Coastal Megacities: The Case of Lagos

International Journal of Research and Innovation in Social Science (IJRISS) | Volume II, Issue IV, April 2018 | ISSN 2454-6186

Coastal Megacities: The Case of Lagos

IBEABUCHI Uwadiegwu, Egbu, A U and KALU Obialo A

Abstract: This paper studies the risk and vulnerable of Lagos as a megacity in Nigeria due to flooding as result of rainfall being one of the major environmental problem of the coastal areas. Statistical, GIS and remote sensing techniques was adopted to map urban growth and seasonal simulation of flood water level changes using HEC-RAS simulation model and their impact on physical environment. The rainfall distribution and seasonal variations were studied. The result reveals that Flood incidents are higher in summer (JJA) and autumn (SON) than in autumn (SON) and lesser in winter (DJF) in Lagos. Vulnerability index was computed by selecting multiple indicators which represents each of the three major components (exposure, sensitivity and adaptive capacity) and the role of rainfall induced climate change was highlighted and stressed using statistical analysis-Ordinary Least Squares (OLS) regression techniques (using ArcGIS software). Flood Risk Index and factors was determined for Lagos which includes uncontrolled expansion of the built-up area, the lack of infrastructure and the failure not only to expand storm water drainage but also to maintain existing drainage systems. In bid to mitigate and adapt to flood control and management in Lagos optimal performance would be insightful to consider policies institutionalization and structural decentralization of operations along the governance framework identified.

Keywords: Megacity, Lagos, Flood, Risk Index, Vulnerability Index, GIS, Remote sensing.

I. INTRODUCTION

In June 10, 1988, Lagos, Nigeria, was struck by rainfall and the widespread flood that occurred around LUTH, Ishaga was described as being very disastrous, due to the aftermath of the flood over 300,000 people were rendered homeless with properties worth billions of naira wasted (Yang et al., 2010). While rainfall in 1995 was one of importance as it provided an indication of what the future potentially holds for a changing climate in Lagos State? Storm surges accompanied by high tides inundated the beaches and virtually connected the Kuramo Lagoon to the Atlantic Ocean. Many of the streets and drainage channels were flooded, resulting in an abrupt disruption of socio‐economic activities in Victoria and Ikoyi Islands during the flooding period. Storms and floods are often associated with loss of life, property and infrastructure damage, loss of GDP and other socio-economic setbacks. These also pose a big challenge to disaster risk management (DRM) (MOE, 2012).

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