Abstract

With substantial variations to flood occurrence predicted as a result of climate change it becomes significant to investigate how global hydrological models process climate-forcing data. The paper presents reasonable analyses of projected hydrological effects of climate change on the Niger Delta region, Nigeria. Runoff simulated represent the present and future flood risk for the catchment of the River Niger using Global Hydrological Models (GHMs) from EU WATCH project driven by three GCMs. The simulated discharges are compared with the monthly gauge measurement along the River Niger from the Global Runoff Data Centre (GRDC). A period of (1970-2050) was chosen to understand the climatic variability across the Niger Delta region. The GHMs under Special Report on Emissions Scenarios A2 scenario were used to provide future climate scenarios over the Niger River. The hydrological models from EU WATCH project were used to calculate flood extents for different model outputs. The simulation shows clears trends of increased in river discharge over the catchment although uncertainty cannot be over role. Considering the future climate suggests that river flow from the basin could be substantially increased, especially in the long term when compare to the reference period. It is not applicable to formulate precise recommendations for management of runoff in the Niger Delta region as Todd highlighted that the degree of uncertainty in future projections of river flow is consider as a constrained towards developing applicable adaptation activities. The rationale behind this work is the need to understand in clear terms the climate change threats on the Niger Delta region; this will form a practical basis for developing adaptation strategies to manage future climate risks.

Keywords: Climatic variability; Hydrology; Runoff; Rainfall; Quantification; Venerability; Adaptation; Flooding; Uncertainty; Climate change