With the effects of climate change growing more serious, Iran will have other devastating floods in the future.
Recent floods have devastated parts of Western Europe, yet there were no casualties in the Netherlands.
Zamaneh asked Dutch experts about their success in dealing with the recent floods in Europe and what Iranians could learn from the Dutch experience.
Long-term planning for flood control, proper management of water resources, and relying on adequate flood warning systems are key to reducing casualties and financial losses.
Bas Jonkman is a professor of Hydraulic Engineering at Delft University in the Netherlands. He focuses on research and education in the fields of hydraulic structures and flood risk.
In an interview with Zamaneh, Professor Jonkman explained why there were fewer fatalities in the Netherlands than elsewhere:
“Rainfall was much more extreme in Germany [and Belgium] than in the Netherlands. Also, the geographies are different. In Germany and Belgium, there are steeper catchments [and valleys], so there was more sudden and extreme ‘flash flooding,’ followed by landslides in some areas. Warning systems did not work everywhere.”
“In the Netherlands, we had out-of-bank flooding in local streams and rivers (e.g., Valkenburg), but the Meuse River stayed within its banks. The inhabited areas around the Meuse are protected by dikes, which just held. Some mass evacuations were ordered,” Professor Jonkman said.
Only a few days after the Iranian New Year (Nowruz), heavy rainfall caused flash floods across Iran, affecting 25 out of 31 provinces and leaving at least 76 dead and 200 wounded. About a third of the country’s infrastructure was damaged during the floods. The main question is, what is the chief cause of this unprecedented flood? Poor water resources management, climate change, or both?
What caused the delayed flood of 2019 in Iran?
Record rainfall in the spring of 2019 led to unprecedented flooding across several Middle Eastern countries, including Iran. The heavy rains were unparalleled in the past four decades and were in stark contrast to the previous dry year.
It isn’t easy to determine the cause of a particular phenomenon or event without a long-term analysis of the situation when it comes to climate change. However, scientists can “speculate” that the sharp transition from dry to wet may “potentially” result from climate change.
Research conducted by Amin Dezfuli, a senior scientist at NASA’s Goddard Space Flight Center, examined Iran’s 2019 floods and their causes.
According to this study published in the Bulletin of the American Meteorological Society in 2020, the flood of 2019 in Iran was an example of rapid dry-to-wet transitions and intensification of extremes, potentially resulting from climate change.
In his research, Dezfuli attributes the recent devastating flood in Iran to the “atmospheric river” phenomenon, writing that a powerful atmospheric river (AR) originating from the North Atlantic Ocean substantially affected Iran.
“The nearly 9,000-km-long AR propagated across North Africa and the Middle East and was fed by additional moisture from several other sources on its pathway,” Dezfuli explained in his article.
Dezfuli named this atmospheric river Dena (after the peak of the Zagros Mountains) and believes that Dena has played an important role in the unprecedented 2019 rainfall.
ARs are responsible for some of the hydroclimatic extremes worldwide, but Dena was rare in terms of intensity and effects.
Rainfall in some areas along this atmospheric river was recorded up to 400 mm.
According to the study, moisture transport by AR Dena was equivalent to more than 150 times the aggregated flow of the four major rivers in the region: the Tigris, Euphrates, Karun, and Karkheh.
The Iranian flood was not unpredictable. NASA’s Meteorological Forecasting Model can predict atmospheric river phenomena between five and seven days before they occur.
Lessons from the Dutch
During the recent floods in Western Europe, the results in Germany and Belgium were different than those of their neighbor, the Netherlands.
Apart from geographical differences, the Netherlands has a long history of water management and flood control.
The Netherlands is built on water and is vulnerable to flooding from not only the sea, but also from its rivers.
The Dutch use dams, dikes, and canals masterfully to protect the country from the water. The Dutch battle with the sea is a fight that is nearly a thousand years old.
In the recent floods in the Netherlands, no city was completely submerged, and not a single person was killed.
City officials were better prepared and communicated with the public promptly, minimizing damage and casualties by diverting floodwaters and evacuating citizens on time.
We asked Professor Jonkman how Iran can learn from the Dutch experience in flood control.
“The Netherlands invests a lot of money in flood protection, €1 billion per year, and has specific organizations [water boards] for this. This continuous approach, which combines finance, organization, technical measures, and know-how, is important,” Professor Jonkmansaid.
“Also, we follow a risk-based approach to balance investments. For example, investments in flood-risk reduction are balanced with the potential damages and risks in the area, so that there is a good cost-benefit ratio,” he added.
The delta of Europe’s three major rivers (Rhine, Meuse, and Scheldt) is located in the Netherlands. Most of the country is lower than the sea level. The Dutch government says 60% of the country is always at risk of flooding.
Rijkswaterstaat is a 200-year-old organization that manages roads and waterworks on behalf of the Dutch Ministry of Infrastructure and Waterworks.
A spokesman for Rijkswaterstaat told Zamaneh that the Netherlands has spent a long time planning to contain the floods and reach the flood control stage.
“We had a scary situation in 1993 and 1995, and it took us 20 years to complete the works. The time depends on the organization of the government in the areas that need to be adapted to extreme weather conditions. Central control is often better for the larger waterways, regional control for the minor rivers or brooks. But you will need to have strong cooperation and proper planning” he said.
According to the spokesman, the design and implementation of these projects, especially on a large scale, should be done with local governments and the central government based on regional needs.
“Iran’s challenge with extreme weather is that it needs to find ways to retain the rainwater higher up for as long as possible and have flood routes clear of obstacles and urban development on the way down. Vegetation planting programs and bigger dams can help retain water and prevent mudslides. Proper drainage size in bridges prevents damage to infrastructure. Wide flood plains give room for the water,” a spokesman for Rijkswaterstaat said.
The spokesman told Zamaneh that governments must pay for extreme weather either way:
“Either you pay for the colossal damage and the loss of economic activity, or you pay for the waterworks program. The second one is preferable because this will provide jobs and a stimulus to the economy, and you can do it on your own terms and schedule.”
The great flood of 2019 may have been the strongest in recent years, but it will not be the last. Iran will continue to have other devastating floods due to climate change. Long-term planning for flood control and an effective flood warning system is currently the only way to reduce casualties and financial losses.
Iran suffered another deadly flood last week. Floods left eight dead throughout 15 provinces: West Azerbaijan, East Azerbaijan, Alborz, Isfahan, Bushehr, Chaharmahal and Bakhtiari, Kohkiluyeh, and Boyer-Ahmad, Kerman, Fars, Sistan and Baluchestan, Semnan, Mazandaran, Hormozgan, Yazd, and Kurdistan.
The humanitarian organization Red Crescent Movement estimates that 2,578 people were affected by the floods and that 611 people were displaced from their homes.