A parametric approach to estimate streamflow quantiles using annual flow–duration curves

Abstract

Abstract The flow–duration curve (FDC) is a significant instrument used in solving many hydrological and environmental problems such as evaluating water quality, examining water supply and use for hydroelectric generation and irrigation, and investigating sedimentation and low flows. However, the insufficiency of flow data allows FDCs to be used only for gauged basins or gauged locations in a basin. Therefore, obtaining regional relationships that provide effective estimates about a region, by using the records of existing stations in the region, becomes necessary. This paper illustrates a simple parametric approach, where droughts are characterized by using the lower part of the annual flow–duration curve. The paper uses the actual instantaneous flow data of 30 basins in Western Anatolia and 21 basins in Southwestern Anatolia, Turkey to offer a new perspective for the estimation of streamflow quantiles using Areal Scale Factors (ASFs), which efficiently represent the relationship between flow quantile and basin area.