I believe, I have seen reports suggesting the usual blame on climate change!
Do not trust or put to much credence on long-term forecasts, not for climate change nor for subsidence!
Learn from the Netherlands how to successfully deal with low (below sea level) lying lands!
"Subsidence, the lowering of Earth’s land surface, is a widespread and sometimes dramatic process. Potentially 19% of the global population is at high risk of being affected by this process. Such sinking is caused by a range of natural or anthropogenic factors, including human-induced underground fluid withdrawal, which is generally considered the most important driver. However, present understanding of subsidence is fragmented and qualitative, including measurements, attribution to drivers, prognosis, and appropriate responses. ... Ao et al. report using a radar technique called interferometric synthetic aperture radar (InSAR) to map consistent large-scale measurements of vertical land motion across all the major urban areas of China. Its successful application to quantify subsidence points the way to a systematic approach for assessing its causes as well as potential responses in real time and in the future."
"... Some 16% of the mapped area of China’s major cities is sinking “rapidly” — faster than 10 millimetres every year. An even greater area, roughly 45%, is sinking at a “moderate” rate, the paper says, meaning a downward trajectory of greater than 3 mm annually. Affected cities include the capital Beijing, as well as regional capitals, including Fuzhou, Hefei and Xi’an. ...
In the famously low-lying Netherlands, roughly one-quarter of the land has subsided to below sea level. ..."
In the famously low-lying Netherlands, roughly one-quarter of the land has subsided to below sea level. ..."
"Nearly half of China’s major cities, including Beijing, are sinking—and one in 10 residents of some coastal cities could be living below sea level within a century, according to a new study in Science.
Why it’s happening: Groundwater depletion, the weight of buildings and transport systems, underground mining, and natural factors like the depth of a city’s bedrock.
Meanwhile, climate change fuels sea-level rise.
What can be done: Long-term, sustained control of groundwater extraction, Nature reports.
Success story: Tokyo slowed its sinking from a rapid 240 mm to 10 mm a year between the 1960s and 2000s, thanks to laws limiting groundwater pumping. ..."
From the editor's summary and abstract:
"Editor’s summary
Radar observations from satellites can track ground deformation. Over many years, radar can pick up even relatively small changes on the order of millimeters per year. Ao et al. used satellite observations to determine the extent of land subsidence across 82 major cities in China ... They found that about 40% of the land is undergoing moderate to severe subsidence, which adds to the risk of flooding for a large population. ...
Abstract
China’s massive wave of urbanization may be threatened by land subsidence. Using a spaceborne synthetic aperture radar interferometry technique, we provided a systematic assessment of land subsidence in all of China’s major cities from 2015 to 2022. Of the examined urban lands, 45% are subsiding faster than 3 millimeters per year, and 16% are subsiding faster than 10 millimeters per year, affecting 29 and 7% of the urban population, respectively. The subsidence appears to be associated with a range of factors such as groundwater withdrawal and the weight of buildings. By 2120, 22 to 26% of China’s coastal lands will have a relative elevation lower than sea level, hosting 9 to 11% of the coastal population, because of the combined effect of city subsidence and sea-level rise. Our results underscore the necessity of enhancing protective measures to mitigate potential damages from subsidence."
Nearly half of China’s major cities are sinking — some ‘rapidly’ Tens of millions of people in the country’s coastal lands might find their homes below sea level by 2120 owing to sinking and sea-level rise.
Perspective: Earth’s sinking surface (no public access) China’s major cities show considerable subsidence from human activities
A national-scale assessment of land subsidence in China’s major cities (no public access)
No comments:
Post a Comment