Effects of climatic conditions and vegetation changes on actual evapotranspiration in Mu Us sandy land

Based on the MOD16A3GF data, spatial regression analysis was conducted to explore the annual trends of actual evapotranspiration (AET) and characteristics of its spatial distribution in Mu Us sandy land between 2000 and 2020, and combined meteorological data and MOD13 NDVI data to analyze its effects on AET by trend analysis and correlation coefficient. The results showed that (1) The AET exhibited significant regional differences; (2) The AET showed a rapid upward trend from 2001 to 2020, with an average rate of change of 5.68 mm a(-1). The increase in AET rate increased from fast to slow in the order of Shaanxi > Ningxia > Inner Mongolia; (3) The correlation coefficient between AET and precipitation was 0.74, and there was no obvious correlation with temperature. The decreasing trend of water ET did not coincide with the AET trends; (4) AET was consistent with the NDVI spatial distribution and interannual variation curves. Under the influence of precipitation and NDVI, AET increased significantly from 2001 to 2020. Precipitation was the main factor affecting climatic conditions of AET, and NDVI was the dominant factor affecting AET in the same period. This provides a theoretical and scientific basis for the conservation and protection of Mu Us sandy land.