What is the reason for the climate drought in northwest China?

The reason for the drought in the northwest: the northwest is located in the middle of Eurasia, far from the ocean, and it is difficult for humid air to reach the inland areas in the west. Coupled with the image of the Qinghai-Tibet Plateau, in summer, the Qinghai-Tibet Plateau is a heat source and the surrounding area is a relatively cold source. The cold air in the already arid western region blows to the Qinghai-Tibet Plateau, and the water vapor is even less. In winter, the Qinghai-Tibet Plateau is the cold source, and the surrounding area is the relative heat source. The sinking of cold air makes the climate in the western region drier, and the western region is also affected by Siberian cold air in winter.

The drought in northwest China is mainly caused by the distribution of land and sea and the uplift of Qinghai-Tibet Plateau. Fan Guangzhou, a researcher at the Institute of Environment and Engineering in Cold and Arid Regions, Chinese Academy of Sciences, believes that tens of thousands of years ago, there was an ancient sea called the Deputy Tethys Sea, which went deep into China in the southeast, changing the land and sea distribution and making the surrounding climate moist. However, after that, the amount of seawater gradually shrank, which led to the rapid drought in Central Asia and the gradual enhancement of continental climate characteristics. In addition, with the crustal movement, the altitude of the Qinghai-Tibet Plateau began to rise, and eventually the whole plateau rose, thus blocking the warm and humid summer monsoon air flow northward, and gradually forming a climate of drought, little rain and large evaporation in the inland areas of northwest China.