Saltwater damage in the Vietnamese Mekong Delta: A case study of agricultural livelihoods in Hung My commune, Tra Vinh province

Tra Vinh Province, located in the Mekong Delta, is severely affected by saltwater intrusion. This study assesses the spatiotemporal dynamics of salinity and land use/land cover (LULC) across four districts: Chau Thanh, Cau Ngang, Duyen Hai, and Duyen Hai town from 1995 to 2020. Using Landsat imagery and the Random Forest algorithm on Google Earth Engine, LULC was classified into four classes with high accuracy (OA > 92%, Kappa > 0.88). The results show a 27.5% decline in vegetated areas (loss of 8,708 ha), while water bodies and impervious surfaces expanded by 25,221 ha and 9,913 ha, respectively. Soil salinity, indicated by Electrical Conductivity (EC), intensified significantly as the mean EC nearly doubled from 2.06 dS/m to 3.91 dS/m. Notably, very high salinity zones (EC > 16 dS/m) expanded over fifteenfold, from 151 ha to 2,338 ha. These findings demonstrate a strong correlation between vegetation degradation and salinity expansion, especially during the extreme years of 2010, 2015, and 2020. This research provides a robust geospatial framework for sustainable land management and climate adaptation in coastal landscapes.