The cause of the drought.

The cause of drought is not only related to natural factors such as meteorology, but also related to human activities and the ability to cope with drought. Specifically, it can be divided into the following aspects:

(1) Meteorological reasons: Meteorological conditions such as no precipitation for a long time or less precipitation are the main factors causing drought and little rain.

(2) Topographic reasons: Topographic conditions are an important cause of regional drought.

(3) Insufficient water source conditions and drought resistance: Drought is also closely related to poor water source conditions caused by insufficient water conservancy facilities, such as reservoirs and wells. )

(4) Population factor: Due to the sustained growth of population and the rapid development of local social economy, the water consumption for living and production is increasing, which leads to over-exploitation of water resources in some areas, which exceeds the carrying capacity of local water resources, and droughts often worsen when they occur.

(5) The effective utilization rate of water resources is low: due to more precipitation and less water shortage in normal years, the effective utilization rates of agricultural water, industrial water and domestic water are obviously different from those in domestic perennial water shortage areas, which is not conducive to drought relief.

Extended data:

The damage degree of drought to crops is related to its season, crop species, varieties and growth period. Early spring affects spring sowing, or causes spring sowing crops to lack seedlings and break ridges, which affects the normal growth of overwintering crops. The summer drought in July and August affected the normal growth of corn, sorghum and rice in northern China, causing cotton buds and bolls to fall off.

In the south, it affects the normal filling of early and middle rice and the survival of late rice transplanting. Autumn drought affects autumn crop yield and overwintering crop sowing. Drought in summer and autumn will make the soil water content insufficient and aggravate the spring drought in the following year.

The drought resistance of crops is called drought resistance. Different crops have different drought resistance. Rice has the worst drought resistance, and its yield will be seriously reduced without irrigation. Upland rice is the second, barley, wheat, rye, oats, peanuts and other crops have moderate drought resistance, while millet, sorghum, green bristlegrass, millet, potato, sweet potato and mung bean have strong drought resistance.

Crops have different responses to different types of drought. For example, some leguminous crops have developed root systems and strong resistance to soil drought, but they cannot tolerate atmospheric drought, and corn has strong resistance to atmospheric drought and cannot tolerate soil drought.

The worst drought areas in China are central Gansu, southern Ningxia, Shanxi and northwestern Shaanxi, central and western Inner Mongolia Autonomous Region and Bashang area in Hebei Province. Drought resistance mainly depends on developing water conservancy, planting trees, reforming agricultural structure, improving farming system and strengthening farmland capital construction.

Baidu encyclopedia-drought