TY  - THES
AU  - Tetzlaff, Björn
TI  - Die Phosphatbelastung großer Flusseinzugsgebiete aus diffusen und punktuellen Quellen
VL  - 65
PB  - Universität Hannover
VL  - Dr. (Univ.)
CY  - Jülich
M1  - PreJuSER-55217
SN  - 3-89336-447-1
T2  - Schriften des Forschungszentrums Jülich. Reihe Umwelt / Environment
SP  - 287 S.
PY  - 2006
N1  - Record converted from VDB: 12.11.2012
N1  - Universität Hannover, Diss., 2006
AB  - This dissertation is embedded in the inter-disciplinary project named ”REGFLUD“ which is funded by the German Federal Ministry for Education and Research. The overall aim of the thesis is to develop and apply a GIS-based model for the analysis of P-fluxes from point and diffuse sources in macroscale river basins. For this purpose two stuy basins with varying natural conditions are chosen, i.e. the River Ems catchment (12,940 km$^{2}$) and parts of the River Rhine catchment (12,160 km$^{2}$). The new empirical phosphate model MEPhos allows the quantification of mean longterm P-inputs via drainage, groundwater-borne runoff, erosion, wash-off, rainwater sewers, combined sewers overflows, municipal sewage treatment plants and industrial effluents. Additionally the model takes into account P-retention in both running and standing waters. Diffuse P-entries to surface waters via drainage, groundwater-borne runoff, erosion and wash-off are modelled area-differentiated based on a phosphotope-approach. Phosphotopes are homogeneous sub-area types with defined properties and are used to discretize the river basin. To derive phosphotopes highly-resolved data sets are clipped in GIS. This approach enables the localization of “hot spots”, i.e. subareas with high potential for P-output. Because natural and agricultural conditions of these sub-areas are known, efficient reduction measures can be proposed. Pemissions from municipal waste water treatment plants and industrial effluents are quantified for every plant, inputs via rainwater sewers and combined sewers overflows are modelled integratively for river sub-basins. The modelled mean annual P-entries to surface waters (1995-1999) sum up to 1666 t/a for the Ems study basin and to 1574 t/a for the Rhine study basin. The relations between diffuse and point sources are 87:13 for Ems and 32:68 for Rhine. In the lowland catchment of the River Ems P-entries via the drainage pathway dominate the diffuse load (69 %). The contrasting natural conditions in the sub-catchment of the River Rhine as well as the far higher population density lead to a totally different relevance of sources. P-entries from municipal waste water treatment plants make up 41 % of the total load. Among diffuse sources erosion plays the most important role (11 %). The highest contribution to the diffuse P-load in the River Ems basin is made by the phosphotope “drained raised bogs under grassland use”. This sub-area type emits about 30 % of all diffuse entries, while it makes up only 3.5 % of the basin area. In the River Rhine sub-basin about 24 % of all diffuse P-entries originate from the phosphotope “hydraulically connected arable land with erosion potential of more than 15 t/(ha·a)“, which has an area share of only 0.7 %. Due to the combination of small area share and high share of the overall diffuse P-load efficient reduction measures should concentrate on these two phosphotopes. The validation of MEPhos modelling results against loads, estimated from measured water quality and runoff data, is performed for 58 sub-catchments. It shows good correlations between measured and modelled mean annual P-loads (1995-1999). Sustainable use of water resources creates the demand for data as a basis for decision making. The implementation of the EU-water framework directive requires river basin district management programmes. In this context MEPhos modelling results can be of use.
LB  - PUB:(DE-HGF)11 ; PUB:(DE-HGF)3
UR  - https://juser.fz-juelich.de/record/55217
ER  -