Influence of human activities on erosion, delivery and deposit of basin system in hilly-gully loessic area
黄土丘陵沟壑区人类活动对流域系统[2]侵蚀、输移和沉积的影响

From long term point of view, sediment delivery ratio of a drainage basin with a control degree reaching 70% can be reduced by around 50% in contrast to pre control conditions. The effect of erosion control is quite significant. In the management process, although delivery ratio drops considerably in comparison to pre control conditions, yet the previous retained sediment can still be carried, resulting in the situation of delivery ratio greater than 1 since erosive strength of rainstorm induced erosion is greater than project designed standard in a short spell following dike breach and scouring. In the loess plateau region, individual rainstorm event related delivery ratio under either pre or post control conditions in drainge system can be obtained by using runoff depth, and dynamic mechanism for changes of delivery ratio can be explained with shear force changes following fluctuations of runoff depth.