Between 19 and 23 January 2020, Storm Gloria left its mark on Catalonia, breaking records as it did so. Now, a month later, CREAF’s Anabel Sánchez and Annelies Broekman, experts on water and climate change, reflect on how the territory ought to be managed in the face of increasingly frequent flooding and drought.

“Scientists have known for some time that extreme climate events, such as drought and floods, are going to become more frequent and severe in the Mediterranean region”, muses Anabel Sánchez, one of CREAF’s experts in water management, while looking at images from the European Space Agency’s Sentinel satellite showing the effects of Storm Gloria on the Ebro and Tordera deltas. “Now we have to prepare the territory to cope with them”, she says.

“The rivers are bringing sediment as well as water; the sediment discharge is as significant as the flow of liquid”

In the images, much of the Ebro Delta, including a sizeable portion of the Barra del Trabucador isthmus, is under water, and the huge amount of sediment deposited in the sea by the river can be seen. The same phenomenon is also visible in the images of the Tordera, where it has led to a small island of sand forming in front of the delta. “The rivers are bringing sediment as well as water; the sediment discharge is as significant as the flow of liquid”, explains Annelies Broekman, another of CREAF’s water management experts. “The island in the Tordera is the result of that and of the relief of the seabed causing sediment to accumulate there.”

“Every year, storms cause flooding that affects the facilities along the riverbanks and the seafront, such as campsites, promenades and industrial sites”, Broekman continues. “We should adapt our use of this land to the situation in question. We need to look at flood dynamics and make decisions on that basis.”

The experts advocate adaptative land management. “You can’t apply a measure and then just forget about it”, says Sánchez. “You have to evaluate its success in dealing with risks or problems”, she explains. “If it isn’t working, you need to be able to change it or take a different approach.”

“At present, land is managed without considering the risks”, remarks Sánchez. “There are buildings on riverbanks, industrial estates in flood-prone areas, and railway infrastructure and the like next to the coast. They are protected by means of elements such as mounds and breakwaters, but engineering-based management measures of that kind are highly inflexible and offer little scope for modification and adaptation to reduce risks.”

Projects for the protection of the Tordera

Broekman and Sánchez coordinated the ISACC TorDelta project, which, supported by the Spanish Ministry for Ecological Transition’s Biodiversity Foundation, sought to identify strategies for adapting the Tordera Delta to the effects of climate change. They have consequently developed an approach to tackling such complex problems. “For nine months between 2017 and 2018, we analysed the territory from a socioeconomic and an environmental point of view, which resulted in us learning from the past”, says Broekman. “We generated new knowledge and formed a picture of the area based on the experience of local people and specialists”, she continues.

Since October 2019, Broekman and Sánchez have been coordinating REDAPTA, a project that builds on ISACC TorDelta by proposing specific adaptation measures and is also supported by the aforementioned Biodiversity Foundation. “We’re drawing on the results of ISACC TorDelta to codesign recommendations for political authorities, monitor measures through citizen participation, and establish a network for exchanging experience-based knowledge”, states Broekman. “REDAPTA looks to innovate in terms of the way decisions are made”, she adds.

Ultimately, both projects share the objective of making land less vulnerable to climate change, something they aim to achieve by integrating and harmonizing local socioeconomic and environmental interests. The projects have shown Broekman and Sánchez that a new approach to taking action is crucial. “Coordination between the authorities has to be vertical – municipal, regional and national – and horizontal – territory, urban planning, agriculture, water and so on – and local stakeholders absolutely must be included in decision-making”, says Sánchez. “It’s not easy, but it’s the only way.”

“The statistical probability of extreme climate events will be higher, with those previously liable to happen every 100 years now being likely to occur every 50 or 25 years”.

While storms like Gloria are nothing new, we can expect them to come along more often in the future. This is the essence of short and medium-term climate change. “The statistical probability of extreme climate events will be higher, with those previously liable to happen every 100 years now being likely to occur every 50 or 25 years”, warns Broekman. “Managing land with that in mind is what adapting to climate change is all about”, concludes Sánchez.