Effect of Oil Spill on Ecology of Forcado River in Delta State, Nigeria.

The aim of the study as to assess the ecological risks of oil spill effect on Forcado River in Delta State, Nigeria;four objectives guided the study; identify the oil spillage locations between 2010 to 2020, analyse the effect of oil spill on the abiotic ecological factors ,analyse the impact of oil spillage on the identified ecological factors,evaluate the fire incidence caused by oil spill to the environment using the Normalized Burn Ratio(NBR) from 2010 to 2020, to carry out this research, Geographic information system (GIS) and remote sensing (RS) tools were used to assess the effect of ecological risk of oil spill on Forcado River in Delta State, Nigeria. The Landsat satellite imagery of 2010, 2015 and 2020 with 30 meters resolution and the Advanced Space borne Thermal Emission and Reflection Radiometer (ASTER) were used for the study. The geospatial Database of the oil spill record was collected from National Oil Spill Detection and Response Agency (NOSDRA). The oil spill geospatial database in excel sheet format was imported to ArcGIS 10.1 to map out the oil spill spot in the study area. The principal component analysis (PCA) was applied to the indices to assess the major ecological factor affected in the study area. The zonal statistical Analysis was used to estimate the impact of spillage on the ecological factor. The Normalized Burn Ratio was used to highlight the burned areas and estimate severity of fire. The study found that from 2010 to 2020, the health of the vegetation and wetland in the Forcado River area significantly deteriorated due to oil spills. A total of 294,996.42 hectares of the ecological environment were affected, with the wetland being the most impacted (185,150.07 ha), followed by water bodies (69,810.48 ha), farmland (2,255.4 ha), and forests (light forest: 490.41 ha, thick forest: 12,205.62 ha). Sand dunes (4,923.99 ha) and shallow water areas (18,060.84 ha) were also contaminated. Therefore, it is very important to evaluate the regional ecological environment from the combined effects of multiple ecological factors Ecological Index (EI). The EI index should be recommended for assessment of Ecological factor impacting in oil spill because is completely based on the index of remote sensing information and natural factors.