黄土丘陵沟壑区降雨产流产沙特性及治理模式

根据径流实验站的实测资料分析了黄土丘陵沟壑区典型沟道小流域的降雨径流特性 :该地区均为短历时的超渗产流 ,次产流降雨历时小于 70 m in,相应的径流量小于5 0 m m。根据极限含沙量的概念 ,在小流域内减少汛期径流就能有效地控制水土流失。通过坡改梯和淤地坝等水土保持措施 ,可以有效地拦蓄汛期径流 ,从而显著减少黄河中游多沙粗沙区进入黄河干流的泥沙 ,减缓来沙量大于水流挟沙力的矛盾 ,使危害黄河的灾害泥沙保留在坡面上和小沟道内而成为资源泥沙

Characteristics of runoff and sediment yield in gullied hilly loess areas and soil conservation measures

The varying trends of water and sediment supply in the Yellow River are discussed. The rainfall characteristics, the runoff process and sediment yield are analyzed based on field data from small typical drainage basins in the gullied hilly loess areas. The data shows that the sediment transport capacity of the main flow of the Yellow River is less than the sediment supply rate and the runoff yield is characterized by a short duration of rainfall excess. Soil and water conservation measures are proposed to reduce the sediment into the Yellow River, such as terracing the slope and building earth dams to impound the runoff in the flood season. With these measures, the anticipated harmful sediment flowing into the Yellow River is kept on the slope surface and in ditches as useful resource. This will play an important role in enhancing the sustainable development of North West China and decreasing sedimentation in the downstream region of the Yellow River.