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  • 301.
    Boberg, Molly
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Selander, Märta
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Systematic and Automatized Hydrogeological Data Capturing for Provision of Safe Drinking Water in Daudkandi, Bangladesh2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Arsenic-contaminated drinking water exposes ~230 million people worldwide to increased risks of several diseases and is considered one of the greatest threats to public health. In Bangladesh, arsenic-contaminated water has been declared the largest poisoning of a population in history, where 39 million people are exposed to arsenic levels above the WHO guidelines (>10 μg/L). Drinking water is mainly provided by tube-wells installed by local drillers and the majority are located in aquifers with high arsenic levels. The major challenges of identifying arsenic-safe aquifers consist of a lack of a common tool for quality assurance of hydrogeological data, post-processing of the data, and a possibility to forward analyzed data to national and local stakeholders. Therefore, the purpose of this study was to investigate the potential of applying a digital solution for collecting and managing hydrogeological data in a quality assured platform. This study was a pilot-project in the sub-district Daudkandi, Bangladesh in collaboration with the KTH-International Groundwater Research Group. To fulfill the purpose, a method was developed for systematic and automated data capturing of hydrogeological information in GeoGIS, an advanced software that proved to be an efficient tool for visualizing hydrogeological data. The results show that collecting a few field data in a systematic and automated way is helpful for interpreting aquifer sequences and will enable better prerequisites for targeting safe aquifers and installing safe tube-wells. Conclusions are that the integration of a digital platform as a decision tool may significantly improve arsenic mitigation strategies. Furthermore, providing information to public and private sectors in Bangladesh would increase the transparency of hydrogeological conditions and may help improve safe water access to high arsenic areas of Bangladesh. 

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  • 302.
    Bodin, Hristina
    et al.
    Division of Natural Sciences, Kristianstad University, Kristianstad, Sweden.
    Ehde, Per Magnus
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Weisner, Stefan
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Attenuation of Pharmaceutical Substances: Phytoremediation using Constructed Wetlands2018In: 13th Society of Wetland Scientists (SWS) Europe Chapter Meeting: Management of Wetland Ecosystem Services: Issues, Challenges and Solutions, 2018, p. 19-22Conference paper (Refereed)
    Abstract [en]

    Introduction: Currently, wastewater treatment plants (WWTPs) do not efficiently remove pharmaceutical substances (PS). Thus, such substances are now frequently found in aquatic ecosystems worldwide. Also, concentrations of some PS in treated effluents exceed Environmental Quality Standards proposed by EU legislation. One resource-efficient option for increasing PS removal in WWTP effluents is to use constructed wetlands (CWs) as an attenuation step (Breitholtz et al. 2012; Li et al. 2014). However, very little research has been done on how to maximize the PS attenuation capacity of CWs. Therefore, a project with the aim to investigate reduction of different pharmaceutical substances in CWs with different vegetation compositions and water depths, was performed at the Experimental Wetland Area (EVA) located 20 km north of Halmstad, Sweden. 

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  • 303.
    Bodin, Hristina
    et al.
    Kristianstad University, Faculty of Natural Science, Research environment Man & Biosphere Health (MABH). Kristianstad University, Faculty of Natural Science, Avdelningen för miljö- och biovetenskap. Swedish University of Agricultural Sciences.
    Ehde, Per Magnus
    Halmstad University.
    Weisner, Stefan
    Halmstad University.
    Attenuation of pharmaceutical substances: phytoremediation using constructed wetlands2018In: 13th Society of wetland scientists (SWS) Europe chapter meeting: management of wetland ecosystem services: issues, challenges and solutions, 2018, p. 19-22Conference paper (Refereed)
    Abstract [en]

    Introduction: Currently, wastewater treatment plants (WWTPs) do not efficiently remove pharmaceutical substances (PS). Thus, such substances are now frequently found in aquatic ecosystems worldwide. Also, concentrations of some PS in treated effluents exceed Environmental Quality Standards proposed by EU legislation. One resource-efficient option for increasing PS removal in WWTP effluents is to use constructed wetlands (CWs) as an attenuation step (Breitholtz et al. 2012; Li et al. 2014). However, very little research has been done on how to maximize the PS attenuation capacity of CWs. Therefore, a project with the aim to investigate reduction of different pharmaceutical substances in CWs with different vegetation compositions and water depths, was performed at the Experimental Wetland Area (EVA) located 20 km north of Halmstad, Sweden. 

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  • 304.
    Bohman, Anna
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    I vått och torrt? : En studie av nationell vattenkatastrofgrupp VAKA: Underlag till den statliga dricksvattenutredningen2016Report (Other academic)
    Abstract [sv]

    Den här rapporten har studerat VAKA-gruppens verksamhet med speciellt fokus på hur de som larmat VAKA upplevt hjälpen, vilka konsekvenser som kunnat undvikas genom VAKA:s stöd samt hur insatserna skulle kunna organiseras och finansieras framöver. Studien utgår från 26 intervjuer med aktörer som larmat VAKA någon gång mellan 2010 och 2015.

    Sammanfattningsvis kan det konstateras att de intervjuade kommunerna upplever att VAKA erbjuder en synnerligen effektiv och professionell hjälp som bidragit till att olycksförloppen kunnat både mildras och förkortas avsevärt. Man har bistått med kvalificerad experthjälp vad gäller lägesanalys, provtagningar och analyser, bistått i organisationen av krisledningen och även förmedlat erfarenheter och kunskaper gällande media hantering samt kommunikation gentemot allmänheten. VAKA har dessutom tillgång till ett brett kontaktnät och har i de fall då man själv inte besitter rätt expertis snabbt kunnat förmedla kontakt med rätt person/instans. De intervjuade kommunerna har framhållit att man fått mental stöttning av VAKA i situationer som varit belastande för krisledningen. Att ha tillgång till erfarna människor som bollplank och som en part i diskussionen i ett kritiskt läge framhålls som otroligt viktigt för de inblandade.

    Flertalet av de intervjuade bedömer att det kan finnas en viss betalningsvilja för VAKA:s tjänster på kommunal nivå men ser en överhängande risk med att vissa kommuner eventuellt avvaktar en kontakt om denna är avgiftsbelagd. I sammanhanget bör man också beakta att andra aktörer än kommuner i dagsläget är berättigade att nyttja VAKA:s tjänster varför en exklusiv kommunavgift inte framstår som en optimal lösning framgent.

    Ingen av de intervjuade ser någon fördel med att VAKA verksamhet skulle organiseras på privat konsultbasis alternativt ersättas med regional kompetensutveckling. Det senare alternativet menar man känns inte realistiskt med tanke på att VAKA besitter vad som måste betraktas som nationell spetskompetens och att det skulle vara svårt att sprida denna till alla regioner.

    Förslag på verksamhetens utveckling som framkommit gäller bl.a. tillgången till nödvattenutrustning där tillgängligheten skulle kunna förbättras både via tätare avstånd mellan lagren samt en koordinering av samutnyttjande av resurser mellan kommuner. Man tror även att kännedomen om VAKA skulle kunna förbättras via informationsinsatser.

    Ytterligare ett förslag på verksamhetens utveckling gäller tillgång till laboratorier där man föreslår att VAKA alternativt Livsmedelsverket skulle administrera en central upphandling för att säkerställa att det alltid finns tillgång till laboratorieresurser.

    Baserat på rapportens samlade bedömning rekommenderas det att VAKA gruppens verksamhet även fortsättningsvis bör bedrivas i sin nuvarande form men med en fast finansiering från näringsdepartementet som möjliggör en mer långsiktig planering av verksamheten.

    Avslutningsvis bör det återigen understrykas att effekterna av framtida klimatförändringar medför att riskerna för dricksvattenförsörjningen ökar och att antalet incidenter kopplat till dricksvattenförsörjning med stor sannolikhet kommer att öka. Behovet av VAKA-gruppens tjänster blir därmed större i framtiden.

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  • 305.
    Boklund, Ingrid
    Sveriges lantbruksuniversitet.
    Ekosystemtjänster & grönstrukturplanering: Att synliggöra ekosystemtjänsternas nytta och värde i den kommunala planeringen med hjälp av ArcGIS-verktyget Matrixgreen2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Ecosystem services are the direct and indirect contributions of ecosystems to human well-being. Clean air, clean water, pollination and biodiversity are all examples of ecosystem services that humans depend on and whose value needs to be integrated into decision-making processes in all different levels of society. Local authorities have an important role in this as they at local level through spatial planning have the possibility to steer development towards more sustainable solutions.

    The aim of this thesis is to make ecosystem services in Knivsta municipality visible through the green structure plan and to analyze the ecological connectivity between the ecological structures using the ArcGIS-tool Matrixgreen. A literature study laid the foundation for further work and was followed by a workshop where important ecosystem services to the municipality of Knivsta were identified. Ecological profiles were created where 11 of the 18 prioritized ecosystem services were associated with specific biotopes which in turn could be linked to a biological species or species groups, called target species, with the specific biotope as possible habitat. The habitat preferences of the target species (size requirements and distribution patterns) worked as a framework for how to analyze the connectivity for each biotope. This was followed by gathering of maps and the making of ecological networks in Matrixgreen. The networks were analyzed with respect to position of the patches in the network (Betweenness Centrality analysis) and the overall connectivity in the municipality (Component analysis).

    Common to the four selected biotopes (wetland, grassland, coniferous and deciduous forest) is that they indirectly provide us with the prioritized supporting ecosystem services habitats and biodiversity. The prioritized ecosystem services water treatment, flow regulation and flood control were linked to the biotope wetlands and materials (ornamental) and pollination were linked to the biotope grasslands. The biotopes coniferous and deciduous forest could be linked to the prioritized ecosystem services food (domestic and wild animals, wild plants), raw materials (fiber), bio-energy and climate control. The network analyses show good connectivity for wetland areas and coniferous forest in the municipality. The total connectivity for grasslands and deciduous forest is limited. The analyzes also show that for each biotope a couple of areas are especially important for the overall connectivity. These areas have a high Betweenness Centrality value.

    The ecological profiles upon which the analyzes are based are theoretical profiles, no site visits or surveys have been done to investigate how reality matches theory. The constructed and analyzed networks in this thesis are therefore to be seen mainly as a guide to where in the municipality the selected ecosystem services are available. The networks do not constitute adequate habitats for the selected target species and no conclusions can be drawn as to where in the municipality a specific species exists or not. Biodiversity is an ecosystem service itself but also represents an insurance for the ecosystem that becomes more resilient, i.e. more stable and resilient to external shocks. Resilient ecosystems are essential for the ecosystem services that have been studied. Lack of connectivity in the landscape could lead to increased fragmentation and eventually risk biodiversity depletion.

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  • 306.
    Bollvik, Mikael
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Svensson, Pontus
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Dagvattenhantering på Arenastaden i Växjö2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Rapporten behandlar projekteringen och genomförandet kring det lokala omhändertagandet av dagvatten för de fyra nybyggda arenorna på Arenastaden i Växjö. Granskningen behandlar framförallt underjordiska fördröjningsmagasin men även alternativa lösningar.

    Arbetet har genomförts med hjälp av intervjuer och studier kring olika lösningar för lokalt omhändertagande av dagvatten.

    Förändringsförslagen som presenteras bottnar i mer tid för projektering, förbättrad kommunikation och större användande av mer genomsläppliga ytor.

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    Dagvattenhantering på Arenastaden i Växjö
  • 307.
    Bonde, Carl
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Närsaltsdosering till luftad damm: en åtgärd för ökad TOC-reduktion hos Skoghalls Bruk luftade damm2006Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the process of making carton boards into Skoghall Mill, are great quantities of water being contaminated. This water has to be treated before it is possible to release into the recipient, Kattfjorden. One of the contaminations that is important to extract from the wastewater, is organic carbon (measured as TOC-total organic carbon) because microbiological breakdown can lead to the bottom becomig free of oxygen.

    The wastewater treatment at Skoghall Mill is done through an external wastewater treatment that is located at the factory. The biological treatment (aerated lagoon) is a 140 000 m3 water pool with surface aerator, which is give oxygen to the water. In the lagoon live microorganisms who performs the biggest part of the TOC-reduction.

    One problem with the lagoon is that the treatment of TOC is considerably worse during wintertime than during summertime. The reduction is during wintertime only 40 %, while during summertime it is about 70-80 %. This seasonal variation can to a large extent be explained by, that the water temperature in the lagoon decreases wintertime. The low water temperature does that the biological activity in the lagoon is reduced, which reduces the TOC-reduction. A second reason can also be that the microorganisms do not have enough bioavailable nutrients that is needed for growth of a new biomass.

    In this thesis the need of nutrient has been examined. In two test pools, addings of nutrient were being done, to come to the conclusion of a good dosage of nutrient which would lead to a larger reduction of TOC, without enlarged quantities of nitrogen/phosphorus in the outgoing water. One of the test pools hold a summer temperature (30°C), and the other test pool hold a winter temperature (10°C). The test was performed this way to see if there would be any difference in the need of nutrient between summertime and wintertime.

    The most important conclusion was that a nutrient dosage to the Skoghall aerated lagoon, rise the TOC-reduction wintertime. It was also concluded that it was foremost the nitrogen that contributed to the raised TOC-reduction, and nitrogen is thereby considered to be the growth restraining element wintertime. It seemed like phosphorus had been overdosed during the tests, while enlarged halts of the substance could be seen in the outgoing water, and an optimal dosage of phosphorus could not be done. The recommendation that came as a results from the tests, was that during wintertime add nitrogen and phosphorus according to TOC:N:P-quota 100:0,75:0,10. To the summer pool was no considerable improvement of the TOC-reduction seen, as a result of the nutrient addings. It is also no reason to dosage nutrients in summertime.

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  • 308.
    Boo, Johan
    et al.
    Jönköping University, School of Engineering, JTH, Civil Engineeering and Lighting Science.
    Magnusson, Nils
    Jönköping University, School of Engineering, JTH, Civil Engineeering and Lighting Science.
    Hållbar dagvattenhantering i brant terräng: En fallstudie av ett planerat bostadsområde i Gränna2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Purpose: The continuous densification of urban environments with an increased amount of hard surfaces as a result, along with future climate change, involves a number of challenges that must be taken into account when applying a sustainable stormwater management. In addition to this, there are several other challenges that needs to be considered when planning for a sustainable stormwater management in residential areas located in steep terrain where an increased water volume and water velocity increases the risk of floods and contributes to an increased level of contamination in the runoff.

    This study aims at identifying suitable stormwater solutions for residential areas located in steep terrain.

    Method: The methods used to achieve the objective of the thesis have been literature review, document analysis, qualitative interviews and calculations. A case study of a planned residential area in Gränna, Jönköpings municipality, has been conducted and resulted in the gathering of empirical data.

    Findings: Geophysical, social, economic and legal factors must be taken into account when implementing sustainable stormwater management and in order to best prevent damage caused by floods of buildings and facilities.

    The application of sustainable stormwater solutions to delay and purify water is important where steep terrain leads to large stormwater flows, in order to reduce the risk of floods and the pollution levels in recipients caused by erosion. No single measure is sufficient to fully address the present risks, but by using a combination of open stormwater facilities and infiltration technologies, pollution levels in the drainage and flooding problems can be drastically reduced.

    Implications: The knowledge, and in some extent the will, among Swedish municipalities to implement sustainable stormwater management needs to be strengthened. In the case of construction of new residential areas in steep terrain, enclosed areas should not be exploited but instead be used as a designated area for excess of stormwater. Infiltration methods should be used in combination with open stormwater facilities to better handle the rain with varying recurrence and to reduce erosion damage.

    Limitations: The case study has served as a practical example and the calculations are not generally valid, although with some adjustments they can be applied in similar areas. The results of the literature review and interviews can be applied to residential areas in other Swedish municipalities where the terrains results in an increased water velocity.

    Keywords: Best management practice, erosion, infiltration, low impact development, steep terrain, stormwater pond, stormwater swale, sustainable stormwater management.

  • 309.
    Borchling, Alexander
    et al.
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Kroner, Corinna
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Akselli, Basak
    Turkiye Bilimsel ve Teknolojik Arastirma, Turkey.
    Benková, Miroslava
    Cesky Metrologicky Institut, Czech Republic.
    Büker, Oliver
    RISE Research Institutes of Sweden, Safety and Transport, Measurement Technology.
    Christoffersen, Nikki
    FORCE Technology, Denmark.
    Haack, Søren
    Teknologisk Institut Kongsvang, Denmark.
    Seypka, Veit
    DVGW - Technologiezentrum, Germany.
    Warnecke, Heiko
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Die Welt der Wasserzähler im Wandel2023In: GWF, Wasser - Abwasser, ISSN 0016-3651, Vol. 2023, no 6, p. 89-93Article in journal (Refereed)
    Abstract [en]

    Like everywhere else, time does not stand still for water meters. The requirements change, whether through technological progress, e.g., through the use of electronic meters, or changes in drinking water consumption. A revision of relevant normative documents is currently taking place at the international level. Against this background, various studies have been carried out in recent years and infrastructure has been built up with which the measurement behaviour of water meters can be examined more closely under real operating conditions, even at the laboratory level. This article presents the infrastructure. Furthermore, two current studies on the measurement behaviour of water meters are presented. In these studies, the effect of water quality and the effect of discrete measurements on the measurement accuracy of electronic water meters were investigated. 

  • 310.
    Borg Berggren, Alma
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Dagvattenhantering på underbyggda gårdar inom kvartersmark2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With the expansion and densification of cities, green areas are removed while the proportion of hard surfaces are increased. Rain and melt water are not allowed to infiltrate through the hard surfaces, and instead it runs off like stormwater. With this and the expected increase of precipitation due to climate changes, it is becoming increasingly important to plan for the disposal of stormwater in new urban areas. Several Swedish municipalities are today providing restrictions regarding the diversion of stormwater on private properties and requirements that need to be met before connection to the public water network. Meanwhile, densification means that builders today are often forced to build residential yards on underground garages. There was a need to clarify and investigate today's situation regarding stormwater treatment in combination with underground garages.The purpose of this thesis was to analyse today's state of knowledge about stormwater treatment on yards with underground garages and to investigate how different actors experience the requirements. Qualitative interviews with representatives from the three groups of actors, stormwater sewer operators, planning divisions and developers were conducted. The aim was also to design a tool for highlighting connections between stormwater management and other interests on private properties.This thesis was delimited to study green roofs, plant beds and detention tanks. Five interests were identified on yards with underground garages: landscape architecture, architecture, construction, management and HVAC. A tool was designed including the stormwater facilities containing four steps: Today’s and future construction, Stormwater requirements, Choice of facilities and Further recommendations or suggestions for corrections. Within the tool, four checklists were established to describe connections between stormwater treatment on yards with underground garages and the interests.The interview results show that several interviewees find it difficult to impose restrictions for stormwater management due to legal uncertainties. Meanwhile developers find following the restrictions can be difficult with yards with underground garages, mainly due to lack of space. The checklists are intended to serve as guiding points that should be taken into consideration in stormwater management on underground garages and to help balance different interests. The hope is that the checklists can contribute to an increased understanding of the relationships between stormwater management with underground garages and other interests. The results of the thesis show that interaction between the various interests is needed to create conditions for a good stormwater management and that communication about a joint purpose for the yard with an underground garage is important for maintaining the function of the yard.

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  • 311.
    Borris, Matthias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Future trends in urban stormwater quality: effects of changes in climate, catchment characteristics and processes and socio-economic factors2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Climate change and progressing urbanization cause numerous environmental concerns, including the impacts on urban drainage. Such impacts were addressed during the last two decades with focus on hydraulic overloading of drainage systems and the means of overload remediation by stormwater management. However, modern urban drainage also serves to provide and protect broad environmental services chiefly by controlling stormwater quality. During the past 40 years, a sizeable investment has been made in urban drainage systems to improve stormwater quality and protect receiving water ecosystems. Such investments are at risks, because of impaired performance of stormwater quality controls now and in the future for the following reasons: (i) Hydraulic and Pollution overloading (ii) the aging of stormwater management systems and (iii) insufficient attention paid to socio-economic issues. The primary objectives of the thesis that follows is to address the above issues by examining future trends in stormwater quality and the influential factors affecting these trends. Trends in urban stormwater quality, in response to projected changes in the climate, urban catchments and their drainage systems, and environmental practices and policies, were studied by systematically describing these changes by a set of scenarios, which were then applied to several test catchments in simulations with two well-established computer models of urban drainage (US EPA SWMM and WinSLAMM). In runoff simulations, stormwater quality was described Total suspended solids (TSS) and three heavy metals, namely Cu, Pb and Zn. The assessment of uncertainties in the simulation process and potential changes in sewer pipe materials further inspired two additional studies: Potential improvements in modelling trace metal transport and control by clarifying the role of coarse sediments on road surfaces, and water quality implications of using sewer pipes made from three different materials. Simulations with up-scaled rainfall data produced changes in stormwater quality, depending on the type of storm events. Generally pollutant loads increased due to climate changes characterized by higher depths and intensities of rainfall in future scenarios. Storms with low to intermediate depths and intensities showed the highest sensitivities to climatic changes, because runoff producing areas increased with higher storm intensities (i.e., leading to contributions of pervious areas), and sufficient pollutant supplies on catchment surfaces; for high intensity events, such supplies were quickly exhausted. TSS loads exported from catchments with low imperviousness were most sensitive to climatic changes, but the magnitudes of TSS loads were low compared to those from catchments with high imperviousness. Furthermore, potential changes in catchment characteristics and drainage systems were identified to be of importance. Future scenarios combining changes in climate and socio-economic factors showed that the impacts on stormwater quality caused by climatic changes were smaller than those caused by changes in socio-economic factors. However, future urbanization impacts on stormwater quality could be controlled by incorporating modern stormwater management measures in future catchments. Simulations of such controls indicated that they were highly effective in protecting the stormwater quality. Finally it was noted that the two applied computer models produced somewhat different results and high uncertainties when assessing the future stormwater quality. This was due to their different descriptions of the underlying processes. Hence, it was desirable to examine the feasibility of improving stormwater quality modelling, particularly with respect to heavy metals. During laboratory experiments coarse particles were identified to potentially release significant amounts of heavy metals (mostly in the particulate bound phase) during runoff events. Site/runoff event specific factors (e.g., traffic intensity and street sweeping routines) and characteristics of the particles (i.e. organic content) were identified as influential factors affecting the release of heavy metals. This finding may help improve the description of pollutant transport processes in stormwater quality models. Laboratory experiments showed that various pipe materials (PVC, concrete and corrugated steel) affected the stormwater quality differently, depending on the characteristics of the stormwater used in experiments. The concrete pipe contributed to increase pH of the transported stormwater. Metal concentrations were mostly unaffected in the PVC pipe, decreased in the concrete pipe (due to particle deposition and metal adsorption to the pipe surface), and while Zn concentrations increased in the corrugated steel pipe due to elution, Cu and Pb concentrations were reduced (due to particle deposition in the corrugations). Since the impact of climatic changes on stormwater quality was relatively small compared to changes in socio-economic factors, future efforts to maintain or improve stormwater quality should focus on implementing pollutant abatement strategies, including implementation of well-designed and maintained stormwater treatment measures.

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  • 312.
    Borris, Matthias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Influential factors in simulations of future urban stormwater quality: Climate change, progressing urbanization and environmental policies2013Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Climate change is regarded as one of the main future challenges implyingchanging hydrological conditions in urban areas. At the same time many urbanareas are expected to grow due to increasing population, which will most likelycause a higher level of urbanization. Combined effects of climatic changes andprogressing urbanization will have an impact on the abundance of pollutantsand the capacity for their transport. Due to this it is most likely that stormwaterquality will change as well. Effects of climatic changes, progressingurbanization and changing environmental policies on urban stormwater qualitywere studied by means of computer simulations for different test catchments inSweden. Scenarios accounting for such changes were developed and simulatedwith the Storm Water Management Model (SWMM), in which stormwaterquality was described by total suspended solids (TSS) and two heavy metals,namely copper and zinc. The simulation results showed that pollutant loadsdepended mainly on rainfall depth and intensity, but not on antecedent periods.Storms with low to intermediate depths and intensities showed the highestsensitivities to climatic changes and the reason for that was the contribution ofpervious areas and pollutant supply limited conditions. Catchments with lowimperviousness were most sensitive to climatic changes, but the total TSSloads were low compared to catchments with high imperviousness. Generallypollutant loads increased due to climatic changes characterized by higherdepths and intensities of rainfall in future scenarios. Furthermore stormwaterquality changed significantly for scenarios considering a progressingurbanization. A changing catchment area and impervious fraction caused highchanges in runoff volumes and pollutant loads. Thus changes in suchcatchment characteristics were identified as the most influential factors; inmost of the cases changes caused by climate change were exceeded.Environmental policies, as for example the reduction of directly connectedimpervious areas were effective in reducing runoff volumes and consequentlypollutant loads. Furthermore pollutant source controls, including materialsubstitution, were identified to be an effective tool for reducing pollutant loadsand improving stormwater quality. Generally changes produced by climaticchanges were small compared to the effects of changes in land use and this hasimplications for the management of stormwater quality.

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  • 313.
    Borris, Matthias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Gustafsson, Anna-Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    National Water Research Institute, Environment Canada, 867 Lakeshore Rd, Burlington ON, Canada.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Continuous simulations of urban stormwater runoff and total suspended solids loads: influence of varying climatic inputs and catchment imperviousness2014In: Journal of Water and Climate, ISSN 2040-2244, Vol. 5, no 4, p. 593-609Article in journal (Refereed)
    Abstract [en]

    Potential implications of climate change for future stormwater management were addressed by undertaking continuous simulations of runoff and total suspended solids (TSS) loads for three urban catchments, with imperviousness varying from 23 to 63%, which were exposed to five rainfall regimes during the snow-free part of the year: the current climate and four climate change scenarios projecting higher rainfalls. Simulated runoff volumes increased in all the future scenarios, particularly in the sub-arctic climate and the fixed uplift scenario (plus20) indicating appreciable rainfall increases. Simulated runoff volumes increased depending on the projected increases in rainfall and increasing runoff contributions from pervious areas when more intense future rainfalls exceeded hydrologic abstractions. The increased runoff volumes then contributed higher TSS loads, which were highly variable for the rainfall regimes tested. In cold climate regions, residues of solids from winter road maintenance may contribute to high initial accumulations of TSS on the catchment surface and high washed off loads. In general, the study suggests that intermediate design-life stormwater management facilities require flexible design allowing for future step-wise adaptation by gradually increasing design capacities and modifying treatment trains.

  • 314.
    Borris, Matthias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Leonhardt, Günther
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Österlund, Helene
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Source-based modeling of stormwater quality response to projected future changes in climatic and socio-economic factors2015In: Urban Drainage Modelling 2015: Poster presentations : Proceedings of the 10th International Conference of Urban Drainage Modelling, Mont-Sainte-Anne, Québec, Canada 20-23 Swptember 2015 / [ed] Thomas Maere; Sovanna Tik; Sophie Duchense; Peter A. Vanrolleghem, 2015, p. 73-78Conference paper (Other academic)
  • 315.
    Borris, Matthias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Leonhardt, Günther
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Österlund, Helene
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Source-Based Modeling Of Urban Stormwater Quality Response to the Selected Scenarios Combining Future Changes in Climate and Socio-Economic Factors2016In: Environmental Management, ISSN 0364-152X, E-ISSN 1432-1009, Vol. 58, no 2, p. 223-237Article in journal (Refereed)
    Abstract [en]

    The assessment of future trends in urban stormwater quality should be most helpful for ensuring the effectiveness of the existing stormwater quality infrastructure in the future and mitigating the associated impacts on receiving waters. Combined effects of expected changes in climate and socio-economic factors on stormwater quality were examined in two urban test catchments by applying a source-based computer model (WinSLAMM) for TSS and three heavy metals (copper, lead, and zinc) for various future scenarios. Generally, both catchments showed similar responses to the future scenarios and pollutant loads were generally more sensitive to changes in socio-economic factors (i.e., increasing traffic intensities, growth and intensification of the individual land-uses) than in the climate. Specifically, for the selected Intermediate socio-economic scenario and two climate change scenarios (RSP = 2.6 and 8.5), the TSS loads from both catchments increased by about 10 % on average, but when applying the Intermediate climate change scenario (RCP = 4.5) for two SSPs, the Sustainability and Security scenarios (SSP1 and SSP3), the TSS loads increased on average by 70 %. Furthermore, it was observed that well-designed and maintained stormwater treatment facilities targeting local pollution hotspots exhibited the potential to significantly improve stormwater quality, however, at potentially high costs. In fact, it was possible to reduce pollutant loads from both catchments under the future Sustainability scenario (on average, e.g., TSS were reduced by 20 %), compared to the current conditions. The methodology developed in this study was found useful for planning climate change adaptation strategies in the context of local conditions.

  • 316.
    Borris, Matthias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Grus på väg – Fällor och källor för dagvattnets tungmetallhalter2016Other (Other academic)
    Abstract [sv]

    När det gäller dagvattnets föroreningstransport, så har forskningen hittills fokuserat små partiklar som oftast bär relativt höga föroreningshalter och lätt medföljer till recipienter. En studie utförd inom kluster Dag&Nät belyser ivilken mån stora partiklar (t.ex. grus), som stort sett inte medföljer strömmande dagvatten under regn, detta till trots kan bidra till höjda föroreningshalter i dagvatten. Kunskap om i vilken mån stora kvarblivande partiklar påverkar dagvattnets kvalitet kan hjälpa kommuner och andra att bättre planera underhållsåtgärder för att minska utsläppet av föroreningar till recipienter.

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  • 317.
    Borris, Matthias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Gör valet av rörmaterial skillnad?: Rörmaterialets påverkan på dagvattenkvaliteten2016Other (Other academic)
    Abstract [sv]

    Idag består Sveriges dagvattennät till ungefär 75% av betongledningar. Ålder och slitage gör att en väsentlig andel måste förnyas i den närmaste framtiden. I dagsläget finns en rad olika material som kan användas för att tillverka dagvattenledningar, t.ex. plast, betong eller stål. Beroende på användningsområde är vissa material mer fördelaktiga än andra, t.ex. i lägen med hög mekanisk belastning väljs oftast korrugerade stålrör, då de bättre motstår höga marktryck. Inom kluster Dag&Nät genomfördes år 2016 en studie för att belysa hur val av rörmaterialer kan påverka dagvattenkvaliteten. Framkomna resultat kan stödja val av rätt material såväl vid läggning av nya rör som vid utbyte av gamla rör.

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  • 318.
    Borris, Matthias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Gustafsson, Anna-Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    National Water Research Institute, Environment Canada.
    Modelling the effects of changes in rainfall event characteristics on TSS loads in urban runoff2014In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 28, no 4, p. 1787-1796Article in journal (Refereed)
    Abstract [en]

    The effect of changes in rainfall event characteristics on urban stormwater quality, which was described by total suspended solids (TSS), was studied by means of computer simulations conducted with the Storm Water Management Model for a climate change scenario for northern Sweden. The simulation results showed that TSS event loads depended mainly on rainfall depth and intensity, but not on antecedent conditions. Storms with low-to-intermediate depths and intensities showed the highest sensitivity to changes in rainfall input, both for percentage and absolute changes in TSS wash-off loads, which was explained by the contribution of pervious areas and supply limitations. This has significant implications for stormwater management, because those relatively frequent events generally carry a high percentage of the annual pollutant load

  • 319.
    Borris, Matthias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Gustafsson, Anna-Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Simulating future trends in urban stormwater quality for changing climate, urban land use and environmental controls2013In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 68, no 9, p. 2082-2089Article in journal (Refereed)
    Abstract [en]

    The effects of climatic changes, progressing urbanization and improved environmental controls on the simulated urban stormwater quality in a northern Sweden community were studied. Future scenarios accounting for those changes were developed and their effects simulated with the Storm Water Management Model (SWMM). It was observed that the simulated stormwater quality was highly sensitive to the scenarios, mimicking progressing urbanization with varying catchment imperviousness and area. Thus, land use change was identified as one of the most influential factors and in some scenarios, urban growth caused changes in runoff quantity and quality exceeding those caused by a changing climate. Adaptation measures, including the reduction of directly connected impervious surfaces (DCIS) through the integration of more green spaces into the urban landscape, or disconnection of DCIS were effective in reducing runoff volume and pollutant loads. Furthermore, pollutant source control measures, including material substitution, were effective in reducing pollutant loads and significantly improving stormwater quality

  • 320.
    Borris, Matthias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Gustafsson, Anna-Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Using urban runoff simulations for addressing climate change impacts on urban runoff quality in a Swedish town2012In: Urban Drainage Modelling: Proceedings of the Ninth International Conference on Urban Drainage Modelling, Belgrade, Serbia, 4-6 September 2012, Belgrade: Faculty of Civil Engineering, University of Belgrade , 2012Conference paper (Refereed)
    Abstract [en]

    The effect of climate change on urban stormwater quality was studied by means of computer simulations conducted with the Stormwater Management Model (SWMM) for common climate change scenarios developed for northern Sweden. The simulation results showed that stormwater quality depended on rainfall characteristics; a climate scenario implying increased rainfall depths and intensities produced higher pollutant loads carried by stormwater, but reduced concentrations, particularly for medium to high intensity storm events. This type of stormwater quality response was explained by pollutant supply limited transport processes and the resulting dilution of such pollutants. Medium intensity events showed the highest sensitivity to climatic changes, since such events strongly affected the contributions of pervious surfaces. This has significant implications for stormwater management, because those relatively frequent events generally carry a high percentage of the annual pollutant load.

  • 321.
    Borris, Matthias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Österlund, Helene
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    An exploratory study of the effects of stormwater pipeline materials on transported stormwater quality2017In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 76, no 2, p. 247-255Article in journal (Refereed)
    Abstract [en]

    Implications of three sewer pipe materials (concrete, galvanized corrugated steel, and polyvinyl chloride (PVC)) for stormwater quality were explored in laboratory experiments, in which three types of stormwater, SW1-SW3, were circulated in 0.5 m long sewer pipe sections. SW1 and SW2 represented synthetic rainwater, without and with fine street sediment added (CTSS = 150 mg/L), respectively, and SW3 was actual stormwater with the same sediment addition as SW2. Following 20-min runs, with an equivalent distance of 500 m travelled by water particles, a number of statistically significant changes in the stormwater chemistry were observed: (i) pH of all the simulated stormwaters increased in the concrete pipe (from 7.0-7.3 to 8.1-9.3), (ii) turbidity decreased in two stormwaters with sediments (SW2 and SW3) in concrete and galvanized corrugated steel pipes (by 50 and 85%, respectively), (iii) the type of stormwater affected the observed copper (Cu) concentrations, with Cudiss concentrations as high as 25.3 μg/L noted in SW3 passing through the PVC pipe, and (iv) zinc (Zn) concentrations sharply increased (Zntot = 759-1,406 μg/L, Zndiss = 670-1,400 μg/L) due to Zn elution from the galvanized steel pipe by all three stormwaters. Such levels exceeded the applicable environmental guidelines.

  • 322.
    Borris, Matthias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Österlund, Helene
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Contribution of coarse particles from road surfaces to dissolved and particle-bound heavy metal loads in runoff: A laboratory leaching study with synthetic stormwater2016In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 573, p. 212-221Article in journal (Refereed)
    Abstract [en]

    Laboratory leaching experiments were performed to study the potential of coarse street sediments (i.e. > 250 μm) to release dissolved and particulate-bound heavy metals (i.e. Cd, Cr, Cu, Ni, Pb and Zn) during rainfall/runoff. Towards this end, street sediments were sampled by vacuuming at seven sites in five Swedish cities and the collected sediments were characterized with respect to their physical and chemical properties. In the laboratory, the sediments were combined with synthetic rainwater and subject to agitation by a shaker mimicking particle motion during transport by runoff from street surfaces. As a result of such action, coarse street sediments were found to release significant amounts of heavy metals, which were predominantly (up to 99%) in the particulate bound phase. Thus, in dry weather, coarse street sediments functioned as collectors of fine particles with attached heavy metals, but in wet weather, metal burdens were released by rainfall/runoff processes. The magnitude of such releases depended on the site characteristics (i.e. street cleaning and traffic intensity), particle properties (i.e. organic matter content), and runoff characteristics (pH, and the duration of, and energy input into, sediment/water agitation). The study findings suggest that street cleaning, which preferentially removes coarser sediments, may produce additional environmental benefits by also removing fine contaminated particles attached to coarser materials

  • 323.
    Borris, Matthias
    et al.
    RISE Research Institutes of Sweden.
    Österlund, Helene
    Luleå University of Technology, Sweden.
    Marsalek, Jiri
    Luleå University of Technology, Sweden.
    Viklander, Maria
    Luleå University of Technology, Sweden.
    Snow pollution management in urban areas: an idea whose time has come?2021In: Urban Water Journal, ISSN 1573-062X, E-ISSN 1744-9006, Vol. 18, no 10, p. 840-849Article in journal (Refereed)
    Abstract [en]

    Needs for extending the principles of a sustainable urban drainage approach to the winter season with snow and pollutant accumulations have been so far unanswered. One of the first steps to remedy this situation is to make available a prototype snow management tool (PSMT) described herein. It is a simple empirical spreadsheet tool, as yet untested, which uses generally available input data to simulate accumulation of snow (as snow water equivalent) and pollutants in an urban catchment, intermittent snowmelt episodes, and snow management options including in situ melting, removal from the catchment, treatment of snowmelt by settling, and snow disposal in the receiving waters. The tool output comprises snow and the selected pollutant mass balances, and pollutant concentrations in snowmelt from individual snow deposits. Such data provide decision support for choosing the methods of disposal for individual snow deposits. The testing and refinement of the tool is planned. 

  • 324.
    Borris, Matthias
    et al.
    Urban Water Management, Research Institutes of Sweden, Borås, Sweden.
    Österlund, Helene
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Snow pollution management in urban areas: an idea whose time has come?2021In: Urban Water Journal, ISSN 1573-062X, E-ISSN 1744-9006, Vol. 18, no 10, p. 840-849Article in journal (Refereed)
    Abstract [en]

    Needs for extending the principles of a sustainable urban drainage approach to the winter season with snow and pollutant accumulations have been so far unanswered. One of the first steps to remedy this situation is to make available a prototype snow management tool (PSMT) described herein. It is a simple empirical spreadsheet tool, as yet untested, which uses generally available input data to simulate accumulation of snow (as snow water equivalent) and pollutants in an urban catchment, intermittent snowmelt episodes, and snow management options including in situ melting, removal from the catchment, treatment of snowmelt by settling, and snow disposal in the receiving waters. The tool output comprises snow and the selected pollutant mass balances, and pollutant concentrations in snowmelt from individual snow deposits. Such data provide decision support for choosing the methods of disposal for individual snow deposits. The testing and refinement of the tool is planned.

  • 325.
    Bosakova, Zuzana
    Kristianstad University, School of Education and Environment.
    Ekonomisk jämförelse mellan trappstegsgaller och hålplåtsgaller: en fallstudie vid Kristianstads Centrala reningsverk2016Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [sv]

    Kristianstads reningsverk är dimensionerat för 205 000 pe. En ny utbyggnad av verket är inplanerad för att förbereda för ökade krav på reningsgraden respektive större utveckling av staden. Verket ska i det närmaste öka sin kapacitet till 350 000 pe.Det första reningssteget är av avgörande betydelse då dess avskiljningsgrad kan påverka respektive medfölja hela den efterföljande processen, från dess början till dess slutgiltiga produkt: slammet. Utan den mekaniska förbehandlingen skulle föremål och partiklar följa med vattnet in i verket och förorsaka driftstörningar i form av igensättning i och slitage av maskiner och pumpar.Reningsverket i Kristianstad har otillräcklig separering av föroreningar i den första fasen av reningen, dvs. mekanisk rening i form av galler. Trappstegsgallret släpper igenom alldeles för stora mängder föremål, såsom bindor, tops, hår, fibermaterial och servetter av olika material.Syftet med studien är att undersöka ekonomiska konsekvenser av att byta filter. Otillräcklig eliminering av fasta föroreningar i det inkommande vattnet genom trappstegsgallret, förorsakar onödiga kostnader för verket. En likhetsgranskning mellan nuvarande utgifter och eventuellt investering i det nya hålplåtsgallret ligger centralt i projektet. Undersökning av annuitetsmetoden vid inköp av varor påvisar att investering i det nya gallret som skulle kosta ca 3 mkr (grundinvestering) och genom beräkningar med hjälp av annuitetsmetoden skulle kapitalsatsning vara vid konstant inbetalning av summan 513 tkr per år under ekonomiskt livslängd 15 år. Differensen mellan satsning i de nya gallerna samt underhållsutgifter (397 tkr) för de nuvarande Step-Screen gallret är 513 tkr minus 397 tkr pekar på resultat 116 tkr. Det tyder på att investering i det nya gallret EscaMax kommer att kosta varje år 116 tkr mer än det görs i dagsläget. Det måste nog poängteras att det togs ingen hänsyn till underhållskostnaderna för de nya hålplåtsgallerna i beräkningar.

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  • 326.
    Bosson, Emma
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Modellstudie av föroreningsretention i Bäckaslövs våtmark: Tillämpning av modellverktygen MIKE SHE WET och MIKE 212004Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    During the nineties, ecological handling of urban storm water became very popular in Sweden. Together with Chalmers University of Technology and two Swedish communities, DHI Water and Environment has been doing research of storm water ponds and constructed wetlands. This thesis work is a part of that research project. The work has been applied at the Bäckaslöv storm water treatment plant in Växjö, Sweden. The plant consists of one storm water pond and a downstream constructed wetland. Simulations in two different modelling programs, MIKE SHE WET and MIKE 21 have been performed. MIKE SHE WET has never been used in practical work. The purpose of the program is to describe chemical and biological processes in wetlands and how the plants affect the retention of nutrients in the water. Since the program never has been used before, the main work has been to test the model to investigate whether it fulfil its purpose or not. MIKE 21 has been used to describe how the geometry influences the retention of suspended material, nitrogen and phosphorus. MIKE 21 has also been used to study how the wetland works without the storm water pond. To be able to describe the natural processes going on in wetlands the program MIKE SHE WET has to be further developed. The work has yet resulted in a package of measures that can improve the model. Science is in need for a model like MIKE SHE WET. If the program will be edited it can contribute a lot to the research of wetlands and storm water treatment. The simulations in MIKE 21 show that today’s shape of the wetland is not most favourable. If the water was spread over a bigger area the retention of nitrogen, phosphorus and suspended material would increase.

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  • 327.
    Bottacin-Busolin, Andrea
    et al.
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn, I-35131 Padua, Italy.
    Marion, Andrea
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn, I-35131 Padua, Italy.
    Zaramella, Mattia
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn, I-35131 Padua, Italy.
    Modellazione a tempi di residenza del trasporto di soluti nei corsi d'acqua: Applicazione al fiume Yarqon, Israele2008Conference paper (Other academic)
    Abstract [it]

    Il trasporto di soluti nei corsi d’acqua è controllato dall’idrodinamica superficiale e da scambi di massa con distinte zone di ritenzione. La propagazione a valle delle sostanze trasportate è generalmente ritardata dall’immagazzinamento temporaneo in zone morte superficiali, tipicamente zone vegetate o sacche di ritenzione laterali, e nei sedimenti sottostanti, nella cosiddetta zona iporeica. In questo articolo viene presentato un modello concettuale per il trasporto di soluti nei corsi d’acqua (STIR, Solute Transport In Rivers) nel quale i singoli processi di scambio sono rappresentati separatamente da una probabilità di “uptake” e da un’appropriata distribuzione dei tempi di residenza. Ciò rende il modello flessibile e modulare, e consente di incorporare l’effetto di una varietà di processi d’immagazzinamento e reazioni chimiche in modo dettagliato. La capacità del modello di rappresentare situazioni reali è qui dimostrata dall’applicazione al fiume Yarqon, in Israele.

  • 328.
    Bouzidi, B.
    et al.
    Centre de Développement des Energies Renouvelables, CDER, BP 69 – Route de l’Observatoire, Bouzareah, Algiers, Algeria.
    Campana, Pietro Elia
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Optimization of photovoltaic water pumping systems for date palm irrigation in the Saharan regions of Algeria: increasing economic viability with multiple-crop irrigation2021In: Energy, Ecology and Environment, ISSN 2363-7692, Vol. 6, no 4, p. 316-343Article in journal (Refereed)
    Abstract [en]

    The Saharan regions of Algeria, which represent almost 90% of the total area of the country, have severe energy problems due to insufficient or lack of energy access. The sustainable development of those areas must aim at securing and increasing primary production, especially in the agricultural and pastoral sectors. The production itself depends on the supply of water available at great depths. However, the potential volumes of water pumped by photovoltaic water pumping systems are generally greater than the annual requirements for crop irrigation. In this study, we optimized the photovoltaic array, the storage tank and efficient use of the water produced by the pumping system for the irrigation of one hectare palm grove. This excess water produced was reduced by a judicious association by planting other crops (tomato, wheat and sweet pepper). The utilization rate has been improved from 56% to 86%, on the one hand. On the other hand, the impact of the yield and the prices on the economic viability was studied. The project is economically viable for a price per kg of date of 500.00 DA and a yield varying from 20 to 50 kg/tree, and the payback period varies from 3.34 to 1.22 years. The project is not economically viable for a price per kg of date of 100.00 DA/kg for a yield less than or equal to 30 kg/tree. A sensitivity analysis has shown that the photovoltaic water pumping system becomes more competitive than conventional diesel water pumping systems for diesel price beyond 53.98 DA/l (0.38 €). The results are very encouraging for the wide use of photovoltaic water pumping systems for multiple-crop irrigation in the Saharan regions. 

  • 329.
    Boyer, Linus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Mechanics.
    DESIGNSTUDIE AV MEDIASTSYEM TILL STÅNGHÄRDLINJE UR ETT MILJÖPERSPEKTIV2021Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    The purpose of this thesis is to analyse if it would be possible to install a steel rod quench and tempering line with all attachments at the SSAB site in Virsbo. Thereto the thesis will overlook if the premises is suited for this production line and its gadgets, like a cooling basin and the relevant pumps, regarding the environmental laws put up by the government and EU. These laws will be compared to the environmental goals set by SSAB themselves and their pledge to reach the SDGs developed by UN.

    The fitting of the Q & T line was done together with the experienced engineers at SSAB after visiting and identifying the buildings characteristics. Inspirations for the new cooling basin were taken from a few of SSABs already existing production lines. To fit the cooling basin in the existing building another survey at the location in Virsbo had to be done due to poor drawings from all the redevelopments the premises has gone through over the years. 

    A proper investigation of the production building showed that it will be perfectly suited to accommodate the facility SSAB has in mind. The different water basins considered ended up with a simple solution where using an old storage will be rebuilt to contain the water.

    By doing a literature study reading about most of the laws and requirements that SSAB must follow it shows complicated systems. There are a few different decision-making bodies, and these have their own systems. SSAB themselves have decided to put more pressure on themselves by setting standards higher than the this. 

    SSAB has set a goal to produce steel without any carbon dioxide emissions by 2045. This project is called HYBRIT and is done by a joint venture company together with Vattenfall and LKAB. HYBRIT will be the solution for SSAB to manage all the laws and many of the SDGs. Together with the newest inventions in steel production and renewing old technology they can reach their highly set goals.

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  • 330. Brandimarte, L.
    et al.
    D'Odorico, P.
    Montanari, A.
    A probabilistic approach to the analysis of contraction scour2006In: Journal of Hydraulic Research, Vol. 44, no 5, p. 654-662Article in journal (Refereed)
  • 331. Brandimarte, L.
    et al.
    Montanari, A.
    Briaud, J. -L
    D'Odorico, P.
    Stochastic flow analysis for predicting river scour of cohesive soils2006In: Journal of Hydraulic Engineering, Vol. 132, no 5, p. 493-500Article in journal (Refereed)
  • 332.
    Brandner, Hanna
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Hydraulic Engineering.
    Idenitfying the Influential Factors of the Temporal Variation of Water Consumption: A Case Study using Multiple Linear Regression Analysis2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis is a part of the water development project conducted by Svenskt Vatten, which is the Swedish Water and Wastewater Association (SWWA) as well as Tyréns, a consultancy company with offices based in Stockholm, Sweden. Prior to this thesis work, a quality assessment was conducted for some of the locations provided by municipalities in Sweden. This thesis builds upon the revised water consumption data, and also continues to work with validating and modifying the water measurement data in order to proceed with the next step of the water development project, which is to identify any trends in the temporal variation of water consumption. The main objective of this thesis work is to investigate the influence of climatic, time-related and categorical factors on water consumption data collected for different regions in Sweden, and includes a number of different sectors such as residential, industrial and agricultural water user sectors. For the analysis of data, spectral analysis and sinusoidal modelling will be applied in order to find the periodicity of the data, and then simulate the fitted sinusoidal equation to the observed water consumption data for the hourly interval period. Multiple linear regression analysis is then used to assess what independent variables such as climate, time-related and categorical variables can explain the variation in water consumption over hourly and daily periods of time. 

    Spectral analysis identifies high peaks in the spectral density of the data at 12 and 24 hour cycles, for the hourly water consumption data. For the total daily consumption of water, there is a peak at 7 days, which clarifies that there is a weekly pattern occurring throughout the year. The results from the simple linear regression analysis, where the linear relationship between temperature and water consumption was determined, reveals that the water consumption tends to increase within an increasing temperature, where in Lönashult, Alvesta municipality the water demand increased by 5.5% with every 2 ºC rise in temperature, at a threshold of 12 ºC. For Kalix municipality the three areas selected have around 1-2 % increase in water demand with every 2 ºC rise in temperature for the period of May to December. In Gothenburg, areas that were mixed villa areas or areas with summer homes there was a rise of around 2-12 % in water demand, however areas that are situated in the inner city Gothenburg, or that have majority student housing, the water consumption tends to decrease by 2-7% in water demand with every 2 ºC rise in temperature, with a threshold of 12 ºC.

    In multiple regression analysis, the hourly water consumption results in adjusted R2 values were in the range from 0.58 to 0.87 (58-87%) for the best model approach and therefore has a significant relationship between water consumption and the explanatory variables chosen for this study. For the daily water consumption, the adjusted R2 values were in the range of 0.22-0.83 (22-83%).  The adjusted R2 values are lower for certain areas and can be explained by a number of factors, such as the different variables used for the daily water consumption analysis, as variables that explain more the periodicity of the data such as the sinusoidal fitted variable and hourly or night/day changes in consumption are not included. As well as this, not all independent variables such as the climate variables were available or complete for particular time periods, and also errors in the data can lead to a significantly lower R2 value. 

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  • 333.
    Bratt, Ola
    Mälardalen University, School of Business, Society and Engineering.
    DEVELOPING METHODS FOR WATER QUALITY MEASUREMENT: Using machine learning and remote sensing to predict absorbance with multispectral imaging2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Water resources play an important role in society and fulfill various functions such as providing drinking water, supporting industrial production and enhancing the overall landscape. Water bodies, such as rivers and lakes, are particularly important in this context. However, as societies and economies develop, the demand for water increases significantly. This also leads to the release of domestic, agricultural and industrial wastewater, which often exceeds the self-purification capacity of water bodies. Consequently, rivers and lakes are getting more and more polluted, endangering the safety of drinking water and causing ecological damage, affecting human health and biodiversity. 

    Water quality monitoring plays a crucial role in evaluating the state of water bodies. Traditional monitoring methods involve labor-intensive field sampling and expensive construction and maintenance of automatic stations. Although these methods provide accurate results, they are limited to specific sampling points and struggle to meet the demands of monitoring water quality across entire surfaces of rivers and lakes. This degree project aim at developing a method that can predict absorbance in water with the aim of remote sensing. Along with multispectral imaging and machine learning this work proves that this is possible. The result from multivariate analysis is an optimal model that can predict absorbance at 420 nm with RSQ of 0,996 and RMSE of 0,00081. 

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  • 334.
    Bredberg, William
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    En utveckling av alternativa metoder för klassificering av avrinningsområden med avseende på bebyggelsetyp och anslutningsförhållanden2020Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Surfaces of varying permeability and different combinations of water pipelines within catchment areas result in different runoff coefficients. Classification of catchment areas with regards to building type and water pipeline connections are therefore commonly used in order to simplify runoff calculations. The work required to perform these classifications is often time consuming as it is performed manually. This master's thesis aims to make the task of classification less labour intensive.

    Three alternative methods for classification with regards to building type and one method for water pipeline connection were considered in this master's thesis. The first two building type classification methods were based on parallellepiped and maximum likelihood classification theory and required a choice of parameters and training data in order to perform classifications. The third method was based on a nearest neighbour algorithm and only required training data in the form of a number of previously classified areas. All three building type classification methods were evaluated against previously obtained classifications for catchment areas using confusion matrices. The method purposed for catchment area water pipeline connections was developed from a given number of predetermined conditions. That method did not have the same evaluation opportunities as no previously made classifications could be obtained. Instead, the method was validated by inspection of individual example areas.

    The method based on the nearest neighbour algorithm proved to perform very well, with a strength of agreement that was almost perfect under certain conditions. The performance of the method was however limited by city formation and area distribution. Hence, future usage of the method require an understanding of how the algorithm performs the classifications and under what circumstances the method may or may not produce sufficient results. All other methods purposed for building type classification produced inferior results with the parameters that were tested. The water pipeline connection classification method followed the outlined conditions and seemed to perform well. It is however subject to data limitations and the method would have to be validated in additional cities on several data sets in order to provide a better basis for evaluation.

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  • 335. Briaud, J. -L
    et al.
    Brandimarte, L.
    Wang, J.
    D’Odorico, P.
    Probability of scour depth exceedance owing to hydrologic uncertainty2007In: Georisk, Vol. 1, no 2, p. 77-88Article in journal (Refereed)
  • 336.
    Broekhuizen, Ico
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hydrological modelling of green urban drainage systems: Advancing the understanding and management of uncertainties in data, model structure and objective functions2021Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The use of green urban drainage systems such as green roofs, swales and pervious areas has in recent years become a popular option to reduce flood risk and water quality problems in a more sustainable way than with traditional pipe-based drainage systems. Computer models are valuable tools for the management of such systems. While uncertainties associated with these models have been investigated for pipe-based systems, their adaptation and application to green areas requires re-examination of these uncertainties, as additional hydrological processes become relevant and new opportunities for model calibration arise. The overall aim of this thesis is to contribute to understanding and reducing of uncertainties in the mathematical modelling of green urban drainage studies. Specific topics adressed are field measurements, data processing, data selection, model structures and objective functions.Weighing-bucket precipitation sensors were confirmed on multiple occasions to be accurate to within ±1% of accumulated precipitation. A new signal processing method was able to convert accumulated precipitation to noise-free 1-minute rainfall rates that reproduced total rainfall volumes with only minor errors.Area-velocity flow sensors were tested and their measurement uncertainties quantified in laboratory experiments for flow rates up to 9 L s-1. Total flow rate uncertainty was ±0.34 L s-1 in optimal conditions (flat pipe), increasing to 0.60 and 0.83 L s-1 for pipe slopes of 2% and 4% respectively. In the presence of an upstream obstacle the uncertainty was 2 to 3 times larger, although in the case of no pipe slope this could be reduced to the same as the optimal conditions by increasing water levels in the pipe.Three different urban drainage models for green areas were compared using long-term simulations of synthetic catchments with different soil types and depth. In all models surface runoff formed a significant component of the annual water balance for some soil profiles, while the models reacted differently to changes in soil type an depth. Inter-model variation was large compared to the variation between different soil profiles.Four different models were tested for the simulation of runoff from two full-scale green roofs. More complex models showed better performance in reproducing observed runoff, while the magnitude and source of model predictive uncertainties varied between the models. It was also found that for all models calibration periods with high inter-event variability in terms of runoff retention provided more information in the calibration process.The use of soil water content observations (SWC) was investigated for the calibration of a detailed model of an urban swale. SWC observations were found to be useful for improving the identifiability of certain model parameters and the model predictions of SWC, and for setting the initial SWC in simulations. Different approaches to combining SWC and outflow observations were compared, revealing that the precision and reliability of model predictions could in some cases be improved by using a different way of determining which parameter sets to use for the generation of uncertain model predictions.The influence of calibration data selection was investigated using a model of a small green urban catchment. Performance of the model when calibrated using different sets of events varied significantly. Two-stage calibration strategies (where first small rainfall events were used to calibrate impervious area parameters, followed by using larger events to calibrate green area parameters) showed good performance especially in terms of runoff volume and peak flow. Finally it was found that the benefits of the two-stage calibration were greater when using a model with a low spatial resolution than with a high spatial resolution.For the same catchment tests were also carried out of an objective function that explicitly allows for timing errors, rather than comparing only simulated and observed values for the same time step. Model predictions generated using this objective function were equally reliable, but more precise and therefore of more practical value.Finally, drawing upon the practical experience from working with different models and drainage systems an overview is provided of the applicability of the modelling techniques used in this thesis for different models and what features may be desirable to add to models to improve this.

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  • 337.
    Broekhuizen, Ico
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hydrologisk modelleringav gröna tak2021Other (Other academic)
    Abstract [sv]

    Gröna tak är en allt vanligare dagvattenåtgärd för att minska avrinningsvolymer vid regn i urbana områden. Utvärdering av gröna tak och deras effekt på dagvattensystemet analyseras ofta med modeller. Det finns dock många olika modeller och det är inte klart hur bra de olika modellerna är. Därför har en jämförelse av fyra olika modeller gjorts med data från två olika gröna tak i olika klimat. Resultaten visar att den allra enklaste modellen har sämre prestanda än mer komplexa modeller. Av de mer komplexa modeller så är olika modeller bättre eller sämre beroende på vilka nyckeltal används för att utvärdera modellens prestanda.

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  • 338.
    Broekhuizen, Ico
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Jordfuktighetsmätningar för modellering av öppna dagvattenlösningar2021Other (Other academic)
    Abstract [sv]

    Öppna dagvattenlösningar blir alltmer populärt för att minska översvämningsrisken i urbana områden. Matematisk modellering är ett vanligt verktyg för att utvärdera dagvattensystem och eventuella ändringar i gestaltningen. Modellerna kräver oftast kalibrering mot uppmätt data, som i vanliga fall bara består av flödesmätningar. Detta skapar osäkerhet när det gäller modellens funktion för att simulera vad som händer när vattnet har infiltrerat i jorden. Därför har denna studie undersökt mervärdet av att använda mätningar av jordfuktighet vid kalibrering av dagvattenmodeller. Studien visar att mätningar av både flöde och jordfuktighet krävs för att kalibrera en modell på ett pålitligt sätt för både variabler.

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  • 339.
    Broekhuizen, Ico
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Uncertainties in rainfall-runoff modelling of green urban drainage systems: Measurements, data selection and model structure2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Green urban drainage systems are used to avoid flooding and damages to people and property, while limiting the downstream flooding and water quality problems caused by pipe-based drainage systems. Computer models are used to analyse and predict the performance of such systems for design and operation purposes. Such models are simplifications of reality and based on uncertain measured data, so uncertainties will be involved in the modelling process and its outcomes, which can affect the design and operation of these systems. These uncertainties have been investigated extensively for traditional pipe-based urban drainage systems, but not yet for green alternatives. Therefore, the overall objective of this thesis is to contribute to improved applicability and reliability of computer models of green urban drainage systems. Specifically, the thesis aims to (1) improve understanding of the uncertainties arising from (a) model structure and (b) calibration data selection, (2) evaluate two alternative calibration methods for green urban drainage models, (3) discuss desirable structural features in urban drainage models, and (4) evaluate several sensors for hydrometeorological measurements in urban catchments.

    The effects of model structure uncertainty were investigated using long-term simulations of synthetic catchments with varying soil types and depths for three different models. First, it was found that surface runoff could be a significant part of the annual water balance in all three models, depending on the soil type and depth considered. Second, differences were found in how sensitive the different models were to changes in soil type and depth. Third, the variation between different models was often large compared to the variation between different soil types. Fourth, the magnitude of inter-annual and inter-event variation varied between the models. Overall, the findings indicate that significant differences may occur in urban drainage modelling studies, depending on which model is used, and this may affect the design or operation of such systems.

    The uncertainty from calibration data selection was investigated primarily by calibrating both a low- and high-resolution stormwater model using different sets of events. These event sets used different rainfall-runoff statistics to rank all observed events before selecting the top six for use in calibration. In addition, they varied by either calibrating all parameters simultaneously, or by calibrating parameters for impervious and pervious surfaces separately. This last approach sped up the calibration process. In the validation period the high-resolution models performed better than their low-resolution counterparts and the two-stage calibrations matched runoff volume and peak flows better than single-stage calibrations. Overall, the way in which the calibration events are selected was shown to have a major impact on the performance of the calibrated model.

    Calibration data selection was also investigated by examining different ways of including soil water content (SWC) observations in the calibration process of a model of a swale. Some model parameters could be identified from SWC, but not from outflow observations. Including SWC in the model evaluation affected the precision of swale outflow predictions. Different ways of setting initial conditions in the model (observations or an equilibrium condition) affected both of these findings.

    The precipitation sensors used in this thesis showed generally satisfactory performance in field calibration checks. Different types of precipitation sensors were associated with different requirements for maintenance and data acquisition. Sensors for sewer pipe flow rates showed good agreement with a reference instrument in the laboratory, as long as installation conditions were good. Higher pipe slopes and upstream obstacles lead to larger measurement errors, but this last effect was reduced by increasing water levels in the pipe. Sensor fouling was a source of errors and gaps in field measurements, showing that regular maintenance is required. The findings show that the evaluated flow sensors can perform satisfactorily, if measurement sites are carefully selected.

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  • 340.
    Broekhuizen, Ico
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Adhikari, Utsav
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Design av biofilter för ökad flödesfördröjning2023Other (Other academic)
    Abstract [sv]

    Biofilter används idag mest i syfte att förbättra vattenkvalitet, men med tanke på framtida klimatförändringar är det intressant att se om de även kan bidra till minskade översvämningsrisker. Att öka lagringskapaciteten kan göras genom att öka lagringsvolymen på ytan eller att öka dräneringslagrets tjocklek. Denna skrift visar vilka effekter detta har på filtrets hydrologiska prestanda.

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  • 341.
    Broekhuizen, Ico
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Leonhardt, Günther
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Calibration event selection for green urban drainage modelling2019Manuscript (preprint) (Other (popular science, discussion, etc.))
    Abstract [en]

    Calibration of urban drainage models is typically performed based on a limited number of observed rainfall-runoff events, which may be selected from a longer time-series of measurements in different ways. In this study, 14 single- and two-stage strategies for selecting these events were tested for calibration of a SWMM model of a predominantly green urban area. The event selection was considered in relation to other sources of uncertainty such as measurement uncertainties, objective functions, and catchment discretization. Even though all 14 strategies resulted in successful model calibration, the difference between the best and worst strategies reached 0.2 in Nash–Sutcliffe Efficiency (NSE) and the calibrated parameter values notably varied. Most, but not all, calibration strategies were robust to changes in objective function, perturbations in calibration data and the use of a low spatial resolution model in the calibration phase. The various calibration strategies satisfactorily predicted 7 to 13 out of 19 validation events. The two-stage strategies performed better than the single-stage strategies when measuring performance using the Root Mean Square Error, flow volume error or peak flow error (but not using NSE); when flow data in the calibration period had been perturbed by ±40 %; and when using a lower model resolution. The two calibration strategies that performed best in the validation period were two-stage strategies. The findings in this paper show that different strategies for selecting calibration events may lead in some cases to different results for the validation period, and that calibrating impermeable and green area parameters in two separate steps may improve model performance in the validation period, while also reducing the computational demand in the calibration phase.

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  • 342.
    Broekhuizen, Ico
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Leonhardt, Günther
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Event selection and two-stage approach for calibrating models of green urban drainage systems2020In: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 24, p. 869-885Article in journal (Refereed)
    Abstract [en]

    The calibration of urban drainage models is typically performed based on a limited number of observed rainfall–runoff events, which may be selected from a larger dataset in different ways. In this study, 14 single- and two-stage strategies for selecting the calibration events were tested in calibration of a high- and low-resolution Storm Water Management Model (SWMM) of a predominantly green urban area. The two-stage strategies used events with runoff only from impervious areas to calibrate the associated parameters, prior to using larger events to calibrate the parameters relating to green areas. Even though all 14 strategies resulted in successful model calibration (Nash–Sutcliffe efficiency; NSE >0.5), the difference between the best and worst strategies reached 0.2 in the NSE, and the calibrated parameter values notably varied. The various calibration strategies satisfactorily predicted 7 to 13 out of 19 validation events. The two-stage strategies reproduced more validation events poorly (NSE <0) than the single-stage strategies, but they also reproduced more events well (NSE >0.5) and performed better than the single-stage strategies in terms of total runoff volume and peak flow rates, particularly when using a low spatial model resolution. The results show that various strategies for selecting calibration events may lead in some cases to different results in the validation phase and that calibrating impervious and green-area parameters in two separate steps in two-stage strategies may increase the effectiveness of model calibration and validation by reducing the computational demand in the calibration phase and improving model performance in the validation phase.

  • 343.
    Broekhuizen, Ico
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Leonhardt, Günther
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Selection of Calibration Events for Modelling Green Urban Drainage2019In: New Trends in Urban Drainage Modelling: UDM 2018 / [ed] Giorgio Mannina, Cham: Springer, 2019, p. 608-613Conference paper (Refereed)
    Abstract [en]

    Urban drainage models are often calibrated using a limited number of rainfall-runoff events, which may be selected in different ways from a longer observation series. This paper compares 13 different single- and two-stage strategies for selecting events used to calibrate a SWMM model of a predominantly green urban area. Most led to successful calibration, but performance varied for various validation events. Most selection strategies were insensitive to the choice of Nash-Sutcliffe Model Efficiency or Root Mean Squared Error as the objective function. Calibrating impervious and green area parameters separately in two-stage strategies can help improve prediction of low-flow events in validation.

  • 344.
    Broekhuizen, Ico
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Leonhardt, Günther
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Adapting weighing-bucket rainfall observations to urban applications2020Conference paper (Other academic)
    Abstract [en]

    •Data collection and processing approach for 1-minute rain valuesfrom weighing buckets.

    •Noise is removed from the record, without affecting event rainfall totals.

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  • 345.
    Broekhuizen, Ico
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Leonhardt, Günther
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Reducing uncertainties in urban drainage models by explicitly accounting for timing errors in objective functions2021In: Urban Water Journal, ISSN 1573-062X, Vol. 18, no 9, p. 740-749Article in journal (Refereed)
    Abstract [en]

    Traditional hydrological objective functions may penalize models that reproduce hydrograph shapes well, but with some shift in time; especially for urban catchments with a fast hydrological response. Hydrograph timing is not always critical, so this paper investigates alternative objective functions (based on the Hydrograph Matching Algorithm) that try to mimic visual hydrograph comparison. A modified version of the Generalized Likelihood Uncertainty Estimation is proposed to compare regular objective functions with those that account for timing errors. This is applied to 2-year calibration and validation data sets from an urban catchment. Results show that such objective functions provide equally reliable model predictions (they envelop the same fraction of observations), but with more precision, i.e. smaller estimated uncertainty of model predictions. Additionally, identifiability of some model parameters improved. Therefore objective functions based on the Hydrograph Matching Algorithm can be useful to reduce uncertainties in urban drainage modelling.

  • 346.
    Broekhuizen, Ico
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Mantilla, Iván
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Flödesstrypning i svackdiken för minskad översvämningsrisk2023Other (Other academic)
    Abstract [sv]

    Klimatförändring och urbanisering leder till allt större översvämningsrisker i våra städer. Därför finns det ett behov av yteffektiva åtgärder för att hålla riskerna begränsade. En sådan lösning kan vara att strypa utflödet från svackdiken för att tillfälligt lagra mer vatten och öka andelen som kan infiltrera i marken. I denna studie har fältförsök genomförts för att kvantifiera effekten av en sådan lösning för regn med återkomsttider mellan 1 och 50 år. Resultaten visar att såväl flödesvolym som maxflöde kan minskas med upp till 32% för mindre regntillfällen. Effekten av flödesstrypningen blir dock mindre för större regntillfällen, och ytterliggare designalternativ bör utredas.

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  • 347.
    Broekhuizen, Ico
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Muthanna, Tone M.
    Norwegian University of Science and Technology, Trondheim, Norway.
    Leonhardt, Günther
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Urban drainage models for green areas: Structural differences and their effects on simulated runoff2019In: Journal of Hydrology X, ISSN 2589-9155, Vol. 5, article id 100044Article in journal (Refereed)
    Abstract [en]

    Mathematical stormwater models are often used as tools for planning and analysing urban drainage systems. However, the inherent uncertainties of the models must be properly understood in order to make optimal use of them. One source of uncertainty that has received relatively little attention, particularly for increasingly popular green areas as part of urban drainage systems, is the mathematical model structure. This paper analyses the differences between three different widely-used models (SWMM, MOUSE and Mike SHE) when simulating rainfall runoff from green areas over a 26-year period. Eleven different soil types and six different soil depths were used to investigate the sensitivity of the models to changes in both. Important hydrological factors such as seasonal runoff and evapotranspiration, the number of events that generated runoff, and the initial conditions for rainfall events, varied significantly between the three models. MOUSE generated the highest runoff volumes, while it was rather insensitive to changes in soil type and depth. Mike SHE was mainly sensitive to changes in soil type. SWMM, which generated the least runoff, was sensitive to changes in both soil type and depth. Explanations for the observed differences were found in the descriptions of the mathematical models. The differences in model outputs could significantly impact the conclusions from studies on the design or analysis of urban drainage systems. The amount and frequency of runoff from green areas in all three models indicates that green areas cannot be simply ignored in urban drainage modelling studies.

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  • 348.
    Broekhuizen, Ico
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Muthanna, Tone Merete
    Norwegian University of Science and Technology.
    Leonhardt, Günther
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Model structure uncertainty in green urban drainage modelsManuscript (preprint) (Other academic)
    Abstract [en]

    Mathematical storm water models are often used as tools for planning and analysis of urban drainage systems, but the models’ inherent uncertainties need to be understood to make optimal use of them. One source of uncertainty that has received relatively little attention, especially for the increasingly popular green areas as part of urban drainage systems, is the choice of the mathematical model structure. This paper analyses the differences between three different widely-used models (SWMM, MIKE MOUSE and MIKE SHE) when simulating green areas over a 26 year period. A wide range of eleven different soil types and six different soil depths was used to investigate sensitivity of the models to changes in both. Important hydrological factors such as seasonal runoff and evapotranspiration, the number of events that generated runoff, and the initial conditions for rainfall events, varied strongly between the three models. MOUSE generated the highest runoff and was insensitive to changes in soil type and depth, while SHE was sensitive mainly to changes in soil type, and SWMM, which generated the least runoff, was sensitive to changes in both soil type and depth. Explanations for the observed differences were found in the descriptions of the mathematical models. The differences in model outputs could significantly impact the conclusions from design or analysis studies of urban drainage systems. The amount and frequency of runoff from green areas in all three models indicates that green areas cannot be simply ignored in urban drainage modelling studies.

  • 349.
    Broekhuizen, Ico
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Muthanna, Tone Murete
    Norwegian University of Science and Technology.
    Leonhardt, Günther
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Model structure uncertainty in urban drainage models for green areas2017In: 14th IWA/IAHR International Conference on Urban Drainage: Conference Proceedings, 2017, Prague, 2017, p. 1490-1494Conference paper (Refereed)
    Abstract [en]

    Two urban drainage models (SWMM and MOUSE) were used to study the impact of model structureuncertainty on long-term simulation of green areas. Depending on the soil profile being consideredsignificant differences were observed between the models, both on an annual and event basedscale. In general MOUSE generates more runoff and is more sensitive to changing soil depth. Thedifferences can be explained by the conceptual approaches used to model infiltration, which alsoaffects how much water is apportioned to evapotranspiration, surface runoff, and baseflow.

  • 350.
    Broekhuizen, Ico
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Rujner, Hendrik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Leonhardt, Günther
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Roldin, Maria
    DHI Sweden.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Improving hydrological modelling of urban drainage swales through use of soil water content observations2020In: Journal of Hydrology X, ISSN 2589-9155Article in journal (Refereed)
    Abstract [en]

    Flow observations alone may not provide sufficient information for calibration of detailed hydrological models of urban drainage swales. Therefore this study investigated the added value of using soil water content (SWC) observations made throughout the swale. This can be done by (1) including SWC in the likelihood function that is used to quantify model performance or (2) by using the SWC observations to set initial conditions in the model. The results show that combining outflow and SWC in the likelihood function is necessary to obtain reliable and precise predictions for both variables, and that this increases the number of parameters that are identifiable from the data. Using SWC observations to set initial model conditions improves model performance and affects the degree to which soil hydraulic parameters are identifiable. Overall, it is concluded that SWC observations may be a valuable complement to outflow observations in the modelling of urbanswales.

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