Ecological System Health Evaluation Of Urban Wetlands In Nanchang City

Having significant ecological function, urban wetlands are important foundation for maintaining city’s ecological security. With the rapid development of the city, there have been many issues appeared in urban wetlands, such as landscape fragmentation, degradation of water quality and decrease of wetlands area. These issues have influence the ecosystem health and functional performance of urban wetlands dicrectly, and influence the sustainable development of city. So it has significant meaning for protection and restoration of urban wetlands ecology to assess ecosystem health and evaluate main influence factors and mechanism of urban wetlands.Base on reviewing domestic and foreign researches on urban wetlands ecosystem health and evaluation of nanchang’s basic situation on social and economic and environmental aspect, this paper at first assess the critical index—water environmental quality comprehensively, and then use (PSR) model to build evaluation index system and to assess the ecosystem health of urban wetlands of nanchang. Investigate result show that overall water environmental index of Nanchang’s urban wetlands equal:WQI=3.05, belongs to moderate pollution level, and overall ecosystem health equal:EHI=77.22, belongs to Sub-level health status. The propotion of water which is lower than Ⅲ level standard is close to80%, and the most serious pollution water locate in intermediate zone between urban and suburban area. In central area of city the main pollution factors include CODcr、BOD5、NH3-N, and in surburban area the main pollution factors include TN、TP。The main influence factors of urban wetlands ecosystem health are urbanization, industrial results and landuse and so on.This paper has compared urban wetland water environment and ecosystem health difference between each functional zone and also analysised the influence, this provides reference for treating the protection of wetland in each functional zone differently. At the same time, by giving overall water environmental quality and wetland ecosystem health, paper also provides scientific foundation and theoretical support for Nanchang city wetlands’ planning and resource development and protection.