Flood disasters in major cities: – We have to think differently

Buildings collapsing from water bodies. Subway tunnels and metro systems that swim over them. Cars float like boats on streets that have turned into rivers.

In recent years, many such photos have been seen from cities around the world.

This summer, it was again observed that floods caused severe damage in many countries in Europe.

Flood disaster in the western part of Germany, Belgium, Holland and Luxembourg, It killed about 200 people and led to massive disasters As more people were lost, homes collapsed and electricity was cut off.

In an area near Liege in Belgium, 271 millimeters of rain was measured in 48 hours, more than double what typically falls during July, according to CNN.

– It could happen in Norway

London was also affected, on Sunday, by a heavy rainstorm that caused major floods in both the streets and underground in the subway, This creates huge problems in public transportation.

Two hospitals also had to dismiss patients whose injuries were not severe, because the hospitals were damaged by the massive amounts of water, he writes. CNN.

– I’ve never seen anything like that

According to Trine Jahr Hegdahl, a hydrologist at the Norwegian Directorate of Water Resources and Energy (NVE), flooding is something we can also expect more of in this country.

Yes, we imagine this could also happen in Norway in the future in conjunction with more intense precipitation and higher temperatures. This in turn can lead to greater destruction, because we are building more than ever before, we have more values ​​and more people, Hegdahl tells Dagbladet.

Norway can be hit

urban flood

According to CNN, many climate and infrastructure experts have warned for many years that London, like many other major cities, is not prepared for climate change that we will see more of in the future. This is because cities have outdated infrastructure and outdated drainage systems that cannot withstand torrential amounts of rain.

In Norway, on the other hand, solutions are found in urban planning to ensure that floods cause as little damage as possible in the future.

We are now working to secure Norway’s cities for the future. There are many cities in the country that can be particularly affected by urban flooding. Hegdal says that the municipalities of many large cities in Norway are now actively working to find solutions.

She also says they are now looking at important solutions, such as opening waterways, and creating alternative green roofs where water can take the way.

– Want to see more of this

– There are many researchers in the country who are also actively working to try to find out how big the consequences could be, and to what extent, says the hydrologist.

– Don’t hold up today

One of these researchers is Tun Merit Muthana. She is a professor in the Department of Civil and Environmental Engineering at NTNU, and her research areas include urban surface water management and urban flooding.

She explains that although Norway has come a long way in research in this area, there are still many things left to prevent a major devastation.

– We can’t turn this around

In Norway, we have a three-step strategy for dealing with surface waters, where small incidents are compromised and medium-sized incidents are compromised and delayed, and larger incidents must be dealt with in flood safe ways. Especially the last step, Al Muthanna tells Dagbladet, it is safe flood roads that are challenging and we have worked a lot on how to secure these flood roads.

She further explains that this is complicated in cities and urban areas where development takes place step by step over many decades. In addition, it is also a challenge in cities where the downtown area is the lowest point, and rises in height around it. Examples of such cities are Oslo and Bergen.

As is well known, the water flows down, and then ends up in an old infrastructure that was not built for the volumes and intensity of precipitation today. We must solve this by thinking long-term when building infrastructure, creating rooftop flood-safe roads using streets, roads and green infrastructure such as parks and public areas, says the professor.

However, she points out, this is also complicated, due to climate change.

What we made 50 years ago is no longer relevant today, she says.

forces of nature

Cecily Sachs-Olsen, a researcher at the Institute of City and Regional Research (NIBR) in Oslo Mitt, agrees that new thinking is necessary to secure cities in the future. She believes that we will have to look at the nature-based solutions that we can create.

Olsen believes that one can look to landscape architecture for the best solutions.

– It looks like a ghost town

In the past, the routine was to build firm and stable structures and dams to prevent rivers from flooding. Now it has been found that it is best to make porous solutions, raceways, so that they can survive over time and water can find its own way. Figuratively speaking, this means that we should act to improvise with the forces, not against them, says the researcher to Dagbladet.

She explains that attempts have been made in the past to repair, control or stabilize nature through a few methods that are not necessarily appropriate in all contexts. But nature is dynamic and uncontrollable.

– We have to think differently. We must learn from nature and find ways in which we can emulate this. This in turn relates to how one thinks of urban planning, which is not just about humans (man is the center of nature. Editor’s Journey), but that we also think about—and with—nature and other wildlife. If we think this way, there may also be new solutions, she says.

new solutions

There has been some criticism after the floods in Germany this summer that they were not well prepared, says hydrologist Trine Gahr-Hegdahl, that the drainage network was outdated and not perfect.

There are extreme forces and many lost values, so one must consider all possibilities to minimize the extent of damage caused by such incidents, says Heegdahl.

However, she points out that many cities in Europe are in the process of inventing new solutions for the future.

She cites the example of a flood that hit Copenhagen in 2011.

– stuck in trees

Measured approx. 150 mm of rain in two hours in the capital of Denmark, and the damage after the rain was enormous. After the city witnessed this and many similar events, the city created one plan On how to deal with heavy rain.

Tun Merit Muthana explains that the Danes have worked a lot on how to secure the city and build more resilient infrastructure since 2011.

– But in Denmark everything is flat, so we cannot use exactly the same solutions in Norway, as we have in Denmark. The speed and depth of the water affect the extent of the damage and the danger. It is difficult to secure infrastructures in Norway, because we have many slopes and heights. Al Muthanna points out that it is important to have a good multidisciplinary approach that includes both construction technology, water infrastructure and transportation.