Assessment of Impact of Land-Use Activities at the Watershed of Njaba River Imo State Using GIS and Remote Sensing Technology

Background and Objective: The Njaba River watershed in Imo State, South-East Nigeria, has experienced significant environmental degradation due to various land-use activities. This study aims to evaluate the impact of these activities on the watershed using GIS and remote sensing technology. The objective is to classify land-use and land-cover types to understand the extent of human-induced changes and to recommend sustainable land-use practices. Materials and Methods: Satellite imagery from the Landsat 11 mission was utilized for this study. The analysis was conducted using ArcGIS 10.8 software. The classification process involved creating training areas and signature files and classifying the imagery into five categories: Vegetation, agriculture, waterbodies, urban lands and open/gully lands. Data were collected through reconnaissance surveys and image classification to quantify the land-use changes over time. Results: The study revealed significant degradation of the Njaba River watershed due to human activities such as deforestation, unregulated sand mining and waste disposal. Vegetation covers 62% of the watershed, while urban land comprises 28%, agriculture 1%, waterbodies 5% and open/gully land 4%. The reduction in vegetation and the increase in urban areas highlight the adverse impact of human activities on the watershed. Eutrophication, caused by waste dumping, has further degraded the river's quality. Conclusion: Effective watershed management strategies are urgently needed to mitigate the adverse effects of human activities, through legislation, education and sustainable practices. Transforming the watershed into a protected area can restore ecological balance and enhance tourist potential.