Simplified approach to consider watersheds heterogeneity in direct runoff estimation using SCS-CN model
| Autor: | Soulis, K., Palli-Gravani, S., Kalivas, D. |
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| Rok vydání: | 2023 |
| Zdroj: | XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
| DOI: | 10.57757/iugg23-0283 |
| Popis: | The most established method for direct runoff estimation is the Soil Conservation Service-Curve Number method (SCS-CN). Despite the wide use of this method, there is no established and commonly accepted procedure for estimating the curve number (CN) from rainfall and runoff measurements. Previous studies have shown that the major problem is the large variation observed in the estimated CN values for different rainfall events with different total precipitation depths. A key study showed that this can be attributed to the spatial heterogeneity of watersheds’ physical characteristics and proposed a methodology to estimate the spatial distribution of CN in the watershed based on rainfall - runoff measurements.In this paper, the effect of impervious surfaces on direct runoff estimation with SCS-CN method is investigated and a simplified method considering watersheds heterogeneity in SCS-CN model is proposed. This method considers the spatial distribution of impervious surfaces in the watershed in the process of estimating CN from rainfall and runoff measurements at the watershed outlet. The proposed method has improved performance compared to the original SCS-CN method and similar to that of SCS-CN method in entirely spatially distributed form. Its application is much easier since it does not prerequisite the detailed spatial distribution of soil - land cover characteristics of the watershed and avoids the problems of over-parameterization. Finally, as the method requires just the percentage of impervious surfaces and weighted CN value of the rest of the studied watershed as parameters, it makes it suitable for lumped hydrological models. The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) |
| Databáze: | OpenAIRE |
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