黄土高原高含沙水流形成的自然地理因素

黄土高原半干旱的气候条件、稀疏的植被和疏松易蚀的黄土物质,是该地区高含沙水流形成的自然地理因素。这一地区高含沙水流的发育程度,特别是最大断面含沙量的大小表现出明显的地域差异,这种差异与悬移质泥沙的粒度组成有密切的关系。存在着某种特定的悬移质泥沙粒度组成,使得悬移质含沙量达到最大值。这种特定的泥沙粒度组成与流域中黄土、基岩及风成沙的分布有关,而它的出现,则是特殊的水力、风力交换作用的结果。

Physico Geographical Factors for the Formation of Hyperconcentrated Flows in the Loess Plateau of China

Semi-arid climate, poor vegetation cover and highly erodibleloess can be regarded as the main natural factors responsible for the formation ofhyperconcentrated flows in the Loess Plateau, China. The degree, to which thehyperconcentrated flows develop, especially their extreme suspended concentration, shows asignificant areal differentiation. This is closely related to the grain-size compositionof suspended sediment.