Evaluation of drought utility of IMERG and SM2RAIN satellite precipitation estimates in Ziya River Basin

Abstract

Drought is a complicated extreme climate phenomenon, which has caused serious losses to agricultural production, economic development, water resources management and ecological environment in various countries and regions. The Ziya River Basin has been seriously affected by climate change and human activities for a long time, and the frequency and scope of drought events in the basin have shown an increasing trend in recent years. At present, satellite-based precipitation quantitative estimation shows great potential in drought monitoring, and in-depth research on the meteorological drought identification ability of different types of satellite products in the basin has important scientific significance for future drought warning, water resource allocation and agricultural production in the Ziya River Basin. The spatio-temporal accuracy, error and accuracy of monthly rainfall data of IMERG-F and SM2RAIN-ASCAT in Ziya River Basin were systematically evaluated based on three meteorological drought indices(SPI, SPEI and CI). Drought monitoring ability and drought event identification ability of satellite precipitation products on multiple time scales and spatial scales were evaluated comprehensively. The difference of drought grade spatial distribution and spatial efficiency index among satellite precipitation products was compared with typical drought events. The result show that: IMERG-F showed good performance in drought index estimation and drought event identification(R²>0.821, RMSE<0.448, POD>0.814, FAR<0.187). The drought effectiveness of SM2RAIN-ASCAT was poor(R²>0.081, RMSE<1.2, POD>0.442, FAR<0.571). IMERG-F and GAUGE show similar spatial drought patterns(0.507<spaef<="" p=""> </spaef

Keywords

meteorological drought / IMERG-F / SM2RAIN-ASCAT / drought characteristics / regional drought