孔兑流域产沙关系浅析

Analysis on the Relationship of the Sediment Yield in Tributary Basin

十大孔兑的洪水泥沙对孔兑下游安全极其不利,同时造成黄河干流严重淤堵。研究孔兑产沙关系及其变化对于流域治理规划、合理评价径流泥沙变化趋势具有重要意义。利用实测水文泥沙资料,结合十大孔兑流域综合治理的发展,以流域治理前和治理后相对稳定期为对比年份,以日降雨量大于10,25mm的累计降雨量和年输沙量为参数,建立了有水文资料的毛不浪、西流沟和罕台川3条孔兑不同时期降雨—产沙的关系,说明了下垫面变化对产沙关系的巨大影响。分析表明,在降雨量相近的情况下,近期输沙量较基准期减少约90%,多年平均有效降雨条件下,3孔兑的减沙比93%~98%。研究表明孔兑大规模治理、植被恢复和淤地坝建设,对孔兑输沙量锐减发挥了重要作用。研究成果可对评估孔兑流域综合治理措施的效果提供重要依据。

The flood and sediment of ten tributaries are extremely unfavorable to the safety of the lower reaches,and cause serious lifting silt in the main Yellow River.The study on the relationship of sediment yield and changes is very important for watershed management planning and reasonable evaluation of runoff and sediment trend.Based on the measured hydrological and sediment data,combing with the development of comprehensive treatment of ten tributaries basin,taking the relative stable period of before and after treatment as comparison years,the cumulative rainfall and annual sediment discharge when daily rainfall is more than 10 mm and 25 mm as parameters,we set up the relationship between rainfall and sediment yield of different periods of Maobulang,Xiliugou and Hantaichuan.The result shows that there is great influence of underlying surface variation on sediment yield.The analysis shows that the recent sediment discharge is reduced by about 90%than the base period in the case of similar rainfall,and the reductions of specific sediment yield of three tributaries are between 93%and 98%under the annual average effective rainfall condition.The results show that the large-scale treatment,vegetation restoration and check dam construction play important role in reducing sediment in the basin.The research results can provide an important basis for evaluating the effect of watershed comprehensive management measures.