Eagle Island Wetland Mapping Using Satellite Imagery and Bathymery

Wetlands are ecosystems characterized by low drainage quality, slow moving water or sometimes standing water body that is filled with soil (Olalekan, Abimbola, Saheed,& Damilola, 2014). Wetlands are a vital part of our economic future and are among the earths most productive eco-system. The natural ability of wetlands cannot be overlooked in as much as land areas are needed because the wetland complements other physical environmental activities such as runoff draining, carbon sinks, ground water filtering, etc. needed for the sustenance and use of the land by man. Therefore, the mismanagement of wetlands could result in disasters and hinder sustainable development. Irrespective of these facts, the Eagle Island wetland may be threatened by urban development due to the resultant effect of lack of research and control to their conversion, irrespective of the sizes as well as unavailability of spatial and topographic information of Eagle Island. Wetland mapping is key to the enhancement and management of the wetlands and boosts environmental sustainability in the midst of pressures from urban development. The aim of this study is to produce maps of Eagle Island that depict the changes in the wetland areas, flow patterns and bathymetric charts. The study analyzes land cover /land use changes (LCLU) using SPOT 5 and SENTINEL 2A satellite imageries for two epochs, 2005 and 2016 respectively. The satellite images covering the study area were acquired and analyzed using ArcGIS10.3, and ENVI 5.0. Surfer 10 for contour and vector map generation and SDE 28s for processing bathymetric data acquired on the adjoining estuary. The total area analyzed was 224.87hectares. The maximum likelihood method of classification adopted produced four (4) feature classes; Built-up, Water body, Wetland, Sand dunes. The results were validated using the Kappa Index of Agreement (KIA) yielding values of 0.83 for 2005 and 0.98 for 2016. About 20.5 % of eagle island wetlands have been lost between 2005 to 2016. The study concluded that there is need for wise use of wetland resources within the study area and recommends the regular mapping of wetlands to avoid indiscriminate conversion of wetlands. Remote sensing methods for wetland mapping and impact assessment should be the basis for planning and decision making in all regions.