The residents of Lagos, one of Africa’s biggest cities, are faced with increasingly severe annual flooding of their city, which is threatened by sea level rise and sinking at a rate of up to ~87 mm per year.
Lagos floods
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Undermining futures
The ability of this sinking city to cope with flooding is significantly hampered by poorly maintained waterways and drainage systems. The city is rapidly expanding as the population grows and people flock from rural areas towards urban centres in hopes of better economic opportunities.
Moreover, the city faces another deadly threat in the form of a hidden industry, sand mining. Sand mined at the country’s shorelines to supply a construction boom in the area leads to eroding coastlines and the destruction of coastal ecosystems, which are critical components in protecting the inhabitants from storms and rising seas. In the past decade alone, 59 per cent of the wetlands in Lagos have been lost, a predicament directly linked to the worsening flood problem in the city, which displaces thousands of people, making it clear that the short-term economic gain of sand mining under lax regulation puts at risk the future of many communities in Lagos.
As grand building projects spring up for those that can afford them, the vulnerable people in the city are continually pushed to the margins and into harm’s way by development and disasters. Sand mining exposes them further by undermining coastal protection and damaging ecosystems that they rely on for coastal protection and livelihoods (e.g. fisheries).
The hidden industry of sand mining will become an even bigger threat to Lagos residents in the future. By 2050, climate change increasing precipitation rates and the risks of subsequent flooding will be twice as high as today and sea level rise will result in half of the city at risk of being underwater by 2100 and many people in vulnerable areas at risk of permanent displacement.
As grand building projects spring up for those that can afford them, the vulnerable people in the city are continually pushed to the margins and into harm’s way by development and disasters.
Wider picture
Global demand for sand and gravel to satisfy the booming appetite for construction materials is driving unsustainable and often illegal practices that are degrading ecosystems and increasing vulnerability to various hazards. Despite being one of the most sought-after and traded commodities on the planet, second only to water, it is still flying largely under the radar of government policy and public awareness, and addressing the problem is key for sustainability and reducing future risk, particularly in places such as Lagos.Root Causes
Unequal distribution of economic opportunities and limited livelihood options
Pressures related to increasing consumptive demands for goods, such as food, energy and industrial materials
A lack of perception, awareness or preparation in governance relating to risk management and response
Pursuit of economic or developmental interests with a lack of consideration for impacts on the environment
Gases released into the atmosphere by human activities contribute to increasing global warming and climate change
Cases where maximizing profit is prioritized over other social concerns, increasing risk
Drivers
Planned and controlled criminal activities that perpetuate a hazard or vulnerability.
Landscape change via increasing growth and expansion of cities and neighbourhoods.
Absence or ineffective enforcement of regulations connected to other risk drivers
An absent or poorly communicated warning of a hazard’s impending arrival.
Human activities altering the natural function or flow of freshwater bodies including rivers, lakes, wetlands and groundwater reservoirs.
Any product or substance in a concentration harmful for human or environmental health
Increasing temperatures in the ocean or atmosphere, for example from climate change
Infrastructure vulnerable to extreme events, often due to lack of investment, maintenance, inadequate planning or poor construction.
Impacts
Water security can be impacted by tipped systems and disasters when sufficient availability or access to water for health and livelihoods is disrupted. Water sources can also get contaminated and make vectors for other risks
Tipping point impacts and disasters can force people to move from their homes due to the loss of shelter, livelihoods or the risk of further incidents occurring. People may be temporarily displaced or urged to migrate to other areas
Public and private structures and systems can be affected by disasters and risk tipping points impacts, from homes and properties to physical assets critical for providing health services, transport, food, water, communications and more
Even those surviving disasters or tipping point impacts when they occur can be at risk of short- and long-term health impacts cascading from pollution, damage of critical infrastructure, livelihood disruption or other consequences of systems being affected
Just like people, nature also feels the impacts of systems tipping and various hazards resulting in threats to health and physical damage to individuals, populations, communities or entire ecosystems
Solutions
Floating architecture: Designing floating structures in lowelevation coastal areas is an innovative approach for adapting to sea level rise and flooding. While prototypes from houses to neighbourhoods and even small cities are being developed, the research, regulations and policy needed for further development needs to keep pace with innovation.
Participatory waste management: Engaging communities in waste management planning is a costeffective strategy to prevent flash floods related to drainage blockages. Integrating informal waste collectors or running training programs can turn local residents from part of the problem into part of the solution while also fostering material recycling and resource recovery, generating jobs and improving air quality.
Alternative construction materials: Replacing traditional building materials with alternative, sustainable materials such as recycled aggregates, wood and other biomaterials can reduce flood risk by preventing sand mining and greenhouse gas emissions related to concrete production. However, it requires major reforms in construction regulations and building standards, as well as some financial incentives, for the construction industry.
Ecosystem restoration: Vegetated coastal ecosystems help to enhance coastal protection by stabilizing shorelines, reducing erosion and diffusing wave energy. Conserving and restoring such ecosystems also supports biodiversity, local livelihoods and fisheries. Ecosystem restoration must be implemented on a large scale and with a long-term perspective to fully benefit from it.
Forecasting mobile applications: By providing real-time flood forecasting, educational messages and awareness-raising notifications to users, mobile applications can help residents to better prepare and respond to flood events. A key consideration is the coverage of technology and awareness in vulnerable communities or at-risk areas.
