Aquifer - Subsidence

Subsidence

In unconsolidated aquifers, groundwater is produced from pore spaces between particles of gravel, sand, and silt. If the aquifer is confined by low-permeability layers, the reduced water pressure in the sand and gravel causes slow drainage of water from the adjoining confining layers. If these confining layers are composed of compressible silt or clay, the loss of water to the aquifer reduces the water pressure in the confining layer, causing it to compress from the weight of overlying geologic materials. In severe cases, this compression can be observed on the ground surface as subsidence. Unfortunately, much of the subsidence from groundwater extraction is permanent (elastic rebound is small). Thus, the subsidence is not only permanent, but the compressed aquifer has a permanently reduced capacity to hold water.

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Other articles related to "subsidence":

Longwall Mining - Comparison With Room and Pillar Method
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Pennsylvania Coal Co. V. Mahon - Result - Subsequent Research
... Fishel explains that subsidence did not happen often and the vast majority of coal companies worked hard not to allow subsidence to happen, and when it did the companies generally paid ... Most of the subsidence issues were cracks in foundation and the settling of parts of houses ... However, when Fischel investigated about subsidence issues surrounding mining for anthracite coal in Pennsylvania he was, "struck by how little was written about the subsidence problem, which was in ...
Groundwater-related Subsidence
... Groundwater-related subsidence is the subsidence (or the sinking) of land resulting from groundwater extraction, and a major problem in the developing world as major metropolises ... One estimate has 80% of serious land subsidence problems associated with the excessive extraction of groundwater, making it a growing problem throughout the world ... It has been argued that there is little consequence to subsidence in a wide, flat, agricultural basin, since the settlement is uniform ...
Subsidence - Seasonal Effects
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Subsidence (atmosphere)
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