Study On The Theory And Evaluation Method Of Regional Water Environment Carrying Capacity

As a basic factor of society and economy development, water environment plays an important role to support a regional development. How to evaluate a regional Water Environment Carrying Capacity (WECC) and guide the regional planning and development with WECC has been attracting more attention from governments, a hot topic in water science research as well. Under the concept of the harmony between human beings and water, the regional WECC was studied with multidisciplinary approach of hydraulics, water environment science, ecology, and system theory. The main contents include as follow:(1) The current situation of water resources and main issues in water environment were detaildely analyzed. Theory, approach, and advances of water environment and its bearing capacity were comprehensively reviewed.(2) The concept of water environment was improved to be a composite system of socioeconomic, water resources and ecological environment. Based on the analysis for component elements, structural function and operation mechanism of water environment system, the bearing relationship and bearing mechanism were studied, the WECC was defined in generalized level and narrow level respectively, and it was mathematically described.(3) The narrow WECC was regarded as pollutants bearing capacity. Water quantity was calculated with the basic Saint-Venant equations of one-dimensional unsteady flow and verified with measured data of water level and flow discharge. The mathematics model to calculate narrow WECC was developed. Take Taizou as a case, the narrow WECC was studied and the measures to improve water environment were suggested.(4) Based on the characteristics of water environment composite system and comprehensive evaluation index system including the socio-economic, water resources and ecological environment, the generalized WECC was studied. The set pair analysis (SPA) method for regional WECC assessment was improved through introducing entropy weight method. Taking Guangdong province as a case, assessment indicator system was constructed according to the practical situation of water environment in Guangdong Province. Regional WECC in Guangdong province and its three sub-systems were comprehensively appraised adopting the improved SPA method. Finally, the improved measures of regional WECC are presented.