黑河上游径流对极端气候变化的响应研究

Response of Runoff to Extreme Climate Change in the Upper Reaches of the Heihe River

为深入认知黑河上游径流变化与极端气温、极端降水指数间的关联机制,使用1960-2014年黑河上游祁连、托勒、野牛沟3个气象站点的逐日气温、降水资料和莺落峡水文站逐日径流量资料,通过趋势分析、相关分析、多元回归分析和主成分分析等方法,分析黑河上游极端气候指数和极端水文事件的变化趋势、极端气候指数与径流的相关关系以及径流对降水的滞后效应。结果表明:(1)黑河上游表征低温的极端气温指数呈下降趋势,表征高温的气温指数呈上升趋势。极端降水指数呈小幅增加趋势。年极端洪水总量呈增加趋势,极端枯水呈显著减少趋势,与黑河上游径流总量增加的变化趋势一致。(2)极端降水指数与极端洪水总量的相关性显著,说明黑河上游极端降水是影响极端洪水总量的主要因素。(3)洪水对祁连站降水量的响应存在1~2天的滞后期,初步分析得出黑河上游降水量的时间和空间差异以及东、西支河流河网密度的差异是产生滞后性响应的主导因子。

In order to deeply understand the correlation mechanism between runoff change and extreme temperature and precipitation indices in the upper reaches of Heihe River,the article use the daily temperature,precipitation data of Qilian,Tuole,Yeniugou meteorological stations and daily runoff data of the Yingluoxia hydrological station in the upper reaches of the Heihe River from 1960 to 2014,by means of trend analysis,correlation analysis,multiple regression analysis and principal component analysis to analyze the trends of climate indices and extreme hydrological events,and the correlation relationship between extreme climate indices and runoff,and the hysteresis effect of extream flooding on precipitation in the upper reaches of the Heihe River.The results show that:(1) The temperature indices characterized by low temperature in the upper reaches of the Heihe River shows a downward trend,and the extreme temperature indices indicating high temperature shows an upward trend.Extreme precipitation events showed a slight increase.Extreme flooding showed an increasing trend,and extreme low water showed a significant decreasing trend,which was consistent with the increasing trend of total runoff in the upper reaches of the Heihe River.(2) The correlation between extreme precipitation indices and extreme flooding is significant,indicating that precipitation in the upper reaches of the Heihe River is the main factor affecting runoff.(3) The response of the flood to the precipitation of the Qilian station has a lag of 1~2 days,Based on the preliminary analysis,it is concluded that the time and spatial difference of precipitation in the upper reaches of Heihe River and the difference of river network density in the east and west branches are the leading factors to produce hysteresis response.