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| Titel |
Estimation of Surface Runoff in the Jucar River Basin from Rainfall Data and SMOS Soil Moisture |
| VerfasserIn |
Julio A. Garcia Leal, Teodoro Estrela, Arancha Fidalgo, Onofre Gabaldo, Maura Gonzalez Robles, Eddy Herrera Daza, Samiro Khodayar, Ernesto Lopez-Baeza |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250084917
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| Zusammenfassung |
| Surface runoff is the water that flows after soil is infiltrated to full capacity and excess water
from rain, meltwater, or other sources flows over the land. When the soil is saturated and the
depression storage filled, and rain continues to fall, the rainfall will immediately produce
surface runoff.
The Soil Conservation Service Curve Number (SCS-CN) method is widely used for
determining the approximate direct runoff volume for a given rainfall event in a particular
area. The advantage of the method is its simplicity and widespread inclusion in existing
computer models. It was originally developed by the US Department of Agriculture, Soil
Conservation Service, and documented in detail in the National Engineering Handbook, Sect.
4: Hydrology (NEH-4) (USDA-SCS, 1985).
Although the SCS-CN method was originally developed in the United States and mainly
for the evaluation of storm runoff in small agricultural watersheds, it soon evolved well
beyond its original objective and was adopted for various land uses and became an integral
part of more complex, long-term, simulation models. The basic assumption of the
SCS-CN method is that, for a single storm, the ratio of actual soil retention after
runoff begins to potential maximum retention is equal to the ratio of direct runoff to
available rainfall. This relationship, after algebraic manipulation and inclusion of
simplifying assumptions, results in the following equation given in USDA-SCS
(1985):
(P–-0,2S)2
Q = (P + 0,8S)
where Q is the average runoff (mm), P the effective precipitation (mm) and S is potential
maximum retention (mm) after the rainfall event.
The study has been applied to the Jucar River Basin area, East of Spain. A selection of
recent significant rainfall events has been made corresponding to the periods around 22nd
November, 2011 and 28-29 September and 10 October, 2012, from Jucar River Basin
Authority rain gauge data. Potential maximum retention values for each point have been
assumed as the first SMOS soil moisture values available at the closest DGG node
immediately after saturation produced by the rain.
The results are shown as maps of precipitation and soil moisture obtained using a V4
integration method between a linear and nearest neighbour methods. Surface runoff
maps are consequently obtained using the SCS-CN equation given earlier. These
results have also been compared to COSMO-CLM model simulations for the same
periods.
It is envisaged to obtain precipitation maps from MSG-SEVIRI data. |
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