降水与人类活动对大凌河流域径流演变的影响分析

Impacts Analysis of Precipitation and Human Activities on Runoff Variations of Daling River Basin

基于1960-2011年辽宁省大凌河干流代表测站年降水量和径流资料,分析了该流域降水量和径流的演变特征,并评价了降水和人类活动因素对大凌河流域径流演变的影响。大凌河流域降水量无显著减小趋势,而径流深显著减小;1960-1979年为天然时期,人类活动对径流影响很小,与之相比,以后各时期降水—径流关系具有相同降水量对应的径流深明显降低、径流对降水的敏感程度降低、降水-径流关系趋于紊乱,相关性逐渐降低等特点;对于1980年代和2000-2011年两个枯水期,各区间降水和人类活动因素对径流深均为减小作用,两者对径流减少的贡献率分别为44%、56%;1990年代降水因素对大城子径流为减少作用,减少量为11.73mm,对大城子-凌海、凌海的径流为增加作用,增加量分别为11.81、7.99mm,但由于人类活动,其径流深仍为减小。

Based on the annual runoff and precipitation data from 1960-2011of two hydrometric stations on the main stream of Daling River in Liaoning province,variation characteristics of precipitation and runoff were analyzed.And the contributions of precipitation and human activities to runoff variation were estimated.Overall,the precipitation of Daling River appears no decreasing trend while runoff depth decreases significantly.The precipitation-runoff double mass analysis indicates that 1960-1979is the natural period while the human activities has little impact on runoff.Compared to the natural period,the precipitation-runoff relationship in recent periods show three characteristics：firstly,given the same precipitation,the runoff depth decrease obviously;secondly,the runoff responds to the precipitation less sensitively,i.e.the slopes of the linear regression equations of precipitation and runoff decrease;thirdly,the runoff and the precipitation are less related.Both precipitation and human activities reduce runoff in 1980 sand 2000s,and the contributions of two factors to runoff reduction are 44% and 56%,respectively.For 1990 s,the precipitation reduces the runoff of Dachengzi station and contributes 11.73 mm of reduction in runoff depth,but increases the runoff of Dachengzi-Linghai and Linghai station,with the contributions of increasing 11.81 mm and 8.0mm to the runoff.However,because of human activities,the runoff depth of two stations is still reduced.