Changes of land use and landscape pattern along sea–land gradient in developed coastal region: A case study of Jiangsu Province, China

• Impact of sea–land gradients on changes in land use and landscape patterns are quantified. • The highest land use dynamic degree are observed within 0–5 km of the sea. • The landscape becoming aggregated in 0–10 km while fragmented in 10–60 km gradient zone. Sea–land gradient zonality is one of the most fundamental geographic features that may have critical impact on changes in land use and landscape pattern. However, specialized sea–land gradient distance analysis remains insufficient. Here, we selected a 60 km stretch along the coastline of Jiangsu Province, China, establishing 12 equidistant (i.e., 5 km) gradient zones, so as to analyze the characteristics of changes in land use and landscape patterns along sea–land gradient. Our results showed that significant differences in the distribution and area changes of land use types across the gradient zones. Cropland increased only within the 0–5 km gradient zone, while decreasing in all other zones, generally showing a greater decrease farther from the sea. The dominant feature of land use transformation in Jiangsu’s coastal area over the past 30 years has been the conversion of cropland to built-up land. Interestingly, the area of land use transfer in the 0–30 km gradient zone shows a decreasing trend, while the area of land use transfer in the 30–60 km gradient zone shows an increasing trend. Overall, proximity to the sea correlates with higher land use dynamics, especially within the 0–5 km gradient zone. Additionally, sea–land gradient significantly affects landscape patterns, leading to increased fragmentation across most gradient zones from 1990 to 2020. This study findings will furnish critical decision-making support for advancing ecological preservation and sustainable land utilization strategies specific to the Jiangsu coastal region, while also serving as a valuable reference for effectively managing analogous coastal areas globally.