Côte d'Ivoire's online flood-risk platform sets out the cost of inaction
Country: Côte d'Ivoire Source: UN Office for Disaster Risk Reduction A national flood-risk profile puts a price on every year of delay — and shows that USD 380 million of defences pays for itself within nine year 160,000 people affected by floods each year under current conditions USD 168m in annual losses across buildings, roads and agriculture USD 620m annual losses under the pessimistic climate pathway, over 3× today 9 years to break even on Scenario 3 defences, costing USD 380 million USD 1.44bn savings over 30 years from Scenario 5, extended nationwide Lack of data often hampers efforts to persuade key decision-makers that preventing disasters is cheaper than fixing the havoc they wreak. It can be hard to justify investing limited budget resources in prevention when the benefits of doing so, and, more importantly, the costs of not doing so, remain unquantified. In line with its wide-ranging efforts to help governments across the world invest before disasters strike, UNDRR worked with the Government of Côte d'Ivoire to develop a national flood-risk profile that quantifies risk, compares protection options and demonstrates the economic returns of prevention. This profile is accessible via an interactive online platform. Floods regularly cause fatalities, destroy homes and roads, and exacerbate food insecurity in Côte d'Ivoire. A long rainy season running from April through July generates seasonal flooding across southern and central regions, compounded by unplanned urban expansion into flood-prone areas. Under current conditions, floods affect close to 160,000 people in these regions and cause an estimated USD 168 million in losses across urban buildings, roads and agriculture. Agriculture is particularly exposed. The sector employs 53.5 per cent of the Ivorian workforce and drives 16.5 per cent of GDP, with key export crops vulnerable to flood damage. If greenhouse gas emissions continue rising without new mitigation efforts (the “pessimistic” climate pathway), annual losses to the sector caused by floods are projected to more than triple, from the current USD 50 million to USD 180 million. Despite the scale of these risks, decisions about where to invest in flood protection were, until recently, made without a systematic national evidence base. As a result, it was difficult to quantify the benefits of preventive investment and thus to build a convincing case for the ministries whose support was needed. The lack of precise data on risk zones complicates planning because it forces us to respond reactively, sometimes without anticipating critical points. Lieutenant-Colonel Nimba Stéphane Bony, Head of Operations at Abidjan's Military Firefighters Group (GSPM), a key component of the country’s flood-response architecture. “This leads to greater consumption of resources and higher exposure for our teams,” he added. Thanks to the new platform, planners and policymakers in Côte d'Ivoire now have the evidence they need to make the case for investment before the next flood strikes. While this work builds on 17 disaster risk profiles previously developed by UNDRR, the Ivorian iteration is the first to feature an interactive online version that allows users to explore a wide range of data and cost-benefit analyses of flood defence infrastructure and land-use planning. Côte d’Ivoire is also one of four pilot countries where UNDRR is developing risk and resilience metrics. The platform draws on a combination of regional and local data to assess flood hazard and risk at district level across the country. It covers impacts across four sectors (people, urban buildings, roads and agriculture) and models how those impacts change under different climate pathways and five levels of flood defence investment. Critically, it goes beyond diagnosis to analyse the financial returns of investing in these protection “scenarios”, giving decision-makers a basis for comparing the costs of action against the costs of inaction. People Urban buildings Roads Agriculture From now on, advocacy will be built on quantitative data, on evidence explained Dr Amour Achy, a research associate at the National Institute of Public Health. “We will be able to visualize the areas at risk, the populations at risk. This will allow decision-makers to better evaluate the returns on investment,” he added. The following three data visualizations illustrate the utility and versatility of the platform. This map shows the average annual number of people affected by floods in each of Côte d'Ivoire’s 14 districts under the current climate pathway and today’s level of flood protection. Platform users can use filters to generate maps that quantify the impact of other climate pathways and of increased levels of flood protection. As well as numbers of people affected, these projectable impacts include the average annual losses (AAL) to various sectors, including built-up areas, roads, and specific agricultural crops. For first responders such as Lt. Col Bony, the ability to accurately anticipate priority areas of intervention makes “the difference between being caught up in an incident and preventing it. Today, a significant proportion of our crisis management efforts is devoted to assessing the situation in real time: knowing where the victims are, which roads are blocked, and which neighbourhoods are flooded.” He added that the platform’s maps allow his teams “to convert some of this time spent on assessment into time for action: resources pre-positioned, evacuation routes already surveyed, and the most vulnerable populations already identified and made aware of the situation in advance.” These charts compare the average annual losses caused by floods to buildings, agriculture and roads under current, optimistic and pessimistic climate pathways, and under different levels of flood protection, namely Standard, Scenario 3 and Scenario 5. These can be defined as follows: Current:Reflects today's climate and rainfall patterns, based on historical data, with no future emissions trajectory applied. Optimistic:Assumes global greenhouse gas emissions peak soon and decline significantly under strong mitigation policies. Pessimistic:Foresees greenhouse gas emissions continuing to rise without new mitigation efforts Standard:Current level of flood defences, used as a baseline. Scenario 3:Defences are reinforced in the regions responsible for approximately 50 per cent of national losses, protecting against floods of a scale that are expected to recur, on average, every 50 years. Scenario 5:Defences are extended nationwide to cover up to 75 per cent of national losses, protecting against floods of a scale that are expected to recur, on average, every 100 years. Under the current climate pathway, losses with standard protection in place run to around USD 170 million per year. Investing in Scenario 5 defences reduces that figure to around USD 100 million. The picture becomes more urgent when climate projections are factored in: under the pessimistic pathway, losses with standard protection rise to over USD 620 million annually, more than three times the current level. The platform's cost-benefit analysis puts the investment case in precise terms. Scenario 3 costs USD 380 million, generates annual savings of 9 to 19 per cent of total economic losses, and breaks even within nine years. Over 30 years, Scenario 3 could save up to USD 670 million, while Scenario 5 — extended nationwide at a cost of USD 1,070 million — could save as much as USD 1,440 million over the same period, with investments in either scenario fully recovered within 9 to 11 years. Roads are the arteries of development and of the economy that flood protection helps keep moving. This chart shows the average length of road network flooded annually across four of Côte d'Ivoire's districts (chosen at random to demonstrate the versatility of the platform), under three protection scenarios. Under standard flood defences, Bas-Sassandra emerges as the most severely affected, with more than 18 kilometres of roads flooded each year on average, a figure that reflects both the district's river network and its rapid economic development in flood-prone areas. Abidjan, despite its denser population, sees 9.3 kilometres affected annually under the same conditions. The value of targeted investment becomes clear when the scenarios are compared. Moving from standard protection to Scenario 3 reduces road flooding significantly across all four districts, with Bas-Sassandra seeing the sharpest absolute reduction. Roads matter beyond the obvious disruption to daily life: flooded routes delay emergency response, sever supply chains for agricultural exports and cut off the most vulnerable communities at precisely the moment they need access most. The platform quantifies road losses at USD 36 million per year under current climate conditions, rising to USD 133 million under the pessimistic pathway. Across all districts combined, floods affect around 90 kilometres of road per year under current conditions. This figure could rise to 300-350 kilometres under projected climate pathways in the absence of additional investment in flood defences. For Lt-Col Bony, the platform has already moved from theory to practice. His unit has begun cross-referencing its data with the GSPM's own historical intervention records and with rainfall mapping from Côte d'Ivoire's state-owned meteorological agency, La Société d’Exploitation et de Développement Aéroportuaire, Aéronautique et Météorologique (SODEXAM), using the combined picture to map priority areas, pre-position equipment and strengthen awareness campaigns in the most vulnerable neighbourhoods. His message to his counterparts elsewhere in the region is direct: “By having access to reliable data, the emergency services can shift from a reactive to a proactive approach, which profoundly improves operational efficiency and the protection of the public.” Dr Achy said that for stakeholders in other West African countries it was “essential to invest in this project because today it is an indispensable tool for advocacy and resource mobilization.” Côte d'Ivoire's flood-risk profile was developed with financial support from the Government of Italy and implemented by UNDRR, under the overall coordination of the Ivorian government and under the auspices of the national DRR platform and technical partner the CIMA Foundation. This achievement marks a step in the right direction for Côte d'Ivoire, having been identified as a key deliverable of the country's 2020–2030 national DRR strategy. Several Sahel and West African countries were invited to the risk profile's validation workshop, to learn from Côte d'Ivoire's experience in developing and applying the tool. How many people are affected by floods in Côte d'Ivoire each year? Under current conditions, floods affect close to 160,000 people in southern and central Côte d'Ivoire and cause an estimated USD 168 million in losses across urban buildings, roads and agriculture. Does investing in flood defences in Côte d'Ivoire pay off? Yes. Scenario 3 costs USD 380 million, generates annual savings of 9 to 19 per cent of total economic losses and breaks even within nine years. Over 30 years it could save up to USD 670 million; Scenario 5, extended nationwide at USD 1,070 million, could save as much as USD 1,440 million, with either investment fully recovered within 9 to 11 years. What is Côte d'Ivoire's flood-risk platform? It is the interactive online version of the national flood-risk profile developed by UNDRR with the Government of Côte d'Ivoire. It assesses flood hazard and risk at district level across four sectors — people, urban buildings, roads and agriculture — under different climate pathways and five levels of flood defence investment. How will climate change alter flood losses in Côte d'Ivoire? Under the pessimistic pathway, annual losses with standard protection rise to over USD 620 million, more than three times the current level, and annual agricultural losses are projected to more than triple from USD 50 million to USD 180 million. How much of the road network floods each year? Around 90 kilometres of road per year under current conditions, potentially rising to 300–350 kilometres under projected climate pathways without additional flood defences. Road losses are quantified at USD 36 million per year today, rising to USD 133 million under the pessimistic pathway. Who funded and developed the flood-risk profile? It was developed with financial support from the Government of Italy and implemented by UNDRR, under the overall coordination of the Ivorian government, under the auspices of the national DRR platform and with technical partner the CIMA Foundation.
ReliefWeb•UN Office for Disaster Risk Reduction10h ago
