Sinking Cities in the U.S. and the Weight of Population Growth
- NPG
- November 12, 2024
- NPG Commentary
- 0 Comments
The Impact of Population Growth on Our Sinking Cities
Urban land subsidence (the slow and gradual sinking of land) is an increasingly critical issue that challenges the stability of our cities. As urban areas grow, the weight of buildings, infrastructure, and concentrated human activities exerts continuous pressure on underlying soils, especially in cities constructed on water-saturated sediments, such as coastal and river delta areas. The added pressure from structures and paved areas diminishes soil porosity, limiting its capacity to absorb water, which can exacerbate land compaction. When combined with factors such as groundwater extraction and escalating sea levels, this strain can accelerate the sinking of these cities, heightening their susceptibility to flooding and environmental pressures.
In places like New Orleans, neighborhoods such as the 9th Ward experience intensified flooding due to both the sinking ground and encroaching waters. Miami, particularly areas like Miami Beach, grapples with frequent saltwater intrusion and a heightened risk of flooding as sea levels rise. Similarly, parts of New York City, including Lower Manhattan, face land subsidence due to the amassed weight of dense populations and skyscrapers. These effects are evident—decaying infrastructure, rising flood instances, and diminishing property values.
The underlying causes are evident. Excessive groundwater extraction, unchecked urban expansion, the construction of dense infrastructure on unsuitable foundations, and burgeoning population numbers are chief contributors to this troubling phenomenon. In New Orleans, groundwater removal leads to land sinking, while in Miami, relentless development strains public services and natural resources. New York City encounters severe land subsidence owing to its heavy construction loads. Climate change further exacerbates these challenges by amplifying sea-level rise’s impact on our coastal cities.
Globally, cities like Jakarta, Bangkok, Venice, and Mexico City face similar challenges as those in the U.S., with urban land subsidence posing a significant threat to their sustainability. Jakarta, Indonesia’s capital, experiences rapid sinking primarily due to excessive groundwater extraction and insufficient urban planning, leading to plans for relocating the capital—a stark indication of the issue’s seriousness. Likewise, Bangkok deals with land sinking aggravated by dense populations and inadequate drainage systems. Mexico City, founded on an ancient lakebed, contends with sinking and water scarcity due to groundwater extraction and a growing populace. Venice, built on islands, continues to face regular flooding, worsened by rising tides and climate change. These situations underscore the urgent need to address urban land subsidence and encourage sustainable development practices.
Given these pressing challenges, it is vital to pursue comprehensive strategies to address and eventually reverse these trends. Strengthening zoning policies can limit development in sensitive areas and ensure new construction meets strict sustainability criteria. Implementing sustainable practices and materials in urban planning and construction can reduce our environmental impact and relieve soil stress.
Even more importantly, however, we must outline realistic and lasting efforts to slow, halt, and eventually reverse population growth. Only then can we truly develop long-term sustainability efforts that will survive several generations.
Your voice, advocacy, and support are crucial in driving policy changes and promoting true sustainability. Join NPG in this important endeavor. Together, we can make a meaningful impact and protect the future of our cities.
Through your continued support and donations to NPG, we can advocate for these necessary changes.
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