关键词: 蒸散发, GLEAM, GLDAS, SSEBop, 数据融合, 干湿变化, 干旱监测, 水文气象学

Abstract: At present, the research on evapotranspiration and drought is not comprehensive, the mechanism of evapotranspiration in the process of drought formation and development is not clear, and there is no objective understanding on the significance of evapotranspiration in drought monitoring. GLEAM, GLDAS and SSEBop evapotranspiration data are evaluated and merged based on their accuracy. Four drought indices(SPI, RDI, ESI, SMI) were used to analyze aridity changes over China in recent years. The results showed that: ① Merged ET data had better accuracy than each individual product; ② From 2001 to 2015, the northwestern plain of Northeast China, the northern part of Inner Mongolia, the North China Plain, the Yunnan-Guizhou Plateau, most of the Qinghai-Tibet Plateau, and the center of Tarim Basin showed a significant drying trend whereas major mountains in northeastern and northwester China show a trend of wet; ③ 1-motnth scale SPI and RDI indices could better reflect the beginning and end of a drought, but poorly reflect the persistence of the drought; ESI and SMI change lag behand SPI and RDI, and they can better indicate the severity and persistence of drought.

Key words: evapotranspiration, GLEAM, GLDAS, SSEBop, data fusion, aridity variation, drought monitoring, hydrometeorology