According to research published in the April 16, 2022, issue of “Geophysical Research Letters,” coastal cities around the globe are sinking. The team from the University of Rhode Island led by Matt Wei looked at 99 coastal cities on six continents and found that they were sinking by a few centimeters each year. The team relied on data from two European satellites to reach their conclusion. This is an essential problem, according to the team, because it means that flooding is going to become much worse.
Factors Causing Sinking Cities
National Autonomous University of Mexico earth scientist Darío Solano-Rojas, who was not involved in the study, says that two factors caused the results. The first is that sea levels are rising globally. At the same time, people are moving to these coastal communities, so more groundwater is removed, causing the ground to sink. In some coastal communities, the land is sinking at about 10 millimeters per year.
Southeast Asia of Major Concern
A similar study conducted in conjunction with NASA Jet Propulsion Laboratory and the University of Minnesota found comparable results. Both studies show that the ground is sinking fastest in Southeast Asia. In particular:
Fastest Sinking Cities
| City | Sinking at Centimeters per Year |
|---|---|
| Tianjin, China | 5.22 |
| Semarang, Indonesia | 3.96 |
| Jakarta, Indonesia | 3.44 |
| Shanghai China | 2.94 |
| Ho Chi Minh City, Vietnam | 2.81 |
| Hanoi, Vietnam | 2.44 |
| Chittagong, Bangladesh | 2.35 |
| Koba, Japan | 2.26 |
| Kerala, India | 1.96 |
| Houston | 1.96 |
Why Are Cities Sinking?
The two studies show that cities are sinking because of groundwater removal and rising sea levels, but other research shows varied reasons, including oil and gas drilling and rapid construction.
World Health Organization Claims About Sinking Cities
Authorities with the World Health Organization say that by 2100 some metropolitan areas will be completely underwater. These include:
- Jakarta, Indonesia
- Lagos, Nigeria
- Houston
- Dhaka, Bangladesh
- Venice, Italy
- Virginia Beach, Virginia
- Bangkok
- New Orleans
- Rotterdam, the Netherlands
- Alexandria, Egypt
- Miami
Problems With Sinking Cities
In order to determine what might happen in the future, the research team working with NASA Jet Propulsion Laboratory looked at Rio de Janeiro. They say an area of about 1 square mile will be constantly submerged by 2030. Therefore, almost 11,000 people could see their homes disappear under the sea.
What Solutions Are Available for Sinking Cities?
According to the United Nations, about 10% of the world’s population lives on a coastline, and these cities will be the first to sink.
Some cities are not waiting for their cities to sink into the sea. Instead, they are trying innovative approaches to stop the damage. For example, the government is moving the capital from Jakarta to Kalimantan in Indonesia. The plan will see over 1.5 million civil servants move to keep their jobs. Unlike Jakarta, Kalimantan is on a large island located in a tropical forest. Government officials hope the lower water demand will stop the city from sinking. The new capital will become effective January 18, 2023.
Other countries have banned the removal of underground water in hopes that finding other solutions will stop or slow down the rate at which cities are sinking.
While researchers have long known that some cities were sinking because of rising flood levels, they have now determined that some cities are dropping faster than expected in major metropolitan areas because people are removing underground water and energy products. This has caused some cities to take significant steps, such as moving their capital cities. Yet, scientists are not sure if it will be enough to stop these cities, where approximately 10% of the world’s population lives, from sinking.
