Abgeschlossene Arbeiten seit 2004
Nutzen Sie die Recherchemöglichkieten im Forschungsinformationssystem (FIS) zur weiteren Einschränkung der aufgelisteten Abschlussarbeiten.
Modelling nutrient emissions in a mesoscale river catchment, with integration and mining strategies of extended input information
Art der Abschlussarbeit
Master
Autoren
- Kibui, Martin Manyiri
Betreuer
- Dipl.-Hydrol. Björn Helm
Abstract
Water degradation due to excessive loading of nutrients such as nitrogen and phosphorus, into aquatic systems is occurring in many watershed around the world. Watershed models are therefore applied to quantify the nutrient loads, identify the sources of such loads, and evaluate alternative strategies for nutrient reductions in aquatic systems and thus helping policy makers to select the most effective source control measures to achieve a reduction of nutrient levels in the aquatic systems. However, the scarcity of data for modelling purpose hinders the process of watershed modelling especially in watersheds without extended measurement base. Hence data integration approaches play an important role in such watersheds as these approaches assist in the acquisition of the necessary data required for watershed modelling. In this thesis, different approaches for data integration in mass balance oriented nutrient emission models are identified from literature review. The approaches used for acquisition of model inputs required by the MONERIS model to quantify nutrient emissions from urban systems and point sources are applied and compared. This is done for Western Bug river catchment, which faces data scarcity due to lack of an extended measurement base. It is found out that the approaches are applicable and efficient for use in a data scarce watershed as the approaches are able to estimate lacking model input data, from readily available data such as statistical data and literature values etc. and to fill data gaps, in available data having temporal data gaps. Hence enabling the modelling of nutrients from the Western Bug river basin by use of MONERIS model. The MONERIS model is manually calibrated and validated for the period from 2000 to 2008 and the modelling results obtained for the same period, show that the diffuse sources contributed a sum of 1398 t/a nitrogen and 267 t/a phosphorus (i.e. 66.1 % and 61.7 % of total nitrogen and total phosphorus emissions in the catchment) for the period from 2000 to 2008, while the point sources contributed 716 t/a nitrogen (33.9%) and 165 t/a phosphorus (38.3%). The point source pathway was found to be the most relevant/ dominant pathway for emission of both nitrogen and phosphorus in the catchment and this was mainly attributed to the Lviv WWTP. The phosphorus emissions were found to have increased by 13.2% from 2000 to 2008, while the nitrogen decreased by 4.93% for the same period. The MONERIS model results are assessed for each pathway contributing nutrient emissions into Western Bug river basin. A scenario analysis is carried out and the following measures are found out to reduce nutrient emissions into Western Bug river systems namely, reduction of slopes on arable land increasing the storage for combined sewers , use of free P laundry detergents, and increasing the WWTPs nutrient removal efficiency.
Schlagwörter
Nutrient modelling, water quality, data mining, model calibration, model parameterization
Berichtsjahr
2011