Sinking cities

Waltham, Tony

doi:10.1046/j.1365-2451.2002.00341.x

Cited by 30 publications

(28 citation statements)

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“…As groundwater and petroleum are extracted from aquifer materials located within deltas, pore water pressures in aquifer and adjacent clay materials is decreased and the sediment compacts (Waltham, 2002). This compaction occurs in conjunction with natural subsidence and will be referred to here as accelerated subsidence.…”

Section: Accelerated Subsidencementioning

confidence: 99%

“…Deltas such as the Chao Phraya, Bengal, Yangtze and Nile have drawn large populations while maintaining substantial agricultural production. This has forced the increasing use of groundwater to supplement diminished surface-water supplies resulting in accelerated subsidence (Waltham, 2002). In addition, some deltas are the site of significant oil and gas accumulations and extraction as in the Niger, Magdalena, Mahakam, MacKenzie, and Mississippi deltas (Rainwater, 1975;Onu, 2003).…”

Section: Accelerated Subsidencementioning

confidence: 99%

See 1 more Smart Citation

Effective sea-level rise and deltas: Causes of change and human dimension implications

Ericson¹,

Vörösmarty²,

Dingman³

et al. 2006

Global and Planetary Change

781

500

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Section: Accelerated Subsidencementioning

confidence: 99%

Section: Accelerated Subsidencementioning

confidence: 99%

Effective sea-level rise and deltas: Causes of change and human dimension implications

Ericson¹,

Vörösmarty²,

Dingman³

et al. 2006

Global and Planetary Change

781

500

View full text Add to dashboard Cite

“…Clay compaction is largely an irreversible, one-way process, and it is the major source of severe pumping-induced land subsidence (Terzaghi 1925;Holzer 1984;Phien-wej et al 2006). When groundwater is recharged into the starved aquifers to recover the pore pressure, expansion of aquifer sand and gravel layers occurs and contributes to lifting up the ground surface as an elastic rebound (Waltham 2002). During piezometric head rises, the recharged sections of the aquifer release the formerly imposed compressive strain to show dilatation, producing elastic rebound.…”

Section: Mechanisms Of Land Subsidence Analysismentioning

confidence: 99%

Land subsidence in Tianjin, China

Fang

et al. 2010

Environ Earth Sci

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Land subsidence has been affecting Tianjin for the past 50 years. It leads to comprehensive detrimental effects on society, the economy and natural environment. Overpumping of groundwater is the main cause. In 2008, the maximum cumulative subsidence reached 3.22 m and the total affected area nearly 8,000 km 2 . The subsidence reached its most critical state in the early 1980s when it occurred at a rate as high as 110 mm/year. At the same time, groundwater extraction had also reached a maximum of 1,200 million m 3 . By importing the Luan River to Tianjin and restricting exploitation of groundwater, hydraulic heads gradually recovered after 1986 in all aquifers, and this has continued to the present in the second aquifer. The subsidence rate in urban areas dropped to 10-15 mm/year. The area of groundwater extraction expanded to the suburban area with economic growth in the 1990s, and it was shifted to the third and fourth aquifers. At present, with a subsidence rate of 30-40 mm/year, four new suburban subsidence centers have been formed. Several measures were adopted to mitigate and prevent land subsidence disasters. These included restricting groundwater exploitation, groundwater injection, prohibiting use in the specific zone, a pricing policy for water resources, advocating water-saving technology, and strict enforcement of groundwater laws. Although the subsidence area is still increasing slowly, the subsidence rate is being controlled.

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“…extraction of oil, gas and groundwater) has been reported in many urban environments (e.g. Waltham 2002, Marfai and King 2008, Brown and Nicholls, 2015. Land subsidence is recognized as a chronic hazard affecting urban flooding, especially in coastal/delta megacities such as Tokyo, Osaka, Shanghai, Taipei, Bangkok, Jakarta, Manila and New Orleans (Dixon et al 2006;IPCC 2007b;Syvitski et al 2009;Jago-on et al 2009).…”

Section: Introductionmentioning

confidence: 99%

Modelling the impact of land subsidence on urban pluvial flooding: A case study of downtown Shanghai, China

Yin

Wilby

2016

Science of The Total Environment

126

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This paper presents a numerical analysis of pluvial flooding to evaluate the impact of land subsidence on flood risks in urban contexts using a hydraulic model (FloodMap-HydroInundation2D). The pluvial flood event of August 2011 in Shanghai, China is used for model calibration and simulation. Evolving patterns of inundation (area and depth)are assessed over four time periods (1991, 1996, 2001 and 2011) for the downtown area, given local changes in topography and rates of land subsidence of up to 27 mm/yr. The results show that land subsidence can lead to non-linear response of flood characteristics. However, the impact on flood depths is generally minor (< 5cm) and limited to areas with lowest-lying topographies because of relatively uniform patterns of subsidence and micro-topographic variations at the local scale. Nonetheless, the modelling approach tested here may be applied to other cities where there are more marked rates of subsidence and/or greater heterogeneity in the depressed urban surface. In these cases, any identified hot-spots of subsidence and focusing of pluvial flooding may be targeted for adaptation interventions.

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Sinking cities

Abstract: When water supplies are abstracted from alluvial sands, interbedded clays compact and cause ground subsidence. Entire cities are being gently lowered, with serious consequences for those on low coastal sites.

Cited by 30 publications

References 0 publications

Effective sea-level rise and deltas: Causes of change and human dimension implications

Effective sea-level rise and deltas: Causes of change and human dimension implications

Land subsidence in Tianjin, China

Modelling the impact of land subsidence on urban pluvial flooding: A case study of downtown Shanghai, China

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