No abstract

Assessment of the source and geometry of contaminated soils by hydrocarbon spills is the first step towards designing an effective remediation programme. Electrical Resistivity Tomorgraphy and Ground Penetrating Radar are shown in this review to easily delineate spills under certain conditions. On a 2D-geoelctric profile of the subsurface, recent hydrocarbons spills are reflected as highly resistive anomalous zones, as biodegradation occurs spills become more conductive and may be masked by conductive soil. On a radargram fresh hydrocarbon spills are observed in zones of saturation where resistive fresh hydrocarbon spills displaces conductive water in pore spaces creating anomalous zones. Accurate interpretation of geoelectric profiles and radargrams in the Niger Delta requires knowledge of the lithology of the site of contamination which could easily be obtained by shallow drilling or pitting. Mini-review Article

The change detection analysis has been investigated between 1990, 2015 and 2020 using Remote Sensing and Geographical Information Systems in Yenagoa, Bayelsa State of Nigeria. With the aid of ArcGIS and Erdas Imagine software to classify the environment, using the supervise classification method in categories of water bodies, built-up areas, bare land, and vegetation, it was revealed that the area covered by water bodies was 11% of the total area in 1990, decreased to 9% in 2015, and further reduced to 4% in 2020. The built-up area was 4 % of the total area of Yenagoa in 1990. It increased to 17% in 2015 and further increased to 23 % in 2020. Bare land covered 20% of Yenagoa in 1990. This area increased to 27 % in 2015 and further increased to 35 % in 2020. Yenagoa vegetation covered about 65 percent of the area in 1990. This was reduced to 47% in 2015 and was further reduced to 35% in 2020. Yenagoa water bodies and vegetation are being depleted in an unsustainable manner that will lead to environmental challenges in the near future if proper planning mechanisms are not put in place.