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 trends of the annual change of AET and the characteristics of its spatial distribution in Mu Us Sandy Land between 2001 and 2020. Combined meteorological data and 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 in Mu Us Sandy Land, with an overall low northwest and high southeast distribution pattern; (2) The AET showed a rapid upward trend from 2001 to 2020, with an average rate of change of 5.68 mm·a-1; (3) The correlation coefficient between AET and precipitation was 0.74, and there was no obvious correlation with temperature; (4) AET was consistent with the NDVI spatial distribution and interannual variation curves. Under the combined influence of precipitation and NDVI, AET increased significantly in Mu Us Sandy Land 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 basis and scientific basis for the conservation and protection of ecological water source in Mu Us Sandy Land.