Analysis On The Effect Of Malianhe Watershed Soil And Water Conservation World Bank Loan Project On Ecological Environment Of Qing Yang City

Based on investigation of natural and social economic conditions in QingYang city of east GanSu, this paper studied the largest project of ecological environment construction, water conservation project of Malian river which moneyed by world bank, and its affection on the ecological environment in this area. The items we studied were the affection analysis that the project exerts on water and soil erosion, water environment, soil environment, atmospheric environment, regional climate, and biological diversity. The research has significant practical applied value in improving ecological environment, promoting sustained development of society, economy, and resources in this area. The results are as follows:1. The project was carried out by building terrace, afforestation, grass seeding, building central dam, and warping dams, the reservoir capacity was increased to 2.53×107m3, the amount of mud annually holding up increased by 4,696,000 ton, With these measures, water and soil erosion decreased deeply, module hare has decreased from 31400 m3/km2of the early stage to 2550 m3/ km2 in this area, runoff depth decreased from 31.4mm to 25.5mm, the flood was lessened, and drought fighting capacity was enhanced.2. With these measures, the soil environment changed greatly, physical indices of soil in terrace, orchard, woodland, and grassland increased year after year, soil fertility improved obviously except in the woodland. These changes altered structure of soil, decreased desertification of soil, and increased resistance of soil.3. With these measures, the coverage of wood and grass was enlarged, and the coverage rate increased from 15.8% to 40.7%. The increased vegetations not only changed character and granulation of surface soil, which are benefit for formability of precipitation , but also degrade some harmful gas in this area and which in turn, make local air quality improved.4. With the implementation of project, large scale construction of terrace,, covering trees or grass instead of tillage., planting trees and grass on the bored mountains . land utilization of this area has been greatly improved, the ratios of land using of agriculture ,forest, heredity each has changed from earlier 32.8%,14.19% and 40.39% to 25.39%,31.98% and 29.85%. and land utilization ratio also increased by 19.8%.5. With the implementation of project, the area of new increased forest is 58501hm2, the vegetation degree of coverage was enlarged, the local species of animal and plant increased in quantity, biological diversity has made a recovery and the stability of ecological environment system in this area has been enhanced.