小理河流域产汇流特性变化

Change in characteristics of runoff generation andconvergence in Xiaolihe basin

通过对小理河流域1959年以来的降水、径流、泥沙、蒸发等水文要素的分析,揭示了该区水文要素的变化趋势:降雨量呈逐年代减少的趋势,而径流量在20世纪60～80年代逐渐减少,90年代有所增大,但还未达到60年代水平;年降雨量减少的幅度并不大,但径流量减少的幅度较大,而输沙量的减少则非常显著。

This paper shows the changing trend of hydrological elements in Xiaolihe basin by analyzing some main hydrological factors such as rainfall, runoff, sediment and evaporation since 1959. The results show that there was a decreasing trend in rainfall over the past decades, while there was a decreasing trend in 1960's^1980's in runoff, and a increasing trend of that in 1990's but did not reach the level in 1960's yet. It also shows that the decreasing magnitude in annual rainfall is not too big, but the decreasing magnitude in runoff is relatively larger, while the sediment transportation has reduced greatly.