GA-PIC: An improved Green-Ampt rainfall-runoff model with a physically based infiltration distribution curve for semi-arid basins

摘要

Modeling rainfall-runoff processes in semi-arid regions remains challenging due to the heterogeneity of rainfall, soil type and topography. The goal of this study is to develop an improved rainfall-runoff model for flood forecast for semi-arid regions. A physically based infiltration distribution curve is developed and added to the Green-Amps based rainfall-runoff (GA-PIC) model. Validation tests for two semi-arid basins suggest that the GAPIC model has lower forecast errors of runoff depth and peak flow than the traditional Green-Amps model as the physically based infiltration distribution curve effectively captures the impacts of spatiotemporal variability of rainfall and land surface conditions on runoff generation. A higher density of rainfall stations and a smaller computational time step lead to improved flood forecasting accuracies for semi-arid basins.