嫩江流域生态干旱影响因素及其时空演变格局  

Influencing factors of ecological drought in Nenjiang River Basin and its spatial and temporal evolution pattern

作　　者：庞金凤 门宝辉[1] PANG Jinfeng;MEN Baohui(College of Water Resources and Hydropower Engineering,North China Electric Power University,Beijing 102206,China)

机构地区：[1]华北电力大学水利与水电工程学院,北京102206

出　　处：《生态学报》2024年第13期5646-5657,共12页Acta Ecologica Sinica

基　　金：国家“十三五”重点研发计划专题(2016YFC0401406)。

摘　　要：近几十年来,嫩江流域湿地大面积萎缩、土地盐碱化严重,干旱频发,严重威胁生态安全、水环境安全和社会经济可持续发展。为量化嫩江流域干旱对生态系统的影响,利用标准化生态缺水指数(SEWDI),结合旋转经验正交函数、累积和曲线和Pearson相关性分析法分析嫩江流域1980—2017年生态干旱的时空演变规律,并利用游程理论提取生态干旱特征。结果表明:(1)生态干旱与影响因子间的相关系数排序为相对湿度>归一化植被指数>径流>降水>气温,其中生态干旱和相对湿度相关系数最大且大于0.5,呈现显著相关性,其余因子的相关系数均小于0.5,呈现低度相关性;(2)从SEWDI变化曲线上看,1980—1999年干湿交替呈现出一定的周期性,生态干旱以轻旱和中旱为主,总体呈加剧趋势;2000—2017年极端干旱和极端湿润事件频发,生态干旱总体呈缓解趋势。从累积和曲线上看,1980—1995年为嫩江流域生态干湿状态的正常波动时期,1996—2009年为嫩江流域生态干旱期,2012—2017年为生态湿润期;(3)生态干旱的干旱历时和烈度显示流域西南部严重程度较大,长期干旱风险较高,而流域北部干旱强度较大,较易发生单次较为严重的短期干旱。In the past few decades,the wetlands in the Nenjiang River basin have shrunk significantly,with serious soil salinization and frequent droughts,posing a severe threat to ecological security,water environment safety,and socio-economic sustainable development.Consequently,these issues have presented a serious challenge to the ecosystem in the Nenjiang River basin,resulting in a significant impact on the ecological balance.To gain a better understanding of the impacts of drought on ecosystems in the Nenjiang River Basin,this study analyzed the spatial and temporal evolution of ecological drought in the Nenjiang River Basin from 1980—2017 using the standardized ecological water deficit index(SEWDI)combined with the rotated empirical orthogonal function,cumulative sum,and Pearson correlation analysis,and extracted ecological drought characteristics using the runs theory.The findings revealed the following:Firstly,the correlation coefficients between ecological drought and the influencing factors ranked as relative humidity>normalized difference vegetation index>runoff>precipitation>temperature.The correlation coefficients of ecological drought and relative humidity were the largest and greater than 0.5,showing significant correlation,while the correlation coefficients of the rest of the factors were less than 0.5,showing a low degree of correlation.Secondly,from the change curve of the standardized ecological water deficit index,the alternation of wet and dry from 1980 to 1999 showed periodicity,and the ecological drought was dominated by mild and moderate drought,with a general trend of intensification;The extreme drought and extreme wet events occurred frequently from 2000 to 2017,but with an overall mitigating trend.The cumulative sum analysis revealed that 1980—1995 was the ecological normal fluctuation period of ecological dry and wet status in the Nenjiang River basin,1996—2009 was the ecological dry period,and 2012—2017 was the ecological wet period.Thirdly,the drought duration,severity and intensity ch

关 键 词：生态干旱 累积和曲线 旋转经验正交函数 嫩江流域 干旱演变 

分 类 号：P426.616[天文地球—大气科学及气象学]