黄河源头地区泥沙来源的初步分析

Preliminary analysis on the sediment source in the Yellow River source area

黄河源头扎陵湖、鄂陵湖为吞吐湖泊,是黄河源头二大主要湖泊。扎陵湖、鄂陵湖等众多的湖泊的滞洪拦沙,使大量泥沙淤积在湖泊中,黄河源头控制站黄河沿站实测输沙量、含沙量、输沙模数也难以全面反映整个黄河源头产沙状况。在统计分析黄河沿站实测输沙量的基础上,初步分析了黄河源头泥沙来源和分布。黄河沿站泥沙主要来源于鄂陵湖出口—黄河沿站区间,同时估算了进入扎、鄂二湖沙量,年平均进入扎、鄂二湖泥沙量约为13万t左右,大部分淤积在扎陵湖内。黄河源头输沙模数呈自东向西递减的分布规律,认为在鄂陵湖以上多年平均输沙模数一般为5～10t(km·a),鄂陵湖出口以下多年平均输沙模数在20～40t(km2·a)之间。

Zhaling Lake and Eling Lake are the two major lakes in the Yellow River source area.Due to the existence of lakes like Zhaling and Eling,large quantity of sediment is trapped.Therefore the measured sediment amount,concentration and erosion index at Huangheyan hydrological station can hardly reflect the actual situation of sediment yield in the Yellow River source area.Based on the measured sediment discharge at Huangheyan station,the author preliminarily analyzed the source and distribution of incoming sediment.The sediment through Huangheyan station mainly comes from the area between Eling Lake outlet and Huangheyan station.The estimated sediment amount trapped in the two lakes annually is about 0.13 million tons.The erosion index decreases from the eastern part to western part.Erosion indexes in the upper inlet and down outlet of Eling Lake are 5～10t(km5a)^-1 and 20～40t(km5a)^-1 respectively.