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

Abstract

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. HIGHLIGHTS Mu Us Sandy Land is a key area in China for implementing ecological engineering.; The spatial and temporal patterns of AET, hydrothermal conditions, and vegetation changes were studied.; The average annual water surface evaporation monitored at eight weather stations was counted.; The annual average NDVI and ET were divided into six levels.; The climatic conditions are not the main factor of AET variation.;

Keywords

• climatic conditions
• evapotranspiration
• influencing factors
• mu us sandy land
• spatial and temporal distribution
• vegetation change