近40年辽东湾北部围垦区内外滨海湿地景观演替特征及驱动力分析

以辽东湾北部区为研究对象,利用1977~2014年Landsat卫星的5期遥感影像作为数据源,通过RS和GIS技术,分析研究区海岸线空间格局变化以及围垦区内外滨海湿地景观的演替路径与模式。结果表明：① 研究期内海岸线长度呈波动增长且整体表现为向海扩张趋势。1985~1993年和2002~2014年是辽东湾北部区海岸带显著发生向陆侵蚀和向海扩张时期,大凌河河口西岸和大辽河河口西岸的自然岸线大量转为人工岸线。② 围垦活动已经使研究区85%的自然滨海湿地转为人工滨海湿地和非湿地,景观破碎度不断增强,但在2002~2014年,芦苇、潮间带盐沼植被在围垦区外围逐渐生长,景观多样性持续增加。③ 在围垦区内部,传统的景观演替路径是自然滨海湿地-内陆盐植/芦苇-水产养殖/耕地-建设用地。然而,由于先进的围垦和快速脱盐技术,滨海湿地景观演替的路径不仅简化而且时间缩短。④ 不同的围垦强度和方式显著地影响区域景观格局的演变。加强保护大辽河西岸由水产养殖到内陆盐植的逆向演替以及双台子河河口两岸的湿地区域,对于区域生态环境改善具有重要意义。

Driving Forces Analysis and Landscape Succession Features of Coastal Wetland Both Outside and Inside Reclamation Areas in the Northern Liaodong Bay,China in Recent 40 Years

Reclamation is considered to be an effective measure to solve the problem of land shortage in urban and industrial expansion. However, the extent and intensity of coastal development has caused serious damage to the coastal wetland ecosystem. Analyzing the characteristics and trends of coastal wetland evolution influenced by reclamation activities is of great significance for developing regional ecological coping strategies. Using Remote Sensing (RS) and Geographic Information System (GIS), this study took the northern area of Liaodong Bay as a case study to reveal shoreline changes and to delineate the paths and patterns of coastal wetland landscape succession both outside and inside reclamation areas. Results showed that: 1) The length of the coastline increased and showed a seaward advancing change in the period of research. In 1985-1993 and in 2002-2014, the coastal zone in the Northern Liaodong Bay experienced significant landward erosion and seaward expansion. The natural shorelines in the west banks of Daling River Estuary and Daliao River Estuary turn into artificial shorelines. 2) Reclamation has converted 85% of natural coastal wetlands into artificial coastal wetlands and non-wetland, landscape fragmentation increased. But in the 2002-2014, reed and intertidal salt marsh grew gradually outside reclamation area, the landscape diversity increased. 3) The traditional landscape succession over nearly four decades went from natural coastal wetlands to inland halophytes/reed swamps to aquaculture ponds/cultivated lands and then to built-up areas. Due to advanced reclamation and fast desalination technologies, the successional process was simplified and the time was shortened. 4) The evolution of regional landscape pattern is significantly influenced by different reclamation intensity and way. Strengthening the protection of the reverse succession from aquaculture ponds to inland halophytes on the west bank of the Daliao River and the wetland area on both sides of the Shuangtaizi Estuary is of great significance for the improvement of regional ecological environment.