水文变异下长江流域的生态径流变化、影响及归因  

Ecological Instream Flow in the Yangtze River Basin under the Hydrological Variation: Changes, Impacts, and Attributions

作　　者：何亚男 王双玉 顾西辉[1,2,3] HE Yanan;WANG Shuangyu;GU Xihuil(School of Environmental Studies,China University of Geosciences,Wuhan 430074,Hubei,China;Collaborative Innovation Center for Western Ecological Safety,Lanzhou University,Lanzhou 730000,Gansu,China;State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences,Xi'an 710061,Shaanxi,China)

机构地区：[1]中国地质大学(武汉)环境学院,湖北武汉430074 [2]兰州大学西部生态安全省部共建协同创新中心,甘肃兰州730000 [3]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,陕西西安710061

出　　处：《武汉大学学报（理学版）》2023年第3期313-322,共10页Journal of Wuhan University:Natural Science Edition

基　　金：兰州大学中央高校基本科研业务费专项资金(lzujbky-2021-kb12);黄土与第四纪地质国家重点实验室开放基金(SKLLQG2108)。

摘　　要：气候变化和人类活动可能引起水文序列出现变异,对流域水文生态系统的稳定性产生严重影响。根据1961—2020年长江流域64个水文站点的逐日河道流量观测数据,采用Pettitt突变检验法识别径流序列突变点,利用广义极值分布估计变异前、后河道生态需水;基于流量历时曲线估算河流生态盈余和赤字,结合水文改变程度指标D_(0)和DHRAM(Dundee水文情势改变法)评价长江流域水文整体改变程度及其对生物多样性的影响,并对生态盈余/赤字变化进行归因分析。研究结果表明:1)由于长江流域水库、大坝等调蓄作用,长江流域枯水期生态盈余(生态赤字)呈上升(下降)趋势,而在丰水期则呈现相反的变化;2)长江流域干流水文改变程度最高(D_(0)达到50%以上),河流水文情势和生态系统受到高风险影响(DHRAM总分数大于10),生物多样性呈现显著的下降趋势;3)气候变化与人类活动对长江流域生态径流有相反的影响,即气候变化使得生态盈余增加,而人类活动使得生态盈余减少,整体上气候变化是影响生态盈余的主导因素(相对贡献率高于50%)。Climate change and human activities may cause change points in hydrological processes, which has serious impacts on the stability of watershed hydrological ecosystems. Based on daily streamflow data during 1961—2020 at 64 hydrological stations across the Yangtze River Basin, the Pettitt test method was used to identify change point in streamflow time series, and the generalized extreme value distribution was used to estimate the ecological water demand. The results show that: 1) due to the regulation of reservoirs and dams, ecological surplus(ecological deficit) tends to increase(decrease) in the dry season of the Yangtze River Basin, while these trends in ecological surplus/deficit are opposite in the wet season;2) the degree of hydrological alterations in the trunk stream of the Yangtze River Basin is the highest(D_(0)reaches 50% or more), the river hydrological ecosystem is under high risk(the total DHRAM(Dundee hydrological regime alteration method) score is more than 10 points), and the biodiversity shows a significant downward trend;3) climate change and human activities have opposite impacts on ecological instream flow of the Yangtze River Basin, that is, climate change/human activities increases/decrease ecological surplus. Overall, climate change is the leading factor affecting ecological surplus(the relative contribution is more than 50%).

关 键 词：水文变异 生态径流 生态需水 水文改变程度 长江流域 

分 类 号：TV11[水利工程—水文学及水资源]