无定河流域典型淤地坝水资源效应比较研究——以辛店沟、韭园沟和裴家峁为例

The Water Resources Effect of Typical Soil-saving Dams in Wudinghe River Drainage Basin——A Case Study in Xindian,Jiuyuan and Peijiamao Ditch

通过实地考察,应用无定河流域典型淤地坝土壤水分的实测记录和统计分析方法,对淤地坝的水资源效应进行了探讨。研究发现总体上淤地坝的土壤含水率韭园沟高于裴家峁沟高于辛店沟,支沟坝低于主沟坝,在一定的深度基本上会存在较明显的湿土层或干土层,土壤含水率在坝地中部变化比较平缓,在6m以内随着土层深度的增加,土壤水分含量基本上呈现增长趋势,在坝地中尾部某一深度会达到稳定状态。淤地坝蓄水减水效益非常明显,辛店沟、韭园沟和裴家峁流域坝系土体的总贮水量分别为5.14×104m3、63.67×104m3和15.21×104m3,蓄水效益分别为39.39%、20.94%和8.85%,减水效益分别为48.27%、44.06%和38.16%。辛店沟流域淤地坝约减少地表水资源9.87×104m3。三个流域所有淤地坝至少可以减少地表水资源88.75×104m3,对无定河径流量减少的贡献率为0.093%。淤地坝的这种土壤水分效应和蓄水减水效应是人为因素对水资源影响的一个重要表现。

Through spot investigation, using the measured records and statistical analysis method, the water resources effect of typical soil - saving dams in Wudinghe River drainage basin was analyzed. The conclusions were as follows ： soil water content of soil - saving dams in Jiuyuan Ditch is higher than that of Peijiamao Ditch ; the latter is higher than that of Xindian Ditch. Soil water content of soil - saving dams in the offset ditches is lower than that in the main ditches. There exists in the main obvious moist or dry soil layers in some depth. The change of soil water content in the middle part of soil - saving dams is gentle. In six meters, with the depth increasing, soil water content showed increasing trend basically. Soil water content in the middle and end part of soil - saving dams would come to a stable condition in some depth. The benefit of water accumulation and decrease of soil - Saving dams are very obvious. The total soil pondages of soil -saving dams system in Xindian Ditch, Jiuyuan Ditch and Peijiamao Ditch basin are respectively 5.14×10^4m^3 , 63.67 ×10^4m^3 and 15.21 ×10^4m^3 ; The benefits of water accumulation are respectively 39.39%, 20.94% and 8.85% ; The benefits of water decrease are respectively 48.27% , 44.06% and 38.16%. The soil - saving dams system of Xindian Ditch basin lead to surface water reduce by 9.87×10^4m^3. The contribution of all soil - saving dams in the three basins to the decrease of runoff of Wudinghe River is 0.093%. The effect of soil water and the benefit of water＇s accumulation and decrease are the important representation that human factors influence the water resources.