三川河流域重点治理减沙效益分析

Analysis of the Benefits of Sediment Reduction in the key Harnessment of the Sanchuanhe River Basin

三川河流域自1983年列入全国八大重点治理区后,至1992年底止,10年新增治理面积1129km^2,流域累计治理程度达到57.6％。采用水文法与水保法分析该流域重点治理以来的减沙效益,前者的分析结果是,重点治理期间的年均输沙量较重点治理前减少59.03％,每毫米汛期降雨所产生的输沙量分别比1957～1972年、1957～1982年减少61.30％和52.23％;后者的分析结果是年均输沙量分别比1957～1972年、1957～1982年减少44.26％和55.18％。考虑到降雨变化对水文法分析产沙的影响,故10年重点治理期间较重点治理前多年平均输沙量年均减少约为50.0％。

In the Sanchuanhe river basin, 1129 km2 of eroded area were harnessed in the past 10 years. The accumulatively harnessed area took up 57. 6% of the total eroded area, with an average annual rate of 4.1%, among which, the accumulatively harnessed area constituted 80. 8% of the total eroded area in the first turn key harnessed 71 small watersheds, with an average harnessment rate of 6. 47%. Through key harness-ment, considerable development had been gained in base farmland and economic forest in the whole basin, bio-environment improved, GNP grew at an annual rate of 7. 8%, pet capita income increased from 69 yuan to 409 yuan, 98.7% of the poverty-stricken people had gotten off poverty, and the amount of sediment entering into the Yellow River decreased over 50% than that before the harnessment.