Construction and Application of a Coastline Ecological Index: A Case Study of Fujian Province, China

Coastlines are at the forefront of interactions between the ocean and land, and have important ecological significance. Remote sensing technology, with its advantages in obtaining large-scale and multiscale data, has become an important aid in constructing comprehensive ecological environment indicators. Based on the Landsat TM/ETM+/OLI/TIRS data sources and remote sensing technology, a comprehensive index to evaluate the ecological health of the coastline, the coastline ecological index (CEI), was proposed, and the mainland coastline ecology of Fujian Province from 1992 to 2022 was evaluated. Case studies show that the ecological health of Fujian Province's coastline, as measured by CEI values, decreased from 98.1 in 1992 to 16.6 in 2007 and then gradually increased to 37.6 in 2022, demonstrating a trend of initial decline followed by a rise. During the study period, the total length of Fujian Province's coastline decreased from 3373.1 km in 1992 to 2985.5 km in 2012 and then increased to 3123.4 km in 2022, accompanied by the transformation of a large number of natural coastlines into artificial coastlines. The study found that before 2007, China carried out unreasonable development of its coastline for economic development, which caused natural coastline damage and a decline in the CEI value. Since 2012, China has combined environmental protection with economic development. Policy adjustments have reduced coastline damage and increased restoration efforts, and the CEI value has risen. The CEI constructed in this study has good adaptability for application in Fujian Province, and changes in CEI values can better reflect changes in the ecological degree of the coastline in Fujian Province. Following a case study and detailed discussion, we believe that CEI has universal applicability for the comprehensive evaluation of coastline ecology.