Flood disasters devastate communities and cause long-lasting economic damage every year. In July 2021, extreme rainfall in Europe, the Chinese province of Henan, Maharashtra state in India and Nuristan, Afghanistan brought flooding that claimed thousands of lives and caused billions of dollars of damage.
In Australia, the NSW Government declared 16 natural disaster zones in March 2021 as major floods devastated communities in Western Sydney, the Hunter region and the Mid North Coast. Five people died in these floods and more than 18,000 were evacuated.
Major flooding is becoming more frequent due to climate change. As global temperatures rise, the amount of water vapour in the atmosphere increases, which leads to more rainfall.
Current disaster risk-reduction strategies rely on structural flood mitigation measures such as levees, reservoirs, diversion channels and spillways, and non-structural measures such as Flood Early Warning Systems (FEWS), land-use planning and zoning, rainwater harvesting, flood insurance schemes and awareness campaigns.
FEWS are an “integrated system of hazard monitoring, forecasting and prediction, disaster risk assessment, communication and preparedness activities systems and processes that enable individuals, communities, governments, businesses and others to take timely actions to reduce disaster risks in advance of hazardous events”. The system has been shown to reduce flood risk.
However, a survey of flood forecasting centres in 53 countries found that most “flood-prone countries lack critical resources to carry out their functions”, according to a senior researcher at the United Nations University, Hamid Mehmood.
Many countries lack the resources to produce data-intensive historical inundation maps that help to forecast flood risk accurately. “Existing inundation and flood-risk maps in most developing countries are out-of-date,” Mehmood writes. “They also don’t consider rapid urban development or the impacts of climate change.”
New tools to reduce flood risk
Tools developed by the United Nations University’s Institute for Water, Environment and Health, based in Canada, seek to address this shortfall, particularly in the global south, “where the data and information gaps are prominent and annual losses due to floods are high”.
The Flood Mapping Tool, launched in 2021, and Flood Risk Prediction tool, due for release in 2022, use publicly available data to improve inundation and flood-risk maps, flood-warning systems and forecasting models to reduce the impact of flood disasters.
“They will provide critical input to flood mitigation and emergency response, land-use planning and investment in resilient infrastructure, insurance schemes, and overall public awareness of flood risks,” writes Mehmood.
“Together, these tools will improve the coverage of national and regional flood early warning and risk-management systems. The system will also help build the capacity of flood forecasting centres in the global south to use artificial intelligence models, big data and cloud computing to analyse the impacts of climate change.”