Joseph Igharo ← All work

Case study · Research · GIS

Flood risk mapping of Lagos Island

Role
Lead author and GIS analyst
Tools
ArcGIS Pro, AHP
Status
Paper under review
Flood risk map of Lagos Island Local Government Area showing low, medium and high flood risk, with high risk along the water’s edge and a large patch in the centre of the island
Flood risk across Lagos Island LGA. High risk covers 35.1% of the area, medium 42.5% and low 18.1%.

Flooding is a yearly problem on Lagos Island. For my study, I mapped flood risk across the Local Government Area in ArcGIS Pro, using AHP to weight the factors that drive flooding. About a third of the area came out as high risk, mostly along the water’s edge, with a large patch in the centre of the island.

Checking it on the ground

To test the map, I went out during the rainy season and checked 20 random points. 17 matched what the map predicted, 2 were a partial match, and only 1 didn’t flood where the map said it would.

Where it’s going

The map is part of my paper on flood risk vulnerability in Lagos Island, which is currently under review.