Abstract: The environmental benefits accruable to mankind through wetland ecosystems are unquantifiable. The wetland ecosystem services principally include the gradual recharge of groundwater and provision of habitat for fauna and flora. The increase in human population over the years has accelerated growth in anthropogenic activities, which, have led to the conversion of wetlands to other land uses. In the sequel, it has become imperative for researchers to focus on the mapping of wetlands through time-efficient, automated and low-cost methods to preserve the existing wetlands. In pursuance of this, geospatial technology was deployed in this study to assess the spatial characteristics of the wetland ecosystem in Abeokuta North Local Government Area (LGA). Landsat imagery and Shuttle Radar Topography Mission (SRTM) were the major data used. Object-based classification, Normalized Difference Vegetation Index (NDVI), Modified Normalized Difference Water Index (MNDWI), Elevation and Topographic Wetness Index (TWI) algorithms in ArcGIS 10.4 software were deployed in data generation and analysis. The Land use land cover (LULC) showed that the Forest area was 20338 ha (26%), 13440 ha (17%), and 10427 ha (13%) in the years 2001, 2011 and 2021 respectively. The results of the mapped wetland showed that in 2001, about 10803 ha of the study area was occupied by wetlands and water bodies. In 2011, it decreased to 10443 ha, with a difference of about 360 ha. It further decreased to 8598 ha in 2021. Government and private organizations should establish policies aimed at minimizing the growing dangers to wetland ecosystems, as a recommendation. This might be accomplished by preventing farmers and other land developers from encroaching into wetlands.
Key words: Geospatial techniques, MNDWI, NDVI, SRTM, TWI, Wetland