A new study has found that all 28 of the most populous cities in the United States are sinking, leading to increased risks of flooding and damage to urban infrastructure. This includes cities such as Denver and Dallas, which are not coastal, highlighting the widespread nature of this issue. The main cause of this subsidence is the extraction of groundwater to meet the needs of growing populations and commerce.
The research, published in Nature Cities, utilized interferometric synthetic aperture radar (InSAR) measurements taken from satellites to detect upward and downward deformations of Earth’s surface down to the millimeter scale. This method provided granular data that revealed the extent of sinking in these cities. The study found that at least 20 percent of the area in all 28 cities examined was sinking, with rates exceeding two millimeters per year in many cases.
Cities like Houston, Fort Worth, and Dallas had some of the highest rates of subsidence, with certain areas sinking by more than 10 millimeters per year. While these numbers may seem small, they can add up over time and lead to significant damage to buildings and infrastructure. In fact, the study identified around 29,000 buildings in areas of concern, where the risk of damage due to sinking ground is higher.
The uneven rates of sinking across cities can cause buildings to tilt and collapse, as seen in the tragic collapse of a condominium in Surfside, Florida, in 2021. Additionally, sinking ground can create subsidence bowls that trap water and increase the risk of flooding in urban areas. The study found that 80 percent of the sinking was related to groundwater extraction, emphasizing the importance of sustainable water management practices to prevent further subsidence.
Overall, the findings of this study highlight the urgent need for cities to address the issue of sinking ground and take proactive measures to protect their infrastructure and residents. By understanding the causes and effects of subsidence, city planners and policymakers can work towards sustainable solutions that mitigate the risks associated with sinking cities. Cities in drought-prone regions, like Texas, face a unique challenge when it comes to subsidence. As aquifers become more depleted during droughts, the risk of subsidence increases significantly. This is a cause for concern, as subsidence can lead to a range of issues such as sinkholes, infrastructure damage, and water contamination.
According to Ohenhen, a researcher studying subsidence in drought-prone regions, the probability of subsidence occurring during a drought is incredibly high. This means that cities in these regions need to be particularly vigilant and proactive in addressing the issue before it escalates further.
A recent study conducted by Pritchard has shown that subsidence is not just a problem in well-known cities like New Orleans, but is a widespread issue that can affect urban areas of all sizes. This finding underscores the importance of addressing subsidence on a broader scale and not just in major metropolitan areas.
In light of these findings, it is crucial for cities in drought-prone regions to take action to mitigate the risk of subsidence. This may involve implementing measures to reduce water consumption, investing in alternative water sources, and monitoring subsidence levels regularly.
By taking proactive steps to address subsidence, cities can protect their infrastructure, water supply, and overall quality of life for residents. It is essential that this issue is taken seriously and addressed promptly to prevent further damage and ensure the long-term sustainability of these communities.
