论文部分内容阅读
无定河是黄河中游的一条多沙河流，水土流失相当严重，其入黄水量、沙量及其变化对黄河水沙变化有较大影响。５０年代以后在该流域开展了水利水保工作，流域下垫面发生了显著变化。经过几十年的综合治理，水土流失得到了一定的控制，流域的生态环境也得到改善，流域水沙特性发生了较大变化。分析认为：①在相同降雨条件下，雨强小，水利水保工程的减水减沙作用大；雨强大，其减水减沙作用就小。②如果遭遇大暴雨，流域仍可能出现较大洪水，并挟带较大沙量。
Wudinghe is a multi-stream river in the middle reaches of the Yellow River. Soil erosion is quite serious. The inflow of yellow water, sediment yield and their changes have a great influence on the change of water and sediment in the Yellow River. Since the 1950s, water conservancy and soil conservation work has been carried out in the basin, and the underlying surface of the river basin has undergone significant changes. After several decades of comprehensive management, the soil and water loss has been controlled to a certain extent, and the ecological environment of the basin has also been improved. The water and sediment characteristics of the basin have undergone great changes. The analysis shows that: ① Under the same rainfall conditions, the rainfall intensity is small, and the water and soil conservation project has great effect of reducing water and sediment; the rain is strong, and the effect of water and sediment reduction is small. ② In the event of a heavy rainstorm, the watershed may still have a larger flood and carry a larger amount of sand.