Analyzing Wetland Dynamics Using Geospatial Techniques: A Case of Abay Choman and Jimma Geneti Watershed, Horo Guduru Wollega Zone, Western Ethiopia

Abstract

Wetland ecosystems are one of the most important areas that provides different ecosystems services as well as habitat for plant and animal species. In spite of multipurpose, wetland ecosystems are under threats. This study attempts to analyze wetland dynamics of Abay Choman and Jimma Geneti watershed in Horo Guduru Wollega Zone, Western Ethiopia using geospatial techniques. The land use land cover (LULC), the Normalized Difference Vegetation Index (NDVI), and Normalized Difference Water Index (NDWI) were investigated using Landsat 5 TM of 1991, Landsat 7ETM+ of 2003, and OLI/TIRS of 2021. In the present study, the LULC was classified using a supervised classification method with maximum likelihood algorithm. The red and infrared bands of Landsat imagery from three different time periods were used to calculate NDVI, while the NDWI was estimated using the green and near infrared (NIR) bands of multispectral Landsat images. Results show that wetland ecosystem in the study area decreased by about 125.2 km2 (8.8%) with the rate of 4.2 km2/year. In contrast, agricultural land increased by 223.4 km2 with the rate of 7.4 km2/year between 1991 and 2021. About 66.7 km2 wetland was converted to cultivated land whereas 29.3 and 24.7 km2 of grassland and shrubs land were converted into cultivated land. As a result, the maximum NDVI and NDWI values were decreased between 1991 and 2021. To minimize the rapid loss of wetland and water bodies in the study area, proper land use planning and environmental education should be promoted.

Coastal wetlands of Indus River Delta are under risk due to reclamation: A spatiotemporal analysis during the past 50 years from 1972 to 2022

“…From 2002 to 2012, there was a net gain of wetlands from barren land, suggesting successful restoration efforts. Wetlands restoration is a critical strategy for conserving and restoring wetland ecosystems globally(Moisa et al, 2023). Our results are consistent with many other wetlands studies in the world.…”

“…From 1972 to 1986, wetlands were lost primarily to settlement and gained to cultivated land. With estimates indicating that more than 40% of the world's wetlands have been converted to agricultural land, the conversion of wetlands to agriculture and settlement poses a serious threat to wetlands conservation globally(Moisa et al, 2023). From 2002 to 2012, there was a net gain of wetlands from barren land, suggesting successful restoration efforts.…”