There are many sandstorms in northwest China every year. Please analyze the causes of this weather according to your knowledge and put forward countermeasures in combination with the reality.

Due to the decrease of forest and grassland area in northwest China, the soil water storage capacity is reduced; The destruction of vegetation makes the soil bare and sandy, and there is sand everywhere, which reduces the forest area and reduces the ability of wind prevention and sand fixation. In spring, when the climate is relatively dry, sandstorms are prone to occur. Sandstorm weather has a serious impact on local industrial and agricultural production and people's daily life. In recent decades, the sandstorm weather in northwest China has increased, so we should build shelter belts, protect grasslands, control the number of livestock, return farmland to forests and grasslands, and vigorously carry out afforestation.

Therefore, the answer is: the reduction of forest and grassland area reduces the soil water storage capacity; The destruction of vegetation makes the soil bare and sandy, and sand is everywhere; With the decrease of forest area, the ability of windbreak and sand fixation is declining. It is necessary to build shelter forests, protect grasslands, control the number of livestock, return farmland to forests and grasslands, and vigorously plant trees.