Landuse and Landcover Mapping to Assess Forest Ecosystem Change in Ihiala Lga, Southeastern Nigeria

The result of landuse and landcover (LULC) change detection indices is very useful for natural resource monitoring and landuse management. Hence, this study aimed at assessing the forest ecosystem variation of Ihiala Local Government Area (LGA), southeastern Nigeria using remote sensing technique. The major source of the data were the LANDSAT-TM (1987), LANDSAT-7ETM (2003), LANDSAT OLI-TIRS (2015) and LANDSAT-8 (2022) satellite imageries that were acquired online from the website of U.S. Geological Survey. The research methodology was purely remote sensing analysis of the satellite imageries of 1987, 2003, 2015 and 2022. The classification resulted in six land use and land cover classes of built-up areas, forest cover, grassland/farmland, bare surface, Lake and other water body, while the ENVI version 5.0 and ArcGIS version 10.5 software were applied in digital image processing and thematic map production. The Maximum Likelihood as a widely used supervised classification method was employed, to detect the land cover types within the zone, ground truthing and error matrix analysis were done to validate the image classification results, the user accuracy and kappa index assessment falls within acceptable limit of 85%.The LULC image classification proved that there is a change in LULC classes with continuous reduction in forestland by 16,358.90 hectares in 1987 to 8,742.96 hectares in 2022 and a continuous increase in built-up area by 3,011.71 hectares in 1987 to15, 780.53 hectares in 2022. The study concludes that forest ecosystem in Ihiala LGA, like other tropical forests, has significantly declined in the availability of natural resources as a result of Landuse and landcover modification and weak policies. It therefore recommends that pertinent agencies in-charge of urban development should ensure control in developmental activities around the existing land areas to prevent unsustainable meddling into conserved areas. This control action will as well contribute to improving carbon storage potentials of the zone.