Vulnerability of Nigerian Coast to Inundation Consequent on Sea Level Rise

Complex and interrelated processes drive coastal changes. Inundation, which is one of several possible responses to sea level rise, will be the primary response in many coastal regions. This is inclusive of the Nigerian coastal zone especially in the Niger Delta as there is minimal sediment transfer due to the Kainji Lake reservoir, which traps a significant portion of the sediment load of the Niger River. Hence, the Nigerian coast is dependent on its elevation in its fight against inundation. Much of the Nigerian coast is low-lying with a consequence that a 1 to 2 meters rise in sea level, which may result from climate change will have a cataclysmic effect on human activities in these regions. This study examines the consequences of continued sea level rise with a focus on the inundation of the Nigerian coast. The Nigerian coast was delineated. A Geographic Information System (GIS) was used to develop inundation models and examine the impact scenarios that SLR will have on critical elements, which include land, population, and economic activity (Gross Domestic Product - GDP), with the aid of the best available spatially disaggregated global data. Population and GDP scenario data projected for the year 2100 were obtained from AR2 and B2 scenarios of the Greenhouse Gas Initiative. These were overlaid with the study area, reprocessed, and analyzed. Results indicate that substantial loss to inundation is expected for all scenarios considered both for the years 2015 and 2100. The study examines the uncertainties of the elevation data model employed. This brings about the recommendation for the use of digital elevation models with high vertical accuracies for sea level rise vulnerability assessments