The residents of northern France are facing a nightmare scenario as two rivers, the Aa and the Liane, have burst their banks and flooded dozens of towns and villages.
The Pas-de-Calais department has been on red alert for flooding and rain since Monday, and more than 1,500 firefighters have been deployed to rescue people and protect properties.
The interior minister, Gerald Darmanin, has promised to declare a state of natural disaster for the affected areas.
The cause of the disaster is a week of torrential rain that has dumped up to 100 mm of water on some parts of the region, almost seven times the normal amount for November.
The rain has been accompanied by thunderstorms and strong winds, creating a perfect storm for flooding.
Red alert for two rivers after heavy rain
LIONEL BONAVENTURE/AFP via Getty Images
Northern France is facing a serious flooding crisis as two rivers, the Aa and the Liane, have reached record levels after heavy rain.
The Pas-de-Calais department has been placed on red alert for flooding and rain, and dozens of schools have been closed.
More than 1,500 firefighters have been mobilized to help the affected residents, and seven people have been injured.
The flooding has impacted around 60 municipalities, causing significant damage to homes, roads, and infrastructure.
Some areas are only accessible by boat, and some residents have been evacuated due to fears of dyke breaches.
It was described as "exceptional" by the weather service Météo-France, which said that some parts of the Pas-de-Calais region received 80 to 100 mm of rainfall, nearly seven times the normal amount for November.
The link between climate change and extreme weather events
The floods in northern France are not an isolated incident, but part of a global trend of more frequent and intense extreme weather events due to climate change.
According to the Intergovernmental Panel on Climate Change (IPCC), human-induced greenhouse gas emissions have increased the likelihood and severity of heavy precipitation and flooding in many regions of the world.
Climate change also affected the water cycle, which determines how much water is stored in the atmosphere, the land, and the oceans.
Warmer temperatures increase the evaporation of water from the surface, creating more moisture in the air.
This can lead to more rainfall when the air cools and condenses, especially in areas where the atmospheric circulation is favorable for storm formation.
Moreover, climate change can alter the patterns of the jet stream, a band of fast-moving winds that influences the weather in the mid-latitudes.
A weaker and wavier jet stream can cause weather systems to stall or move slowly, resulting in prolonged or repeated rainfall over the same region.
This is what happened in northern France, where a low-pressure system remained stationary for several days, bringing continuous rain and floods.
The challenges and opportunities for flood prevention and mitigation
The floods in northern France have exposed the vulnerability of the region to the impacts of climate change and the need for effective flood prevention and mitigation measures.
These measures can be classified into three categories: structural, non-structural, and nature-based.
Structural measures refer to physical interventions that aim to reduce the exposure or susceptibility of people and assets to flood hazards.
These measures can provide a high level of protection, but they can also be costly, disruptive, and environmentally damaging.
They can also create a false sense of security, leading to more development in flood-prone areas and increasing the potential losses in case of failure.
Non-structural measures refer to policies, regulations, and practices that aim to reduce the exposure or vulnerability of people and assets to flood hazards.
These measures can be more flexible, adaptive, and cost-effective than structural measures, but they can also face political, social, and institutional barriers.
They require the participation and cooperation of multiple stakeholders, such as governments, communities, businesses, and individuals.
Nature-based measures refer to solutions that use natural or semi-natural ecosystems to provide flood protection and other benefits.
These measures can enhance the resilience and sustainability of the environment, while also providing co-benefits such as biodiversity, water quality, carbon sequestration, and recreation.
However, they can also have trade-offs, such as land acquisition, maintenance, and uncertainty.
The choice and combination of these measures depend on the local context, the availability of resources, and the preferences of the stakeholders.
There is no one-size-fits-all solution for flood prevention and mitigation, but rather a need for a holistic and integrated approach that considers the multiple dimensions and scales of the problem.
