人类活动影响的辽宁省大凌河流域水文干旱演变特征

Characterizing the hydrological drought evolutions under human interventions:A case study in the Daling River Basin in Liaoning Province

为了揭示人类活动干扰对不同时空尺度水文干旱的影响,本文以辽西北大凌河流域为例,利用SWAT(Soil and Water Assessment Tool)模型重建天然状态下的历史水文序列,基于多时间尺度的标准化径流指数(SSI),对比评估天然状态和人类活动影响下的流域水文干旱演变特征。结果表明,人类活动干扰是流域径流序列在2000年发生显著突变的主要原因。在时间尺度上,人类活动对水文干旱的影响主要体现在月、季尺度,对年尺度、多年尺度的影响相对较小。在空间分布上,中游水文干旱受人类活动的干扰较下游更为显著。干旱季节性变化的分析表明,人类活动的影响导致冬、春季出现干旱的频率降低,而秋旱的频率增加;季尺度干旱的历时和烈度的均值和离散程度均呈上升态势。

To reveal the impact of human disturbance on hydrological drought at different spatiotemporal scales,this paper took the Daling River Basin in northwestern Liaoning as a case study area,and used SWAT(Soil and Water Assessment Tool)model to reconstruct historical hydrological series under natural conditions.Based on Standardized Streamflow Index(SSI)at multiple time scales,we compared and evaluat⁃ed hydrological drought evolution characteristics under the influence of human activities.The results show that the disturbance of human activities is the main reason for the significant abrupt change of the runoff sequence in 2000.In term of time scale,the impact of human activities on hydrological drought is mainly reflected in the monthly and seasonal scales,and the impact on the annual and multi-year scales is relative⁃ly small.In term of spatial distribution,the hydrological drought in the middle reaches is more disturbed by human activities than in the lower reaches.The analysis of seasonal changes in drought shows that human activities led to a decrease in the drought frequency in winter and spring,while the autumn drought frequen⁃cy increased.In addition,due to the interference of human activities,the average and dispersion of the dura⁃tion and intensity of seasonal droughts both rise.