高级检索

基于PPFS框架的武汉市湿地脆弱性时空演变分析

Spatiotemporal evolution analysis of wetland vulnerability in Wuhan City based on the PPFS framework

  • 摘要: 人类活动对湿地生态系统造成了显著干扰,探索湿地脆弱性动态演变对有效保护湿地和提升生境质量具有重要意义。以武汉市湿地为研究对象,利用全尺度跳跃连接网络(Full-Scale Connected U-Net, UNet3+)提取2016—2024年湿地分布信息,并采用“模式−过程−功能−胁迫”(PPFS)框架评估湿地脆弱性值。研究结果表明,武汉市湖泊与河流面积稳步回升,干支流水系连通性显著增强,但受农业开发压力影响,西南部沼泽萎缩明显,呈现向养殖塘或农田转化的趋势;武汉市湿地脆弱性(WVI)整体呈波动下降趋势,生态系统稳定性增强;生态模式(EPI)显示中心区及滠水流域斑块破碎度较强,生态过程(EPOI)表现为典型的“内高外低”格局,生态功能(EFI)逐渐趋于平稳,生态胁迫(ESI)由中心城区集聚向全市均匀分布转变。武汉市湿地治理取得阶段性成效,未来应从“面积扩张”转向“质量提升”,重点加强对中心城区及脆弱值高值区的精准监测与修复,以构建韧性更强的城市湿地生态安全格局。

     

    Abstract: Wetlands are transitional ecosystems formed through interactions between terrestrial and aquatic environments. They are among the most important ecosystems on Earth and provide essential ecological functions, including hydrological regulation, carbon cycling, biodiversity conservation, and water purification. Wuhan, one of the major transportation hubs and economic centers in China, possesses abundant wetland resources. However, rapid urbanization and increasing human activities have exerted considerable pressure on its wetland ecosystems in recent decades. Wetland vulnerability reflects the tendency of wetland ecosystems to undergo degradation or functional loss under external disturbances. Therefore, investigating the dynamic evolution of wetland vulnerability is essential for wetland conservation and regional ecological management. In this study, Wuhan wetlands were selected as the research object. Remote sensing image preprocessing was conducted on the Google Earth Engine (GEE) platform. A total of 43 spatiotemporal variables were constructed from four categories: polarization features, spectral features, texture features, and topographic features. NDVI and NDWI time series were reconstructed using the Harmonic Analysis of Time Series (Hants) algorithm to capture seasonal and phenological characteristics of wetlands. Based on automatically generated sample datasets, the UNet3+ model was employed to extract wetland types in Wuhan from 2016 to 2024. To evaluate urban wetland vulnerability comprehensively, a ‘Pattern-Process-Function-Stress’ (PPFS) framework was established. Principal Component Analysis (PCA) was used to determine indicator weights objectively, and the Jenks Natural Breaks method was applied to classify wetland vulnerability into five levels. The results showed that the areas of lake and river wetlands in Wuhan generally exhibited a recovery trend, and the connectivity of major river systems was significantly improved. However, marsh wetlands in the southwestern region decreased substantially due to agricultural development. These wetlands showed a clear conversion trend toward aquaculture ponds and cultivated land. The Wetland Vulnerability Index (WVI) displayed an overall fluctuating downward trend, indicating a gradual improvement in wetland ecosystem stability. This finding confirms the positive effects of watershed ecological restoration and environmental governance. Nevertheless, the WVI of several important wetlands increased during the study period, suggesting that these areas should remain priorities for future conservation and restoration. The Ecological Pattern Index (EPI) revealed relatively high landscape fragmentation in the central urban area and the Sheshui River Basin. The Ecological Process Index (EPOI) showed a typical spatial pattern characterized by ‘high values in central areas and low values in peripheral areas’. The Ecological Function Index (EFI) gradually became more stable over time. Meanwhile, the Ecological Stress Index (ESI) shifted from concentration in the urban core to a more dispersed distribution across the city, indicating that urbanization pressure has gradually expanded toward suburban regions. Overall, wetland restoration and ecological management in Wuhan have achieved notable progress. However, future wetland governance should shift from area expansion to quality improvement. Greater attention should be given to precise monitoring and ecological restoration in core wetland regions and highly vulnerable areas. These efforts are necessary for building a more stable and resilient urban wetland ecological security pattern. Future research should further optimize sample spatial distribution and improve classification accuracy. In addition, the wetland vulnerability assessment framework should be refined according to the ecological characteristics of Wuhan. This study reveals the spatiotemporal heterogeneity of wetland vulnerability in Wuhan and provides scientific support for wetland restoration and sustainable urban ecological management.

     

/

返回文章
返回