Geospatial analysis of land use changes and wetland dynamics in Kaduna Metropolis, Kaduna, Nigeria

Abstract

Wetlands are among the world's most valuable ecosystems, and changes in  land use have an impact on their distribution, health, quality, functions,  and provision of services. This study assessed how land use change and  socioeconomic activities drove wetland conversion in Kaduna Metropolis  from 1986--2023. Landsat images (189/053) and SRTM DEMs were obtained  from the USGS. The index-based classification was used to identify and map  the wetlands in the study area and was also used for land use/land  cover analysis classification via eCognition 9.0. A land change modeler on  Idrisi Terrset was used to carry out land use/land cover change detection  and transition analysis. The analysis of the results revealed an overall  accuracy of 92% (0.93 Kappa) for the 1986 classification and 90% (0.88  Kappa) for the 2023 classification. The LULC analysis revealed that built-up areas and vegetation increased by 194.9 km² and 60.9 km², respectively,  whereas bare land decreased by 136.5 km² . With respect to wetland  dynamics, marshlands lost a total of 15 km² , riparian vegetation lost 28.6  km², and water bodies declined by 2.6 km² . The study concluded that  settlement expansion and agricultural activities are the primary drivers of  wetland changes in Kaduna metropolis. The study therefore recommends  the creation of buffer zones around the wetlands to prevent further    encroachment.