The Analysis Of Current Situation And The Countermeasure Of Soil Erosion Of Jilin Province

Jilin province as a major agrarian province is an important productive base of grains in China and is rich in the resources of water, forest and minerals. However, it is also an area where soil erosion becomes such a serious problem that it leads to the decline in productive forces, the deterioration of ecological environment and the high frequency of floods. The problem threatens people` s existence, impairs the agrarian production in Jilin province, and hinder the sustained development of regional economy and sustained exploitation of resources. Therefore, we are obligated to prevent and treat soil erosion and protect water and soil resources in order to accelerate the sound development of ecology, economy as well as society.This dissertation mainly researches into the features and laws of the distribution of soil erosion, analyses the dynamic changes, harmful effects and the formation of soil erosion, and furthermore, provides concrete measures to comprehensively work on this problem while taking into consideration the differences in physical geography and the development of society and economy in different regions.Jilin province covers a total soil erosion area of 31,519.6 km2 and they are distributed mainly over the mountains of medium and low height in the middle and east, the low mountains and hilly land, Manchuan and Man Gangtai area, and the dune-covered plain in the west. With the rising of the sea level, the degree of water erosion changes; the artificial damage is less serious; the vegetation grows better; and the degree of wind erosion diminishes from southwest to northeast. Soil erosion has become a serious environmental problem and caused the decline of the productive forces of the earth and the damage of soil resource. The average amount of washed-away soil is 130 million tons every year, including 33.61 million tons of soil on cultivated hillside fields whose erosion speed is one hundred times of mature soil if converted into the washed-away surface soil of 3mm. Besides, soil erosion leads to soil accumulation in rivers reservoirs and lakes and makes it possible to bring the water conservancy projects into full play. Serious soil erosion can even force the riverbed up and is the underlying cause of floods. Among all the natural factors contributing to soil erosion, vegetation and terrain are most influential. The eastern mountain area, with a thicker cover of vegetation, has less soil washed away, whereas the middle-eastern area, with a thinner cover of vegetation and steeper and longer slope, is much more terrible in soil erosion. The western area, with a still thinner cover of vegetation, a flat earth` s surface, little rainfall and heavy wind, is more inclined to suffer form wind erosion. Artificial factors refer to ill-intended activities of production and contribution which destroy the vegetation and the earth` s surface and these are also major causes of soil erosion. According to the statistics, since the foundation of China up to 1985, the area of west-land reclaimed by deforestation covered 380,000 km2; by deforestation, destroying grass and removing sand, 1,327,000 km2; by excessive deforestation, excavating Chinese herbal medicines and planting ginsengs, 1.08 million km2; by exploiting mines, building roads, picking stones and other productive construction, 349,000 km2. According to the features and causes of soil erosion and diversity in local environment and social and economic development in different regions, we have to adapt different stratagems of prevention and treatment. The eastern mountain areas mainly need to be protected, especially the existent natural and artificial forests, and even to be closed to afforest. In the area of low mountains and hills in the east, we should focus on the protection of water resource, diminish the pollution of the source of water and soil accumulation in lower reaches of the river and reservoirs and enhance the exploitation rate of water. In the Manchuan and Man Gangtai area in the middle, we should emphasize on the protection of bla...