Response of ecological restoration to rainfall in arid zones

Rainfall in arid and semi-arid areas converts faster in the local SPAC system. Deluge in drylands may be an important source of groundwater recharge. We have been conducting a thirty-year observational in the Mu Us sandy land at the northwest China, we use remote sensing imagery to observe changes in the water body area and in situ observations to monitor rainfall infiltration. A total of 30 periods of Landsat remote sensing images were processed using the Google Earth platform to obtain the characteristics of surface water body changes. The results show that there are strong seasonal characteristics in the changes of water bodies area in the Mu Us sandy land, with two peaks in April and August, and the inter-monthly area increases of 44.867 km² (28.60%) and 47.832 km² (28.31%) respectively. 379.770 km² to 275.492 km², a total reduction of 104.278 km² (27.46%). Deep soil as a percentage of annual precipitation of woodland, shrubland, grassland, farmland and bare land were 2.88%, 17.36%, 3.64%, 1.21% and 44.30%, respectively. The change in the water body area in the Mu Us sandy land is mainly influenced by three factors, rainfall, vegetation coverage, and human activities, with a correlation coefficient of 0.57 (α=0.05) between rainfall and water body area. The correlation coefficients were 0.79, 0.79 and 0.86 (α=0.05) for the years 1991-1997, 1998-2005 and 2006-2017, respectively; vegetation coverage and water body area were negatively correlated overall in 30 years. The correlation coefficient was 0.57 (α=0.05), indicating that human activities in the Mu Us sandy land have a greater impact and human activities in the sands should be reduced in order to manage the sands.