滦河流域径流的长期演变规律及其驱动因子

Analysis on the Long-term Evolution of Runoff Volume and Its Affecting Factors in the Luanhe River Basin

根据滦河主要代表站三道河子、潘家口水库、滦县1956-2008年天然径流资料,应用Mann-Kendall趋势检验、功率谱分析等数理统计方法,分析滦河径流的历史演变规律。同时,选用代表气象站1957-2008年气象资料以及1985-2000年土地利用数据,对径流变化的驱动因子进行分析。结果表明:滦河径流整体上呈减少趋势,其中上游减少达到显著水平;汛期径流减少趋势不明显,而汛前及汛后径流减少有增强趋势,说明干旱、洪涝等水文过程发生频率加大;滦河径流在1959年发生一次减少突变,第二次减少突变发生在1996年,20世纪80年代末径流有所增加,1998年后呈现明显的减少趋势;滦河径流存在16年变化周期,中、下游径流还存在9～10年和2～3年较显著周期,上游径流存在64年长显著周期。降水与蒸发是影响径流变化的主要因素,地表覆被变化也对径流变化产生重大影响。

Based on the data of runoff volume in the Luanhe River Basin during the period of 1956-2008,the M-K test and power spectrum analysis were used to analyze the evolution of runoff volume in the Luanhe River Basin.Meteorological data observed by 9 meteorological stations during the period of 1957-2008 and the land use data during the period of 1985-2000 were used to identify the factors affecting the change of runoff volume.The results show that the runoff volume was holistically in a decrease trend,especially in the upper reaches.The decrease trend was more significant during the low-flow periods,which indicates that drought and flood may occur more frequently.The results also show that the runoff volume was sharply decreased in 1959 and 1996,increased in the late-1980s,and decreased again after 1998.There was a 16-year periodicity of runoff volume change in the Luanhe River Basin and a 64-year one in the upper reaches,and there were also the 9-10-year 2-3-year periodicities in the middle and lower reaches.The most important climate factors affecting runoff volume were precipitation and evaporation,and then land use cover change.