基于DFA的桑干河水文气象因子的趋势分析

研究区域的气象因子(气温、降水和蒸发)及径流的长期演变特性,对于水文水资源系统的预报、模拟具有十分重要的作用。采用非趋势波动(DFA)分析法,对桑干河近55年(1955年-2010年)的气象因子的变化及石匣里水文站1955年-1990年的径流量的变化进行了分析,计算得到气温、蒸发、降水和径流的标度指数的数值分别为0.523 9、0.696 8、0.723 7、1.201 1,其中气温、降水和蒸发的标度指数居于0.5～1之间,而径流的标度指数大于1,分析结果表明,未来该流域的气温将呈升高的趋势,而蒸发和降水呈逐渐减少的趋势,降水的减少将更为显著,径流未来的变化趋势不能用DFA法来识别,有待于进一步的研究。

Trend Analysis of Hydrological and Meteorological Factors in Sanggan River Based on DFA

The hydrological and meteorological factors(temperature,precipitation and evaporation) and long-term evolution characteristics of runoff are very important for forecast and simulation of hydrology and water resources in the study area.In this article,the detrended fluctuation analysis(DFA) method is used to analyze the meteorological factors nearly 55 years(1955-2010) in the Sanggan River and the runoff data from Shixiali hydrological station during 1955-1990.It is found that the scaling exponent of temperature,evaporation,precipitation are respectively 0.523 9,0.696 8,0.723 7,and 1.201 1 all of which is within the range of 0.5～1,but which of runoff is 1.2011(more than 1).The analysis indicates that the basin temperature shows a rising trend in the future,while both evaporation and precipitation show decreasing trend,among of which the precipitation will reduce more significantly.However,the future trend of runoff can not identify by the DFA method and so a further research will be needed.