How Construction technology can mitigate the effect of flood and natural disaster.

A trip around the vast canvas of the earth, to places such as; Maldives, the caves of Ogbunike, the ancient walls of Kano and many more will reveal that nature is beautiful. But in all this beauty, nature has been ravaged by negative influences and occurrences called natural disasters such as floods, landslides, earthquakes and others.

While our forefathers might not have had the technology or analysis to prevent calamity, many countries today have comprehensive plans and legislation for the definite and sometimes unforeseen challenges we face in 2022.

In the past four decades, economic losses due to natural hazards such as flood disasters have increased in folds and have also resulted in major loss of human lives and livelihoods, the destruction of economic and social infrastructure, as well as environmental damages during this period. Recurring floods and other disasters have been identified as a serious threat to sustainable development.

This article takes on a deeper meaning in the wake of the heavy floods that have wreaked havoc on both low-income communities ad urban cities, claimed the lives of people, destroyed infrastructure, submerged hectares of farmland and will cause untold hardship in the country for months to come.

The Nigerian engineering and construction industries should step up to help with the rebuilding efforts and provide their knowledge to decision-makers on how to lessen the impact of future disasters.

This can be done by both big, well-known corporations in the industry and new businesses that are often anchored in local communities and have a wealth of practical knowledge and expertise regarding ways to secure greater levels of sustainability.

Informal settlements in risky locations

In high-risk regions that are susceptible to landslides, flooding, and other natural disasters, an increasing number of informal settlements are emerging. Furthermore, these towns lack access to fundamental services including solid waste management, well-maintained roadways, and water drainage.

According to recent research by the nonprofit organisation Habitat for Humanity, floods and droughts together are responsible for 70% of the economic losses and 80% of the fatalities associated with catastrophes in sub-Saharan Africa. Such disaster recovery is expensive and time-consuming. At least half of all post-disaster recovery costs are spent on temporary accommodation, home repairs, and replacement of household items.

Creating a worst-case scenario plan

It makes sense that we begin making preparations for the worst-case scenarios as we brace ourselves for the upcoming onslaught of catastrophic weather. Constructors and public sector authorities throughout the world are searching for innovative ways to make houses more resilient to natural calamities.

This calls for a “whole-of-society” strategy. To better direct future housing construction and bring communities closer to economic prospects, the various domains of government will need to strengthen their planning procedures. Communities should be made more aware of the risks involved with constructing on cliff faces or inside low-lying flood basins.

There must also be a renewed focus on the performance of local government in the delivery of services such as sanitation, waste removal and road construction – all factors which aggravated the impact of the floods.

Working towards resilience

However, this is also a chance for the engineering and building industries to develop technology solutions that can help create more resilient structures. The truth is that most of the materials utilised to construct homes in low-income areas are subpar and unfit to endure frequent flooding. Income levels affect access to high-quality building materials, and low-income groups that reside in flood-prone locations tend to utilise inferior materials to build their homes.

Recent developments in building technology and materials provide these communities with cost-effective solutions. The industry is increasingly searching for solutions that use low-cost technologies and few technical skills all over the world. The focus is on utilising the resources and abilities already available in communities to develop resilient building materials.

Flood risk mapping

Construction companies and the government must define the area at risk and this should be the basis for all flood damage reduction programmes and subsequent actions.

The purpose of a flood risk map is to:

  1. Increase public awareness of the areas at risk of flooding 
  2. Provide information on areas at risk by defining flood risk zones to give input to spatial planning. 
  3. Support the processes of prioritizing, justifying and targeting investments to manage and reduce the risk to people, property and the environment.

Spatial planning and land management can provide various tools to prevent natural hazards (Kötter, 2003). In the context of flood disasters, spatial planning and land management can be used to support the following essential functions:

  • Early warning system: Spatial planning needs a detailed database, to get sound information about spatial development. In practice monitoring systems have to be extended systematically to inform about natural and environmental risks (UNDP, 1997; Uitto, 1998; Samarajiva et al., 2005). Efficient data acquisition needs special measurement methods that have to be investigated and implemented.
  • Risk assessment and mapping: Prevention of flood disasters needs comprehensive information and data about the reasons and effects of the hazards. Therefore a comprehensive vulnerability analysis needs to be undertaken for disaster-prone areas, incorporating information about past disaster events, the socio-economic conditions of the population living in the affected area, and inventories of major structures liable to damage. Risk assessment and flood hazard mapping would then be used to delineate areas vulnerable to natural hazards and determine the frequency, intensity, impact, return period and other data concerning each category of hazard. 
  • Prevention and reduction: Spatial planning has to analyse the interrelations between spatial influences and the environmental disasters to reduce the impacts.
  • Risk Management: During and after flood disasters, certain infrastructure (evacuation routes and spaces) and the database is needed to realise the emergency plan and risk management.
  • Reconstruction: When damages occur, there is a need to plan the reconstruction of infrastructures. Spatial planning using GIS can assist the reconstruction efforts and also the future prevention of disasters.

Sustainable urban planning and green infrastructure could also be combined with information and communication technology tools. Citizens can use these to communicate with the relevant authorities at the onset of flooding. Addressing Nigeria’s perennial flooding is important for the country to make progress. The human-induced causes of flooding should be addressed urgently. Not doing this will delay its journey to sustainable development.