汾河流域气候变化及其对径流影响探讨

在分析汾河径流量变化趋势、20世纪70年代以来断流气候背景,以及气温、降水变化与径流趋势联系和80年代中期以来气候变化特点基础上,建立了河津站天然年径流量计算公式,探讨了气候变化对径流的影响。结果表明:①自20世纪50、60年代丰水期之后径流量总体呈递减趋势;②20世纪70年代以来汾河水量偏枯和断流趋势发展乃是以北半球增暖效应为背景;③20世纪80年代中期以来气候较前期变化有气温升高、尤其冬季最甚,降水减少、特别是汛期及夏、秋季最显著之特点;④气候变化引起径流量平均每年减少5.67亿m3(24.9%),其中气温影响8.6%,降水影响16.3%。因此,汾河流域气候变化及其对径流的影响较为显著。

Effect of climatic change on runoff in Fenhe watershed

Based on analysis of runoff variation trend,climate background in the Fenhe watershed since 1970s,the relationship among temperature,precipitation and runoff,the climate change on characteristics since the mid-1980s,the natural annual runoff computational formula was established for the Hejin station,the effect of climatic change on runoff was discussed.The results showed that:(1) There was obvious decline in runoff after the high-water periods in 1950s or 1960s;(2) River exhaustion and zero flow in the Fenhe River since 1970s were taken as the background of the heating effect in northern hemisphere;(3) Compared with earlier the raising temperatures in winter,and what the most,the reduce precipitation especially during flood season,or summer and autumn,were most significant;(4)The reduce amount of runoff,which was caused by the climatic change,was 567 million m3/a(24.9%),of which the temperature influence was about 8.6%,rainfall influence was about 16.3%.Therefore,the climate change and its effect on runoff in Fenhe Watershed were significant.