基于遥感的杭州湾湿地鸻鹬类水鸟适宜生境时空变化特征研究

Temporal and Spatial Variation of Suitable Habitat for Shorebird in Hangzhou Bay Wetland Based on Remote Sensing

鸻鹬类是“东亚—澳大利西亚”迁飞通道上最主要的迁徙水鸟,了解鸻鹬类生境的变化对其种群资源的监测和保护、动物流行病的预防都有一定的现实意义.杭州湾滨海湿地位于该候鸟迁徙通道中段,是迁徙水鸟一个重要的能量补给站.研究基于1984—2017年5个时段的Landsat卫星遥感数据,根据不同生境的水分、植被覆盖度、湿度等特征,计算湿地光谱指数,利用监督分类对杭州湾湿地水鸟生境进行分类,并研究生境格局的时空变化,探索杭州湾湿地变化背景下鸻鹬类适宜生境指数的变化趋势.结果表明:1984—2017年间,滨海湿地面积总体增大,边界北移,但鸻鹬类适宜生境面积减少;鸻鹬类适宜生境中,光滩生境的景观趋于连片化,但海三棱藨草生境趋于破碎化;滨海湿地总体的多样性和均匀度有所增加,鸻鹬类适宜生境有向其他生境类型转变的趋势;鸻鹬类适宜生境指数总体呈下降趋势,但近年来在湿地的保护过程中,生境适宜度指数有回升的趋势.人类活动使得湿地中水鸟生境景观的演替速率大幅提升,对鸻鹬类生境构成了一定的威胁,在后期湿地保护的过程中应当考虑对水鸟生境质量加以改善.

Shorebirds are the most important migratory waterfowls on the“East Asia-Australia”migration route.It is of practical significance to understand the changes of shorebird habitat for the monitoring and protection of its population resources and the prevention of animal epidemic.The coastal wetland of Hangzhou Bay is located in the middle of the migratory channel and is also an important energy supply station for migratory waterfowls.Basing on the Landsat satellite remote sensing data for five time periods from 1984 to 2017,the study calculates the wetland spectral index according to the characteristics of water,vegetation coverage and humidity of different habitats.The study also uses supervised classification to classify the habitat of different waterfowls in Hangzhou Bay Wetland,studies the temporal and spatial changes of the habitat pattern in wetlands,and explores the changing trend of suitable habitat indicators under the background of the changes of wetland in Hangzhou Bay.The main results show that during 1984-2017,the total area of coastal wetland increase and the boundary move northwards,but the suitable habitat area for shorebirds has decreased.In the shorebirds’suitable habitat,the landscape of bare flat habitat tends to be contiguous,while the habitat of Scirpus mariqueter tends to be fragmented.The overall diversity and evenness of the coastal wetland have increased,and the suitable habitat for the shorebirds has shifted to other types of wetlands.Shorebird habitat suitability index(SHSI)has declined in the past,but now the index of suitability habitat has risen because of the process of wetland protection.Human activities have greatly increased the succession rate of waterfowls’habitat landscapes in the wetlands,which pose a certain threat to the terrestrial habitats.In the later stage of wetland protection,the improvement of aquatic bird habitat quality should be considered.