人类活动干扰下丰满Ⅱ区流域水文干旱演变特征分析

Analysis of Hydrological Drought Evolution under Human Activities in Fengman Sub-basinⅡ

基于游程理论识别丰满Ⅱ区流域水文干旱事件,分析干旱频率、烈度、历时特征及其演化规律,并采用SWAT模型量化气候变化与人类活动对水文干旱特征变化的贡献。结果表明:人类活动对丰满Ⅱ区流域1976—2016的水文干旱严重化起主要贡献,与流域相对天然期(1956—1975)相比,人类活动使1976—2016年间水文干旱频率由0.30增加至0.41,干旱事件的平均烈度增大了65%、平均历时延长了22%,并促进了超长期水文干旱的发生。流域内大量水库、塘坝的季节性拦蓄径流行为是造成流域出口断面处径流大幅减小,水文干旱发生频率增加、历时与烈度增大的主要原因。

This paper analyzed the frequency,intensity,duration and evaluation law of hydrological drought events in Fengman sub-basin II based on run theory,and established SWAT model to evaluate the effects of climate change and human activities on hydrological drought char⁃acteristics.The results show that the increasing severity of hydrological drought during the impact period(1976-2016)was mainly due to hu⁃man activities.Compared with natural period(1956-1975),human activities increased the frequency of hydrological drought in the impact pe⁃riod from 0.30 to 0.41,and increased the average intensity and duration of drought events by 65%and 22%,respectively.Moreover,the occur⁃rence of ultra-long-term hydrological drought also increased.The impoundment of reservoirs and ponds within the basin are the main reasons for the significant decrease in runoff at the outlet,as well as the increase in the frequency,duration and intensity of streamflow drought.