湄公河上游沙湾拿吉-桔井区域水生态功能分区研究

近年来，随着全球气候变暖、水资源开发利用与人类活动的不断加剧，湄公河流域水生态系统健康状况正遭受着严重威胁，其区域社会经济发展呈严峻态势。以湄公河干流老挝沙湾拿吉-柬埔寨桔井段及重要支流为研究区域，结合生境要素空间异质性，利用空间聚类法对其进行水生态功能分区研究。研究结果表明，基于区域地貌特征提取的水生态2个一级区能较好的体现区域水资源分配状况和供给功能；基于流域水系河网、土壤及土地利用特征提取的5个二级分区能反映人类活动对区域水生生境及水质的影响。水文、水生生物及水质数据分别验证了分区结果的合理性。研究结果可为跨界河流水资源管理和水生态环境保护提供了科学支撑。

Regionalizing Hydroecological Function in the Savannakhet-Kratie Area of Mekong River

Global warming, water resource development and utilization, and intensified human activities, pose a serious threat to aquatic ecosystem health in the Mekong River basin, and make regional socio-economic development difficult. In this study, the mainstream of Mekong River between Savannakhet in Laos and Kratie in Cambodia, together with several key tributaries were selected for research. Regions of aquatic ecological function were delineated based on a water ecological function evaluation index developed as part of the study. The evaluation index consisted of two primary indices (elevation and slope) and five secondary indices (river density, soil type, proportion of farmland area, proportion of forest area and degree of soil erosion). Spatial heterogeneity of habitat elements and spatial clustering were used to delineate regions according to aquatic ecological function. The investigated area included two Level 1 water ecological function zones and five Level 2 water ecological function zones. The Level 1 ecological zones were based on the regional geomorphic features and well-represent the distribution and supply functions of regional water resources. The Level 2 zones derived from the river network, soil and land use characteristics of the watershed reflecting the impact of human activities on regional aquatic habitat and water quality. The water ecological function zones were verified using data on hydrology, aquatic organisms, and water quality. The results of this study provide scientific support for water resource management and hydroecological protection of transboundary rivers.