Collapsed buildings, Flooding, Fissures: Not a Good Story from Sinking Cities

Beijing, China's capital, subsides each year by as much as eleven centimeters, or more than four inches, posing a threat to more than twenty million residents, with the city witnessing large-scale subsidence in the past eighty years, the eastern part of it experiencing land subsidence at a rate greater than 100 meters per year.

Tianjin, home to 15 million people in northern China, subsides each year by as much as 5.22 centimeters a year, posing danger to its residents, with fissures appearing at the middle of roads, water seeping through cracks in walls of residential buildings.

Shanghai, another major Chinese city, subsided at an average rate of 22.94 millimeters per year from 1921 to 2007, sinking around three meters over the past one hundred years, bringing numerous challenges to almost 26 million residents.

The situation with regards to these three cities came up once again in a recent study about land subsidence in Chinese cities, but the condition takes place in other parts of the planet, making it a global challenge.

Lagos, Nigeria's commercial capital, experiences the condition of land subsidence in its major districts from climate change, at rates between two and 87 millimeters per year, putting close to three million people in affected areas under pressure, through such occurrences as building collapses and flooding.

Mexico City, the capital of Mexico, subsides each year from climate change and overuse of groundwater, sinking by as much as 20 inches, creating havoc to the infrastructure, about nine million people unable to make a positive move to solve a persistent challenge.

London, Britain's famous and iconic capital, subsides from climate change and the overuse of groundwater, going down each year by 1.5 millimeters, or 1/16 inch per year, nine million residents put on alert over the continuing trend, with River Thames, the city's principal river, unable to keep the city safe from the rising tides.

Jakarta, the capital of Indonesia, subsided at more than 16 feet over the past 25 years in its hardest-hit areas, acquiring the reputation as the fastest sinking megacity on the planet, and needing to find a solution to the challenge by 2050, or it could sink beneath the Java Sea, forcing millions of residents to flee.

In other words, the Chinese situation isn't exceptional, as Jakarta, London, Lagos, and Mexico City show the same trend of sinking cities, but the trend means grievous consequences to the affected areas.

For example, Alexandria, one of the major cities in Egypt, home to 5.4 million people in 2021, experiences the consequences, facing the problem of land subsidence at the rate of more than three millimeters, with the best case scenario of having a third of the city  under water by 2050, with 1.5 million people having to flee.

Mumbai, India's financial capital, sinks into the sea at the rate of two millimeters each year, bringing the possibility of mega-floods by 2050, since the Arabian Sea rises by 0.5 to three millimeters each year, putting the city's seven islands under a severe pressure.

New York City, famous and influential in the United States, also subsides, at the rate of one to two millimeters per year, with the financial institutions facing the risk of inundation as sea levels rise two feet higher by 2055.

With New York City, Mumbai, Alexandria, and Jakarta showing consequences of land subsidence, replicating the examples of Chinese cities, solutions must be found to prevent grievous consequences.

Bangkok, Thailand's capital, sinks at the rate of two-thirds of an inch every year, but its policies and investments to restrict the amount of groundwater extraction provided a solution, reducing the rate of land subsidence, giving hope to millions of residents.

Tokyo, the capital of Japan, subsided by nearly six feet over the course of several decades, because residents drew too much of the groundwater, but once the city undertook a policy to restrict the use of groundwater, the rate of subsidence decreased.

Perhaps if Chinese cities take the cue from authorities in Tokyo and Bangkok, land subsidence from groundwater depletion and climate change might be reduced, cues cities like Lagos, London, New York, Mexico City, Mumbai, Jakarta, and the others could take to mitigate future suffering.

What to Eat

Vegan foods from India, Credit, Times of India