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| Titel |
Modeling of storm runoff and pollutant wash off processes during storm event in rapidly urbanizing catchment |
| VerfasserIn |
H. P. Qin, X. Y. Yu, S. T. Khu |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250020231
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| Zusammenfassung |
| Many urban catchments in developing countries are undergoing fast economic
growth, population expansion and land use/cover change. Due to the mixture of
agricultural/industrial/residential land use or different urbanization level as well
as lack of historical monitoring data in the developing area, storm-water runoff
pollution modeling is faced with challenges of considerable spatial variations and data
insufficiency.
Shiyan Reservoir catchment is located in the rapidly urbanizing coastal region of
Southeast China. It has six sub-catchments with largely different land use patterns
and urbanization levels. A simple semi-distributed model was used to simulate the
storm-water runoff pollution process during storm event in the catchment. The
model adopted modified IHACRES model and exponential wash-off functions to
describe storm-runoff and pollutant wash-off processes, respectively, in each of six
sub-catchments. Temporary hydrological and water quality monitoring sites were set at the
downstream section of each sub-catchment in Feb-May 2007, spanning non-rain and rain
seasons. And the model was calibrated for storm-runoff and water quality data
during two typical storm events with rainfall amount of 10mm/4hr and 73mm/5hr,
respectively.
The results indicated that the Nash-Sutcliffe (NS) coefficients are greater than 0.65 and
0.55 respectively for storm-runoff model calibration and validation. However although NS
coefficients can reach 0.7~0.9 for pollutant wash-off model calibration based on measured
data in each storm event, the simulation data can not fit well with the measured
data in model validation. According to field survey observation, many litters and
residuals were found to distribute in disorder in some sub-catchments or their drainage
systems and to instantaneously wash off into the surface water when the rainfall
amount and intensity are large enough. In order to improve storm-water runoff
pollution simulation in the catchment, the variations of pollutant source and wash off
processes in different storm intensity should be consider in future monitoring and model
development.
Keywords: storm runoff; wash off; urbanization; catchment modeling; litter; residual |
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