English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

. The combination of groundwater withdrawal, hydrocarbonextraction, salt-dome movement and faulting have caused widespreadsubsidence in the Houston-Galveston region (HGR). Subsidence results fromprimary consolidation consisting of inelastic (nonrecoverable) and elastic(recoverable) compaction caused by subsurface fluid withdrawal and secondaryconsolidation (creep) over time caused by overburden pressure. Subsidence inthe HGR is monitored using borehole extensometers that were installed at 13locations across Harris and Galveston counties between 1962 and 1980. By1977, withdrawals from the Chicot and Evangeline aquifers resulted ingroundwater-level declines of about 114 and 115 m relative topredevelopment water levels, respectively in parts of Harris County. By1979, as much as 3 m of land subsidence was estimated to have occurred inlocalized areas of the HGR. Land subsidence can be hazardous in populatedareas because it exacerbates the effects of storm surge and impedesstorm-water runoff by decreasing land-surface elevations in areas wherewater accumulates. To assess aquifer compaction in response to changes ingroundwater levels, a bulk land-surface subsidence rate is assumed to be thesum of the primary consolidation rate and the negligibly variable componentof overburden pressure referred to as the “pseudo-constant secondaryconsolidation rate.” From 1931 to 1976, groundwater levels decreased asgroundwater withdrawal rates increased from 0.57 to 4.3 million m 3  d −1 ,causing pressure heads in aquitards the Chicot and Evangeline aquifers tocontinually decline. In response to reductions in groundwater withdrawalrates from 4.3 to 3.0 million m 3  d −1 between 1976 and 2001, groundwaterlevels rebounded, decreasing inelastic compaction rates in some parts of theHGR from as much as about 40 mm yr −1 in the early 1980s tonegligible amounts by 2000. Inelastic consolidation from about 1937 to 2000contributed to land-surface subsidence and its associated effects.Land-surfaces have rebounded in localized areas of the HGR where groundwaterlevels rebounded significantly. Pseudo-constant secondary consolidationrates were computed at each of the 13 extensometers and ranged from 0.48 to8.49 mm yr −1 in areas where groundwater levels in the twoaquifers were stabilizing. This secondary consolidation subsidence is beyondthe control of any groundwater-level management schemes because it is causedby geohistorical overburden pressure on the two aquifers.

The Secondary Consolidation (Creep) due to Geohistorical Overburden Pressure in the Houston-Galveston Region, Texas