北洛河流域分期径流变异诊断及成因分析

采用Mann-Kendall变异诊断法和有序聚类法,诊断了北洛河流域枯汛交替期、汛期、汛枯交替期、枯期等分期径流系列变异点并划分了变异等级,采用基于SIMHYD模型的径流还原方法,计算并区分气候变化和人类活动对分期径流变异的贡献率。结果表明:各分期径流变异等级从0级无变异到4级较强变异,排除0级的无变异点,各时期均发生了变异;径流变异程度与径流量有关,径流量较大时期(汛期、汛枯交替期)的变异等级低,径流量小的时期(枯汛交替期、枯期)变异等级高,径流量最小的枯期为4级较强变异;人类活动对枯汛交替期径流变异的贡献率较大,人类活动是主要驱动力;其余3个时期气候变化的贡献率较大,气候变化是主要驱动力。

Diagnosis of runoff variation in different periods in Beiluo River Basin and its causes analysis

Mann-Kendall mutation diagnosis method and serial cluster analysis method were employed to diagnose the variation points of runoff series in the Beiluo River Basin during dry-flood alternating period, flood period, flood-dry alternating period, and dry season, and the variation grades were classified. The runoff reduction method based on SIMHYD model was applied to calculate and distinguish the contribution rates of climate change and human activities to runoff variation in different periods. The results show that the runoff variation grade in different periods ranges from grade zero to grade four. Excluding the non-variation point of grade 0, the variation occurred in all periods. The runoff variation grade is related to runoff. The runoff variation grade is lower in the period of large runoff(flood season, dry-flood alternating period)and higher in the period of small runoff(flood-dry alternating period, dry season). The lowest dry period of runoff is 4-level strong variation. The contribution rate of human activities to the variation of runoff in the dry-flood alternating period is larger, and human activities are the main driving force. The contribution rate of climate change in the remaining three periods is larger, and climate change is the main driving force.