长江流域生态系统水分利用效率时空演变特征及驱动分析  

Spatio-Temporal Evolution Characteristics and Driving Analysis of Ecosystem Water Use Efficiency in Yangtze River Basin

作　　者：张苹 陈燕飞 丁佳伟 徐述邦 ZHANG Ping;CHEN Yanfe;DING Jiawei;XU Shubang(College of Resources And Environment,Yangtze University,Wuhan 430100,China)

机构地区：[1]长江大学资源与环境学院,湖北武汉430100

出　　处：《人民珠江》2025年第3期82-92,共11页Pearl River

基　　金：智慧长江与水电科学湖北省重点实验室开放研究基金项目(ZH21020001)。

摘　　要：生态系统水分利用效率(Water Use Efficiency,WUE)能很好地解释生态系统水损失和碳增益间的权衡,揭示WUE的时空格局及内在驱动机制有助于理解流域内植物生态策略及水资源循环过程。基于长江流域长时序的卫星遥感数据,利用趋势分析、方差分解及Hurst指数等方法分析了2010—2019年生态系统总初级生产力(Gross Primary Productivity,GPP)、蒸散量(Evapotranspiration,ET)和WUE的时空特征,并探究GPP与ET对WUE的贡献度,以及该贡献度变化趋势的持续状态。结果表明:(1)流域内WUE的分布呈现自上游向下游递增的空间格局,年际变化趋势为0.013 gc(/m^(2)·a);(2)流域内GPP、ET及交互作用对WUE的贡献度总体年际变化趋势分别为-0.003 5、-0.005 1、0.009 6/a,且在不同的气候分区间差异较大;(3)流域内GPP、ET及交互作用对WUE的贡献度年际变化的Hurst指数分别为0.51、0.60和0.61,表明持续状态均为正向持续性,但在各气候分区间差异较大。揭示了WUE的时空格局及内在驱动机制,对于应对环境变化对生态系统碳、水循环过程的影响至关重要。Ecosystem water use efficiency(WUE)is a good explanation of the trade-off between water loss and carbon gain in ecosystems.Uncovering the spatio-temporal patterns of WUE and the underlying driving mechanisms can help to understand the ecological strategies of plants and water cycling processes in basins.This study employed a long time series of satellite remote sensing data of the Yangtze River Basin to analyze the spatio-temporal characteristics of ecosystem gross primary productivity(GPP),evapotranspiration(ET),and WUE from 2010 to 2019 by using trend analysis,variance decomposition,and Hurst index.In addition,it investigated the contribution of GPP and ET to WUE and the persistence of the trend of this contribution.The results show:①The distribution of WUE in the basin shows a spatial pattern of increasing from upstream to downstream,with an inter-annual variation of 0.013 gc/(m^(2)·a);②The overall inter-annual variations in the contributions of GPP,ET,and their interactions to WUE in the basin are−0.0035,−0.0051 and 0.0096/a,and they varied considerably across climate zones;③The Hurst indexes for inter-annual variation in the contributions of GPP,ET,and their interactions to WUE in the basin were 0.51,0.60 and 0.61,indicating that the persistence states were all positively but varied considerably across climate zones.The study elucidated the spatio-temporal patterns of WUE,as well as the intrinsic driving mechanisms,which was of great importance to dealing with the impact of environmental change on the carbon and water cycle of the ecosystem.

关 键 词：水分利用效率 方差分解分析 HURST指数 驱动因素 长江流域 

分 类 号：TV1[水利工程]