摘要
高含沙水流是黄土高原地区普遍存在的自然现象。在一定意义上，它是侵蚀的产物，但它一旦形成之后，便作为一种强大的侵蚀和搬运营力，在侵蚀过程中发挥了重要作用。进入高含沙水流范畴之后，能耗减小，挟沙能力增大，因而具有较强的侵蚀搬运能力，使坡面侵蚀发育迅速地由片状侵蚀、细沟侵蚀发育到冲沟阶段。高含沙水流搬运与重力侵蚀之间存在着很强的耦合关系，这是黄土高原高强度侵蚀产沙过程形成的重要因素。黄河中游若干支流的泥沙输移比很高，接近于１，这一特征也可以较好地用高含沙水流的作用来解释。由于高含沙水流具有特殊的侵蚀产沙特征。
Hyperconcentrated flows are observed in the middle Yellow River basin. They occur as a result of erosion, but once they form on slopes, they operate as a strong eroding and sediment carrying force and play an important role in drainage basin erosion and sediment production processes. Since the energy expenditure is less and sediment carrying capacity is greater, hyperconcentrated flows have very high eroding and transporting abilities. These exists a strong coupling relation between hyperconcentrated flow transport and gravitational erosion, which ensures a rapid removal of mass wasted materials. Hyperconcentrated flows are an important factor responsible for the high intensity erosion and sediment yield in the middle Yellow River basin. Many previous studies have indicated that the sediment delivery ratio on the Loess Plateau approaches 1. This can be explained by action of hyperconcentrated flows. As hyperconcentrated flows exhibit some particular behaviors in erosion and sediment production processes, the study suggests that the erosion by hyperconcentrated flows was regarded as a special type of erosion.
基金
国家自然科学基金
