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无定河是黄河中游较大的一级支流,发源于陕西省白于山,流经陕西省的榆林、延安地区11个县(市)和内蒙古伊克昭蒙,在清涧县河口村注入黄河。陕西省境内流域面积21615平方公里,占总流域面积的71.4％。全流域有风沙区、黄土丘陵沟壑区、河源梁境墹区三个类型,地形破碎,土壤疏松,抗蚀性差,水土流失严重,是黄河河口镇至龙门区间泥沙的主要来源地,每年向黄河输送泥沙达2.52亿吨,其中陕西省境内2.46亿吨。由于严重的水土流失,造成粮食产量低而不稳,生态环境恶化,经济水平低下,群众生活极度贫困。 在中央的关怀和重视下,1983年将无定河流域列为全国八大重点治理区之一,其中169条小流域列为第
Wudinghe is a large tributary of the middle reaches of the Yellow River. It originated from Baishan Mountain in Shaanxi Province and flows through 11 counties (cities) in Yulin and Yan’an areas in Shaanxi Province and Ike Zhao Meng in Inner Mongolia. It injects into the Yellow River in Hekou Village, Qingjian County . Shaanxi Province watershed area of 21,615 square kilometers, accounting for 71.4% of the total catchment area. There are three types of aeolian and sand area, loess hill and gully area in the whole basin, and Jinganghe area in Heyuan. The terrain is fragmented, the soil is loose, the corrosion resistance is poor and the soil erosion is serious. It is the main source of sediment in the Yellow River estuary to Longmen interval. Sediment reached 252 million tons, of which 246 million tons were in Shaanxi Province. Due to the serious soil and water loss, the grain output is low and unstable, the ecological environment is deteriorating, the economic level is low, and the mass life is extremely poor. Under the care and attention of the Central Government, in 1983, Wudinghe River Basin was listed as one of the eight key areas under national jurisdiction, of which 169 were designated as