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马莲河流域水土保持世行贷款项目,是黄土高原水土保持世行贷款项目的分项目,总面积4304km~2.该流域内水土流失严重,土壤年平均侵蚀模数5616t/km~2,最高超过10000t/km~2,严重的水土流失不仅破坏了土地资源,恶化了生态环境,危害着农业生产,而且大量的泥沙下泄,使下游河道淤塞,河床抬高,造成洪害,严重威胁着下游人民生命财产安全.为了根冶水土流失,减少泥沙下泄,建国以来,项目区的人民大力开展水土流失治理,兴建了一批水土保持治沟骨干工程.到1990年底,马莲河流域已建成淤地坝64座.骨干工程9座,淤地1800hm~2,其中,项目区已建成淤地坝33座,拦泥约6510万t,淤地930hm~2.
The project is a subproject of the World Bank Loan Loess Plateau Rehabilitation Project with a total area of 4304km ~ 2. The water and soil loss is serious in this basin, with an average annual soil erosion modulus of 5616t / km ~ 2 and a maximum of over 10000t / km ~ 2. Severe soil and water loss not only destroyed the land resources, deteriorated the ecological environment, harmed agricultural production, but also caused a large amount of sediment to escape, causing siltation and river bed upheaval in the lower reaches of the river and causing flood damage, which seriously threatened the downstream people In order to root out soil and water loss and reduce sediment discharge, since the founding of the People’s Republic of China, the project area people vigorously carry out soil and water loss control, construction of a number of soil and water conservation ditch the backbone of the project. By the end of 1990, Malian River Basin has built silt dam 64 blocks, 9 backbone projects and 1800 º 2 warpage sites, of which 33 dam sites have been built in the project area, with about 65.1 million tons of mud and 930 hm2 of silt.