黄河内蒙古段异源水沙输移特性

河流悬移质泥沙的输移方式按照水沙来源可以分为水沙同源与水沙异源两大类。黄河内蒙古段水沙来自不同的区域,冲泻质泥沙主要来源于陇西黄土高原区,而径流则主要来自唐乃亥以上的山区,呈现异源特性。通过分析内蒙古河段石嘴山与巴彦高勒水文站1951-2003年的水文数据,发现期间共发生了13次大流量和29次高含沙事件且大流量、高含沙量同时出现现象很少,多呈现大流量、低含沙量,或者小流量、高含沙量的态式。同时,通过改变传统流量-含沙量幂函数公式C_i=aQ^b(C_i为悬移质浓度,Q为流量)的参数项,建立了2种水沙异源情况下流量-含沙量的公式。

Transport Characteristics of Water and Sediment from Different Sources in Inner Mongolian Reach of the Yellow River

According to the sources of water and sediment, the transport way of river suspended sediment can be divided into two categories: the same sources of water and sediment and the different sources of water and sediment. The water and sediment in Inner Mongolia reach of the Yellow River are from different regions. This wash load sediment originates from the Loess region of Longxi, with the high runoff mainly originating from the rock mountains of its upstream basin. These transport characteristics result in a mismatch between water and sediment sources in this river reach. The observation of two hydrologic stations Shizuishan and Bayangaole of Inner Mongolia reach from 1951 to 2003 showed 13 times of high runoffs (HR) events and 29 times of high suspended sediment concentration (SSC) flows events. The results indicated that it was a low probability event of HR with high SSC flows, however higher runoff with lower SSC levels (HR-LS) and lower runoff with higher SSC values (HS) occurred. Depending on the typical power form for flow discharges, C_i=aQ^b, where C_i is SSC and Q is flow discharge, by improving the parameters to build two formulas about the different sources of water and sediment.