Geospatial analysis of wetland dynamics in the lower bilate river basin, Southern Ethiopia (1991–2022)

Abstract

Wetlands are among the most productive ecosystems on Earth, playing a crucial role in sustaining both human and non-human biotas. Despite their ecological importance, wetlands and associated ecosystems face significant threats of depletion and degradation. This study aims to evaluate the changes in the wetland over time and across different transects Chokare Anisa watershed, focusing on land use and land cover changes and the factors driving these dynamics. The study utilized remotely sensed image data from Landsat 5 (1991–2001), Landsat 7 ETM + (2011), and Landsat 8 (2022) to generate Land Use and Land Cover (LULC) maps and detect linked variations. Additionally, 315 household heads were surveyed using systematic sampling techniques, and focus group discussions (FGDs) were conducted at various watershed locations with eight members per group. Data analysis incorporated descriptive statistics (frequency, tables, and graphs) along with remote sensing image interpretation. The investigation exposed that 44.79% of the marshland area and 50% of the natural vegetation in the study area were lost over the last 31 years. The most significant reduction occurred between 2001 and 2011. Key drivers of these changes include population growth, expansion of cultivated land, improvements in agricultural technologies, and settlement expansion. The findings highlight the urgent need for effective wetland and natural vegetation management. The study recommends that governmental organizations and NGOs develop strategies for the conservation and monitoring of the Chokare wetland to mitigate ongoing degradation and promote sustainable management practices.