|
Titel |
Investigation of the direct runoff generation mechanism for the analysis of the SCS-CN method applicability to a partial area experimental watershed |
VerfasserIn |
K. X. Soulis, J. D. Valiantzas, N. Dercas, P. A. Londra |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1027-5606
|
Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 13, no. 5 ; Nr. 13, no. 5 (2009-05-15), S.605-615 |
Datensatznummer |
250011860
|
Publikation (Nr.) |
copernicus.org/hess-13-605-2009.pdf |
|
|
|
Zusammenfassung |
The Soil Conservation Service Curve Number (SCS-CN) method is widely used
for predicting direct runoff volume for a given rainfall event. The
applicability of the SCS-CN method and the direct runoff generation
mechanism were thoroughly analysed in a Mediterranean experimental watershed
in Greece. The region is characterized by a Mediterranean semi-arid climate.
A detailed land cover and soil survey using remote sensing and GIS
techniques, showed that the watershed is dominated by coarse soils with high
hydraulic conductivities, whereas a smaller part is covered with medium
textured soils and impervious surfaces. The analysis indicated that the
SCS-CN method fails to predict runoff for the storm events studied, and that
there is a strong correlation between the CN values obtained from measured
runoff and the rainfall depth. The hypothesis that this correlation could be
attributed to the existence of an impermeable part in a very permeable
watershed was examined in depth, by developing a numerical simulation water
flow model for predicting surface runoff generated from each of the three
soil types of the watershed. Numerical runs were performed using the
HYDRUS-1D code. The results support the validity of this hypothesis for most
of the events examined where the linear runoff formula provides better
results than the SCS-CN method. The runoff coefficient of this formula can
be taken equal to the percentage of the impervious area. However, the linear
formula should be applied with caution in case of extreme events with very
high rainfall intensities. In this case, the medium textured soils may
significantly contribute to the total runoff and the linear formula may
significantly underestimate the runoff produced. |
|
|
Teil von |
|
|
|
|
|
|