During Germany’s terrible floods last year, a seismometer might have been more useful than river gauges. This showed researchers that earthquake sensors could be a vital tool during other kinds of disasters.
New research shows that earthquake sensors can spot floods coming at them quickly. The authors of a recently published paper say that this information is especially helpful for people who are making early warning systems for floods. These systems could give people important time to get to safety, which could save lives and prevent flood damage.
In July 2021, there was a terrible flood in Germany’s Ahr Valley that washed away homes and killed almost 200 people. When the researchers looked into that disaster, they found that a nearby seismometer station, which was meant to watch for earthquakes, picked up important information about the flood as it was happening.
In a news release from the American Geophysical Union, Dietze, the lead author of the new research and a postdoctoral researcher at the University of Gottingen, said in a news release that the data stream from that station had been available and analyzed as our research now shows, important real-time information on the size and speed of the flood would have been available.
“The network of water level stations we have now is not enough to be ready for future events.”
Even though it’s just one case study, the researchers think that other earthquake sensors, like the one studied in Ahr Valley, could also be used in the future to find flooding that is just as bad. That could be a big deal for other places that are prone to flooding because, as Dietze put it, “the current network of water level stations is not enough to be ready for future events.”
In July 2021, when it rained more than ever before, floodwaters were strong enough to knock buildings off their foundations. They also destroyed three hydrological stations used to measure water levels along the Ahr river. As the river continued to rise, the river gauges became useless quickly. As water levels rose in an exponential way, the new paper says, “the lack of information about any of these dynamics left decision makers basically in the dark.”
On the other hand, the seismometer could safely detect the movement of the flood from about 1.5 kilometres away. The sensor not only stayed alive, but it was also able to collect more information than the hydrological stations could have, even if they had stayed standing. Most river gauges can only measure how much water is in a river. The earthquake sensor, on the other hand, can read seismic signals to estimate water level, flood speed, and even what dangers the floodwaters are carrying, like cars or the rubble of destroyed homes.
According to the paper, the seismometer could have helped answer all of these questions during the flood.
Even though this study was focused on the flood in Germany in 2021, its results could be used to help people get early warnings of floods in the Ahr Valley and other places with similar terrain. Water level gauges are hard to find in many parts of the world. If they are there, they are easy for raging floodwaters to destroy. Plus, the data they collect is usually only about the water level, and there is usually a time gap between readings. Because of all of these things, the researchers say that it makes sense to back them up with existing seismic sensors, which are already made to pick up on unusual rumblings quickly.
The lack of early warning systems is a problem all over the world.
Obviously, the more seismic sensors there are, the better the information is for warning people about dangers like earthquakes, floods, and landslides. So, the networks of earthquake sensors that are already in place would need to be made stronger by adding more sensors and equipment. The paper’s authors say that this could be done in the Ahr Valley and other flood-prone areas of Europe with similar terrain for a tiny fraction of the tens of billions of euros of damage caused by the 2021 disaster.
But the United Nations says that there aren’t enough early warning systems around the world. A report from October says that only half of the countries in the world have good early warning systems for natural and climate-driven disasters. Even less information that could save lives is available in countries with less money. While the report was being written, Pakistan was hit by terrible floods that killed 1,700 people.
When the report came out, UN Secretary-General António Guterres said, “Whole populations are being caught off guard by cascading climate disasters without any way to be warned beforehand.” Scientists have found that climate change made both the floods in Pakistan this year and in Germany in 2021 worse. As the climate crisis gets worse, it becomes even more important to give people enough warning before disasters strike.
