长江上游人类活动增沙量推算的研究

A preliminary Study on the Calculation of the Sediment Inerement from Human Activities on the Upper Reach of the Yangtze River

本文根据长江上游宜昌站60年代和80年代两个丰沙段的水沙量资料,采用灰色系统理论,分别建立了反映60年代和80年代长江上游来沙量逐年累积变化的状态模型 GM。进而通过对状态模型的重演和对比分析,发现人类活动对长江上游的增沙影响相当大。本文推算,如按目前的人类活动增沙速率发展下去,50年后长江上游宜昌站年平均来沙量,将由50年代的5.2亿 t,80年代的6.59亿t 增加到7.51亿 t。由于长江上游人类活动增沙影响的复杂性和区域性,加上缺乏足够的实测水、沙量资料序列和试验数据,使得难以按白色系统准确描述人类活动的增沙影响。本文推算长江上游人类活动增沙量的方法是一种新尝试。

In this paper,with the theory of Grey Systems,the auther has set up two state models GM (1,2) to simulate seperately accumulation sediment load year by year at Yichang Station on the upper reach of the Yangtze River in 1960's and in 1980's,through the annual runoff and sediment load in the corresponding periods,and performed mathematical calculation on GM(1,2)again byexchanging annual runoff sequences By means of contrasting between the sixties' and eighties'accumulating sediment load through the same runoff sequences,it has been found that impact of human activities on sediment is great.On evaluating the Three Georges Dam,neglect of the sediment increment from human activities is not scientific.According to the preliminary study in this paper,the result obtained is that the annual average sediment load at Yichang Sta- tion is 659 million tons and would be 751 million tons in fifty years,but only was 520 million tons in 1950's.Because it is complex and related to the area feature,it is difficult to calculate accurately the sediment incre- ment from human activities of the upper reach of the Yangtzs River in white system,without sufficient observation value series of runoff and sediment load and experimental data.No doubt this paper provides a new method to calculate the sediment increment from human activities of the upper reach of the Yangtze River.