Mexico City is sinking faster and there is no hope for its recovery
Mexico City is sinking primarily due to the over-extraction of groundwater. As a metropolis with a growing population, the demand for water in the city has led to extensive pumping from underground aquifers.
This excessive extraction causes the ground to settle and results in subsidence, contributing to the city’s gradual sinking. Moreover, the city was built on an ancient lakebed, known for its unstable soil composition.
Tenochtitlan was founded 700 years ago in the region of what is currently Mexico City. It was the capital of the Aztec Empire and was situated on the island located near the left coast of the Lake of Texcoco.
Unfortunately, during colonial times, the water in the area was drained.
Today the consequences of these actions are perceived, since for more than 100 years there have been records of Mexico City sinking, due to the constant compaction of the old lake bed on which it was built.
Since 1900 it was known that the city was sinking at a rate of 9 centimeters per year, and by the 1950s it increased to 29 centimeters per year. Due to this, measures were implemented to combat the situation.
However, the rate of subsidence in Mexico City dramatically has increased over the past two decades, reaching an alarming 50 cm per year, and, according to a study, there is no hope that this can be reversed.
The research was carried out by a team of Mexican and American scientists, who used 115 years of ground measurements and 24 years of space measurements using Interferometric Synthetic Aperture Radar (InSAR).
Using the data, the team concluded that the subsidence is almost irreversible, and is responsible for damage and fractures to urban infrastructure, such as buildings, historical sites, sewers, and gas and water lines.
Over the next 150 years, the soil will become more compact, causing Mexico City to sink another 30 m. Unless decisive action is taken to manage water resources, the stage is set for a double water crisis and subsidence.
Land subsidence challenges in Mexico City
Some areas in Mexico City are more susceptible to subsidence than others.
For example, the ground of the Historic Center area is more porous and is experiencing noticeable sinking. Colonia Roma and Colonia Condesa, both popular residential areas, are also facing similar challenges.
These areas are characterized by their soft soil composition, exacerbating the impact of groundwater extraction.
Land subsidence poses a significant threat to the city’s infrastructure. Buildings, roads, and other structures can be damaged as the ground sinks unevenly. The risk of flooding increases as the land subsides, impacting both residential and commercial areas.
Additionally, subsidence can strain sewage and drainage systems, leading to further complications.
Authorities in Mexico City are implementing measures to address land subsidence. These include regulations on groundwater extraction, investments in alternative water sources, and the development of sustainable urban planning strategies.
Collaborative efforts between government agencies, researchers, and the public are essential for effective mitigation. While short-term measures are crucial, addressing the root causes of land subsidence requires long-term planning.
This involves sustainable water management practices, promoting the use of rainwater harvesting, and investing in technologies that can monitor and control groundwater extraction.
Public awareness campaigns educate residents about water conservation and its impact on the city’s stability. The issue of land subsidence in Mexico City is a complex challenge that requires a multifaceted approach.
The research has been published in the Journal of Geophysical Research.
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