Ecological Risk Zones Assessment and Delineation in Bayelsa State Nigeria From Remotely Sensed Imageries

Ecological risks such as flooding and coastal processes such as accretion and shoreline changes in the vulnerable ecosystem of the Niger Delta mostly in Bayelsa Sate Nigeria as a result of natural processes as well as anthropogenic activities have been a serious concern. The aim of this study was to assess and delineates the ecological risk zones in the study from remotely sensed imageries. The specific objectives of this study includes: the identification/delineation of prevalent ecological risk zones, of the area, the determination of the landuse and landcover distribution , from multi-temporal remote sensing data, to carry environmental/socioeconomic characteristics analysis of the study and to suggest measures needed to tackle the risk problems of area. The study entails the identification of variables needed for ecological risk zones assessment and delineation including an analysis of the socioeconomic and environmental factors enhancing these ecological risks. Remotely sensed imageries used in the study includes classified LandSat 7 ETM+ images for 2008, 2013 with spectral band combination of 7,4,3 and LandSat 8 Image of 2018 with a band combination of 7,5,3 obtained from the United States Geological Survey(USGS) pre-processed using ERDAS imagine version 14.0 and ArcGIS 10.6 capabilities covering an area of 937441.4km 2 . The land covers distribution foundin the study area includes: vegetation, mangrove, built-up areas and water bodies while land uses includes: agricultural, transportation, residential and industrial uses. The flow chart of materials and methods was developed for the study. A ground validation (ground-truthing) was carried out to identify samples of some the zones risk zones in the area. The socio-economic and environmental evaluation survey was to ascertain certain information that could also aide drawing conclusions. Arising from the results of the study, it concludes that the study area lacks viableup-to-date spatially-enabling maps/data and therefore recommended space-based technologies spatiotemporarily needed to determine risk zones of the area for effective ecosystem monitoring and management.