汾河上游兰村站径流及基流的趋势性分析

Trend analysis of runoff and base-flow atLan Village Station on the upper Fen River

为揭示汾河流域径流及基流变化规律,基于汾河上游兰村站1956-2020年的径流序列资料,运用数字滤波法,将日径流量划分为直接径流量和基流量,通过M-K检验法判别径流和基流演变规律,采用重标度极差(R/S)分析法进行年径流和年基流的长程相关性分析。结果表明:兰村站基流指数(BFI)在不同年代间的变化表现为先减小后增加的趋势;基流深及径流深变化过程呈显著下降趋势,径流深的突变点出现在1974年,基流深的突变点是1972年;年径流深和基流深时间序列均呈现强的长期相关性,即未来有进一步下降的趋势。

In order to reveal the change rule of runoff and base-flow in the Fen River basin,based on the runoff sequence data from 1956 to 2020 at Lan Village Station in the upper Fen River,the daily runoff was divided into direct runoff and base-flow by using digital filtering method,runoff and base-flow were discriminated by the M-K test,and the long range correlation analyses of the annual runoff and annual base-flow were carried out by using the rescaled-pole(R/S)analysis method.The results show that:The base flow index(BFI)of Lan Village Station showed a trend of decreasing and then increasing between years;the change process of base flow depth and runoff depth showed a significant decreasing trend,and the mutation point of runoff depth appeared in 1974,and the mutation point of base flow depth was in 1972;the time series of annual runoff depth and base flow depth both showed a strong long term correlation,i.e.,there is a tendency of further decreasing in the future.