汉江上游流域生态系统水源供给服务变化

目的]研究汉江上游流域2000—2010年生态系统水源供给服务的时空变化及其影响因素,为区域水资源的科学管理与政策制定提供科学依据。方法]基于InVEST模型的产水模块分析汉江上游流域生态系统的水源供给服务。结果]10a间研究区林地、湿地和人工表面面积有所增加,耕地面积有所减少,草地面积基本稳定。年平均植被覆盖度总体呈上升趋势,变化率为0.005 1/a。2000,2005,2010年,汉江上游流域平均水源供给量分别为4.67×1010,5.22×1010,4.73×1010 m3。结论]研究区水源供给量的时空变化是气候变化和土地利用共同作用的结果;降水增加对水源供给量增加起到一定的积极作用,土地利用变化导致的下垫面改变及生态系统好转可能是水源供给量下降的主要驱动力。

Water Source Supply Service Variations of Ecosystem in Upper Hanjiang Basin

Objective] Studying the spatial-temporal variation and the influencing factors of ecosystem water source supply service in Upper Hanjiang Basin during 2000 and 2010, in order to provide basis for scientific management and policy formulation of regional water resources.Methods] The water yield module within InVEST model was used to analyze the supply service.Results] Forestland, wetland and construction land areas increased in the decade, while farmland area decreased. Grassland area remained stable. Annual mean vegetation coverage was in an overall rise with a gradient of 0.005 1/a. Water yields of upper Hanjiang basin in 2000, 2005 and 2010 were 46.70, 52.21 and 47.29 billion cubic meters, respectively.Conclusion] Spatiotemporal variation of water source supply amount in the study area was a combination result of climate and land use change. Increased precipitation had a positive role in increasing water yield. Change of underlying surface caused by land use change and ecosystem improvement could be the main driving forces of the declined water supply in upper Hanjiang basin.