基于Budyko方程的小理河流域径流响应研究

Study on runoff response in Xiaolihe basin based on Budyko equation

环境变化对径流影响是综合作用的过程,为此定量区分气候变化和人类活动对径流变化的贡献具有一定的现实意义。本文以小理河流域的降水量、潜在蒸散发量和径流深为研究对象,采用Mann-Kendall方法分析了三者的变化趋势,运用有序聚类法和滑动T检验法诊断径流深序列变异点,采用Budyko方程定量计算气候变化和人类活动对径流变化的影响程度。结果表明:流域径流序列在1998年发生变异,相比于1978—1997年的多年平均径流深,1998—2010年的多年平均径流深减小了7.06mm,其中气候因素变化使得径流深增加6.64mm,而大规模人类活动使径流深减小了13.7mm。通过累积量斜率变化率比较法与Budyko方程定量计算结果的对比分析可知,两者结论相近,人类活动是导致该流域径流深减小的主要驱动因子,证明了Budyko方程定量分析结果的可靠性以及在黄土高原地区的适用性。

The impact of environmental changes on runoff is comprehensive,and it is necessary to quantitatively distinguish the contribution of climate changes and human activities to runoff.In this paper,the precipitation,potential evapotranspiration and runoff in Xiaolihe basin were studied.The Mann-Kendall method was used to analyze the trends of the hydrometeorological elements above,the sequential clustering method and sliding Ttest were used to diagnose runoff abrupt change points,and the Budyko equation was used to quantitatively calculate the impact of climate and human activities on runoff changes.The results showed that runoff in Xiaolihe basin has a abrupt change point in 1988;compared with the multi-year average runoff depth from 1978 to 1997,the annual runoff from 1998 to 2010had a decrease of 7.06 mm,and human activities lead to a reduce of 13.7mm,while climate changes resulted in an increase of 6.64 mm.By comparing the results by the method for the sloop change ratio of cumulative quantity to Budyko equation,it is proved that both conclusions are similar,that human activities are the main reason leading to the decrease in runoff in Xiaolihe basin,and that the quantitative analysis of Budyko equation in Loess Plateau region is applicable.