Analysis of the Regional Flow Duration Curve for Dongjiang Basin, South China

Abstract

A regional flow duration curve is a very useful tool in hydrological applications. The regional flow duration curve is generated by using flow data and the underlying surface characteristics of the thirteen catchments in Dongjiang basin. The flow duration curve for the each catchment is obtained by the traditional method, and, then the flows of various exceedance percentages Q_p% are calculated. Based on the relationship between the flow of various exceedance percentages and the area and slope of the catchments, an empirical formula for the region flow duration curve is founded over eleven catchments out of the thirteen catchments. The empirical formula is then validated at the two other catchments in which the synthetic flow duration curves are very close to the actual flow duration curves. The validation results suggest that the method adopted in this study has the ability to generate the synthetic flow duration curves at ungauged catchments in the study region, and the flow duration curves of ungauged basins can be calculated using the empirical formulas of region flow duration curves.