Ecological Degradation and Geospatial Assessment of Wetlands in the Ziway-Shalla Basin, Ethiopian Rift Valley (2004-2024)

This study characterizes the spatiotemporal dynamics and identifies the primary drivers of wetland degradation in the Ziway-Shalla Basin of the Ethiopian Rift Valley from 2004 to 2024. Using multitemporal Landsat and Sentinel-2 imagery integrated with geographic information systems and ancillary data, we performed land use/land cover classification, wetland delineation, and change detection analysis. The results indicate a significant decline in natural land covers: wetlands contracted by 34.75%, grasslands by 82.33%, and forests by 32.05%. Conversely, bare land and settlements increased dramatically by 177.94% and 157.88%, respectively. Spectral index analysis (normalized difference vegetation index, normalized difference water index, and modified normalized difference water index) confirmed declining vegetation health and water presence in wetland buffers. The degradation is driven predominantly by the expansion of irrigated agriculture, urbanization, and resource mismanagement, compounded by climatic variability. The findings underscore an urgent need for integrated, site-specific management policies that balance ecological conservation with socioeconomic development to ensure the sustainability of these vital ecosystems.