1991-2020年西藏水源涵养时空演变特征  

Spatiotemporal evolution of water conservation from 1991 to 2020 in Tibet,China

作　　者：项巧 范继辉[1] 杨紫滟 XIANG Qiao;FAN Jihui;YANG Ziyan(Key Laboratory of Mountain Surface Processes and Ecological Regulation,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610299,Sichuan,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院、水利部成都山地灾害与环境研究所山地表生过程与生态调控重点实验室,四川成都610299 [2]中国科学院大学,北京100049

出　　处：《草业科学》2024年第11期2495-2507,共13页Pratacultural Science

基　　金：国家自然科学基金项目(U2240216、41871072)。

摘　　要：西藏是“亚洲水塔”的一部分,探明全球变化背景下西藏水源涵养量的时空演变特征,可为区域生态安全屏障构建提供支撑。基于生态系统服务和权衡的综合评估模型估算了西藏1991-2020年的水源涵养量,并探讨了关键因子的影响。结果表明:1)西藏多年平均水源涵养深度为84.32 mm,呈西北低东南高的空间分布格局;2)1991-2020年,其距平值以0.72 mm·a^(-1)的速率显著(P<0.05)增加,全域有81.98%的区域呈上升趋势;3)西藏全域除东部外,气候向暖湿化转变,降水增幅大于蒸散发需求,主导水源涵养呈正向变化;4)草地的退化导致西藏水源涵养能力降低了21.14%,在缺水地区,草地土壤相较于林地具有更强的持水能力。为了保护西藏生态安全屏障,应考虑在怒江源等区域设立保护区,并实施保护草原、控制人工林在缺水地区种植等措施。Tibet is an essential part of the“Asian Water Tower”.Exploring the spatiotemporal patterns of water conservation in the context of global change is of great importance.In this study,the integratedvaluation of ecosystem services and trade-offs(InVEST)model was used to estimate water conservation in Tibet from 1991 to 2020,and the main influencing factors were investigated.The results are:1)The mean water conservation depth is 84.32 mm,and a spatial pattern with lower values in the northwest and higher values in the southeast of Tibet is observed;2)There is a significant increase in water conservation from 1991 to 2020 at a rate of about 0.72 mm per year(P<0.05).Meanwhile,there is an upward trend in water conservation over 81.98%of the area in Tibet;3)Except for the eastern part of Tibet,the climate is changing toward warm and humid,and the increase in precipitation is greater than the evapotranspiration demand.Therefore,the water conservation is changing positively;4)The degradation of grasslands has resulted in a 21.14%reduction in water conservation in Tibet.Notably,the water retention capacity of grassland soils in Tibet exceeds that of forested land in drylands.Strategic measures are needed to protect the ecological integrity of Tibet.These include establishing protected areas such as the source of the Nujiang River in Tibet,implementing measures to conserve native grasslands,and regulating the cultivation of plantations in water-scarce regions.

关 键 词：生态系统服务和权衡的综合评估模型 水源涵养 气候变化 土地利用覆被 

分 类 号：X171.1[环境科学与工程—环境科学]