基于“3S”技术的瓯江流域生态系统健康评价

Study on the Health Assessment of Oujiang River Basin Ecosystem Based on“3S”Technology

流域尺度的生态系统健康对区域经济与可持续发展具有重要意义,中小尺度的健康评价并不能完全反映流域尺度下的生态系统健康问题。结合《河湖健康评估技术导则》,基于“3S”技术构建流域尺度下生态系统健康评价指标体系并对瓯江流域开展生态系统健康性评价。评价结果表明:瓯江流域总体处于健康和亚健康状态。其中,宣平溪、小溪等流域健康状况较好,生态系统结构和功能较完善;浮云溪、好溪等流域健康状况相对较差。流域内生态系统健康胁迫因子以河湖纵向连通性为主。结合现场调研,对评价结果进行验证,发现浮云溪和好溪流域人类活动强度较大,植被覆盖率较低,生态系统健康状况较差,基于“3S”技术的流域尺度健康评价方法具有良好的评价效果。

The health of ecosystem at the watershed scale is of great significance to the regional economy and sustainable development.The health assessment at the medium or small scale cannot fully reflect the ecosystem health issues at the watershed scale.Therefore,referring to Technical Guidelines for River and Lake Health Assessment,this paper constructed an indicator system for aquatic ecosystem health evaluation at the watershed scale based on“3S”technology,and adopted the index system method to comprehensively evaluate the aquatic ecosystem health in the Oujiang River Basin.The evaluation results show that the ecosystem of Oujiang River Basin is generally in a healthy or a sub-healthy state.For specific performance,the health status of Xuanping River Basin and Xiaoxi River Basin are better,where their ecosystem structure and function are relatively complete.However,the health status of Fuyun River Basin and Haoxi River Basin are relatively poor.The main factor that threatens the health of ecosystem in Oujiang River Basin is the longitudinal connectivity of rivers and lakes.Combined with field investigations,the evaluation results are verified,and it is found that the human activities in the Fuyun River and Haoxi river are relatively intense,and the vegetation coverage is low.The watershed-scale health assessment based on“3S”technology has an ideal evaluation effect.