*2.1. Location and Climate*

The study area of this research is the Yinchuan region in northwest China. Geographically, the study area encompasses the Xingqing District, Xixia District, Jinfeng District, Yongning County, and Helan County, and is located near the upper reaches of the Yellow River. It is bounded by the Helan Mountains in the west, and the Yellow River's western bank in the east. The Yinchuan region has a typical continental climate characterized by a long winter, a short summer, low levels of rain and frequent droughts, high wind and evaporation, and dramatic temperature changes [27,28]. The dry season runs from February to May, while the rainy season runs from June to September. The total precipitation in the rainy season accounts for about 70% of the total rainfall throughout the whole year.
