摘要
水分利用效率(water use efficiency,WUE)是联系生态系统水碳循环耦合关系的重要指标,探明生态系统水分利用效率时空演变特征及其影响因素,对优化区域水、碳资源综合管理和提升生态系统生产力至关重要。基于MODIS遥感数据、CRU气象数据以及CCI土地利用数据,利用MK检验与Sen趋势分析以及偏相关分析,探讨了伊犁河⁃巴尔喀什湖流域不同时空尺度生态系统WUE的空间分布与时间变化规律,讨论了其影响因素。结果表明:流域春秋两季与多年平均WUE值从东南部至西北部呈现先增后减再增的变化特征,但夏季恰好相反,而冬季绝大部分区域都接近于0;全流域四季的多年平均WUE由高到低依次为夏季、春季、秋季、冬季;全流域年平均WUE呈略微上升趋势,上升区域主要集中在WUE较低的下游;全流域90%以上区域的夏季年平均WUE呈下降趋势,其中巴尔喀什湖、伊犁河谷与天山山脉附近区域下降趋势显著(P<0.05);上中下游年尺度WUE值依次由高到低变化,且它们的年际变化程度和趋势均不明显;上中下游夏季WUE值的排序与年尺度正好相反,且均呈下降趋势,其中上下游的下降趋势显著(P<0.05);不同区域WUE的年内分配极不均匀,峰值均出现在8月;就影响因素而言,总初级生产力和降水对WUE的影响要分别大于蒸散发和气温。
Water use efficiency(WUE)is an important indicator to link the coupling between ecosystem water and carbon cycles.Understanding the spatiotemporal variation of ecosystem WUE and its influencing factors is essential for optimizing the integrated management of regional water and carbon resources and improving ecosystem producti⁃vity.With remote sensing data from MODIS,meteorological data from CRU,and land use data from CCI,the spa⁃tial distribution and temporal variations of ecosystem WUE in Ili River⁃Balkhash Lake Basin were investigated by using MK test and Sen’s trend analysis.The factors influencing WUE were further detected by partial correlation analysis.The results showed that the multi⁃year average values of annual,spring and autumn WUE illustrated same change patterns from the southeast to northwest,with a trend of increasing at first,then decreasing,and increasing at last.However,WUE values in summer displayed an opposite spatial variation as described above and WUE val⁃ues of most areas in winter were close to zero.WUE values were highest in summer,followed by spring,autumn,and winter.The average annual WUE value over the whole basin increased slightly with time,with significantly increasing annual WUE in the lower reaches.The summer WUE values decreased with time in more than 90%of the basin,especially in the areas near Balkhash Lake,Ili River Valley,and Tianshan Mountains.Moreover,the annual WUE values in the upper reaches of the basin were obviously higher than those in the middle reaches,and the annual WUE values were lowest in the lower reaches of the basin.The interannual variations and trends of annual WUE values in the upper,middle and lower reaches of the basin were not significant.The rank of summer WUE values in the upper,middle and lower reaches of the basin was absolutely reverse to that of annual WUE values.The summer WUE values in the upper and lower reaches of the basin showed a significant decreasing trend,while the decreasing trend in the middle reaches of the basin was not significant.The intra⁃annual distribution of WUE in the basin was extremely uneven,with a peak value in August.In terms of influencing factors,gross primary productivity and precipitation showed stronger influences on WUE than evapotranspiration and temperature,respectively.
作者
崔罡
李琼芳
赵建华
陈启慧
CUI Gang;LI Qiongfang;ZHAO Jianhua;CHEN Qihui(College of Hydrology and Water Resources,Hohai University,Nanjing 210024,China;Suqian Branch of Jiangsu Hydrology and Water Resources Survey Bureau,Suqian 223899,Jiangsu,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2023年第11期2712-2720,共9页
Chinese Journal of Ecology
基金
新疆维吾尔自治区寒旱区水资源与生态水利工程研究中心(院士专家工作站)合作研究项目(2020.E⁃001,2020.E⁃002,2020.E⁃004)
中央高校基本科研业务费项目(国际河流专项)(B210204024,B210204025,B210204026)资助。
