太湖流域磷排放对区域城市化过程的响应——以宜兴市为例

在系统分析基础上,利用系统动力学方法,以宜兴市为典型区,模拟城市化过程对磷发生量的影响,建立二者间的定量响应关系.结果表明,不论是在何种城市化发展速度下,磷的发生总量都会有较大幅度的增加,而目前规划的污水处理水平只能小幅度削减流域内磷的排放量,不足以从根本上扭转太湖水质持续恶化的趋势.在推进太湖流域城市化的进程中,必须加大投入,进一步加强环境基础设施建设,更大幅度地削减磷等营养物质的排放.

Impact of Urbanization on Phosphorus Emission in Taihu Lake Watershed—A Case Study in Yixing, Jiangsu Province

Phosphorus is the limiting factor of Taihu Lake eutrophication and domestic sewage is its leading P source.In this regard,reducing phosphorus emission from urban section is an urgent priority.However,rapid urbanization in the watershed has a negative impact on the water quality improvement of the lake because most of the municipal effluent in the area is now discharged into river systems without or with only minor treatment.In this study,a system dynamic model was developed and applied in Yixing City,a case area in Taihu Lake watershed,to relate phosphorus emission and urbanization rate.Phosphorus generated in the case area will continue to rise with the urban expansion.Planned waste water treatment capacity can only slightly reduce P emission from its present level in the near future.The improvement of water quality of the lake lies largely on enlarged capacity of municipal domestic sewage treatment.The results of this study can be used as a theoretical base for realizing sustainable coordinative development between society,economy and environment in the area.