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一、基本情况及治理的意义 庆阳地区是黄河中游水土流失重点地区之一。长期以来,由于自然因素和社会因素综合作用的结果,造成植被稀少,水土流失严重。全区总土地面积2.72万平方公里,其中水土流失面积2.5万平方公里。每年流失泥沙2.138亿吨(包括入境泥沙),平均侵蚀模数6190T/年·Km~2,严重的达11000T/年·Km~2。全区5公里以上较大的沟道有531条。小毛沟33000余条,沟壑密度一般在2Km/Km~2左右,大的在3～4Km/Km~2,境内沟壑纵横,丘陵起伏。严重的水土流失,加剧了农业生态系统的
First, the basic situation and the significance of governance Qingyang area is one of the key areas of soil erosion in the middle reaches of the Yellow River. For a long time, as a result of the combined effect of natural and social factors, vegetation is scarce and water and soil erosion are serious. The total land area of 27,200 square kilometers, of which soil erosion area of 25,000 square kilometers. The annual sediment loss of 213.8 million tons (including the entry of sediment), the average erosion modulus 6190T / year · Km ~ 2, severe up to 11000T / year · Km ~ 2. There are 531 larger channels in the region of more than 5 kilometers. More than 33,000 small furrows, gully density is generally about 2Km / Km ~ 2, large in 3 ~ 4Km / Km ~ 2, the territory of ravines aspect, hilly. Serious soil erosion aggravates the agroecosystem