陕北地区坝库参数与年均减沙效益关系研究

根据最新资料,对黄河中游陕北地区8条支流坝库控制面积占比、坝库单位面积库容等坝库参数与水利水土保持措施年均减沙效益的关系进行了研究,同时研究了陕北地区各支流水土流失治理度与水利水土保持措施年均减沙效益的关系.研究结果表明：①陕北地区年均减沙效益主要由坝库工程产生.年均减沙效益提高10%,坝库单位面积库容需要提高5万m3/km^2.要使流域水土保持综合治理年均减沙效益达到20%以上,坝库单位面积库容应在6万m^3/km^2以上.②在黄河中游多沙粗沙区,要实现40%左右的年均减沙效益,坝库单位面积库容应达到16万m3/km2以上.③陕北地区水土流失治理度与年均减沙效益呈正相关关系.二者关系可以明显分为两个区,其单位治理度的年均减沙效益基本相等.当第二区的治理度小于16%时,基本没有年均减沙效益.“川两河”要想取得10%以上的年均减沙效益,治理度至少应在30%以上.

Study on relationship between annual sediment reduction benefit and reservoir indices in Northern Shaanxi

The reservoir indices used here include the percentage of reservoir-controlled area,unit-area reservoir capacity and so on.According to the latest data,the relationship between the annual sediment reduction benefit and reservoir indices is studied. Meanwhile,the relationship between the annual sediment reduction benefit and the percentage of harnessing area is studied as well.The results indicate that:(1) the annual sediment reduction in the Northern Shaanxi mainly results from reservoirs,silt warping dams,and other key projects on the main steam gully. An increase of 50,000m~3/km~2 in reservoir capacity will lead to 10% increase in annual sediment reduction.Correspondingly,20% increase in annual sediment reduction benefit requires an increase of 60,000m~3/km~2 in reservoir capacity.(2) In coarse silt abundance area,40% increase in annual sediment reduction needs 160,000m~3/km~2 increase in reservoir.(3)Annual sediment reduction benefit positively correlates to the percentage of harnessing area,and the relationship could be divided into two zones.And the annual sediment reduction benefit of per harnessing percentage in the two zones is almost same.When the harnessing percentage in the second zone is less than 16%,the annual sediment reduction benefit is almost equal to zero.Therefore,for the four tributaries named by "Liangchuanlianghe",10% of annual sediment reduction benefit needs 30% of harnessing percentage.