近30年来京津冀地区湿地景观变化及其驱动因素

湿地是水陆生态系统的转换区,是地球上生物多样性和生产力最高的生态系统之一。在快速城镇化和社会经济发展的推动下,京津冀地区湿地生态环境面临较大地威胁。利用1980年代末到2015年7期土地生态遥感解译数据,运用GIS空间分析和主成分分析方法,分析了京津冀地区湿地景观时空变化及其驱动力。研究结果表明:(1)1980s末—2015年期间,京津冀地区湿地面积的变化呈现从略微增长到快速减少趋势,近十年减少趋势略有减缓。湿地总面积减少了2695.05 km2,较1980s末年减少了20.08%;河北省湿地面积减少最多,且天然湿地减少占据主导地位,其次是天津市和北京市。(2)湿地面积损失较为严重的区域主要分布在环渤海区域、北京市和河北省张家口市和唐山市。湿地受损主要是水田和滩涂向非湿地转换引起的。(3)水田和水库坑塘构成的人工湿地是京津冀地区优势景观类型。湖泊、河渠、滩地破碎度增加,且空间分布离散,连通性差。(4)选取9个驱动因素指标进行主成分分析,人类活动是影响湿地景观格局变化的主要因素,城市扩张和农业发展是侵占湿地的主要表现形式,此外气候和政策等因素也对湿地变化存在一定影响。

Wetland landscape pattern change and its driving forces in Beijing-Tianjin-Hebei region in recent 30 years

Wetlands, which are among the most productive and biodiverse ecosystems on Earth, are areas where aquatic and terrestrial ecosystems converge. Wetland environments are threatened by the rapid urbanization and socio-economic development of the Beijing-Tianjin-Hebei region. In this study, we analyzed the changes in the wetland landscape and its driving forces in the Beijing-Tianjin-Hebei region following GIS and principal component analysis methods. The results are as follows: (1) From the late 1980s to 2015, the wetland area slightly increased and then rapidly decreased, however this decreasing trend slowed slightly over the last ten years. The wetland area of the Beijing-Tianjin-Hebei Region decreased by 2695.05 km², a reduction of 20.08%. The largest reduction occurred in Hebei Province, which is dominated by natural wetlands, followed by Tianjin and Beijing City. (2) Wetland areas were mainly lost in Bohai Bay, Beijing City, and the Zhangjiakou and Tangshan Cities of Hebei Province. (3) Paddy, reservoir, and pond wetlands are the dominant landscape types. Fragmentation is serious and the degree of aggregation is low in lake, river and canal, and beach landscapes, indicating that the spatial distribution of wetlands is discrete with poor connectivity. (4) The driving forces were analyzed using nine indicators following the principal component analysis method. The result showed that human activities were the main driving forces, and urban expansion and agricultural development were the main pathways of degradation. Additionally, the wetland landscape is also influenced by policy and the climate.