Does a smart city these days necessarily have to be a climate-resilient city?
Jens Hasse: I think that’s essential. “Smart” isn’t just about digital technology; it means being clever and doing things intelligently – in this case, thinking ahead about climatic change and extreme weather events that could affect the city in the future. But even the technical and digital aspects of the smart city often touch on climate resilience.
In what way?
Hasse: Digital solutions aren’t just useful for improving streetlights or the energy supply. If we have this technology and infrastructure in place, we can also use it for other services such as climate change mitigation. For example, if you already have a sensor used for managing parking space, you can add to its functionality or at least use the same cables for measuring local weather and climate data. Precise local data coupled to accurate forecasts can be very important in responding to extreme weather events.
To avert flooding disasters, for example.
Hasse: Precisely. We’ve now learned that just channeling rainwater away is not a good solution. We saw this in the Ahr Valley in 2021 but we’ve also seen it in towns and cities like Goslar in 2017 – the runoff water builds up higher and higher and faster and faster until it’s impossible to capture or divert it anymore. So we need smart systems everywhere in the catchment areas of rivers and streams but also in residential areas on higher ground to quickly and intelligently recognize what water can be channeled in which direction and where it can be stored. Reservoirs and retention basins can then be emptied in a controlled way, for example, so that they can collect more water in such scenarios. Smart roofs can also play a role here.
What’s smart about these roofs?
Hasse: The “blue-green” roofs – green roofs that can also hold rainwater – are fitted with a sensor system and connected to the network for the whole neighborhood. They can be managed automatically or even actively according to the current weather situation and forecast. That means they can store excess rainwater and protect buildings and whole districts from the impacts of very heavy rainfall events. And they can also protect from heat and drought by providing water for cooling and for irrigating plants and trees. What’s more, all this is largely automated, so it doesn’t need people to plan and manage it anymore. All these solutions exist already, for example in agriculture or in smart gardening. But, of course, it involves a degree of investment on the part of building owners and municipalities or their drainage services, which partly explains the hesitancy about such technological solutions.