“三江并流”区生态系统供水服务的空间分布特征

摘要

Water supply is an essential ecosystem service for supporting human well-being.By using the InVEST model and GIS techniques, this study mapped the spatial distribution of water supply ecosystem service in the Three Parallel Rivers Region.We then analyzed the distribution of this service on different topography zones and countries, and assessed the capacity of different ecosystem types in providing the service.Our results showed that the annual total of water supply in the region was 41.23 billion m3 , averaged 620.4 mm/hm2; the distribution of water supply service was decreasing progressively from southwest to northeast; the high-value regions of water sup-ply service were primarily located in the rugged and ubac zone ranging from 2 000 to 4 000 m in elevation; Lushui country has the highest water supply capability, followed by Lanping country, Yunlong country, and Fugong country, while Heqing country and Gucheng district have relatively low capability.There is an obvious contrast a-mong the water supply capability of different ecosystem types; glacier ecosystems have the highest water supply ca-pability, followed by shrub, bamboo forest, grassland, meadow, and temperate conifer forest, while deciduous broadleaf forest, warm conifer forest and sclerophyllous evergreen broad leaf forest have relatively low capabili-ty.We conclude that regional climate and the special topography are the main factors affecting the spatial pattern of water supply service in this region.Moreover, human activities could change the water supply ecosystem service in some local areas.%水源供给是一项重要的生态系统服务。本研究采用InVEST模型，对“三江并流”区的多年平均生态系统供水服务量进行空间分布模拟，揭示该服务在不同地形要素和县域上的分布特征，明晰不同生态系统供水功能。结果表明，本区生态系统多年平均供水总量达412.3×108 m3／a，平均单位面积供水量为620.4 mm／hm2；供水服务量由西南向东北逐渐减少，高值地区集中在海拔2000～4000 m、地形陡峭的阴坡地区；单位面积供水量较高的县为泸水县＞兰坪县＞云龙县＞福贡县，较低的为鹤庆县和丽江市古城区。各类生态系统的供水功能：冰雪和冰川＞灌丛＞竹林＞草地＞草甸＞温性针叶林，较小的为落叶阔叶林、暖性针叶林和硬叶常绿阔叶林。气候和特殊的地形是控制本地区生态系统供水服务空间分布差异的主导因素，人类活动会影响局部地区的生态系统供水服务。