The main causes of drought in northwest China are

1, living inland and far from the ocean; There are mountains and plateaus along the way, and ocean water vapor is difficult to reach, so precipitation is scarce and the climate is dry;

2. It is controlled by a single temperate continental air mass all year round, with little precipitation, forming a temperate continental climate.

3. The landform is mainly desert, with less vegetation, fewer rivers, strong wind and large evaporation, which further aggravates the drought.

I hope it helps you.