Reason;
1 Deforestation and destruction of vegetation
In spring, the temperature in the north rises rapidly, and the precipitation is less than the evaporation.
The wind is still strong in winter, and the north is close to the winter wind source.
4 Sand source near the Loess Plateau
Solve:
1 afforestation
2 Returning farmland to grassland
3.。 . . .
Hehe, I really don't want to write. High school is really hard to remember.