Quantifying spatiotemporal variations in tidal flats and coastal land use in Jiangsu Radial Sandbars through remote sensing

Abstract

The Jiangsu Radial Sandbars in China have experienced significant changes due to extensive human activities in past decades. This study provides new insights by coupling multitemporal remote sensing analysis with landscape pattern assessment to comprehensively evaluate tidal flat evolution and land use suitability from 1984 to 2020. The integrated remote sensing approach enabled continuous high-resolution mapping of tidal flats, revealing a 25.9% area loss equaling 123.2 km2, driven mostly by land reclamation, while also quantifying coastline accretion patterns through shoreline position analysis. The coastal landscape analysis systematically assessed land use changes and human impacts through metrics such as diversity and fragmentation, which revealed intensified seaward expansion and increased fragmentation of unused land and underdeveloped nearshore sea areas. The suitability evaluation considered land resources, ecological factors and socioeconomics to assess four key land use types. The method of coupling with landscape analysis provided integrated insights, including 1) identifying ecologically sensitive zones for prioritized conservation based on landscape patterns; 2) quantifying the intensity and spatial pattern of human activities and their impacts; and 3) comprehensively evaluating land use suitability by integrating landscape analysis with other factors. Future research should explore management strategies, assess the impact of climate change, and make predictions to inform policy-making.