The influence of flood disaster, among all kinds of disasters in our nature, the economic losses and casualties caused by flood disaster rank first among all kinds of natural disasters, and the disaster has great influence on our human beings and society. Let's share the impact of the flood.
Impact of floods 1 1. Impact of floods on national economy
The impact of floods on the national economy is mainly reflected in several aspects.
1, the impact on agriculture
Severe storms and floods often cause large areas of farmland to be flooded and crops to be destroyed, resulting in reduced production or even no harvest. During the period from 1950 to 5 1 year in 2000, the average farmland affected area in China was 9.37 million hm2, resulting in 5.23 million hm2 of disasters.
2, the impact on transportation
Railway is the artery of national economy. However, many railway trunk lines in China are seriously threatened by floods. In the middle and lower reaches of the seven major rivers, there are important railway trunk lines such as Beijing-Guangzhou, Beijing-Shanghai, Beijing-Kowloon, Longhai and Shanghai-Hangzhou-Ningbo, and the length of railways threatened by floods exceeds 65,438+100,000 km. Railways in southwest and northwest China are often attacked by mountain torrents and mudslides, and the railway trunk lines in these areas are high-intensity areas with frequent mountain torrents and mudslides.
Due to the flood, the interruption and stop of the railway is very serious. 1954 In the flood, the Beijing-Guangzhou railway, which is the north-south artery, stopped 100d.
China's expressway network has a long mileage, and the impact of the interruption of expressway transportation caused by floods has spread to every corner of the country. With the rapid development of highway construction, the mileage of highway damaged by water has doubled. All mountain roads in China are harmed by mountain torrents and mudslides to varying degrees, and many national and provincial trunk lines in the west 10 are often harmed by mudslides and landslides.
There are 157 large debris flow gullies along the Sichuan-Tibet Highway, which are open to traffic for less than half a year.
3. Impact on cities and industries
Cities are densely populated and are the political, economic and cultural centers of the country. About 80% of the industrial output value is concentrated in cities. Large and medium-sized cities in China are basically distributed along rivers, which are seriously threatened by river floods, and some cities close to mountains and rivers are also endangered by disasters such as flash floods and mudslides. More than 600 cities in China, 90% have flood control tasks.
Since 1990s, the urbanization process in China has obviously accelerated. A large number of people flocked from the mainland to coastal cities along the Yangtze River, and the urban area expanded rapidly. The newly expanded urban areas are often areas with high flood risk and low flood control ability.
Due to the high density of urban assets, the dependence on water supply, power supply, gas supply, transportation, communication and other systems has increased, and once it is hit by floods, the losses will be more serious. Statistics show that the flood losses of cities and industries in some economically developed coastal provinces have accounted for more than 0.60% of the total flood losses.
Second, the impact of flood disasters on the environment.
Flood disaster not only brings huge economic losses, but also causes great damage to human living environment.
This damage to the environment is mainly manifested in the following four aspects.
1, destroying the ecological environment. Soil erosion is one of the serious ecological and environmental problems in China, and heavy rain and flash floods are the main natural factors. By 2000, the area of soil erosion in China was 3.56 million km2, accounting for about 37% of the national territory, and the annual soil loss was about 5 billion tons. Rivers, lakes and reservoirs have deposited a lot of sediment, taking away a lot of nutrients such as nitrogen, phosphorus and potassium. The harm of soil erosion not only seriously restricts the development of agricultural production in hilly areas, but also brings difficulties to land improvement, river management and maintaining a good ecological environment.
2. Damage to cultivated land. The damage of flood disaster to cultivated land is mainly caused by water scouring sand pressure and destroying farmland. For example, in 1963, the Haihe River was flooded, and the farmland that lost its farming conditions due to water erosion and sand pressure reached130,000 hm2. The erosion of land by the Yellow River flood is more serious. Every time the Yellow River bursts, a large amount of sediment covers the fertile land on both sides of the Yanhe River, resulting in the destruction of large areas of farmland.
3. Damage to the river system. Rivers in China are generally sandy, and the flood burst causes sediment deposition, which seriously damages the functions of rivers, especially the Yellow River, and has a wide range of damage to the water system and far-reaching influence.
4. Water pollution. Flood pollutes the water environment, mainly causing the spread of germs and toxic substances, which directly harms people's health.
The impact of flood disaster is 2 1, and crops are affected and reduced. Major floods have caused a large number of farmland to be washed away and flooded, crop production has been reduced or even lost, agricultural products processing industry, light industry and other industries lack raw materials or the cost of raw materials has increased, resulting in factory production reduction and production suspension, followed by workers' unemployment.
2, traffic, communication interruption, information, transportation blocked or delayed, resulting in a large number of products backlog deterioration, insufficient supply of raw materials, so that the production capacity decreased. In particular, emergency relief supplies are blocked, which is likely to expand the existing disaster situation.
3. Major floods have reduced the living standards of the people in the disaster areas, lacking basic living security, and there will be a large number of victims, disrupting the normal social order and impacting all aspects of society.
4. It has caused great damage to the environment on which human beings depend. For example, every year floods will cause soil erosion, and a large amount of soil and its nutrients will be lost, resulting in poor land. At the same time, the sediment content in the water flow will increase, which will lead to the attenuation of river functions, the shrinking of lakes and the desertification of cultivated land, with incalculable serious consequences.
5. The water pollution caused by flood mainly includes the spread and diffusion of toxic and harmful substances such as germs, parasites, industrial waste residue, fertilizers and pesticides, which will seriously endanger people's lives and health. In addition, the flood will also have a major impact on shipping, transportation, tourism and aquaculture.
The impact of flood disaster. Influencing factors of flood disaster
The factors affecting the occurrence of floods include climate and topography, of which climate is the most important factor. For example, the Weihe River basin belongs to the continental monsoon climate zone, and the precipitation in this area is mainly concentrated in summer and autumn, and the distribution is very uneven. Even if the annual precipitation does not increase, sometimes floods will occur.
Disasters are divided into "flood" and "waterlogging", which refer to torrential rain, rapid waterway, flash floods, river flooding, farmland flooding and destruction of environment and various facilities caused by rainstorm. The precipitation conditions when modern floods occur show that the occurrence of low-grade small and medium-sized floods is generally caused by short-term rainstorm or short-term rainstorm, while the occurrence of large floods and extraordinarily large floods is generally not caused by short-term rainfall, and floods generally occur in the rainy season.
After the rain falls to the ground, part of it seeps into the ground; Some evaporate into the air; Some of them flow along the ground, pass through small ditches and streams, and enter rivers.
The harm of flood disaster
The social and economic harm of flood disaster is various. In addition to causing death and disability of people and animals, it also causes serious direct losses, indirect losses and derivative losses. Direct losses and derivative losses refer to the losses caused by floods, such as crop production reduction or even failure to harvest, damage to houses, equipment, materials, transportation and other engineering facilities, shutdown, business suspension, flood control and emergency rescue expenses of factories, enterprises and shops due to disasters.
Indirect losses are losses caused by direct losses, such as losses caused by reduced production of agricultural products in agricultural products processing enterprises and light industries, losses caused by damage to transportation facilities, overstock of products in factories and enterprises, interruption of raw material supply or increase in transportation detour costs.
Derived losses are the extension of disaster losses, such as casualties caused by floods, epidemic diseases, social instability, destruction of cultural relics in disaster areas, cultural education and deterioration of ecological environment. Severe storms and floods often cause large areas of farmland to be flooded, crops to be destroyed, and crops to be reduced or even not harvested. The main targets of flood disasters are crops such as grain, cotton and oil.