Dynamic analysis of spatial evolution of landscape pattern in the tidal flat wetlands at Liao River Estuary
WANG Yini, KANG Yaru, CHEN Xu, GUO Congcong, ZHANG Mingliang, DING Cunli
1.College of Ocean Science and Environment, Dalian Ocean University, Dalian 116023, China; 2.State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, China;3.Panjin Pink Beach Travel Ltd, Panjin 124216, China
Abstract: The remote sensing images of Landsat-5 TM and Landsat 8 OLI from 1986 to 2018 were used as the main data sources to analyze the dynamic change characteristics of the coastal wetlands(121°30′-122°00′E, 40°50′-41°20′N) in Liao River Estuary (LRE). The landscape pattern of long time series and then the impact factors influcing landscape pattern dynamic changes were investigated from type level and whole level based on eCognition and ArcGIS platform by coupling the object-oriented classification method. The results showed that the natural landscape area in 2018 was reduced to 41.58% of that in 1986, and most were transformed into artificial landscape including aquaculture ponds, ports, architectures and farmland. The length of the coastline, whose types transformed from natural shoreline to artificial shorelines such as aquaculture shoreline, urban shoreline, ports and wharves shoreline, was found to be increased and expanded to the southern sea area. In the level of landscape types, the dominant landscape position of the tidal flat in LRE was lost, with simple and regular shape, and the landscape pattern of the tidal flat wetlands was fragmented in LRE. The construction of LRE directly led to affect the area and the spatial distribution of each landscape, and to accelerate the process of the landscape succession from sea grass Suaedaheteroptera to reed. The artificial activities including breeding industry and hydraulic engineering construction had a great impact on the landscape pattern of the tidal flat in the LRE. The project of “returning breeding ponds to the tidal flat” should be strengthened to effectively improve the habitat of the coastal wetlands and realize the reverse succession of salt marsh vegetation in the LRE.