三川河水沙变化及人类活动影响

通过对三川河流域降雨、径流和泥沙资料统计,分别提出了以汛期降水为主要变量的流域天然状态下的两种产沙量计算方法,并应用于计算之中。进入80年代,流域水沙量大幅度减少,水量由基准期(1957～1969年)的年均3.23亿m~3减少到1.91亿m~3,沙量由基准期的3681万t减少到963万t,分别减少了40.9％和73.8％。用水文法和水保法对流域80年代水利水保措施减沙量进行计算的结果表明,降雨和人类活动对减沙的影响大体各占50％。

Water and Sediment Variations of Sanchuan River and Effects by Human Activities

Through statistics of precipitation, runoff and sediment data of the Sanchuan River basin, the paper has put forward two kinds of methods for calculating the sediment yield under the natural conditions of the basin which is taking precipitation in flood season as the main variable and use the methods in calculation. Since entering the eighties, the amount of water and sediment of the basin has been reduced greatly. The water volume has been reduced from 323 million cubic meters of the average in the datum period (1959-1969) to 191 million cubic meters, and the amount of sediment reduced from 36.81 million tons in the datum period to 9.63 million tons, reducing 40.9% and 73.8% respectively. The effects of precipitation and human activities on sediment reduction make up roughly 50% by 50% shown by the results of using the Hydrology Method and Soil Conservation Method to calculate the amount of sediment reduction of the basin since the eighties.