Multi-decadal shoreline change along the Kuwaiti coast using Google Earth Engine and the Digital Shoreline Analysis...

Monitoring shoreline change in environments characterized by extensive tidal flats and turbid waters presents significant methodological challenges. This study applies and evaluates a robust, cloud-based framework to overcome these limitations and accurately assess shoreline dynamics along the Kuwaiti coast from 1985 to 2023. The approach integrates the Modified Normalized Difference Water Index (MNDWI) with the Maximum Spectral Index Composite (MSIC) algorithm within Google Earth Engine to consistently delineate shorelines at their maximum water extent, thereby minimizing the influence of tidal flats and tidal fluctuations. Shoreline change was quantified using shoreline change indicators comprising the end point rate (EPR), linear regression rate (LRR), and net shoreline movement (NSM) within the Digital Shoreline Analysis System (DSAS). Results derived from 15,318 transects distributed along 531 km of coastline reveal pronounced spatial heterogeneity in shoreline behavior. The northern coast and Kuwait Bay experienced substantial erosion, with mean retreat rates reaching - 2.2 m/year, whereas the southern coast exhibited shoreline progradation, with mean accretion rates of approximately + 0.8 m/year. Net shoreline movement across the entire Kuwaiti coastline over the 38-year period indicates an overall mean retreat of - 19 m. These patterns reflect the combined influence of natural processes and widespread anthropogenic modification. The proposed methodology achieved high positional precision, with an estimated annual error of ± 7.9 m/year, demonstrating its suitability for analyzing complex, tide-influenced coastlines. Overall, the findings highlight the urgent need for adaptive coastal management strategies, including Integrated Coastal Zone Management (ICZM) and nature-based solutions. This study provides a comprehensive assessment of shoreline dynamics in Kuwait and presents a transferable framework for monitoring vulnerable, sediment-rich coastal environments worldwide.