Drought promotes further deterioration of ecological environment
(1) The warm and dry climate causes lakes and rivers to drop in water level, partially dry up and cut off. Due to the shortage of surface water supply caused by drought and water shortage, people can only rely on a large amount of over-exploitation of groundwater to maintain the livelihood of residents and the development of industry and agriculture, however, over-exploitation of groundwater has led to a series of ecological and environmental problems, such as the decline of groundwater level, the expansion of funnel area, land subsidence and seawater intrusion.
(2)Drought leads to degradation of grassland vegetation. Most areas of China are in the ecological fragile zone of arid and semi-arid and sub-humid. The climate is characterized by the prevailing southeast monsoon in summer and the same season of rain and heat, and the precipitation mainly occurs in April-September of each year. Although the rainy season in northern China is also from April to September every year, there is a great spatial heterogeneity with the characteristics of ten years and nine years of drought. Due to the changes of climate and environment and unreasonable human disturbance activities, the vegetation has been seriously degraded. After entering the 21st century, drought has an aggravating trend for several consecutive years, and the continuous drought in spring, summer and autumn is very unfavorable to the fragile ecosystem.
(3) Climate drought aggravates the process of land desertification.
Other natural disasters are caused by the warm and dry climate
Drought in winter and spring is easy to cause forest fires and grassland fires. Since 2000, due to the rising global temperature, the climate in northern China is droughty, the temperature of woodland is high, the period of grassland withered is long, and there is a growing trend of forest underground fire and grassland fire.
Causing economic and people's loss of life and property
Drought has caused more and more losses to national economic construction and people's lives and property, seriously affecting social and public security, national economic development and people's living environment. With the development of economy and the growth of population, the absolute value of losses caused by drought is increasing obviously.
Main measures to prevent drought
The formation of drought is caused by many factors, and the defense against drought should be a combination of long-term, short-term and emergency measures.
(1) Adjusting the structure of agriculture, forestry and animal husbandry to improve the agricultural ecological environment in arid areas
Afforestation and improvement of regional climate to curb the deterioration of ecological environment and reduce the harm of drought.Forest and grassland have the functions of biological coverage, biological penetration, wind-proof and sand-fixing, soil and water conservation and so on.In arid areas of North China, there are not only mountains, plateaus, hills and basins, but also gullies, valleys, rivers and slopes, the terrain is complex and the climate is diverse. Agriculture can not only focus on grain production, but also on the comprehensive management of mountains, waters, soil, grass, forests and fields, the agricultural ecological structure that combines agriculture, forestry and animal husbandry should be implemented according to local conditions.
(2) Grasp the law of drought and adjust the distribution of crops
We should adjust crop planting structure, improve farming system, change crop composition, breed drought-tolerant varieties and make full use of limited rainfall.In drought-prone areas, agricultural production should pay attention to selecting drought-tolerant and yield-stable crops, which is one of the fundamental measures to overcome or avoid the threat of drought.To grasp the law of drought and crop growth and development period and to arrange agricultural production rationally are effective measures to prevent drought and seize harvest.
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