Modification of the Xin’anjiang Model for Flood Forecasting in Karst Area, Southwestern China

Abstract

Abstract Hydrological modeling of a karst environment is challenging because of the characteristically thin soil and low soil water retention capacity. The purpose of this study was to simulate floods in a complex karstic river basin that comprised a large karst depression, high mountainous karstic areas, springs, and downstream karst areas. In such an environment, deterministic models (e.g., SWAT) are unable to compute the additional contribution from the subsurface. In this paper, a modified Xin’anjiang model was proposed and a specific method was presented for characterizing the karst aquifers flow systems by calibrating parameters from a spring hydrograph analysis. The simulated results indicated that the karst depression, as a storage element, provides a considerable buffer to the effects of a rainstorm. The application of the modified Xin’anjiang model demonstrated its applicability to the karst regions in southwestern China. Thus, it can provide better understanding of such hydrological systems and offer an improved basis for their future hydrological management.