快速城市化地区湿地生态安全评价--以深圳市为例

Ecological Security Assessment of Wetlands in Rapidly Urbanizing Areas:A Case Study of Shenzhen, China

利用深圳市2013年土地利用变更调查数据,结合景观格局指数与InVEST模型,构建适合快速城市化地区的湿地生态安全评价指标体系,综合评价深圳市湿地生态安全。研究结果显示,深圳市湿地破碎化严重;大鹏新区湿地的生态安全值为0.88,表明该区的湿地安全;盐田区湿地的生态安全值为0.62,表明该区的湿地较安全;坪山区、南山区、福田区湿地的生态安全值分别为0.48、0.44和0.43,表明该区的湿地处于低度预警状态;新宝安区、新龙岗区、罗湖区、光明新区、龙华区湿地的生态安全值分别为0.39、0.36、0.33、0.28和0.21,表明该区的湿地处于中度预警状态。深圳市湿地的生态安全受人为胁迫严重,亟待加强对深圳市湿地生态系统的保护与管理。

Urban wetlands are among the most important natural spaces in urban landscapes. The many types of urban wetlands include rivers, lakes, reservoirs, ponds, tidal wetlands, bogs, fens, marshes and swamps. Urban wet- lands form important patches and corridors in the urban landscape, which are foundational to urban ecological secu- rity. To evaluate the ecological security of wetlands in rapidly urbanizing regions, the authors selected Shenzhen as the study area. Since China＇ s reform and opening-up, urbanization has caused wetland fragmentation, with patches disappearing and corridor connectivity weakening in Shenzhen. The ability of urban wetlands to support ecological security is becoming compromised. Our goal is to evaluate the ecological security of wetlands, to provide a scientif- ic basis for wetland protection policies, and to optimize urban landscape patterns. Human disturbance and land use changes have significantly affected urban ecological security in general and have become especially important fac- tors restricting the ecological security of wetlands in Shenzhen. This paper uses the INVEST model to assess the ef- fects of human disturbance and land use on wetlands. With the support of RS and GIS, using 2013 Shenzhen land use data, we extracted the distribution of wetlands. Based on the data obtained, an index was calculated using the IN- VEST model as a quantitative indicator of wetland ecological security. This index was integrated with other indexes to establish an evaluation system. We used expert scoring method to set weights and obtained the final comprehen- sive evaluation by using data standardization and weighted summation methods for each index. In this manner, we analyzed landscape patterns, habitat quality and degradation based on INVEST model, and the ecological security of Shenzhen. Wetland ecological security and the spatial distribution pattern were revealed for Shenzhen. The results show that wetlands have become seriously fragmented, and most wetland ecosystems in Shenzhen are at some de- gree of risk. Although some wetlands have been incorporated into the protection system, the ecological situation is worrisome. Wetland protection policies need to be strengthened. Wetlands outside the original special economic zones are more fragmented with more varied shapes, and greater landscape diversity. The study found an ecological security value for Dapeng District of 0.88, meaning that the ecosystem was in a relatively safe state. Yantian Dis- trict＇ s wetland ecological security value was 0.62, indicating a less safe wetland ecosystem. Wetland ecological se- curity values of 0.48, 0.44, and 0.43 in Pingshan District, Nanshan District, and Futian District are early warnings of wetland ecosystem deterioration. The lowest wetland ecological security values were found to be 0.39, 0.36, 0.33, 0.28, and 0.21 in New Baoan District, New Longgang District, Luohu District, Guangming District, and Longhua District. The ecological security threats in these districts are considered to be very serious. Thus we recommend gov- ernment action to develop appropriate responses to urban wetland ecosystem conservation and management.