GIS Modeling of Flooding Exposure in Nigerian Coastal Areas from Sea Level Rise

Abstract

An SRTM elevation dataset and GIS grid analysis was used to analyze the number of local government areas that would be affected by severe flooding from sea level rise (SLR) of 1meter, 2meter, 3meter, 4meter, 5meter and an extreme 13meters. The GIS overlay of the Political boundaries of the Rivers State in the Niger Delta showed a minimum of 10 LGAs for a 1meter rise in SL and a maximum of 22 out of the 23 local government areas for 13 meter SLR. In all the scenarios developed only Omuma local government was not affected by model output. The relative proportion of land space to be displaced is highest in Degema local government area ranging from 392 sq km at 1meter SLR to 1154 sqkm at 13meter SLR. A number of strategic options including further scientific studies, legal and policy developments are presented as essential steps to actions that will facilitate varying layers of protection, adaptation and contingency planning in worse-case scenarios.

Key words: GIS Modeling, Flooding, Sea Level Rise