Geospatial Assessment of Vegetation Degradation of Otammiri River Basin, South East, Nigeria

Abstract

Vegetation assessment is a prerequisite to achieving optimum utilization of the available land resources. Lack of knowledge on the best way to preserve our natural vegetation and economic importance of vegetation has contributed to the degradation of our natural resource (vegetation). This study aims at assessing the level of degradation and changes in vegetation extent and quality of the Otammiri river basin, delineate the basin area and determine the changes in vegetation using geospatial technology. The study was carried out in Otammiri RiverBasin in South Eastern part of Nigeria. Shuttle Rader Topographic Mission (SRTM) data of 2007 with resolution of 30m and multidate landsat images of 1986, 2001 and 2014 of 30m resolution was obtained from United State Geological Survey (USGS). The basin area was digitized from the SRTM data which enables the delineation of the basin area, converted into a shape file and overlaid on the satellite image to subset the study area. Supervised classification using maximum likelihood was then performed to extract landuse classes in the study area which comprises of vegetation, bareland, waterbody, builtup, wetland and cultivated lands. The results obtained showed that vegetation degradation has occurred extensively for the period of twenty eight years of this study . This was attributed to the high demand of land for settlement as a result of demographic increase, over grazing, slashing and extensive agriculture. Based on the findings, it is recommended that awareness should be taken to the grass root to educate the local farmers and the inhabitants of the study area on the implication of vegetation degradation as well as proving to the researchers the capability of geospatial technology in assessing and monitoring our natural environment.