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利用大理河流域1960—2002年的系列水文资料和水土保持成因分析法计算结果,分析大理河流域减沙效益与措施保存面积、配置比例和汛期降雨量等影响因素的关系,以及大理河流域淤地坝措施减沙量与坡面措施减沙量的关系。结果表明:现状水土流失治理条件下,大理河流域仅靠坡面治理措施取得的减沙效益只有9%,取得最大减沙效益的水土保持措施梯田、林地、草地、坝地最优配置比例为18.6∶73.2∶4.6∶3.6,保持流域水土保持措施较高减沙效益的坝地配置比例为4%;大理河流域水土保持措施减沙量与汛期降雨量关系最为密切,二者呈正相关关系;流域水土保持措施减沙能力表现最充分的汛期降雨量值区间约为300～500 mm;大理河流域治理期有21年坡面措施减沙量小于600万t/a,淤地坝措施减沙量均在3 000万t/a以内变化。20世纪90年代以来,流域坡面措施减沙量与淤地坝措施减沙量关系比较密切,淤地坝措施减沙量的增幅小于坡面措施减沙量的增幅。
Using the series of hydrological data and genetic analysis of causes of soil and water conservation in the Dali River Basin from 1960 to 2002, the relationship between the benefits of sediment reduction in the Dali River Basin and the measures of conservation area, allocation proportion and rainfall in flood season was analyzed. Relationship between Sediment Reduction and Slope Deposition Sediment Reduction by Dams and Dam Measures. The results showed that under the current conditions of soil and water loss management, only 9% of the sediment reduction benefit was achieved by the slope management measures only in the Dali River Basin. The optimal allocation proportion of the soil and water conservation measures for terrace, woodland, grassland and dam was 18.6:73.2:4.6:3.6, the proportion of dam land to maintain high sediment yield and benefits of water and soil conservation in the basin is 4%; the sediment yield of soil and water conservation measures in Dali River Basin is most closely related to rainfall in flood season, and the two are positively correlated; The range of precipitation during the flood season with the best sediment reduction capacity by soil and water conservation measures of the watershed is about 300-500 mm. In the Dali River Basin, the sediment reduction of 21 years of slope measures is less than 6 million t / a. The amount of 30 million t / a within the change. Since the 1990’s, the sediment reduction in the watershed slope has a close relationship with the sediment reduction measures in the check dam system, and the sediment reduction in the check dam measures is less than that in the slope measures.