques C.
    Univ Minnesota, Dept Ecol Evolut & Behav, Minneapolis, MN 55455 USA..
    Forbes, Bruce C.
    Univ Lapland, Arctic Ctr, Rovaniemi, Finland..
    French, Nancy H. F.
    Michigan Technol Univ, Michigan Tech Res Inst, Houghton, MI 49931 USA..
    Gauthier, Sylvie
    Nat Resources Canada, Canadian Forest Serv, Laurentian Forestry Ctr, Toronto, ON, Canada..
    Girardin, Martin P.
    Nat Resources Canada, Canadian Forest Serv, Laurentian Forestry Ctr, Toronto, ON, Canada..
    Goetz, Scott J.
    Woods Hole Res Ctr, Woods Hole, MA USA..
    Goldammer, Johann G.
    Max Planck Inst Chem, Global Fire Monitoring Ctr, Berlin, Germany..
    Gough, Laura
    Towson Univ, Dept Biol Sci, Towson, MD USA..
    Grogan, Paul
    Queens Univ, Dept Biol, Kingston, ON K7L 3N6, Canada..
    Guo, Laodong
    Univ Wisconsin Milwaukee, Sch Freshwater Sci, Milwaukee, WI USA..
    Higuera, Philip E.
    Univ Montana, Dept Ecosyst & Conservat Sci, Missoula, MT 59812 USA..
    Hinzman, Larry
    Univ Alaska Fairbanks, Fairbanks, AK USA..
    Hu, Feng Sheng
    Univ Illinois, Dept Plant Biol, Chicago, IL 60680 USA.;Univ Illinois, Dept Geol, Chicago, IL 60680 USA..
    Hugelius, Gustaf
    Stockholm Univ, Dept Phys Geog, Stockholm, Sweden..
    Jafarov, Elchin E.
    Univ Colorado Boulder, Inst Arctic & Alpine Res, Boulder, CO USA..
    Jandt, Randi
    Univ Alaska Fairbanks, Alaska Fire Sci Consortium, Fairbanks, AK USA..
    Johnstone, Jill F.
    Univ Saskatchewan, Dept Biol, Saskatoon, SK S7N 0W0, Canada..
    Karlsson, Jan
    Umea Univ, Dept Ecol & Environm Sci, Climate Impacts Res Ctr, S-90187 Umea, Sweden..
    Kasischke, Eric S.
    Univ Maryland, Dept Geog Sci, Bethesda, MD USA..
    Kattner, Gerhard
    Helmholtz Ctr Polar & Marine Res, Alfred Wegener Inst, Berlin, Germany..
    Kelly, Ryan
    Neptune & Co Inc, North Wales, PA USA..
    Keuper, Frida
    Umea Univ, Dept Ecol & Environm Sci, Climate Impacts Res Ctr, S-90187 Umea, Sweden.;INRA, AgroImpact UPR1158, New York, NY USA..
    Kling, George W.
    Univ Michigan, Ann Arbor, MI 48109 USA..
    Kortelainen, Pirkko
    Finnish Environm Inst, Helsinki, Finland..
    Kouki, Jari
    Univ Eastern Finland, Sch Forest Sci, Joensuu, Finland..
    Kuhry, Peter
    Stockholm Univ, Dept Phys Geog, Stockholm, Sweden..
    Laudon, Hjalmar
    Swedish Univ Agr Sci, Dept Forest Ecol & Management, S-90183 Umea, Sweden..
    Laurion, Isabelle
    Inst Natl Rech Sci, Ctr Eau Terre Environm, Toronto, ON, Canada..
    Macdonald, Robie W.
    Inst Ocean Sci, Dept Fisheries & Oceans, Toronto, ON, Canada..
    Mann, Paul J.
    Northumbria Univ, Dept Geog, Newcastle Upon Tyne NE1 8ST, Tyne & Wear, England..
    Martikainen, Pertti J.
    Univ Eastern Finland, Dept Environm & Biol Sci, Joensuu, Finland..
    McClelland, James W.
    Univ Texas Austin, Inst Marine Sci, Austin, TX 78712 USA..
    Molau, Ulf
    Univ Gothenburg, Dept Biol & Environm Sci, Gothenburg, Sweden..
    Oberbauer, Steven F.
    Florida Int Univ, Dept Biol Sci, Miami, FL 33199 USA..
    Olefeldt, David
    Univ Alberta, Dept Revewable Resources, Edmonton, AB T6G 2M7, Canada..
    Pare, David
    Nat Resources Canada, Canadian Forest Serv, Laurentian Forestry Ctr, Toronto, ON, Canada..
    Parisien, Marc-Andre
    Nat Resources Canada, Canadian Forest Serv, No Forestry Ctr, Toronto, ON, Canada..
    Payette, Serge
    Univ Laval, Ctr Etud Nord, Quebec City, PQ G1K 7P4, Canada..
    Peng, Changhui
    Univ Quebec, Ctr CEF, ESCER, Montreal, PQ H3C 3P8, Canada.;Northwest A&F Univ, Coll Forestry, State Key Lab Soil Eros & Dryland Farming Loess P, Xian, Peoples R China..
    Pokrovsky, Oleg S.
    CNRS, Georesources & Environm, Toulouse, France.;Tomsk State Univ, BIO GEO CLIM Lab, Tomsk, Russia..
    Rastetter, Edward B.
    Marine Biol Lab, Ctr Ecosyst, Woods Hole, MA 02543 USA..
    Raymond, Peter A.
    Yale Univ, Sch Forestry & Environm Studies, New Haven, CT 06520 USA..
    Raynolds, Martha K.
    Univ Alaska Fairbanks, Inst Arctic Biol, Fairbanks, AK USA..
    Rein, Guillermo
    Univ London Imperial Coll Sci Technol & Med, Dept Mech Engn, London SW7 2AZ, England..
    Reynolds, James F.
    Lanzhou Univ, Sch Life Sci, Lanzhou 730000, Peoples R China.;Duke Univ, Nicholas Sch Environm, Durham, NC 27706 USA..
    Robards, Martin
    Arctic Beringia Program, Wildlife Conservat Soc, New York, NY USA..
    Rogers, Brendan M.
    Woods Hole Res Ctr, Woods Hole, MA USA..
    Schaedel, Christina
    No Arizona Univ, Ctr Ecosyst Sci & Soc, Flagstaff, AZ 86011 USA..
    Schaefer, Kevin
    Univ Colorado Boulder, Cooperat Inst Res Environm Sci, Natl Snow & Ice Data Ctr, Boulder, CO USA..
    Schmidt, Inger K.
    Univ Copenhagen, Dept Geosci & Nat Resource Management, DK-1168 Copenhagen, Denmark..
    Shvidenko, Anatoly
    Int Inst Appl Syst Anal, A-2361 Laxenburg, Austria.;Sukachev Inst Forest, Moscow, Russia..
    Sky, Jasper
    Cambridge Ctr Climate Change Res, Cambridge, England..
    Spencer, Robert G. M.
    Florida State Univ, Dept Earth Ocean & Atmospher Sci, Tallahassee, FL 32306 USA..
    Starr, Gregory
    Univ Alabama, Dept Biol Sci, Tuscaloosa, AL 35487 USA..
    Striegl, Robert G.
    US Geol Survey, Natl Res Program, Boulder, CO USA..
    Teisserenc, Roman
    Univ Toulouse, CNRS, INPT, ECOLAB,UPS, Toulouse, France..
    Tranvik, Lars J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Virtanen, Tarmo
    Univ Helsinki, Dept Environm Sci, FIN-00014 Helsinki, Finland..
    Welker, Jeffrey M.
    Univ Alaska Anchorage, Anchorage, AK USA..
    Zimov, Sergei
    Russian Acad Sci, Northeast Sci Stn, Moscow 117901, Russia..
    Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire: an expert assessment2016In: Environmental Research Letters, E-ISSN 1748-9326, Vol. 11, no 3, article id 034014Article in journal (Refereed)
    Abstract [en]

    As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%-85% of permafrost carbon release can still be avoided if human emissions are actively reduced.

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    fulltext
  • 3. Abbuehl, Luca M.
    et al.
    Norton, Kevin P.
    Schlunegger, Fritz
    Kracht, Oliver
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    El Niño forcing on 10Be-based surface denudation rates in the northwestern Peruvian Andes?2010In: Geomorphology, ISSN 0169-555X, E-ISSN 1872-695X, Vol. 123, no 3-4, p. 257-268Article in journal (Refereed)
    Abstract [en]

    High magnitude precipitation events provide large contributions to landscape formation and surface denudation in arid environments. Here, we quantify the precipitation-dependent geomorphic processes within the Rio Piura drainage basin located on the Western Escarpment of the northern Peruvian Andes at 5 degrees S latitude. In this region, monsoonal easterly winds bring precipitation to the >3000 m asl high headwaters, from where the annual amount of precipitation decreases downstream toward the Pacific coast. Denudation rates are highest in the knickzones near the headwaters, similar to 200-300 mm ky(-1), and sediment discharge is limited by the transport capacity of the channel network. Every few years, this situation is perturbed by westerly, wind-driven heavy precipitation during El Nino events and results in supply-limited sediment discharge as indicated by bedrock channels. The detailed analysis of the stream-long profiles of two river basins within the Rio Piura catchment reveals a distinct knickzone in the transition zone between the easterly and westerly climatic influences, suggesting an En Nino forcing on the longitudinal channel profiles over at least Holocene timescales. Measured trunk stream catchment-wide denudation rates are up to ca. 300 mm ky(-1) and decrease successively downstream along the river profiles. Denudation rates of tributary rivers are ca. 200 mm ky(-1) near the plateau and show a stronger downstream decreasing trend than trunk stream rates. This suggests that the landscape is in a transient stage of local relief growth, which is driven by fluvial incision. This corroborates the results of paleoclimate studies that point towards higher El Nino frequencies during the past ca. 3000 years, leading to higher runoff and more erosion in the trunk channel compared to the hillslopes and thus growth of local relief. Downstream increases in channel gradient spatially coincide with the reaches of highest precipitation rates during El Nino events, we therefore interpret that Holocene landscape evolution has largely been controlled by climate. The ky-timescale of the Be-10 data together with the transience of the landscape implies that El Nino events in northwestern Peru have occurred since at least the Holocene, and that adjustment to channel incision is still taking place.

  • 4. Abbühl, Luca M.
    et al.
    Norton, Kevin P.
    Jansen, John D.
    Schlunegger, Fritz
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Erosion rates and mechanisms of knickzone retreat inferred from (10)Be measured across strong climate gradients on the northern and central Andes Western Escarpment2011In: Earth Surface Processes and Landforms, ISSN 0197-9337, E-ISSN 1096-9837, Vol. 36, no 11, p. 1464-1473Article in journal (Refereed)
    Abstract [en]

    A steep escarpment edge, deep gorges and distinct knickzones in river profiles characterize the landscape on the Western Escarpment of the Andes between similar to 5 degrees S and similar to 18 degrees S (northern Peru to northern Chile). Strong north-south and east-west precipitation gradients are exploited in order to determine how climate affects denudation rates in three river basins spanning an otherwise relatively uniform geologic and geomorphologic setting. Late Miocene tectonics uplifted the Meseta/Altiplano plateau (similar to 3000 m a.s.l.), which is underlain by a series of Tertiary volcanic-volcanoclastic rocks. Streams on this plateau remain graded to the Late Miocene base level. Below the rim of the Meseta, streams have responded to this ramp uplift by incising deeply into fractured Mesozoic rocks via a series of steep, headward retreating knickzones that grade to the present-day base level defined by the Pacific Ocean. It is found that the Tertiary units on the plateau function as cap-rocks, which aid in the parallel retreat of the sharp escarpment edge and upper knickzone tips. (10)Be-derived catchment denudation rates of the Rio Piura (5 degrees S), Rio Pisco (13 degrees S) and Rio Lluta (18 degrees S) average similar to 10 mm ky(-1) on the Meseta/Altiplano, irrespective of precipitation rates; whereas, downstream of the escarpment edge, denudation rates range from 10 mm ky(-1) to 250 mm ky(-1) and correlate positively with precipitation rates, but show no strong correlation with hillslope angles or channel steepness. These relationships are explained by the presence of a cap-rock and climate-driven fluvial incision that steepens hillslopes to near-threshold conditions. Since escarpment retreat and the precipitation pattern were established at least in the Miocene, it is speculated that the present-day distribution of morphology and denudation rates has probably remained largely unchanged during the past several millions of years as the knickzones have propagated headward into the plateau.

  • 5.
    Abeysinghe, Kasun S.
    et al.
    Chinese Acad Sci, Xishuangbanna Trop Bot Garden, Key Lab Trop Forest Ecol, Mengla, Yunnan, Peoples R China.;Univ Chinese Acad Sci, Beijing, Peoples R China..
    Yang, Xiao-Dong
    Chinese Acad Sci, Xishuangbanna Trop Bot Garden, Key Lab Trop Forest Ecol, Mengla, Yunnan, Peoples R China..
    Goodale, Eben
    Guangxi Univ, Coll Forestry, Nanning, Guangxi, Peoples R China..
    Anderson, Christopher W. N.
    Massey Univ, Inst Agr & Environm, Soil & Earth Sci, Palmerston North, New Zealand..
    Bishop, Kevin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Swedish Univ Agr Sci, Dept Aquat Sci & Assessment, Uppsala, Sweden..
    Cao, Axiang
    Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang, Peoples R China.;Guizhou Normal Univ, Sch Chem & Mat Sci, Guiyang, Peoples R China..
    Feng, Xinbin
    Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang, Peoples R China..
    Liu, Shengjie
    Chinese Acad Sci, Xishuangbanna Trop Bot Garden, Key Lab Trop Forest Ecol, Mengla, Yunnan, Peoples R China.;Univ Chinese Acad Sci, Beijing, Peoples R China..
    Mammides, Christos
    Chinese Acad Sci, Xishuangbanna Trop Bot Garden, Key Lab Trop Forest Ecol, Mengla, Yunnan, Peoples R China..
    Meng, Bo
    Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang, Peoples R China..
    Quan, Rui-Chang
    Chinese Acad Sci, Xishuangbanna Trop Bot Garden, Key Lab Trop Forest Ecol, Mengla, Yunnan, Peoples R China..
    Sun, Jing
    Nanjing Agr Univ, Coll Resources & Environm Sci, Nanjing, Jiangsu, Peoples R China..
    Qiu, Guangle
    Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang, Peoples R China..
    Total mercury and methylmercury concentrations over a gradient of contamination in earthworms living in rice paddy soil2017In: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 36, no 5, p. 1202-1210Article in journal (Refereed)
    Abstract [en]

    Mercury (Hg) deposited from emissions or from local contamination, can have serious health effects on humans and wildlife. Traditionally, Hg has been seen as a threat to aquatic wildlife, because of its conversion in suboxic conditions into bioavailable methylmercury (MeHg), but it can also threaten contaminated terrestrial ecosystems. In Asia, rice paddies in particular may be sensitive ecosystems. Earthworms are soil-dwelling organisms that have been used as indicators of Hg bioavailability; however, the MeHg concentrations they accumulate in rice paddy environments are not well known. Earthworm and soil samples were collected from rice paddies at progressive distances from abandoned mercury mines in Guizhou, China, and at control sites without a history of Hg mining. Total Hg (THg) and MeHg concentrations declined in soil and earthworms as distance increased from the mines, but the percentage of THg that was MeHg, and the bioaccumulation factors in earthworms, increased over this gradient. This escalation in methylation and the incursion of MeHg into earthworms may be influenced by more acidic soil conditions and higher organic content further from the mines. In areas where the source of Hg is deposition, especially in water-logged and acidic rice paddy soil, earthworms may biomagnify MeHg more than was previously reported. It is emphasized that rice paddy environments affected by acidifying deposition may be widely dispersed throughout Asia.

  • 6.
    Abrahamsson, Elin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Ekelund, My
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Human Exposure from Mercury in Rice in the Philippines2015Student paper other, 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the western part of the Philippines, in the Palawan province, studies have shown that large quantities of mercury are spread to the surrounding area during heavy rainfall. In addition, mercury is spread to rice fields and bioaccumulated in marine fish and seafood. The mercury originates from the abandoned Palawan Quicksilver Mine. Since mercury is toxic for the human body and new studies have shown that mercury accumulates in rice, it is important to investigate human exposure from mercury in rice.

    This project investigates the total amount of mercury and methylmercury (MeHg) accumulated in rice, soil and water from four different rice fields in Palawan. The soil samples have been taken directly from the fields and water samples have been taken from nearby streams and springs. Rice grains harvested earlier this year from the same fields have been collected from farmers. The soil, water and rice samples were analyzed in Manila and rice samples were as well analyzed in Sweden and China. Furthermore, this project contains a dietary survey and calculation of daily exposure values of MeHg. The survey investigates how often people eat fish and rice and if they have dental amalgam. It also investigates possible health problems related to mercury exposure from rice and fish consumption.

    The analyses from China show that rice samples from all barangays contain total mercury and MeHg. Analyses from Sweden also show that rice from the barangays contains total mercury but the levels were found to be higher than the ones analyzed in China. Furthermore, the health problems found in the diet survey were hard to relate to mercury exposure from rice since the health problems can be caused by other factors. When calculating daily exposure values, the values were found to be as high as the recommended maximum acceptable daily intake in one of the barangays. There might therefore be a risk of eating rice from these four barangays. It is important to consider that these daily exposure values were only based on MeHg exposure from rice consumption, not taking dental amalgam and fish consumption into consideration. This means that the daily exposure values might be even higher than the ones calculated in this study.

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  • 7.
    Addor, Nans
    et al.
    Univ Zurich, Dept Geog, Zurich, Switzerland.;Natl Ctr Atmospher Res, Appl Res Lab, POB 3000, Boulder, CO 80307 USA..
    Rohrer, Marco
    Univ Bern, Oeschger Ctr Climate Change Res, Bern, Switzerland.;Univ Bern, Inst Geog, Bern, Switzerland..
    Furrer, Reinhard
    Univ Zurich, Dept Math, Zurich, Switzerland..
    Seibert, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Univ Zurich, Dept Geog, Zurich, Switzerland..
    Propagation of biases in climate models from the synoptic to the regional scale: Implications for bias adjustment2016In: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 121, no 5, p. 2075-2089Article in journal (Refereed)
    Abstract [en]

    Bias adjustment methods usually do not account for the origins of biases in climate models and instead perform empirical adjustments. Biases in the synoptic circulation are for instance often overlooked when postprocessing regional climate model (RCM) simulations driven by general circulation models (GCMs). Yet considering atmospheric circulation helps to establish links between the synoptic and the regional scale, and thereby provides insights into the physical processes leading to RCM biases. Here we investigate how synoptic circulation biases impact regional climate simulations and influence our ability to mitigate biases in precipitation and temperature using quantile mapping. We considered 20 GCM-RCM combinations from the ENSEMBLES project and characterized the dominant atmospheric flow over the Alpine domain using circulation types. We report in particular a systematic overestimation of the frequency of westerly flow in winter. We show that it contributes to the generalized overestimation of winter precipitation over Switzerland, and this wet regional bias can be reduced by improving the simulation of synoptic circulation. We also demonstrate that statistical bias adjustment relying on quantile mapping is sensitive to circulation biases, which leads to residual errors in the postprocessed time series. Overall, decomposing GCM-RCM time series using circulation types reveals connections missed by analyses relying on monthly or seasonal values. Our results underscore the necessity to better diagnose process misrepresentation in climate models to progress with bias adjustment and impact modeling.

  • 8. Addor, Nans
    et al.
    Rössler, Ole
    Köplin, Nina
    Huss, Matthias
    Weingartner, Rolf
    Seibert, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Robust changes and sources of uncertainty in the projected hydrological regimes of Swiss catchments2014In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 50, no 10, p. 7541-7562Article in journal (Refereed)
    Abstract [en]

    Projections of discharge are key for future water resources management. These projections are subject to uncertainties, which are difficult to handle in the decision process on adaptation strategies. Uncertainties arise from different sources such as the emission scenarios, the climate models and their postprocessing, the hydrological models, and the natural variability. Here we present a detailed and quantitative uncertainty assessment, based on recent climate scenarios for Switzerland (CH2011 data set) and covering catchments representative for midlatitude alpine areas. This study relies on a particularly wide range of discharge projections resulting from the factorial combination of 3 emission scenarios, 10–20 regional climate models, 2 postprocessing methods, and 3 hydrological models of different complexity. This enabled us to decompose the uncertainty in the ensemble of projections using analyses of variance (ANOVA). We applied the same modeling setup to six catchments to assess the influence of catchment characteristics on the projected streamflow, and focused on changes in the annual discharge cycle. The uncertainties captured by our setup originate mainly from the climate models and natural climate variability, but the choice of emission scenario plays a large role by the end of the 21st century. The contribution of the hydrological models to the projection uncertainty varied strongly with catchment elevation. The discharge changes were compared to the estimated natural decadal variability, which revealed that a climate change signal emerges even under the lowest emission scenario (RCP2.6) by the end of the century. Limiting emissions to RCP2.6 levels would nevertheless reduce the largest regime changes by the end of the century by approximately a factor of two, in comparison to impacts projected for the high emission scenario SRES A2. We finally show that robust regime changes emerge despite the projection uncertainty. These changes are significant and are consistent across a wide range of scenarios and catchments. We propose their identification as a way to aid decision making under uncertainty.

  • 9. Addor, Nans
    et al.
    Seibert, J.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Bias correction for hydrological impact studies: beyond the daily perspective2014In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 28, no 17, p. 4823-4828Article in journal (Other academic)
  • 10. Adinugroho, Sigit
    et al.
    Vallot, Dorothée
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Westrin, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Strand, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Visual Information and Interaction. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computerized Image Analysis and Human-Computer Interaction.
    Calving events detection and quantification from time-lapse images in Tunabreen glacier2015In: Proc. 9th International Conference on Information & Communication Technology and Systems, Piscataway, NJ: IEEE , 2015, p. 61-65Conference paper (Refereed)
  • 11.
    Adolfsson Lindahl, Frida
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Identifiering av skyfallskänsliga punkter till Västerås kommunsvattentjänstplan: Risk- och sårbarhetsanalys samt lågpunktskartering2023Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As of January 1st, 2024, all municipalities must have a water service plan. A water service plan must contain each municipality's long-term plan to provide public water services in the future and solutions that need to be taken in the event of a cloudburst to protect water and sewage facilities. The change in law was introduced on January 1st, 2023, which has given municipalities a tight timetable to develop this plan.

    The study has investigated what the water service plan in Västerås municipality needs to contain in order to fulfill the requirement for solutions in the event of cloudbursts, identify points in the waste and stormwater network that are potentially vulnerable to cloudbursts, and provide suggestions for torrential rain measures. In order to fulfill the purpose, a risk and vulnerability analysis has been carried out to identify points in the waste and stormwater network that are potentially vulnerable to cloudbursts. The analysis included a workshop, with key individuals at Mälarenergi Vatten AB, and a risk matrix that was used as an assessment basis. From the risk matrix, points that were potentially vulnerable to cloudbursts were identified and a low-point mapping was performed in SCALGO Live at the selected points. The rain events performed in the mapping were 10-, 20- and 100-year rainfalls. The low-point mapping was compared with a cloudburst mapping with land runoff and conduit network, which is a mapping with a high degree of detail, to investigate whether low-point mapping can be a suitable basis for a water service plan.

    The result of the risk and vulnerability analysis was that seven points, which were given as suggestions during the workshop, had high-risk values and were potentially vulnerable to cloudbursts. Three out of the seven points were selected for further analysis: Branthovda, Skiljebo, and Önsta-Gryta, all of them located in Västerås city. All of these sensitive points were in the stormwater network. The low-point mapping in SCALGO Live performed over these three points showed major flooding during a 100-year rainfall event. The proposed cloudburst solutions for the sites were storage areas and cloudburst roads. When comparing low-point mapping and cloudburst mapping with ground runoff and conduit networks, the cloudburst mapping showed a minor flood for Branthovda and Skiljebo. In Önsta-Gryta, the difference between the mappings was minimal. This was due to the results of the cloudburst mapping showing that the stormwater pipes in the area were overloaded even with a 10-year rain, which was similar to the condition in the low-point mapping that the stormwater pipes are assumed to be filled. With this, only a low point mapping can show an area's potential for being vulnerable to cloudbursts but does not say anything about how the waste or stormwater network is affected. However, low point mapping can help identify areas in built-up areas that could be vulnerable to flooding.

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  • 12.
    AghaKouchak, Amir
    et al.
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA; Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA USA.
    Mirchi, Ali
    Oklahoma State Univ, Dept Biosyst & Agr Engn, Stillwater, OK 74078 USA.
    Madani, Kaveh
    Yale Univ, MacMillan Ctr Int & Area Studies, New Haven, CT USA; Stockholm Univ, Dept Phys Geog, Stockholm, Sweden.
    Di Baldassarre, Giuliano
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Nazemi, Ali
    Concordia Univ, Dept Bldg Civil & Environm Engn, Montreal, PQ, Canada.
    Alborzi, Aneseh
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA.
    Anjileli, Hassan
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA.
    Azarderakhsh, Marzi
    Fairleigh Dickinson Univ, Sch Comp Sci & Engn, Teaneck, NJ USA.
    Chiang, Felicia
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA.
    Hassanzadeh, Elmira
    Polytech Montreal, Dept Civil Geol & Min Engn, Montreal, PQ, Canada.
    Huning, Laurie S.
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA; Calif State Univ Long Beach, Dept Civil Engn & Construct Engn Management, Long Beach, CA 90840 USA.
    Mallakpour, Iman
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA.
    Martinez, Alexandre
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA.
    Mazdiyasni, Omid
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA.
    Moftakhari, Hamed
    Univ Alabama, Dept Civil Construct & Environm Engn, Tuscaloosa, AL USA.
    Norouzi, Hamid
    CUNY, New York City Coll Technol, Brooklyn, NY 11210 USA.
    Sadegh, Mojtaba
    Boise State Univ, Dept Civil Engn, Boise, ID 83725 USA.
    Sadeqi, Dalal
    Kuwait Inst Sci Res, Water Res Ctr, Kuwait, Kuwait.
    Van Loon, Anne F.
    Vrije Univ Amsterdam, Inst Environm Studies, Amsterdam, Netherlands.
    Wanders, Niko
    Univ Utrecht, Fac Geosci, Dept Phys Geog, Utrecht, Netherlands.
    Anthropogenic Drought: Definition, Challenges, and Opportunities2021In: Reviews of geophysics, ISSN 8755-1209, E-ISSN 1944-9208, Vol. 59, no 2, article id e2019RG000683Article, review/survey (Refereed)
    Abstract [en]

    Traditional, mainstream definitions of drought describe it as deficit in water-related variables or water-dependent activities (e.g., precipitation, soil moisture, surface and groundwater storage, and irrigation) due to natural variabilities that are out of the control of local decision-makers. Here, we argue that within coupled human-water systems, drought must be defined and understood as a process as opposed to a product to help better frame and describe the complex and interrelated dynamics of both natural and human-induced changes that define anthropogenic drought as a compound multidimensional and multiscale phenomenon, governed by the combination of natural water variability, climate change, human decisions and activities, and altered micro-climate conditions due to changes in land and water management. This definition considers the full spectrum of dynamic feedbacks and processes (e.g., land-atmosphere interactions and water and energy balance) within human-nature systems that drive the development of anthropogenic drought. This process magnifies the water supply demand gap and can lead to water bankruptcy, which will become more rampant around the globe in the coming decades due to continuously growing water demands under compounding effects of climate change and global environmental degradation. This challenge has de facto implications for both short-term and long-term water resources planning and management, water governance, and policymaking. Herein, after a brief overview of the anthropogenic drought concept and its examples, we discuss existing research gaps and opportunities for better understanding, modeling, and management of this phenomenon.

    Plain Language Summary

    This article reviews research and progress on the notion of anthropogenic drought broadly defined as drought events caused or intensified by human activities. Most commonly used drought definitions are based on deficit in hydrologic/meteorologic drivers such as precipitation and runoff. Within coupled human-water systems, however, drought must be defined and understood as the complex and interrelated dynamics of both natural and human-induced changes. This anthropogenic drought definition considers the full spectrum of dynamic feedbacks and processes (e.g., land-atmosphere interactions and water and energy balance) within human-nature systems. Ideally, anthropogenic drought and the corresponding human interactions should be incorporated in models that include land-atmosphere interactions, water balance, and energy balance. In this article, we review existing research gaps and opportunities for better understanding, modeling, and management of this phenomenon.

  • 13.
    Agnes, Stenlund
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    A Statistical Overview of the Spatial Atmospheric Variability Over Isfjorden, Svalbard2022Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The atmospheric spatial variability over Isfjorden, Svalbard, was investigated through statistical data analysis. The data used in the thesis was measured by mobile weather stations installed on three ships crossing the fjord, and two stationary weather stations close to the shoreline, during the autumn of 2021 and spring to autumn 2022. The spatial distributions of temperature, specific humidity, and wind speed were filtered into categories of season, ambient wind direction, and ambient wind speed, before they were studied.

    Gradients in temperature and humidity are re-occurring patterns along the Isfjorden axis during various seasons and wind directions. The temperature gradient was found to be partly generated by local drainage winds and further to be connected to the difference between air and sea surface temperature. The humidity gradient was consistent across all seasons and predominantly controlled by advection and differences in available water from surrounding land surfaces. A peak in wind speed around the mouth of Sassenfjorden indicated forced channeling effects, as the pattern dominated when the ambient wind aligned with the axis of the fjord. The results indicate local processes that can be expected from previous research.

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  • 14. Agosti, Edoardo
    et al.
    Saraceno, Giorgio
    Rampinelli, Vittorio
    Raffetti, Elena
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Department of Global Public Health Sciences, Karolinska Institute, Stockholm, Sweden.
    Veiceschi, Pierlorenzo
    Buffoli, Barbara
    Rezzani, Rita
    Giorgianni, Andrea
    Hirtler, Lena
    Alexander, Alex Yohan
    Deganello, Alberto
    Piazza, Cesare
    Nicolai, Piero
    Castelnuovo, Paolo
    Locatelli, Davide
    Peris-Celda, Maria
    Fontanella, Marco Maria
    Doglietto, Francesco
    Quantitative Anatomic Comparison of Endoscopic Transnasal and Microsurgical Transcranial Approaches to the Anterior Cranial Fossa2022In: Operative Neurosurgery, ISSN 2332-4252, E-ISSN 2332-4260, Vol. 23, no 4, p. e256-e266Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: 

    Several microsurgical transcranial approaches (MTAs) and endoscopic transnasal approaches (EEAs) to the anterior cranial fossa (ACF) have been described.

    OBJECTIVE: 

    To provide a preclinical, quantitative, anatomic, comparative analysis of surgical approaches to the ACF.

    METHODS: 

    Five alcohol-fixed specimens underwent high-resolution computed tomography. The following approaches were performed on each specimen: EEAs (transcribriform, transtuberculum, and transplanum), anterior MTAs (transfrontal sinus interhemispheric, frontobasal interhemispheric, and subfrontal with unilateral and bilateral frontal craniotomy), and anterolateral MTAs (supraorbital, minipterional, pterional, and frontotemporal orbitozygomatic approach). An optic neuronavigation system and dedicated software (ApproachViewer, part of GTx-Eyes II—UHN) were used to quantify the working volume of each approach and extrapolate the exposure of different ACF regions. Mixed linear models with random intercepts were used for statistical analyses.

    RESULTS: 

    EEAs offer a large and direct route to the midline region of ACF, whose most anterior structures (ie, crista galli, cribriform plate, and ethmoidal roof) are also well exposed by anterior MTAs, whereas deeper ones (ie, planum sphenoidale and tuberculum sellae) are also well exposed by anterolateral MTAs. The orbital roof region is exposed by both anterolateral and lateral MTAs. The posterolateral region (ie, sphenoid wing and optic canal) is well exposed by anterolateral MTAs.

    CONCLUSION: 

    Anterior and anterolateral MTAs play a pivotal role in the exposure of most anterior and posterolateral ACF regions, respectively, whereas midline regions are well exposed by EEAs. Furthermore, certain anterolateral approaches may be most useful when involvement of the optic canal and nerves involvement are suspected.

  • 15. Ahlers, R.
    et al.
    Cleaver, F
    Rusca, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Schwartz, K.
    Unleashing Entrepreneurs or Controlling Unruly Providers?: The Formalisation of Small-scale Water Providers in Greater Maputo, Mozambique2013In: Journal of Development Studies, ISSN 0022-0388, E-ISSN 1743-9140, Vol. 49, no 4, p. 470-482Article in journal (Refereed)
    Abstract [en]

    The existing legal and policy framework regulating water service provision in Greater Maputo, Mozambique appears fixated on the official service areas. In doing so it inadequately addresses the geographically varied service provision modalities which characterise the city. We argue that the predominant legal and policy framework does little to support development of improved services in areas unserved by the formal utility. Although ad hoc measures recognising small-scale providers as a temporary alternative to service provision by a formal utility have been implemented, these measures appear designed to increase control over these providers rather than support the service delivery capacity of small-scale providers.

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  • 16. Ahlers, Rhodante
    et al.
    Cleaver, F.
    Rusca, M.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Schwartz, K.
    Informal space in the urban waterscape: Disaggregation and co-production of water services2014In: Water Alternatives, ISSN 1965-0175, E-ISSN 1965-0175, Vol. 7, no 1, p. 1-14Article in journal (Refereed)
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  • 17.
    Ahlin, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Modellering av dagvattennät utgående från markhöjder2012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    According to The Swedish Water and Wastewater Association (SWWA), a storm waternetwork must be able to handle a rainfall with a return period of 10 years. In order toevaluate whether a drain system is adequately dimensioned, a storm water model can beestablished. This requires knowledge about the levels at which the conduits are situated,and this information is insufficient in many areas. However, the pipes could largely beassumed to follow the topography and the pipes levels can be estimated from it.Therefore, the aim of this study was to develop a method for how the level of stormwater conduits could be assessed from the ground level, and the significance thismethod had for storm water modeling. A further aim was also to, according to thismethod; assess the storm water systems of the Lidingö community, which lackedinformation on the pipe levels. Furthermore, for the method to be useful it wasimportant to make it easily applicable even to large storm water networks.The method was developed using parts of the storm water network in Sundbyberg,Stockholm. The levels of the conduits were known beforehand, and an analysis of themresulted in a method where the depth of the manhole, which controls the levels of theconduits, was estimated to 2 m. An exception had to be made when the conduits were inreverse slope, in which cases horizontal slope was assumed.When evaluating the impact from the depth assessment on the runoff, the uncertaintyfrom the imperviousness was taken into account by using three different scenarios;unchanged, 30% lower and 30% higher imperviousness. The risk of flooding for eachone of the manholes was weighted from the results of these three scenarios. Thisresulted in a pressure level for each manhole, either above ground, below ground orinconclusive. This was done for the model with both known levels for the conduits, andwith the assessed levels. In order to evaluate how well the method for applying thedepth worked, the status of each manhole was compared between the two models.The conclusion from this study was that the method developed here, more or less gavethe same results as when the levels of the conduits were previously known.Discrepancies arose mainly in ditches, but also for a few landlocked areas and outlets.For the Lidingö storm water network, 18 % of the wells ended up with a pressure levelabove ground when applied to a rain with a 10 year return period. Another 16 % of thewells were inconclusive.

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  • 18.
    Ahlstedt, Oskar
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    How variations of the duration and time to peak of the Chicago Design Storm affect the hydraulic response, as well as the areas contributing to peak runoff, of a synthetic urban catchment area2022Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With an expanding urbanization in the world, and thus the expansion of impermeable surfaces, the risk of pluvial floods is an increasing factor that needs to be considered. This, in combination with increasing rain intensities and frequency of rain events indicates a problem both today and for the future. With this in mind, it is an advantage to increase the knowledge of how different variations of extreme rainfall affects the hydraulic response of urban catchments, as well as which areas in urban environments contribute to the flood peak.

    The aims of this study are, with a particle tracking approach, to investigate how the peak runoff contributing areas differ geographically depending on the duration and time to peak of the rainfall event. This also includes the evaluation of what sizes of urban catchment areas are relevant to include when modelling the hydraulic response of Swedish urban catchment in relation to the characteristics of the hyetograph. The catchment area used in this study is made synthetically to represent a generic Swedish urban catchment with regards to the proportions of hardened surfaces, buildings and low points, as well as the slope of the catchment. Various variants of the Chicago Design Storm were implemented in the model. This included three different durations of 2-, 4- and 6 hours of which each, separately, constituted of three different time to peak that is decided by an r-value when creating the design storms. The r-values used in this study is 0.1, 0.4 and 0.8 where the values correlates to an early-, centred- and late peak of the hyetograph. To be able to investigate the peak contributing area, a particle tracking approach was initially used as an equivalent to tracers where the particles are first evenly distributed over the catchment area to then be concentrated to the locations that shows a variation in in the peak contributing area. This was done by using the modelling program MIKE 21 Flow Model FM powered by DHI, which also was used to run the hydrodynamic simulations of the inundation.

    The results of the hydrodynamic simulations showed that the rain events generated more runoff as the duration was extended. In addition, the timing of the peak of the rainfall intensity also had an impact on the result as the runoff increased with increasing r-value. Thus, as the peak of the hyetograph is delayed, it imposes an increasing risk of severe flooding. Furthermore, with the use of particle tracking, it could be concluded that the different design storm had an influence on the peak contributing distance where the distance grew larger when the duration of the rainfall event was extended and when the peak of the storm was delayed.

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  • 19.
    Ahrens, Lutz
    et al.
    Swedish Univ Agr Sci SLU, Dept Aquat Sci & Assessment, Box 7050, SE-75007 Uppsala, Sweden..
    Gashaw, Habiba
    Univ Addis Ababa, Ethiopian Inst Water Resources, Addis Ababa, Ethiopia..
    Sjöholm, Margareta
    Swedish Univ Agr Sci SLU, Dept Aquat Sci & Assessment, Box 7050, SE-75007 Uppsala, Sweden..
    Gebrehiwot, Solomon Gebreyohannis
    Univ Addis Ababa, Ethiopian Inst Water Resources, Addis Ababa, Ethiopia..
    Getahun, Abebe
    Univ Addis Ababa, Dept Zool Sci, Addis Ababa, Ethiopia.;Hawassa Univ, Dept Biol, POB 5, Hawassa, Ethiopia..
    Derbe, Ermias
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Hawassa Univ, Dept Biol, POB 5, Hawassa, Ethiopia..
    Bishop, Kevin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Swedish Univ Agr Sci SLU, Dept Aquat Sci & Assessment, Box 7050, SE-75007 Uppsala, Sweden..
    Åkerblom, Staffan
    Swedish Univ Agr Sci SLU, Dept Aquat Sci & Assessment, Box 7050, SE-75007 Uppsala, Sweden..
    Poly- and perfluoroalkylated substances (PFASs) in water, sediment and fish muscle tissue from Lake Tana, Ethiopia and implications for human exposure2016In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 165, p. 352-357Article in journal (Refereed)
    Abstract [en]

    Lake Tana is Ethiopia's largest lake and there are plans to increase the harvest of fish from the lake. The objective of this study was to assess the levels of poly- and perfluoroalkyl substances (PFASs) in different compartments of the lake (water, sediment, and fish muscle tissue), and its implications for human exposure. The results showed higher PFAS concentrations in piscivorous fish species (Labeobarbus mega-stoma and Labeobarbus gorguari) than non-piscivorous species (Labeobarbus intermedius, Oreochromis niloticus and Clarias gariepinus) and also spatial distribution similarities. The Sigma PFAS concentrations ranged from 0.073 to 5.6 ng L-1 (on average, 2.9 ng L-1) in surface water, 0.22-0.55 ng g(-1) dry weight (dw) (on average, 0.30 ng g(-1) dw) in surface sediment, and non-detected to 5.8 ng g(-1) wet weight (ww) (on average, 1.2 ng g(-1) ww) in all fish species. The relative risk (RR) indicates that the consumption of fish contaminated with perfiuorooctane sulfonate (PFOS) will likely not cause any harmful effects for the Ethiopian fish eating population. However, mixture toxicity of the sum of PFASs, individual fish consumption patterns and increasing fish consumption are important factors to consider in future risk assessments.

  • 20. Akerblom, Staffan
    et al.
    Meili, Markus
    Bishop, Kevin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Uppsala Centre for Sustainable Development, CSD Uppsala.
    Organic Matter in Rain: An Overlooked Influence on Mercury Deposition2015In: Environmental Science & Technology Letters, ISSN 2328-8930, Vol. 2, no 4, p. 128-132Article in journal (Refereed)
    Abstract [en]

    The importance of Hg emissions for deposition will be scrutinized in the future as new legislation to control emissions of Hg to the atmosphere comes into effect. We show that mercury (Hg) concentrations in rainfall are closely linked to organic matter (OM) with consistent Hg/TOC ratios over large spatial scales decreasing from that in an open field (OF, 1.5 mu g g(-1)) to that in throughfall (TF, 0.9 mu g g(-1)). The leaf area index was positively correlated with both TF [Hg] and total organic carbon ([TOC]), but not the Hg/TOC ratio. This study shows that the progression in the Hg/TOC ratio through catchments starts in precipitation with Hg/TOCbulk dep > Hg/TOCsoil (water) > Hg/TOCstreamwater These findings raise an intriguing question about the extent to which it is not just atmospheric [Hg] but also OM that influences [Hg] in precipitation. This question should be resolved to improve the ability to discern the importance of changing global Hg emissions for deposition of Hg at specific sites.

  • 21.
    Akhter, Firoza
    et al.
    KTH Royal Inst Technol, Dept Sustainable Dev Environm Sci & Engn, S-10046 Stockholm, Sweden..
    Mazzoleni, Maurizio
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Ctr Nat Hazards & Disaster Sci CNDS, S-75236 Uppsala, Sweden..
    Brandimarte, Luigia
    KTH Royal Inst Technol, Dept Sustainable Dev Environm Sci & Engn, S-10046 Stockholm, Sweden..
    Analysis of 220 Years of Floodplain Population Dynamics in the US at Different Spatial Scales2021In: Water, E-ISSN 2073-4441, Vol. 13, no 2, article id 141Article in journal (Refereed)
    Abstract [en]

    In this study, we explore the long-term trends of floodplain population dynamics at different spatial scales in the contiguous United States (U.S.). We exploit different types of datasets from 1790-2010-i.e., decadal spatial distribution for the population density in the US, global floodplains dataset, large-scale data of flood occurrence and damage, and structural and nonstructural flood protection measures for the US. At the national level, we found that the population initially settled down within the floodplains and then spread across its territory over time. At the state level, we observed that flood damages and national protection measures might have contributed to a learning effect, which in turn, shaped the floodplain population dynamics over time. Finally, at the county level, other socio-economic factors such as local flood insurances, economic activities, and socio-political context may predominantly influence the dynamics. Our study shows that different influencing factors affect floodplain population dynamics at different spatial scales. These facts are crucial for a reliable development and implementation of flood risk management planning.

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  • 22. Albani, S
    et al.
    Mahowald, N M
    Winckler, G
    Anderson, R F
    Bradtmiller, L I
    Delmonte, B
    François, R
    Goman, M
    Heavens, N G
    Hesse, P P
    Hovan, S A
    Kang, S G
    Kohfeld, K E
    Lu, H
    Maggi, V
    Mason, A
    Mayewski, P A
    McGee, D
    Miao, X
    Otto-Bliesner, L
    Perry, A T
    Pourmand, A
    Roberts, H M
    Rosenbloom, N
    Stevens, Thomas
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Sun, J
    Twelve thousand years of dust: the Holocene global dust cycle constrained by natural archives2015In: Climate of the Past, ISSN 1814-9324, E-ISSN 1814-9332, Vol. 11, no 6, p. 869-903Article in journal (Refereed)
    Abstract [en]

    Mineral dust plays an important role in the climate system by interacting with radiation, clouds, and biogeochemical cycles. In addition, natural archives show that the dust cycle experienced variability in the past in response to global and local climate change. The compilation of the DIRTMAP paleodust datasets in the last two decades provided a target for paleoclimate models that include the dust cycle, following a time slice approach. We propose an innovative framework to organize a paleodust dataset that moves on from the positive experience of DIRTMAP and takes into account new scientific challenges, by providing a concise and accessible dataset of temporally resolved records of dust mass accumulation rates and particle grain-size distributions. We consider data from ice cores, marine sediments, loess/paleosol sequences, lake sediments, and peat bogs for this compilation, with a temporal focus on the Holocene period. This global compilation allows investigation of the potential, uncertainties and confidence level of dust mass accumulation rates reconstructions, and highlights the importance of dust particle size information for accurate and quantitative reconstructions of the dust cycle. After applying criteria that help to establish that the data considered represent changes in dust deposition, 43 paleodust records have been identified, with the highest density of dust deposition data occurring in the North Atlantic region. Although the temporal evolution of dust in the North Atlantic appears consistent across several cores and suggest that minimum dust fluxes are likely observed during the Early to mid-Holocene period (6000–8000 years ago), the magnitude of dust fluxes in these observations is not fully consistent, suggesting that more work needs to be done to synthesize datasets for the Holocene. Based on the data compilation, we used the Community Earth System Model to estimate the mass balance and variability of the global dust cycle during the Holocene, with dust load ranging from 17.1 to 20.5 Tg between 2000 and 10 000 years ago, and a minimum in the Early to Mid-Holocene (6000–8000 years ago).

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  • 23.
    Albertini, Cinzia
    et al.
    Univ Napoli Federico II, Dipartimento Ingn Civile Edile & Ambientale, I-80125 Naples, Italy.;Politecn Bari, Dipartimento Ingn Civile Ambientale Terr Edile &, I-70125 Bari, Italy..
    Mazzoleni, Maurizio
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Ctr Nat Hazards & Disaster Sci, S-75236 Uppsala, Sweden..
    Totaro, Vincenzo
    Politecn Bari, Dipartimento Ingn Civile Ambientale Terr Edile &, I-70125 Bari, Italy..
    Iacobellis, Vito
    Politecn Bari, Dipartimento Ingn Civile Ambientale Terr Edile &, I-70125 Bari, Italy..
    Di Baldassarre, Giuliano
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Ctr Nat Hazards & Disaster Sci, S-75236 Uppsala, Sweden..
    Socio-Hydrological Modelling: The Influence of Reservoir Management and Societal Responses on Flood Impacts2020In: Water, E-ISSN 2073-4441, Vol. 12, no 5, article id 1384Article in journal (Refereed)
    Abstract [en]

    Over the last few years, several socio-hydrological studies have investigated the risk dynamics generated by the complex interactions between floods and societies, with a focus on either changing reservoir operation rules or raising levees. In this study, we propose a new socio-hydrological model of human-flood interactions that represents both changes in the reservoir management strategies and updating of the levee system. Our model is applied to simulate three prototypes of floodplain management strategies to cope with flood risk: green systems, in which societies resettle outside the flood-prone area; technological systems, in which societies implement structural measures, such as levees; and green-to-techno systems, in which societies shift from green to technological approaches. Floodplain dynamics are explored simulating possible future scenarios in the city of Brisbane, Australia. Results show that flood risk is strongly influenced by changes in flood and drought memory of reservoir operators, while risk-awareness levels shape the urbanisation of floodplains. Furthermore, scenarios of more frequent and higher magnitude events prove to enhance social flood memory in green systems, while technological systems experience much higher losses. Interestingly, green-to-techno systems may also evolve toward green floodplain management systems in response to large losses and technical/economical unfeasibility of larger structural measures.

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  • 24.
    Albrecht, Frederike
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Department of Security, Strategy and Leadership, Swedish Defence University.
    Parker, Charles F.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Government.
    Healing the Ozone Layer: The Montreal Protocol and the Lessons and Limits of a Global Governance Success Story2019In: Great Policy Successes / [ed] Paul 't Hart & Mallory Compton, Oxford: Oxford University Press, 2019, p. 304-322Chapter in book (Refereed)
    Abstract [en]

    The Montreal Protocol—the regime designed to protect the stratospheric ozone layer—has widely been hailed as the gold standard of global environmental governance and is one of few examples of international institutional cooperative arrangements successfully solving complex transnational problems. Although the stratospheric ozone layer still bears the impacts of ozone depleting substances (ODSs), the problem of ozone depletion is well on its way to being solved due to the protocol. This chapter examines how the protocol was designed and implemented in a way that has allowed it to successfully overcome a number of thorny challenges that most international environmental regimes must face: how to attract sufficient participation, how to promote compliance and manage non-compliance, how to strengthen commitments over time, how to neutralize or co-opt potential ‘veto players’, how to make the costs of implementation affordable, how to leverage public opinion in support of the regime’s goals, and, ultimately, how to promote the behavioural and policy changes needed to solve the problems and achieve the goals the regime was designed to solve. The chapter concludes that while some of the reasons for the Montreal Protocol’s success, such as fairly affordable, available substitutes for ODSs, are not easy to replicate, there are many other elements of this story that can be utilized when thinking about how to design solutions to other transnational environmental problems.

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  • 25.
    Aldahan, Ala Adin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Morad, Sadoon
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Ion Physics.
    Sturesson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    ElSaiy, A.
    10Be in rhodochrosite nodules from Neogene sediments along the Galapagos Ridge, equatorial Pacific2010In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 268, no 7-8, p. 1253-1256Article in journal (Refereed)
    Abstract [en]

    Microcrystalline, calcian rhodochrosite occurs as nodules around burrows in late Neogene pelagic sediments from the Galapagos Ridge in the Guatemala Basin, eastern equatorial Pacific (DSDP Leg 68; Site 503). Be-10 isotope revealed that the rhodochrosite nodules have formed under growth conditions much faster than those reported for Fe-Mn nodules. The overall REE patterns of the nodules and host pelagic sediments indicate element derivation mainly from marine pore water. However, variations in the shale normalised Eu values suggest influx of hydrothermal fluids into mounds area at Galapagos, which is also evidenced by the similar minor and major element contents in the nodules and host sediments.

  • 26.
    Aldahan, Ala
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Hedfors, Jim
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Ion Physics.
    Kulan, Abdulhadi
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Berggren, Ann-Marie
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Söderström, C.
    FOI, Swedish Defence Research Agency, Stockholm, Sweden.
    Atmospheric impact on beryllium isotopes as solar activity proxy2008In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 35, no L21812Article in journal (Refereed)
    Abstract [en]

    Reconstructing solar activity variability beyond the time scale of actual measurements provides invaluable data for modeling of past and future climate change. The 10 Be isotope has been a primary proxy archive of past solar activity and cosmic ray intensity, particularly for the last millennium. There is, however, a lack of direct high-resolution atmospheric time series on 10 Be that enable estimating atmospheric modulation on the production signal. Here we report quasi-weekly data on 10 Be and 7 Be isotopes covering the periods 1983-2000 and 1975-2006 respectively, that show, for the first time, coherent variations reflecting both atmospheric and production effects. Our data indicate intrusion of stratosphere/upper troposphere air masses that can modulate the isotopes production signal, and may induce relative peaks in the natural 10 Be archives (i.e., ice and sediment). The atmospheric impact on the Be-isotopes can disturb the production signals and consequently the estimate of past solar activity magnitude. Citation: Aldahan, A., J. Hedfors, G. Possnert, A. Kulan, A.-M. Berggren, and C. Soderstrom (2008), Atmospheric impact on beryllium isotopes as solar activity proxy, Geophys. Res. Lett., 35, L21812, doi: 10.1029/2008GL035189.

  • 27.
    Aldahan, Ala
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    El Saiy, A.
    Abdelghany, O.
    Particle-bound Be-10 from a low latitude arid region2014In: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 299, no 3, p. 1709-1713Article in journal (Refereed)
    Abstract [en]

    The Be-10 isotope is widely used in geochronology, climate and environmental analyses and astrophysics where atmospheric deposition model estimate plays a vital role for the initial concentration. Data from arid regions have not been well constrained because of sparse measurement and here we present Be-10 concentration in samples of dust, soil, marine sediments and paleosol collected from an arid to semi-arid low latitude region. These results indicate concentrations that are about a factor of three lower than values expected from latitude zonal models, but are comparable with global atmospheric depositional model. The agreement and discrepancy between model and measured data are rather vital for establishing accurate initial Be-10 in the Earth's surface environment for reconstruction of paleoclimatic variability (precipitation rates and temperature).

  • 28.
    Aldahan, Ala
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Scherer, Reed
    Sjunneskog, C
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Ion Physics.
    Berggren, A-M
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Cosmogenic 10Be as an environmental tracer in subglacial Antarctic Lake2006In: SALE advanced Science and Technology Workshop, 24-26 April, Grenoble, France,, 2006, p. 2-3Conference paper (Refereed)
  • 29. Alda-Vidal, C.
    et al.
    Kooy, M.
    Rusca, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Mapping operation and maintenance: an everyday urbanism analysis of inequalities within piped water supply in Lilongwe, Malawi2018In: Urban Geography, Vol. 39, no 1, p. 104-121Article in journal (Refereed)
    Abstract [en]

    In this article, we analyze the production of inequalities within the centralized water supply network of Lilongwe. We use a process-based analysis to understand how urban infrastructure is made to work and explain the disparity in levels of service by tracing the everyday practices of those who operate the infrastructure. This extends existing analyses of everyday practices in relation to urban water inequalities in African cities by focusing on formal operators, rather than water users, and looking within the networked system, rather than outside it. Our findings show that these practices work to exacerbate existing water stress in poor areas of the city. We conclude with a reflection on how understanding these practices as the product of the perceptions, rationalizations, and interpretations of utility staff who seek to manage the city’s (limited) water as best they can offers insight into what is required for a more progressive urban water politics.

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  • 30. Alda-Vidal, C.
    et al.
    Rusca, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Zwarteveen, M.
    Schwartz, K.
    Pouw, N.
    Occupational genders and gendered occupations: the case of water provisioning in Maputo, Mozambique2017In: Gender, Place and Culture: A Journal of Feminist Geography, ISSN 0966-369X, E-ISSN 1360-0524, Vol. 24, no 7, p. 974-990Article in journal (Refereed)
    Abstract [en]

    Taking issue with how associations between technical prowess or entrepreneurship and masculinity tend to be taken for granted or are seen as stemming from natural or intrinsic gender differences, over the last two decades feminist scholars have developed theoretical approaches to understand the gendering of professions and abilities as the performative outcome of particular cultures and histories. We build on these insights to explore how associations between masculinities, technology and entrepreneurship shape ideas and practices of small-scale water provision in Maputo. Our findings show how activities (i.e. technical craftsmanship, hard physical work) or abilities (i.e. risk-taking, innovativeness) regarded as masculine tend to be considered the defining features of the profession. This shapes how men and women make sense of and talk about their work, each of them tactically emphasizing and performing those aspects best fitting their gender. Our detailed documentation of men’s and women’s everyday involvements in water provisioning challenges the existence of sharp boundaries and distinctions between genders and professional responsibilities. It shows that water provisioning requires many other types of work and skills and male and female household members collaborate and share their work. The strong normative-cultural associations between gender and water provisioning lead to a distinct under-recognition of women’s importance as water providers. We conclude that strategies to effectively support small-scale water businesses while creating more space and power for women involved in the business require the explicit recognition and re-conceptualization of water provisioning as a household business.

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  • 31.
    Alfieri, Lorenzo
    et al.
    European Commiss Joint Res Ctr, TP 122,Via E Fermi 2749, I-21027 Ispra, VA, Italy.
    Feyen, Luc
    European Commiss Joint Res Ctr, TP 122,Via E Fermi 2749, I-21027 Ispra, VA, Italy.
    Di Baldassarre, Giuliano
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Increasing flood risk under climate change: a pan-European assessment of the benefits of four adaptation strategies2016In: Climatic Change, Vol. 136, no 3, p. 507-521Article in journal (Refereed)
    Abstract [en]

    Future flood risk in Europe is likely to increase due to a combination of climatic and socio-economic drivers. Effective adaptation strategies need to be implemented to limit the impact of river flooding on population and assets. This research builds upon a recently developed flood risk assessment framework at European scale to explore the benefits of adaptation against extreme floods. The effect of implementing four different adaptation measures is simulated in the modeling framework. Measures include the rise of flood protections, reduction of the peak flows through water retention, reduction of vulnerability and relocation to safer areas. Their sensitivity is assessed in several configurations under a high-end global warming scenario over the time range 1976-2100. Results suggest that the future increase in expected damage and population affected by river floods can be compensated through different configurations of adaptation measures. The adaptation efforts should favor measures targeted at reducing the impacts of floods, rather than trying to avoid them. Conversely, adaptation plans only based on rising flood protections have the effect of reducing the frequency of small floods and exposing the society to less-frequent but catastrophic floods and potentially long recovery processes.

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  • 32. Alfimov, Vasily
    et al.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Water masses and I-129 distribution in the Nordic Seas2013In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 294, p. 542-546Article in journal (Refereed)
    Abstract [en]

    The application of the radioactive isotope iodine-129 as a tracer of water circulation in the oceans has provided interesting information with respect to sources and mixing of different water masses. We here present results of I-129 distribution in water profiles located in the Nordic Seas and use the isotope to fingerprint water masses in the region. The samples were collected by the US research vessel Knorr in May-June 2002. I-129 signatures along the Norwegian Sea reflect a mixing of I-129-rich surface water along the Scandinavian continental slope and I-129-poor North Atlantic surface water. These two water masses become less segregated along the Fram Strait where apparent I-129 enrichment penetrates the return Arctic flow into the East Greenland Current. The I-129 data further suggest existence of a water mass that is not entirely labeled with respect to origin at the Denmark Strait bottom water. This water parcel probably originates from the Iceland Sea. I-129 data also shed light on the major deep water outflow from the Nordic Seas located at the Faeroe Bank Channel.

  • 33.
    Alfonso, L.
    et al.
    UNESCO IHE Inst Water Educ, Integrated Water Syst & Governance, Delft, Netherlands..
    Mukolwe, M. M.
    UNESCO IHE Inst Water Educ, Integrated Water Syst & Governance, Delft, Netherlands.;Masinde Muliro Univ Sci & Technol, Estates Dept, Kakamega, Kenya..
    Di Baldassarre, Giuliano
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Probabilistic Flood Maps to support decision-making: Mapping the Value of Information2016In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 52, no 2, p. 1026-1043Article in journal (Refereed)
    Abstract [en]

    Floods are one of the most frequent and disruptive natural hazards that affect man. Annually, significant flood damage is documented worldwide. Flood mapping is a common preimpact flood hazard mitigation measure, for which advanced methods and tools (such as flood inundation models) are used to estimate potential flood extent maps that are used in spatial planning. However, these tools are affected, largely to an unknown degree, by both epistemic and aleatory uncertainty. Over the past few years, advances in uncertainty analysis with respect to flood inundation modeling show that it is appropriate to adopt Probabilistic Flood Maps (PFM) to account for uncertainty. However, the following question arises; how can probabilistic flood hazard information be incorporated into spatial planning? Thus, a consistent framework to incorporate PFMs into the decision-making is required. In this paper, a novel methodology based on Decision-Making under Uncertainty theories, in particular Value of Information (VOI) is proposed. Specifically, the methodology entails the use of a PFM to generate a VOI map, which highlights floodplain locations where additional information is valuable with respect to available floodplain management actions and their potential consequences. The methodology is illustrated with a simplified example and also applied to a real case study in the South of France, where a VOI map is analyzed on the basis of historical land use change decisions over a period of 26 years. Results show that uncertain flood hazard information encapsulated in PFMs can aid decision-making in floodplain planning.

  • 34. Ali, A Md
    et al.
    Di Baldassarre, G
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Solomatine, Dimitri P
    Testing different cross-section spacing in 1D hydraulic modelling: A case study on Johor River, Malaysia2014In: Hydrological Sciences Journal, no just-acceptedArticle in journal (Refereed)
  • 35. Ali, A. Md
    et al.
    Solomatine, D. P.
    Di Baldassarre, Giuliano
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Assessing the impact of different sources of topographic data on 1-D hydraulic modelling of floods2015In: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 19, no 1, p. 631-643Article in journal (Refereed)
    Abstract [en]

    Topographic data, such as digital elevation models (DEMs), are essential input in flood inundation modelling. DEMs can be derived from several sources either through remote sensing techniques (spaceborne or airborne imagery) or from traditional methods (ground survey). The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), the Shuttle Radar Topography Mission (SRTM), the light detection and ranging (lidar), and topographic contour maps are some of the most commonly used sources of data for DEMs. These DEMs are characterized by different precision and accuracy. On the one hand, the spatial resolution of low-cost DEMs from satellite imagery, such as ASTER and SRTM, is rather coarse (around 30 to 90 m). On the other hand, the lidar technique is able to produce high-resolution DEMs (at around 1 m), but at a much higher cost. Lastly, contour mapping based on ground survey is time consuming, particularly for higher scales, and may not be possible for some remote areas. The use of these different sources of DEM obviously affects the results of flood inundation models. This paper shows and compares a number of 1-D hydraulic models developed using HEC-RAS as model code and the aforementioned sources of DEM as geometric input. To test model selection, the outcomes of the 1-D models were also compared, in terms of flood water levels, to the results of 2-D models (LISFLOOD-FP). The study was carried out on a reach of the Johor River, in Malaysia. The effect of the different sources of DEMs (and different resolutions) was investigated by considering the performance of the hydraulic models in simulating flood water levels as well as inundation maps. The outcomes of our study show that the use of different DEMs has serious implications to the results of hydraulic models. The outcomes also indicate that the loss of model accuracy due to re-sampling the highest resolution DEM (i.e. lidar 1 m) to lower resolution is much less than the loss of model accuracy due to the use of lowcost DEM that have not only a lower resolution, but also a lower quality. Lastly, to better explore the sensitivity of the 1-D hydraulic models to different DEMs, we performed an uncertainty analysis based on the GLUE methodology.

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  • 36. Ali, Genevieve
    et al.
    Tetzlaff, Doerthe
    McDonnell, Jeffrey J.
    Soulsby, Chris
    Carey, Sean
    Laudon, Hjalmar
    McGuire, Kevin
    Buttle, Jim
    Seibert, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Shanley, Jamie
    Comparison of threshold hydrologic response across northern catchments2015In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 29, no 16, p. 3575-3591Article in journal (Refereed)
    Abstract [en]

    Nine mid-latitude to high-latitude headwater catchments - part of the Northern Watershed Ecosystem Response to Climate Change (North-Watch) programme - were used to analyze threshold response to rainfall and snowmelt-driven events and link the different responses to the catchment characteristics of the nine sites. The North-Watch data include daily time-series of various lengths of multiple variables such as air temperature, precipitation and discharge. Rainfall and meltwater inputs were differentiated using a degree-day snowmelt approach. Distinct hydrological events were identified, and precipitation-runoff response curves were visually assessed. Results showed that eight of nine catchments showed runoff initiation thresholds and effective precipitation input thresholds. For rainfall-triggered events, catchment hydroclimatic and physical characteristics (e.g. mean annual air temperature, median flow path distance to the stream, median sub-catchment area) were strong predictors of threshold strength. For snowmelt-driven events, however, thresholds and the factors controlling precipitation-runoff response were difficult to identify. The variability in catchments responses to snowmelt was not fully explained by runoff initiation thresholds and input magnitude thresholds. The quantification of input intensity thresholds (e.g. snow melting and permafrost thawing rates) is likely required for an adequate characterization of nonlinear spring runoff generation in such northern environments.

  • 37.
    Alm, Micael
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Probability Modelling of Alpine Permafrost Distribution in Tarfala Valley, Sweden2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A field data collection has been carried out in Tarfala valley at the turn of March to April 2017. The collection resulted in 36 BTS-measurements (Bottom Temperature of Snow cover) that has been used in combination with data from earlier surveys, to create a model of the occurrence of permafrost around Tarfala. To identify meaningful parameters that permafrost relies on, independent variables were tested against BTS in a stepwise regression. The independent variables elevation, aspect, solar radiation, slope angle and curvature were produced for each investigated BTS-point in a geographic information system.                 The stepwise regression selected elevation as the only significant variable, elevation was applied to a logistic regression to model the permafrost occurrence. The final model showed that the probability of permafrost increases with height. To distinguish between continuous, discontinuous and sporadic permafrost, the model was divided into three zones with intervals of probability. The continuous permafrost is the highest located zone and therefore has the highest likelihood, this zone delimits the discontinuous permafrost at 1523 m a.s.l. The discontinuous permafrost has probabilities between 50-80 % and its lower limit at 1108 m a.s.l. separates the discontinuous zone from the sporadic permafrost. 

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  • 38. Alonso Vicario, S.
    et al.
    Mazzoleni, Maurizio
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Centrum för naturkatastrofslära, Uppsala.
    Bhamidipati, S.
    Gharesifard, M.
    Ridolfi, Elena
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Centrum för naturkatastrofslära, Uppsala.
    Pandolfo, C.
    Alfonso, L.
    Unravelling the influence of human behaviour on reducing casualties during flood evacuation2020In: Hydrological Sciences Journal, ISSN 0262-6667, E-ISSN 2150-3435, Vol. 65, no 14, p. 2359-2375Article in journal (Refereed)
    Abstract [en]

    Floods are the natural hazards that are causing the most deaths worldwide. Flood early warning systems are one of the most cost-efficient methods to reduce death rates, triggering decisions about the evacuation of exposed population. Although previous studies have investigated the effect of human behaviours on evacuation processes, studies analysing a combination of behaviours, flood onset and warning timing are limited. Our objective is to explore how changes on the aforementioned factors can affect casualties. This is done within a modelling framework that includes an agent-based model, a hydraulic model, and a traffic model, which is implemented for the case study of Orvieto (Italy). The results show that the number of casualties is most impacted by people's behaviour. Besides, we found that a delay of 30 min in releasing the warning can boost the number of casualties up to six times. These results may help managers to propose effective emergency plans.

  • 39.
    Alsadi, Aram
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Sektionen för geokemi och hydrologi, Sveriges lantbruksuniversitet..
    Dynamiken hos organiskt kol i Mälarens avrinningsområde: flöden, drivande faktorer och modellering2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this report, it has been investigated how the amount of organic carbon, TOC, varies in time and space in the basin of Mälaren, and what controls the TOC content in the lake. It is important to understand the dynamics of the TOC in the lake and its catchment because increased TOC in the water affects water quality and causes problems in the preparation of drinking water. Particularly, it can react with chlorine / UV- light and form carcinogenic substances. It can also increase the number of microbes in water distribution systems.

    In addition the work includes analysis of the relation between water chemistry variables, annual fluxes calculations (g/m2/year) of element flows to the lake and a modeling approach to a watershed.

    Annual fluxes calculations (g/m2/year) indicate that the largest supply of TOC to the lake comes from the northeast of the lake. Fyrisån accounts for the largest input of TOC to the lake. The high TOC-flux is due to a small proportion of open water in the catchment.

    Hydrological, chemical and meteorological data have been included in models to estimate the TOC content in the Mälaren. Input data processing, especially precipitation data, has been an important part of the work as it affects the whole model. Temperature, evapotranspiration and precipitation data were used in a hydrological model, HBV model, to simulate the flow from the catchment area. Then a process-based model, INCA-C, operated by the hydrological data and soil moisture, has been used to simulate the temporal patterns in TOC. The input variables to INCA-C- model, soil moisture and HER (Hydrological effective rainfall), have been simulated using the HBV- model.

    Those models were applied in Kolbäcksån, one of the lake's largest catchments. The modeling of Kolbäcksån resulted in a model that captured the dynamics of a few periods of the whole time series. The modeling of Kolbäcksån TOC-concentration resulted in a model that captured the dynamics between 1996 and 2009, but misses it between 2009 and June 2010. R2 and NS values obtained for the model were 0.086 and -0.059, respectively.

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    Aram Alsadi
  • 40. Alshamsi, Dalal M.
    et al.
    Murad, Ahmed A.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Hou, Xiaolin
    Uranium isotopes in carbonate aquifers of arid region setting2013In: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 298, no 3, p. 1899-1905Article in journal (Refereed)
    Abstract [en]

    Groundwater in arid and semiarid regions is vital resource for many uses and therefore information about concentrations of uranium isotopes among other chemical parameters are necessary. In the study presented here, distribution of U-238 and U-235 in groundwater of four selected locations in the southern Arabian peninsula, namely at two locations within the United Arab Emirates (UAE) and two locations in Oman are discussed. The analyses of the uranium isotopes were performed using ICP-MS and the results indicated a range of concentrations for U-235 and (238) U at 3-39 ng L-1 (average: 18 ng L-1) and 429-5,293 ng L-1 (average: 2,508 ng L-1) respectively. These uranium concentrations are below the higher permissible WHO limit for drinking water and also comparable to averages found in groundwater from similar aquifers in Florida and Tunisia. Negative correlation between rainfall and uranium concentrations suggests that in lithologically comparable aquifers, climate may influence the concentration of uranium in subtropical to arid regions.

  • 41.
    Alsmyr, Michaela
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Utvärdering av lufthalts- och nedfallsmätningar gjorda vid Korsnäsverken: Samband mellan miljöförbättrande arbete i pappers- och massaindustrin och föroreningar i närområdet2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A decline has been seen in Sweden and Europe when it comes to air pollution the last decades. The decline is partly due to reduced emissions from industries, switching from heating using oil and coal boilers to district heating and better fuel quality. This study evaluates deposition and air concentration measurements made in the vicinity of the pulp and paper industry Korsnäs in Gävle. The measurement series starts at the late 1970s and goes up to year-end 2009/2010. Deposition of dust, sulphate, sodium, calcium and air concentrations of sulphur dioxide and soot were studied. Comparisons were made with Korsnäs environmental measures and emissions during the same time period and with other measurements made in Sweden and Gävleborgs County.

    The study showed a decrease in sulphur dioxide concentrations in the air. This fits well with a major reduction of sulphur emissions from the factory area in the early 1990s when installations of treatment plants were made at the largest emission sources of sulphur dioxide. Reducing the sulphur content of fuel oil from Karskär Energi AB, an energy combine owned by Korsnäs in the same factory area, contributed to the decrease during the same time period. Air concentrations of soot showed no downward trend over the years, but were seasonal, with higher average soot concentrations in the winter. This was most likely caused by the burning of fuel oil from both the private sector and Karskär Energi AB. The largest air concentrations did not show higher levels of sulphur dioxide and soot when the mean wind direction was easterly and thus blew from factory area toward the monitoring station but when the wind direction was southwesterly and blew from inland. The total dust and calcium deposition showed no decline but had higher average measured levels in the summer. Sulphate deposition showed high levels during the late 1980s but has thereafter decreased. The sodium deposition decreased a little during the time period. No clear connection was found between deposition/air concentrations and emissions from the factory area when the data series were sorted by wind direction, wind speed and after the summer and winter months. Depositions and air concentrations were not higher except for sulphur dioxide when the comparison was made with other measurements in Sweden and Gävleborg County. All measurements were below the then current national limits.

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  • 42.
    Amanda, Eskebaek
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Spridning av släckvattenpartiklar: En studie på spridning av partiklar genererade från brand2015Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    During a fire large amounts of particles and unhealthy agents occur.  Polyaromatic hydrocarbons (PAH) and toxic metals are examples among many others. These agents have a capacity to bond to particles and when the fire is extinguished, the particles can be transferred with the extinguish water into the soil and to the groundwater.

    Recent studies in particles have been conducted. A study by Ulrika Iverfelt (2014) reviled that the particles from a fire contained large amounts of both PAH and metals, which is consistent with earlier analyses. Her column experiments with particles in the size ≤ 11 microns and ≤100 microns in silica sand, reviled that the larger particles was immobilized because the transportation was influenced by sieving or physiochemical particle and surface interactions.

    The transport of the particles in soil and groundwater is regulated by two main mechanisms: physiochemical surface interactions and straining. The particle size and the surface charge are examples of properties that affect the transport. The particle charge is described by the zeta potential, which is an important characteristic for surface interactions with the solid medium. The zeta potential depends on the water chemistry which varies in different extinguish water. The zeta potential was measured to be negative in Iverfelts (2014) study.

    In order to predict and understand the transport of the particles, more column experiments with different properties were requested. In this study several transport experiments where made. The four parameters: grain size, particle size, ionic strength and pH were investigated systematically. The same type of column, sand and source of extinguish water as in Iverfelts study was used. 

    The results from the study indicated that the smaller particles were not affected by sieving, as the larger particles. When the pH was lowered, the results indicated that some of the smaller particles, ≤11 microns were immobilized. This was probably because the zeta potential of the particles was reduced, which allowed the physiochemical particle and surface interactions.

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  • 43.
    Ameli, A. A.
    et al.
    Univ Western Ontario, Dept Biol, Biol & Geol Sci Bldg, London, ON N6A 3K7, Canada.;Univ Saskatchewan, Global Inst Water Secur, Saskatoon, SK, Canada.;Uppsala Univ, Dept Earth Sci Air Water & Landscape Sci, Uppsala, Sweden..
    McDonnell, J. J.
    Univ Saskatchewan, Global Inst Water Secur, Saskatoon, SK, Canada.;Univ Aberdeen, Sch Geosci, Aberdeen, Scotland..
    Bishop, Kevin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Uppsala Centre for Sustainable Development, CSD Uppsala. Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Swedish Univ Agr Sci SLU, Dept Aquat Sci & Assessment, Uppsala, Sweden..
    The exponential decline in saturated hydraulic conductivity with depth: a novel method for exploring its effect on water flow paths and transit time distribution2016In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 30, no 14, p. 2438-2450Article in journal (Refereed)
    Abstract [en]

    The strong vertical gradient in soil and subsoil saturated hydraulic conductivity is characteristic feature of the hydrology of catchments. Despite the potential importance of these strong gradients, they have proven difficult to model using robust physically based schemes. This has hampered the testing of hypotheses about the implications of such vertical gradients for subsurface flow paths, residence times and transit time distribution. Here we present a general semi-analytical solution for the simulation of 2D steady-state saturated-unsaturated flow in hillslopes with saturated hydraulic conductivity that declines exponentially with depth. The grid-free solution satisfies mass balance exactly over the entire saturated and unsaturated zones. The new method provides continuous solutions for head, flow and velocity in both saturated and unsaturated zones without any interpolation process as is common in discrete numerical schemes. This solution efficiently generates flow pathlines and transit time distributions in hillslopes with the assumption of depth-varying saturated hydraulic conductivity. The model outputs reveal the pronounced effect that changing the strength of the exponential decline in saturated hydraulic conductivity has on the flow pathlines, residence time and transit time distribution. This new steady-state model may be useful to others for posing hypotheses about how different depth functions for hydraulic conductivity influence catchment hydrological response.

  • 44.
    Ameli, A.A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Department of Biology, Western University, London, Ontario, Canada.
    Amvrosiadi, Nino
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Grabs, T.homas J.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Laudon, Hjalmar
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Creed, I.F.
    Department of Biology, Western University, London, Ontario, Canada.
    McDonnell, J.J.
    Global Institute for Water Security, School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; School of Geosciences, University of Aberdeen, Aberdeen, UK.
    Bishop, Kevin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Hillslope permeability architecture controls on subsurface transit time distribution and flow paths2016In: Journal of Hydrology, Vol. 543, no A, p. 17-30Article in journal (Refereed)
    Abstract [en]

    Defining the catchment transit time distribution remains a challenge. Here, we used a new semi-analytical physically-based integrated subsurface flow and advective–dispersive particle movement model to assess the subsurface controls on subsurface water flow paths and transit time distributions. First, we tested the efficacy of the new model for simulation of the observed groundwater dynamics at the well-studied S-transect hillslope (Västrabäcken sub-catchment, Sweden). This system, like many others, is characterized by exponential decline in saturated hydraulic conductivity and porosity with soil depth. The model performed well relative to a tracer-based estimate of transit time distribution as well as observed groundwater depth–discharge relationship within 30 m of the stream. Second, we used the model to assess the effect of changes in the subsurface permeability architecture on flow pathlines and transit time distribution in a set of virtual experiments. Vertical patterns of saturated hydraulic conductivity and porosity with soil depth significantly influenced hillslope transit time distribution. Increasing infiltration rates significantly decreased mean groundwater age, but not the distribution of transit times relative to mean groundwater age. The location of hillslope hydrologic boundaries, including the groundwater divide and no-flow boundary underlying the hillslope, changed the transit time distribution less markedly. These results can guide future decisions on the degree of complexity that is warranted in a physically-based rainfall–runoff model to efficiently and explicitly estimate time invariant subsurface pathlines and transit time distribution.

  • 45.
    Ameli, Ali A.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Univ Saskatchewan, Global Inst Water Secur, Saskatoon, SK, Canada.;Western Univ, Dept Biol, London, ON, Canada..
    Controls on subsurface transport of sorbing contaminant2017In: Hydrology Research, ISSN 1998-9563, E-ISSN 2224-7955, Vol. 48, no 5, p. 1226-1239Article in journal (Refereed)
    Abstract [en]

    Subsurface transport of a sorbing contaminant is poorly understood and characterized. Here, a new semi-analytical saturated-unsaturated flow and transport model is coupled to a kinetic sorption algorithm to assess the impact of changes in the subsurface permeability architecture and flow rate on sorption characteristics. The model outputs reveal the pronounced effect of the rate of vertical decline in K-s on the frequency of occurrence and spatial distribution of subsurface sorption as well as the timing and rate of sorbing contaminants discharged into stream. Sorption potential is weakened with infiltration rate. The impact of infiltration rate on the decline in sorption potential becomes more accentuated as the degree of subsurface vertical heterogeneity in saturated hydraulic conductivity increases. Porosity pattern also impacts sorption characteristics; but its effects highly depend upon the degree of vertical heterogeneity in Ks. The results and methodology presented in this paper have potential implications for assessing water quality in integrated groundwater-surface water systems as well as designing remediation systems.

  • 46.
    Ameli, Ali A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Univ Saskatchewan, Global Inst Water Secur, Saskatoon, SK, Canada.;Western Univ, Dept Biol, London, ON, Canada.
    Beven, Keith
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Univ Lancaster, Lancaster Environm Ctr, Lancaster, England..
    Erlandsson, Martin
    Stockholm Univ, Dept Phys Geog, Stockholm, Sweden..
    Creed, Irena F.
    Western Univ, Dept Biol, London, ON, Canada..
    McDonnell, Jeffrey J.
    Univ Saskatchewan, Global Inst Water Secur, Saskatoon, SK, Canada.;Univ Aberdeen, Sch Geosci, Aberdeen, Scotland.;Oregon State Univ, Dept Forest Engn Resources & Management, Corvallis, OR 97331 USA..
    Bishop, Kevin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Swedish Univ Agr Sci, Dept Aquat Sci & Assessment, Uppsala, Sweden..
    Primary weathering rates, water transit times, and concentration-discharge relations: A theoretical analysis for the critical zone2017In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 53, no 1, p. 942-960Article in journal (Refereed)
    Abstract [en]

    The permeability architecture of the critical zone exerts a major influence on the hydrogeochemistry of the critical zone. Water flow path dynamics drive the spatiotemporal pattern of geochemical evolution and resulting streamflow concentration-discharge (C-Q) relation, but these flow paths are complex and difficult to map quantitatively. Here we couple a new integrated flow and particle tracking transport model with a general reversible Transition State Theory style dissolution rate law to explore theoretically how C-Q relations and concentration in the critical zone respond to decline in saturated hydraulic conductivity (K-s) with soil depth. We do this for a range of flow rates and mineral reaction kinetics. Our results show that for minerals with a high ratio of equilibrium concentration ( Ceq) to intrinsic weathering rate ( Rmax), vertical heterogeneity in K-s enhances the gradient of weathering-derived solute concentration in the critical zone and strengthens the inverse stream C-Q relation. As <mml:mfrac>CeqRmax</mml:mfrac> decreases, the spatial distribution of concentration in the critical zone becomes more uniform for a wide range of flow rates, and stream C-Q relation approaches chemostatic behavior, regardless of the degree of vertical heterogeneity in K-s. These findings suggest that the transport-controlled mechanisms in the hillslope can lead to chemostatic C-Q relations in the stream while the hillslope surface reaction-controlled mechanisms are associated with an inverse stream C-Q relation. In addition, as <mml:mfrac>CeqRmax</mml:mfrac> decreases, the concentration in the critical zone and stream become less dependent on groundwater age (or transit time).

  • 47.
    Ameli, Ali A.
    et al.
    Univ British Columbia, Dept Earth Ocean & Atmospher Sci, Vancouver, BC, Canada.
    Laudon, Hjalmar
    Swedish Univ Agr Sci, Dept Forest Ecol & Management, Umeå, Sweden.
    Teutschbein, Claudia
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Bishop, Kevin
    Swedish Univ Agr Sci, Dept Aquat Sci & Assessment, Uppsala, Sweden.
    Where and When to Collect Tracer Data to Diagnose Hillslope Permeability Architecture2021In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 57, no 8, article id e2020WR028719Article in journal (Refereed)
    Abstract [en]

    The permeability architecture has a major influence on hillslope flow path and hydrogeochemistry. To constrain this architecture and overcome equifinality in the diagnosis of hillslope flow paths within hydrologic transport models, different types of complementary data (e.g., tracer) have been recommended. However, there is still little information on the extent to which such complementary data can unravel the permeability architecture, and where and when to measure such data to most efficiently constrain models. Here, we couple a Richards-based flow and transport model with extensive long-term field measurements to compare the relative value of different types of hydrometric and tracer data in discriminating between contrasting permeability (or saturated hydraulic conductivity ()) architectures, in the absence of macropore flow. Our results show that compared to streamflow and water table observations, stream tracer data have a stronger evaluative potential to constrain hillslope vertical pattern in , in particular during seasons when flow is on average low (e.g., winter or summer). Tracer data from within the hillslope are even more helpful to discriminate between different vertical patterns in Ks than stream tracer data. This suggests a higher evaluative potential for hillslope tracer observations. This evaluative potential of hillslope data depends on where and when the data are collected, and increases with depth from the soil surface, with distance from the stream and during seasons when flow is low. The findings also emphasize the importance of incorporating hillslope permeability architecture in hydrologic transport models in order to reduce the uncertainty in the predictions of stream water quality.

  • 48.
    Amvrosiadi, Nino
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Temporal Dynamics of Total Organic Carbon Export Rates in Swedish Streams: Importance of discharge conditions and seasonal effects2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The amount of total organic carbon (TOC) in water is a rough indicator of the waterquality. Driven by the question how the TOC concentration would vary acrossstreams in Sweden under different climate conditions (e.g. more extreme dischargeevents), the temporal dynamics of TOC were examined for different stream subgroupswith six orders of magnitude catchment area span. In addition, the relationshipbetween dissolved inorganic carbon (DIC) export (both downstream and evasion) anddischarge conditions was also studied. Another question addressed was if the amountof TOC exported can be affected by export conditions dominating the previousseason. TOC export followed closely the discharge, which is in agreement withprevious studies, and all 42 catchments studied across Sweden were described by thispositive relationship regardless their size. A linear TOC export response to dischargewas identified during extreme discharge conditions. Furthermore, the TOC export wassignificantly related to the antecedent TOC export conditions for approximately halfof the 18 studied catchments with areas ranging between 2.5·10-3 and 67 km2.

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    Temporal Dynamics of Total Organic Carbon Export Rates in Swedish Streams: Importance of discharge conditions and seasonal effects
  • 49.
    Amvrosiadi, Nino
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    The value of experimental data and modelling for exploration of hydrological functioning: The case of a till hillslope2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Successfully modeling one system response (e.g. hydrograph or solute transport) sometimes gives the false sense of well-characterizing the modeled system. This is partly because of the well-known equifinality issue; during the calibration process multiple parameter combinations can produce similarly good results. One step forward towards a better-defined system is using measured (at relevant scale) values for the model parameters, as well as using multiple conditions to constrain the model.

    But when not enough, or relevant, field measurements are available, virtual experiments (VE’s) can be used as a supplementary method to model calibration. The advantage of VE’s over model calibration is that they can also be used to explore assumptions both on the system hydrological processes, and on the model structure.

    One goal of this study was to utilize both field measurements and models for better characterization of the S-transect hillslope, located in Västrabäcken catchment, Northern Sweden. This included (a) characteristics in space: system vertical boundaries, hydraulic parameters, pore water velocity distribution, spatial correlation of flowpaths, soil water retention properties; (b) characteristic of system’s dynamic behavior: storage – discharge relationship, transit time distribution, turnover time; and (c) outputs’ sensitivity to external forcing, and to small scale structure assumptions. The second goal was to comment on the value of field measurements and virtual experiments for extracting information about the studied system.

    An intensely monitored study hillslope was chosen for this work. Although the hillslope has already been the subject of multiple field and modelling studies, there are still open questions regarding the characteristics listed above. The models used were the Vertical Equilibrium Model (VEM), and the Multiple Interacting Pathways (MIPs) model.

    It was found that the hillslope was well connected; from the near-stream areas up to the water divide the storage – discharge relationship could be described as an exponential function. Also, the dynamic storage (which controls the hydrograph dynamics) was much smaller comparing to the total hillslope storage. The unsaturated soil storage was found to be more sensitive to water table positions than vertical flux magnitude. The dynamic condition of external forcing (precipitation and evapotranspiration) affected the transit time distribution (TTD) shape. And, opposite to expectations, TTD was not sensitive to micro-scale structural assumptions tested here.

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  • 50.
    Amvrosiadi, Nino
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Beven, Keith
    Bishop, Kevin
    Laudon, Hjalmar
    Seibert, Jan
    Value of virtual experiments for a hillslope scale system understandingManuscript (preprint) (Other academic)
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