From a long-term point of view, the balance between erosion and sediment yield in a drainage system can basically realize, i.e., the delivery ratio can be close to 1. However, substantial variations among individual r...From a long-term point of view, the balance between erosion and sediment yield in a drainage system can basically realize, i.e., the delivery ratio can be close to 1. However, substantial variations among individual rainfall events or between annual delivery ratio exist, causing frequent sediment retaining or re-erosion and re-delivery of the retained sediments in a short period of time. Thus the delivery ratio will be < 1 or > 1. The sediment delivery ratio is closely related to the spatial distribution of rainfall and magnitude of rise and fall of peak flood and that of runoff depth in the drainage system. Delivery ratio of single event in a drainage system and changes of delivery capacity of silt-laden runoff in various classes of gullies can be expressed by transformation mechanism of shear force of a single rainstorm event with flood resulting from increase and decrease of peak flood per unit area.展开更多
基金State Key Project for Basic Research and Development Program, G1999043604 Frontier project of knowledge innovation of IGSNRR, C
文摘From a long-term point of view, the balance between erosion and sediment yield in a drainage system can basically realize, i.e., the delivery ratio can be close to 1. However, substantial variations among individual rainfall events or between annual delivery ratio exist, causing frequent sediment retaining or re-erosion and re-delivery of the retained sediments in a short period of time. Thus the delivery ratio will be < 1 or > 1. The sediment delivery ratio is closely related to the spatial distribution of rainfall and magnitude of rise and fall of peak flood and that of runoff depth in the drainage system. Delivery ratio of single event in a drainage system and changes of delivery capacity of silt-laden runoff in various classes of gullies can be expressed by transformation mechanism of shear force of a single rainstorm event with flood resulting from increase and decrease of peak flood per unit area.
