变化环境下清水河流域径流演变特征及驱动力

海河上游清水河流域地处我国北方半干旱半湿润过渡带,水资源短缺且生态环境极为脆弱,对气候变化和人类活动高度敏感。明晰变化环境下清水河流域的径流演变规律及气候变化和人类活动的贡献,对实现流域内水资源的可持续利用以及确保本流域作为首都地区生态屏障的功能定位具有重要的意义。根据清水河张家口水文站和啕来庙水文站近70年的实测径流资料,利用有序聚类分析、小波分析和双累积曲线等方法,系统分析了清水河流域径流演变特性及气候变化和人类活动的影响。结果表明:(1)近70年清水河流域径流呈显著减少趋势,径流深年均减少0.6mm;各月径流亦均呈显著减少趋势,其中以春夏两个汛期的减少最为显著;(2)径流在1979年前后发生突变,径流变化的第一、二主周期分别为27a、8a;(3)径流年内分布的不均匀程度明显增加,春汛(3月-4月)占全年径流总量的比例增加,而夏汛(7月-8月)占全年径流总量的比例则呈现减少态势;(4)双累积曲线分析结果表明径流演变的主要驱动因素为人类活动(89%)。

Characteristics and driving forces of runoff evolution under changing climate in the Qingshui River Basin

The Qingshui Riv er Basin in the upper r eaches of the H ai Riv er is lo cated in the semi2arid and semi2humid transitio n zo ne of no rth China. In this basin, water r eso urces are scarce, and the ecolog ical envir onment is ext remely fr agile. Both water re2 sour ces and ecolog ical env iro nment ar e hig hly sensitive to climate chang e and human activ ities. The analysis o f characterist ics and driv ing fo rces o f runoff evolution under chang ing climate is o f gr eat sig nificance fo r the sustainable use of w ater resour ces, and for maintaining the ecolo gica l ba rrier functio n fo r the capital reg ion. T o ident ify the variability of r unoff in Qingshui Riv er, long term daily runoff data from 195022016 fo r the Zhangjiakou and Tao laimiao stat ions w ere analyzed. To quantify the r unoff e2 v olution and its hy dr olog ical r esponse to climate change and human act ivities, o rder clust er analysis, wav elet analysis and do uble accumulatio n cur ve metho ds wer e applied. T he results are as fo llow s; 1. The mean annual runo ff in the Qing shui Riv er Basin de2 cr eased sig nificantly in the last 70 years, and t he aver age runoff depth decreased at a r ate of 01 6 mm/ a. The mo nthly runoff also decreased sig nificantly, especially in t he spring and summer flo od seasons; 2. An abrupt change w as o bser ved in 1979 in the Qing shui River, while the first and second main perio ds of runoff evolution wer e 27 a and 8 a, r espectively. 3. The non2uniformi2 ty of r unoff distribut ion increased sig nificantly during the year, and spring flo ods ( March2April) account ed for the entire y ear. The pr oportion of to tal r unoff has increased, while the pro po rtion of summer floo d ( July to August) in the tota l runoff has de2 cr eased. 4. T he r esults o f double mass curve analy sis indicated that human act ivit ies w ere the main driv ing factors fo r the r unoff variability, accounts for appro ximately 89% .