基于GIS的洞庭湖区生态系统健康评价

Assessment of Ecosystem Health in Dongting Lake Based on GIS

以洞庭湖区子流域为评价单元,将其划分为陆域、岸边带和水域三部分,从生态系统的物理、化学和生物完整性出发,分别构建评价指标体系,开展生态系统健康评价,揭示洞庭湖区的生态系统健康状况空间分布规律。结果表明:研究区生态系统健康状况总体一般,健康等级为一般的区域面积占总面积的79.4%。各子流域的陆域健康状况一般,大部分健康指数为4～6;岸边带的健康状况差异较大,健康指数为1～8,健康状态良好的区域约占总面积的30%;水域生态系统的健康状况总体良好,健康指数均高于4。位于中心的大通湖子流域健康状况相对较差,需加强退田还湖的力度,积极开展其岸边带的植被恢复与治理。生态系统健康状况较好的是南洞庭湖和新墙河子流域,其生物多样性保护和水土流失的预防及治理是今后需关注的重点内容。

Assessment of ecosystem health by the watershed as a unit is an important foundation for the protection and management of the ecosystem. The sub-watershed of Dongting Lake was studied as evaluation unit, and the evaluation objects were divided into terrestrial, riparian and aquatic ecosystems. The evaluation index system was constructed from the viewpoint of ecosystem＇s physical, chemical, and biological integrity, respectively, and the ecosystem health assessment was carried out to reveal the spatial distribution of ecological health in Dongting Lake area. The results showed that： the ecosystem health condition was general in Dongting Lake area, and the area with general health level accounted for 79.4% of the total area. The terrestrial health condition of all the sub-watershed was general and most heahh indices ranged from 4 to 6. The differences in health status in each nparian ecosystem were large, with the health indices ranging from 1 to 8, and the area with good health conditions accounted for 30% of the total area. The level of aquatic ecosystem health conditions was good and the health indices were higher than 4. Sub-watersheds of Datong Lake located in the central part were in poor health. Measures should be taken to strengthen the efforts of returning farmland to the shores, vegetation recovery and management in riparian zone. South Dongting Lake and Xinqiang River sub-watersheds were in good ecological health, and the biodiversity conservation and prevention and management of soil erosion should be the main concerns in the future.