Diminishing Coastal Vegetation in Parts of Rivers State: An Emphasis on Mangrove Depletion

Abstract

Mangrove vegetation in the Niger Delta has been rapidly declining due to anthropogenic activities. Estimating the extent of mangrove depletion has become a major theme amongst environmentalist in this region. The study was designed to show the extent of mangrove depletion in Eagle Island in Port Harcourt Rivers state, Nigeria between 1993 and 2013. To achieve this, geospatial tools and techniques were deployed and utilized during the analysis. Landsat TM images for 1993, 2003, and 2013 were used for this study. The images were analyzed to classify the land use in the area; examination of land use and land cover changes between 1993 and 2013 ultimately showed that there were significant changes due to the depletion of mangrove cover within this coastal environment. A supervised classification method was adopted to classify the Landsat imageries into six (6) classes or categories using ArcGIS ArcMap 10.2 and Erdas Imagine 9.1 GIS software. The investigation shows that especially mangroves have been impacted profusely as a result of human activities. Between 1993 and 2003 there was a 14% decrease in mangroves, a 34% decrease in mangroves between 2003 and 2013, and a 47% cumulative decrease between 1993 and 2013. This investigation rightly points out that there is a significant loss of mangrove forests hence an urgent need for a balance between human development, land use planning, and conservation of biodiversity elements as the area faces several environmental challenges fueled partly by the pressures caused by human activities such as housing development, road construction, economic development and demographic changes. Therefore, recommendations such as mass sensitization and awareness on the demerits of unstructured development, encouraging community participation, and instituting an integrated coastal zone management program were highlighted to mainstream sustainable use of coastal biodiversity resources.

Keywords: GIS, Mangroves, Depletion, Land-use

DOI: 10.7176/JEES/13-10-02

Publication date: December 31^st 2023