Floods are the most prevalent natural disaster and cause the most deaths worldwide (Doocy et al., 2016; Jonkman, 2015). Floods occur when a large amount of water flows over previously dry ground (Djimesah, Okine & Mireku, 2018). Floods are said to be responsible for about half of all deaths caused by natural disasters (EM-DAT, 2017). Floods are also the most common natural disaster, affecting over 2.8 billion people worldwide and killing over 200 000 individuals in the last three decades (Hashizume, 2016). Floods were responsible for 47 percent of all weather-related disasters worldwide between 1995 and 2015, affecting 2.3 billion people (UNISDR 2015). Floods are naturally induced by rising temperatures, which result in heavy rains, glacier melt, and ocean thermal expansion, leading in a rise in sea levels and inundation of coastal territories (Halgamuge &
Nirmalathas, 2017). Globally, climate change is a major contributor to these situations (Etuonovbe, 2017). Human actions like building dwellings in flood-prone locations (urbanization) and deforestation frequently increase floods (Byrant, 2017). Climate change poses a challenge to emerging countries’ ability to escape poverty, particularly in Africa (Lemos & Tompkins, 2018). Increased disasters, regardless of magnitude, will jeopardize development achievements (ISDR, 2018).
Climate change is also predicted to increase catastrophe risk in the future decade by producing more frequent and intense hazard events and making vulnerable areas more vulnerable to current hazards (ISDR, 2018). The Sustainable Development Goals, one of which is to mitigate climate change and its effects through strengthening resilience and minimizing climate-related hazards and natural disasters, are increasingly receiving more
attention (UN, 2017). Floods in Nigeria are similar to those in Mali, Senegal, Burkina Faso, and Niger (OCHA 2016), however the responses may differ. Floods have caused massive property, infrastructure, and business losses, as well as heightened disease risk. The Ogunpa flood in Ibadan in 2011, for example, killed a large number of people. Around 25% of Ibadan households lost their jobs as a result of the economic downturn (WHO, 2018).
Floods in the states around the Niger and Benue rivers in 2012 and 2017, Lagos in 2011, 2012, and 2017, and the Niger Delta regions in 2012 were similar to those in Ogunpa. Different cultures have tried a variety of solutions, but an integrated and holistic strategy to development, with flood management as a top priority, has proven to be the most successful. The sole long-term strategy to FRM has been identified as sub-system (Jha et al., 2018). This growth strategy will necessitate extensive coordination and integration among Nigeria’s numerous government entities. Inter-agency coordination and integration, as well as FRM, will allow the interrelationships that exist between urbanization processes and systems to be systematically studied and exploited in a complementary way. Water channels developed for flood control, for example, can be engineered to provide water ways to improve movement in areas like Lagos.
In Nigeria, the emphasis has been on structural measures, with an over-reliance on imported skills and technologies. The tendency to grant contracts for the construction of more structural flood defenses, canals, embankments, culverts, and bridges without considering less expensive and more sustainable non-structural options is visible in the nation’s budgets. Unfortunately, these constructions are typically handled by foreign contractors and experts who have poor awareness of the local circumstances, resulting in inadequate knowledge transfer to indigenous professionals (Ugochukwu & Onyekwena, 2014). Other socio-technical issues arise as a result of such systems, which are often clones of solutions taken in other countries and various socio-ecological situations without enough adaptation for the local situation. Soft components such as lobbying, education, stakeholder participation, and consultation are often missing from such projects, making it difficult to foster a sense of project co-production and ownership. For example, a few years after their commissioning, some flood canals and drainages have degenerated into garbage dumps (Nkwunonwo, Whitworth & Baily, 2015) Experience has demonstrated that these high-cost concrete buildings and civil works rarely provide effective or long-term flood protection. This comes on the heels of catastrophic flooding in the United Kingdom, as well as reports of multi-million dollar flood defenses failing in several areas. Non-structural methods, institutional preparedness, and the coping capacity of flood-affected UK communities are becoming increasingly crucial in flood defense. Nigerian stakeholders are gradually realizing the importance of non-structural FRM initiatives (Ajayi et al., 2016).
Alaku Emeka and Peter Daniel (Ph.D.)