Research on the Evolution of Island Coastal Wetland Landscape Pattern

Abstract

The wetland landscape in Ximen Island National Special Marine Protection Area, Zhejiang Province, was adopted as the study object. Remote sensing images in 2006, 2012, and 2017 were interpreted, and landscape indexes, such as the number of patches (NP), largest patch index (LPI), cohesion (COHESION), division, patch density (PD), Shannon diversity index (SHDI), Shannon equilibrium index (SHEI), and landscape shape index (LSI), were used to monitor and analyze the evolution of the coastal wetland landscape pattern on Ximen Island. Results showed that during 2006–2017, the wetland aquiculture area around Ximen Island presented a gradual decrease from 785 hectares to 712 hectares. The wetland vegetation area increased from 292 hectares to 467 hectares, and the area added was transformed from wetland aquiculture and naked mudflat. Total NP and PD decreased from 1,444 to 1,298 and from 60.3 to 52.2, respectively. From the angle of LSI, SHDI and SHEI gradually increased from 1.2515 to 1.358 and from 0.7776 to 0.8432, respectively, indicating a uniform landscape distribution in the wetlands. The COHESION index increased from 97.9281 to 98.26, manifesting a concentrated landscape distribution in the wetlands. The LSI in the protection area declined from 20.6717 to 18.512, showing that the wetland landscape shapes were regular in the protection area.