河龙区间减沙效益与水土流失治理度的关系

Relationship between sediment reduction benefit and control degree of soil erosion in region from Hekouzhen to Longmen

研究黄河中游河龙区间水土保持措施减沙效益与水土流失治理度的关系。结果表明:1)河龙区间减沙效益与水土流失治理度呈正相关关系。二者关系可以按照治理度与减沙效益取值范围的不同,明显分为减沙效益高值区和减沙效益低值区2个区,其单位治理度的减沙效益基本相等。减沙效益低值区的治理度小于15%时,基本没有减沙效益。“两川两河”要想取得10%以上的减沙效益,治理度应超过30%。2)河龙区间减沙效益与水土流失治理度关系分为减沙效益高值区、减沙效益中值区和减沙效益低值区3个区后,减沙效益高值区的治理度提高10%,减沙效益可以提高约8%;减沙效益中值区的治理度提高10%,减沙效益提高8%;减沙效益低值区的治理度提高10%,减沙效益只能提高3.4%。因此,构筑减少黄河粗泥沙的第一道防线,建议首选位于减沙效益低值区的窟野河和皇甫川流域。

Relationship between sediment reduction benefits and control degree of soil erosion in region from Hekouzhen to Longmen was studied and results indicated： 1）sediment reduction benefit positively correlated to control degree of soil erosion, the relationship could be divided into high benefit value zone and low benefit value zone according to the benefit range of sediment reduction, but sediment reduction rates per unit in the two zones are similar. When control degree in the low benefit zone is less than 15 %, there is almost no sediment reduction benefit. Therefore, for the four typical tributaries namely ＂Kuyuhe, Tuweihe, Huangfuchuan and Zhujiachuan＂, control degree needs to be above 30% if above 10% of sediment reduction benefit is required. 2）If the relationship is divided into three zones of high benefit value, medium benefit value, and low benefit value, 10% of control degree increase in high benefit value zone will result in 8% increase in sediment reduction. Correspondingly, 10% of control degree increase in medium value benefit zone and low benefit value zone will lead to 8% and 3.4% increase in sediment reduction respectively. Therefore, in order to construct the first defense line for soil erosion, low benefit value zone which locates in Kuyehe River basin and Huangfuchuan River basin is commanded to be selected firstly.