Terrestrial environmental sensitivity index mapping (TESIM) of the coastal areas of the Niger Delta region of Nigeria

Abstract

It can be argued that despite years of research, the true impacts of oil spill pollution on the environment and human sources of livelihoods are yet to be completely understood. Tools such as environmental sensitivity index (ESI) mapping can provide useful information that can significantly mitigate or help eliminate the known impacts of crude oil pollution, by proactively identifying environmentally sensitive areas. This study adapted the analytical hierarchy process (AHP) and geographic information systems (GIS) based multiple criteria analysis (MCA) approach in the objective determination of sensitive sections of the NDR coastal areas, by combining several competing and or related evaluation criteria. The AHP was used to determine and assign relative weights to the data layers through a pairwise comparison evaluation matrix of mutually exclusive evaluation criteria using the Delphi technique, while the MCA was used to aggregate the evaluation criteria into a single map. The results of the MCA analysis show that over 57 % of the study area is sensitive to oil spill pollution in one form or the other. 68 % of the identified sensitive areas are classified as extremely environmentally sensitive with 11,752.14km2, while 7.1 % are classified as less sensitive. This relative classification of environmental sensitivity in the study area is termed the Niger Delta Relative Environmental Sensitivity Index (NDRESI). The implication of these results is that more has to be done if the very sensitive environment of the NDR is to be conserved by tougher environmental legislations, environmental monitoring and environmental education.