For years, scientists have been monitoring the rising sea levels of the Earth’s oceans, fearing that they’ll eventually overtake coastlines and destroy cities around the globe. The media has reported extensively on this phenomena, bringing awareness to an issue that won’t go away if ignored. However, the preoccupation with the rising sea levels has meant that a major environmental problem has been unintentionally ignored by the global community for decades, one that may be more detrimental to our cities than the rising waters. A recent study published by the Deltares Research Institute in the Netherlands found that many regions of the world are sinking at a rate 10x faster than water level rising, meaning that there is a larger potential for these places to sink into the sea before the sea can overtake them. A crisis that is tied together by nature, this phenomena known as land subsiding has scientists and environmentalists alike wondering what can be done or if it is too late to do anything at all.
There are many factors that are contributing to rapid sinking of coastal cities but the two major ones are population growth and groundwater extraction. Many of the sinking cities are very densely populated, having experience huge booms in their communities in the mid-20 century. These once small metropolises found themselves scouring to locate the resources necessary to support the new influx of people, as basic necessities such as food and water began to run thin. In order to ensure that there would be enough clean drinking water to provide liberally for all, many of these places began to engage in groundwater extraction. This is the process through which the water that lies beneath the Earth’s surface is pumped and filtered for the purpose of providing safe drinking water for people. While this seemed like the perfect solutions to the cities’ water problems, it has actually been the leading factor in the growing land subsiding problem. In Jakarta, Indonesia’s largest cities, it was found that the most heavily populated areas have dropped nearly six and a half feet as more and more groundwater has been pumped.
It is easy enough to say that simply stopping groundwater extraction would help alleviate this problem but, for many cities, it is their only method of obtaining drinkable water. It is also unfortunate to note that, as of this moment in time, it doesn’t seem as if the damage is reversible.
With sea levels rapidly rising and land sinking very quickly, the following major cities could soon find themselves facing a force way beyond our control.
1.) Bangkok, Thailand
Bangkok has been sinking at of rate of 1.2 inches per year for decades now, with no sign of slowing up. Buildings have sunk more than 20 millimeters as soil and clay continue to subside. The problem is being ignored Thailand’s government but scientists warn that unless something done, and done quickly, the city will find itself flooded out.
2.) Mexico City, Mexico
(Photo Via As-Coa)
Scientists have long been aware of the issue of land subsidence in Mexico City, the world’s second most populous city. Sinking at a rate of 3 inches per year, the city’s infrastructure is becoming weaker and weaker as time goes on. To make matters worse, the ground is failing to sink evenly, with some areas falling quicker than others. This phenomena has given the entire city a tangible tilt, felt whether one is lying in bed or walking down the street. The reason for this major problem is that the natural aquifers that lay beneath the city’s roads are being emptied quicker than they can be refilled. As a result, the soft clay foundation grows brittle and fractures before eventually collapsing. With roads buckling, subway lines becoming irreparably damaged, and sewer pipes rupturing, the city is facing a problem bigger than it could have imagined.
3.) Houston, Texas
Scientists have recently discovered that some parts of Houston have sunk a noticeable amount over the course of the last few decades, particular the ares lying in the northwest portion of the city. The problem is the same as those in the other cities: the extraction of groundwater is weakening the foundation and causing a rapid subsidence of land. The rapid development of the neighborhood has led to a greater influx of people, heavily increasing the density of the region. Data show that the neighborhood has sunk more than four feet since it’s development in the late 1930’s and that the rest of Houston may soon follow suit.
Have you been to any of these sinking cities?