The Niger Delta's vulnerability to river floods due to sea level rise

Abstract

An evaluation of vulnerability to sea level rise is undertaken for the Niger Delta based on 17 physical, social and human influence indicators of exposure, susceptibility and resilience. The assessment used geographic information systems (GIS) techniques to evaluate and analyse the indicators and the index of coastal vulnerability to floods, if sea level rise conditions are occurring. Each indicator value is based on data extracted from various sources, including remote sensing, measured historical data series and a literature search. Further on, indicators are ranked on a scale from 1 to 5 representing "very low" to "very high" vulnerability, based on their values. These ranks are used to determine a similar rank for the defined coastal vulnerability index (CVSLRI). Results indicate that 42.6% of the Niger Delta is highly vulnerable to sea level rise, such areas being characterised by low slopes, low topography, high mean wave heights, and unconfined aquifers. Moreover, the analysis of social and human influences on the environment indicate high vulnerability to sea level rise due to its ranking for type of aquifer, aquifer hydraulic conductivity, population growth, sediment supply and groundwater consumption. Such results may help decision makers during planning to take proper adaptive measures for reducing the Niger Delta's vulnerability, as well as increasing the resilience to potential future floods.