Formulation of parameters in the storage-discharge relation for floods in three mountainous basins in Japan
Abstract
While the storage-discharge relation of the type S=aQb have been widely used as the basic equation in many flood runoff models, the optimum parameters, the coefficient a and exponent b, are different in each flood event, and their features are still not fully understood. Reducing the uncertainty of parameters in the storage-discharge relation can contribute to the accurate quantitative estimation of runoff. Here we present a formulation of the optimum parameters, a and b, by performing calibrations, which are carried out for 10,000 simulations of each flood event while changing the values of the parameters using a double-loop algorithm. The study basins are three mountainous basins located in different regions of Japan with different topographical, geological, and climatological conditions. The basin areas are from 233km2 to 472km2 and a total of 61 flood events are selected from hourly data over 15 years for the three basins. The hydrological model used in this study is a combination of the storage-discharge function and the Diskin-Nazimov rainfall infiltration model. The results show that the optimum combination of parameters, a and b, in the storage-discharge relation for floods in each study basin are approximated by a power-law function and form a non-linear curve in a log-log graph; the values of the coefficient of determination of the power-law function of the three study basins are 0.42, 0.74 and 0.84, respectively.
- Publication:
-
EGU General Assembly Conference Abstracts
- Pub Date:
- April 2017
- Bibcode:
- 2017EGUGA..19.3100F