论文部分内容阅读
无定河流域多年平均侵蚀模数１．２ｔ／ｋｍ２，严重的水土流矢成为当地贫困的重要原因，同时大量泥沙下泄，给黄河下游人民的生命财产造成严重威胁。１９８３年无定河流域列为国家重点治理区，榆林地区列入第一期治理的１４２条小流域，经十年重点治理，发生了巨大变化，基本农田人均达到０．１８８ｈｍ２，造林保存面积人均达到０．５７ｈｍ２，人均产粮达到５１７．２ｋｇ，农民人均纯收入达到４１０元。据实测，１９８３～１９９０年与１９８２年相比，无定河年轻流量减少２６．９％，平均含沙量减少４１．２％，年输沙量减少６１．４％。
The average erosion modulus in the Wudinghe basin is 1.2t / km2 for many years. Serious soil erosion has become an important reason for local poverty. Simultaneously, a large amount of sediment is released, which poses a serious threat to the life and property of the people downstream of the Yellow River. In 1983, Wudinghe River Basin was listed as a national key control area. In Yalin area, 142 small watersheds were included in the first phase of governance. After 10 years of key governance, tremendous changes took place. Per capita basic farmland reached 0.188hm2. Reached 0.57hm2, per capita grain reached 517.2kg, per capita net income of peasants reached 410 yuan. It has been measured that from 1983 to 1990, compared with that of 1982, the flow rate at the Wudinghe River decreased by 26.9%, the average sediment concentration decreased by 41.2% and the annual sediment discharge decreased by 61.4%.