Land use land cover change and its potential implications on conservation of Sitatunga antelope in Saiwa wetland, western Kenya

Abstract

Land use and land cover (LULC) changes are significant drivers of global environmental change, impacting ecosystem processes, biological cycles, and biodiversity. This study aimed to describe the LULC changes in Saiwa Wetland from 1993 to 2023 and discuss their potential impacts on the rare Sitatunga antelope. We utilized remote sensing and GIS technologies, downloading cloud-free Landsat images from the USGS website, including Landsat TM, ETM+, OLI, and Sentinel images. These images underwent supervised and unsupervised classification to identify spectral signatures of various LULC classes. Post-classification refinement and a multi-date post-classification comparison algorithm using QGIS were employed for change detection. The analysis identified five LULC classes: forested areas, reeds/papyrus, grass/shrub areas, bare areas, and water areas. Results indicated a decrease in forested areas from 37% in 1993 to 34% in 2023 and a reduction in grass/shrub areas from 19% to 16%. Conversely, reeds/papyrus increased from 24% to 26%, and bare areas increased from 6% to 8%. Water areas also saw an increase from 13% to 16%. These changes are attributed to human activities such as logging, mining, and agricultural encroachment, along with climatic changes. We envisage that the LULC changes could have effects on the habitats of Sitatunga antelope whose population has declined dramatically from 200 individuals in 2018 to 60 in 2021 in the Saiwa wetland ecosystem. Immediate conservation and restoration measures are essential to preserve the integrity of the Saiwa wetland ecosystem and its associated biodiversity.