自然灾害对人类活动的影响（The influence of natural
disasters on human activities） The influence of natural disasters on human activities
Natural disasters refer to a series of events such as casualties, property losses, social instability, resource destruction caused by abnormal changes in nature. Its formation must have two conditions: one is to have a natural change as an incentive, two is to have damage to people and property, resources as the object of disaster bearing.
The natural variation on the earth, including the natural variation induced by human activities, is happening all the time. When this kind of variation brings harm to human society, it constitutes natural disaster. Disasters have negative or destructive effects. Natural disaster is a form of contradiction between man and nature, which has dual nature of nature and society. It is one of the most serious challenges faced by human beings in the past, present and future.
At present, the natural disasters have caused great attention, many kinds of world major unexpected natural disasters, including drought, flood, typhoon and storm tide, frost, hail, tsunami, earthquake, volcano, landslide, debris flow, forest fires, agriculture and forestry pests etc.. The background and reasons of global disasters, a global warming is the profound influence of long-term trend of disaster causing factors; two is due to increased vulnerability, resilience of relative decline as a result of human social disaster. Natural disasters inevitably have
disaster causing factors. The disaster causing factors include natural disaster causing factors and man-made disaster causing factors.
Natural disasters are mainly caused by natural and man-made reasons. Here, we're going to focus on major world class disasters, global warming.
Global warming will have complex and potential impacts on the earth and human beings, both positive and negative. For example, with the increase of temperature in the subpolar regions, may be more suitable for human habitation; under appropriate conditions, a higher concentration of carbon dioxide can promote photosynthesis, so that plants have a higher rate of carbon sequestration, resulting in the increase of vegetation growth, namely carbon dioxide production effect. This is the positive impact of global warming. The negative impact of global warming on human activities will be greater and deeper than that of positive impacts. Because of human activity, the environment is now degraded in many ways, and global warming will accelerate these degradation. (1) as the temperature rises, the glaciers melt and the sea water expands, causing sea levels to rise. Sea level rise will seriously threaten the coastal areas, may drown some low-lying coastal areas, seriously affecting human production and life activities. (2) climate change caused by global warming will lead to great changes in water supply in many places, and the availability of fresh water will be greatly changed. The increase in temperature means that the water falling to the surface will be more evaporated, and if there is more precipitation
to supplement evaporation, it will not have any effect. (3) the impact on agriculture and food supply. First of all, global warming will reduce global food production. In addition, because insects are cold-blooded animal, affected by climate is particularly evident because of climate warming in the distribution area of crop pests may be extended to the edge of the area, but also make many pest overwintering survival rate increased (4) global warming will make the forest resources have been seriously affected, first of all, the forest withered seriously. As a result, natural ecosystems are becoming less and less compatible with their environment, and all species will become susceptible to disease and insect attacks. Secondly, climate change caused by global warming will cause significant loss of species in some ecosystems. (5) human health depends on a good environment, and global warming will become a major factor affecting human health in the next century.
China is one of the few countries with the most serious natural disasters in the world. There are many kinds of natural disasters in China, with high frequency and serious disaster. The formation of natural disasters in China is deeply influenced by natural environment and human
activities. There are obvious differences between North and South and East and west. In the eastern monsoon region, the natural disasters occur frequently and the disaster areas are serious. The north, southwest and southeast coastal areas are prone to natural disasters.
The natural disasters in China mainly include
meteorological disasters, earthquake disasters, geological disasters, marine disasters, biological disasters and forest grassland fires.
Land desertification. Land desertification is rapidly reducing the land we can effectively use. Many reasons
The trend of desertification leads to land degradation, soil structure destruction and soil nutrient loss. And the natural recovery of soil fertility
It takes decades, hundreds, or even thousands of years. If artificial measures should be taken to restore soil fertility, it is necessary to restore soil fertility
The amount of input is difficult to calculate.
Desertification is especially harmful to agriculture. From 4 to May every year, it's spring sowing season, in the desertification area,
Often the seed and fertilizer were blown away, the seedlings were uprooted, soil moisture loss, dry or lethal seedlings
Be buried. Some local remedies should be repeated, and even miss the farming season.
The grassland degradation caused by desertification makes the dominant grass species suitable for livestock gradually reduced or even completely lost
Lost. Grass has become low, sparse, yield decreased obviously, stocking capacity is greatly decreased.
Desertification Causes clogging of rivers, reservoirs and canals. The Yellow River has an average annual sediment discharge of 16 tons, including 12 of the total
Millions of tons come from desertified areas. Every year there are about more than 50 thousand kilometers of irrigation channels by perennial wind damage.
Desertification causes damages to railway subgrade, bridge and culvert in some areas, and makes roadbed and road area
Sand, forcing highway traffic disruption, and even highway abandonment. Sand dust weather caused by desertification, affecting the aircraft
Take off and land.
Sand storms disrupt communications, transmission lines and facilities, resulting in disasters that threaten the safety of residents.
According to monitoring, urban air pollutants in China are mainly micro particles, which is closely related to desertification.
Dust pollution in the vast areas of people's production and living environment, affecting people's health.
自然灾害对人类活动的影响(The influence of natural disasters on human activities)
