Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Predictive Modelling of Aquatic Ecosystems at Different Scales using Mass Balances and GIS
Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences.
2004 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis presents models applicable for aquatic ecosystems. Geographical Information Systems (GIS) form an important part of the thesis. The dynamic mass balance models focus on nutrient fluxes, biotic/abiotic interactions and operate on different temporal and spatial scales (site, local, regional and international). The relevance and role of scale in mass balance modelling is a focal point of the thesis.

A mesocosm experiment was used to construct a model to estimate the nutrient load of phosphorus and nitrogen from net cage fish farming (i.e., the site scale). The model was used to estimate what feeding conditions that are required for a sustainable aquaculture scenario, i.e., a zero nutrient load situation (a linkage between the site scale and the regional scale).

A dynamic model was constructed for suspended particulate matter (SPM) and sedimentation in coastal areas (i.e., the local scale) with different morphometric characteristics and distances to the Sea. The results demonstrate that the conditions in the Sea (the regional and international scale) are of fundamental importance, also for the most enclosed coastal areas.

A foodweb model for lakes was transformed and recalibrated for Baltic Sea conditions (i.e., the international scale). The model also includes a mass balance model for phosphorus and accounts for key environmental factors that regulate the presuppositions for production and biomasses of key functional groups of organisms. The potential use of the new model for setting fish quotas of cod was examined.

For the intermittent (i.e., regional) scale, topographically complex areas can be difficult to define and model. Therefore, an attempt was made to construct a waterscape subbasin identification program (WASUBI). The method was tested for the Finnish Archipelago Sea and the Okavango Delta in Botswana. A comparison to results from a semi-random delineation method showed that more enclosed basins was created with the WASUBI method.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis , 2004. , p. 65
Series
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1104-232X ; 957
Keywords [en]
Earth sciences, mass balance model, dynamic model, scales, marine fish farms, rainbow trout, nutrients, suspended particulate matter, phosphorus, nitrogen, GIS, basin delineation, regionalisation, coastal areas, aquatic foodweb, fishing quotas, Baltic Sea, Archipelago Sea, Okavango Delta
Keywords [sv]
Geovetenskap
National Category
Earth and Related Environmental Sciences
Identifiers
URN: urn:nbn:se:uu:diva-4143ISBN: 91-554-5922-6 (print)OAI: oai:DiVA.org:uu-4143DiVA, id: diva2:164315
Public defence
2004-04-26, Hambergsalen, Geocentrum, Villavägen 16, Uppsala, 10:15
Opponent
Supervisors
Available from: 2004-03-19 Created: 2004-03-19Bibliographically approved
List of papers
1. Modelling nutrient dynamics in a mesocosm fish farming experiment
Open this publication in new window or tab >>Modelling nutrient dynamics in a mesocosm fish farming experiment
In: Aquaculture, ISSN 0044-8486Article in journal (Refereed) Submitted
Identifiers
urn:nbn:se:uu:diva-91540 (URN)
Available from: 2004-03-19 Created: 2004-03-19Bibliographically approved
2. A dynamic compartment model to predict sedimentation and suspended particulate matter in coastal areas
Open this publication in new window or tab >>A dynamic compartment model to predict sedimentation and suspended particulate matter in coastal areas
2004 (English)In: Ecological Modelling, ISSN 0304-3800, E-ISSN 1872-7026, Vol. 175, no 4, p. 353-384Article in journal (Refereed) Published
Abstract [en]

This paper presents a new dynamic mass-balance model for suspended particulate matter (SPM) and sedimentation in coastal areas handling all important fluxes of SPM to, from and within coastal areas, as such areas can be defined according to the topographical bottleneck method. The model is based on ordinary differential equations and the calculation time (dt) is one month to reflect seasonal variations. An important demand, related to the practical utility of the model, is that it should be driven by variables readily accessed from standard monitoring programs or maps. Added to the dynamic core model are several (static) empirical regressions for standard operational effect variables used in coastal management, such as the Secchi depth, the oxygen saturation in the deep water, and chlorophyll-a concentrations. The obligatory driving variables include four morphometric parameters (coastal area, section area, mean and maximum depth), latitude (to predict surface water and deep water temperatures, stratification and mixing) and Secchi depth or SPM-concentrations in the sea outside the given coastal area. The model is based on four compartments: two water compartments (surface water and deep water; the separation between these two compartments is done not in the traditional manner from temperatures but from sedimentological criteria, as the water depth separating transportation areas from accumulation areas) and two sediment compartments (ET-areas, i.e., erosion and transportation areas where fine sediments are discontinuously being deposited, and A-areas, i.e., accumulation areas where fine sediments are continuously being deposited). The processes accounted for include inflow and outflow via surface and deep water, input from point sources, from primary production, from land uplift, sedimentation, burial (the transport of matter from surficial A-sediments to underlying sediments), resuspension, mixing and mineralization. The model has been validated with good results (the predictions of sedimentation are within the 95% confidence limits of the empirical data used to validate the model) against data collected by sediment traps placed in 17 Baltic coastal areas of different character. The paper also presents sensitivity and uncertainty tests of the model. The weakest part of the model concerns the sub-model to predict the ET-areas. Many of the structures in the model are general and have also been used with similar success for other types of aquatic systems (mainly lakes) and for other substances (mainly phosphorus, radionuclides and metals). We also present approaches to indicate how the model could be modified for coastal areas other than those included in this study, e.g., for open coasts, estuaries or areas influenced by tidal variations.

National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-91541 (URN)10.1016/j.ecolmodel.2003.09.036 (DOI)
Available from: 2004-03-19 Created: 2004-03-19 Last updated: 2017-12-14Bibliographically approved
3. WASUBI: A GIS tool for subbasin identification in topographically complex waterscapes
Open this publication in new window or tab >>WASUBI: A GIS tool for subbasin identification in topographically complex waterscapes
2005 (English)In: Environmental Modelling & Software, ISSN 1364-8152, E-ISSN 1873-6726, Vol. 20, no 6, p. 729-736Article in journal (Refereed) Published
Abstract [en]

Spatially distributed modelling is dependent on segmentation of the underlying geographic data and the model output could be improved if relevant compartments are found and used. Herein, we present a method for identifying subbasins in complex topographic waterscapes. The method first finds local troughs and then expands them over a friction surface derived from bathymetry. Friction surfaces generated by different cost growth functions were tested, and shown to give consistent results. The model is sensitive to the quality of the underlying topographic dataset and its spatial resolution. WASUBI (WAterscape SUBbasin Identification) is written in ArcView's built-in scripting language, Avenue, and distributed as a program extension. The method is easy to use, only requiring a digital elevation model (DEM) and the user to give the number of basins to be generated. The segmentation method was tested against datasets covering the Finnish Archipelago Sea and the Okavango Delta in Botswana. Test results showed that the WASUBI delineated subbasins were more enclosed than subbasins created by a semi-random delineation method. The objectives of this study was to construct and critically test algorithms for subbasin identification, based only on readily available DEM data, for use in geographic information system modelling.

National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-91542 (URN)10.1016/j.envsoft.2004.03.016 (DOI)
Available from: 2004-03-19 Created: 2004-03-19 Last updated: 2017-12-14Bibliographically approved
4. A new way of setting fish quotas based on holistic ecosystem modelling and accounting for key environmental factors and foodweb interactions regulating primary and secondary production
Open this publication in new window or tab >>A new way of setting fish quotas based on holistic ecosystem modelling and accounting for key environmental factors and foodweb interactions regulating primary and secondary production
In: Aquatic ecology, ISSN 1386-2588Article in journal (Refereed) Submitted
Identifiers
urn:nbn:se:uu:diva-91543 (URN)
Available from: 2004-03-19 Created: 2004-03-19Bibliographically approved
5. Environmental consequence analyses of fish farm emissions related to different scales and examplified by data from the Baltic
Open this publication in new window or tab >>Environmental consequence analyses of fish farm emissions related to different scales and examplified by data from the Baltic
In: Marine Environmental Research, ISSN 0141-1136Article in journal (Refereed) Submitted
Identifiers
urn:nbn:se:uu:diva-91544 (URN)
Available from: 2004-03-19 Created: 2004-03-19Bibliographically approved

Open Access in DiVA

fulltext(671 kB)2037 downloads
File information
File name FULLTEXT01.pdfFile size 671 kBChecksum MD5
3e5b0997e456c8609e9f017c78e8e72bf510666ee98f13fdcb693a581a6bc51164d8fbfd
Type fulltextMimetype application/pdf
Buy this publication >>

By organisation
Department of Earth Sciences
Earth and Related Environmental Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 2037 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 1195 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf