Areas of karst topography on limestone bedrock are sometimes vulnerable to surface pollution from groundwater.
of Environmental Conservation, and Pennsylvania Groundwater Policy Education Project.
Groundwater deep underground and below oceans may be saline.
By comparison, weathered and fractured crystalline rocks yield smaller quantities of groundwater in many environments.
Groundwater is depleted as is pumped out and used faster than it is replenished.
In brief, the effects of groundwater overdraft (although undeniably real) may take decades or centuries to manifest themselves.
The high specific heat capacity of water and the insulating effect of soil and rock can mitigate the effects of climate and maintain groundwater at a relatively steady temperature.
A confined aquifer or artesian aquifer is one whereby the groundwater is bounded within layers of impermeable substances like dense rock or clay and is very often under pressure.
Water pollution of groundwater, from pollutants released on the surface that can work their way down into groundwater, can create a contaminant plume within an aquifer.
Unconsolidated to poorly cemented alluvial materials that have accumulated as valley-filling sediments in major river valleys and geologically subsiding structural basins are included among the most productive sources of groundwater.
An aquifer is an underground geological formation in the zone of saturation that consists of a layer of porous substrate that can readily contain and yield groundwater.
The most evident problem (as far as human groundwater use is concerned) is a lowering of the water table beyond the reach of existing wells.
The hydrosphere includes the atmosphere, land, surface water, and groundwater.
Love Canal was one of the most widely known examples of groundwater pollution.
The following are some definitions of groundwater and related terms.
A lowered water table may, in turn, cause other problems such as groundwater-related subsidence and saltwater intrusion.
The importance of groundwater to ecosystems is often overlooked.
Like surface water, groundwater continues to move, although more slowly due to the substrate through which it is moving.
Water moves through different reservoirs, including ocean, atmosphere, groundwater, rivers, and glaciers, by the physical processes of evaporation (including plant transpiration), sublimation, precipitation, infiltration, runoff, and subsurface flow.
Groundwater also is withdrawn for agricultural, municipal, and industrial use by constructing and operating extraction wells.
Groundwater is a renewable resource that serves many critical economic and environmental needs.
About twenty percent of the freshwater in the world is made up of groundwater (about 0.61% of the water in the world, including oceans and permanent ice).
Groundwaters sustain streams, wetlands, and lakes, as well as subterranean ecosystems within karst or alluvial aquifers.
Groundwater discharging into a stream provides water to allow the stream to flow throughout the year.
An aquiclude is a substrate with porosity that is so low it is virtually impermeable to groundwater.
Sophocleous (2002) argues that management agencies must define and use appropriate time frames in groundwater planning.
The city of New Orleans, Louisiana is actually below sea level today, and its subsidence is partly caused by removal of groundwater from the various aquifer/aquitard systems beneath it.
The storage of groundwater globally is approximately equal to the amount of freshwater stored in ice pack and snow worldwide, including the south and north poles.
Groundwater or ground water is water located within the ground's zone of saturation, where the soil pore spaces and fractures in the rock are completely filled with water.
That water that is not taken up by plants makes its way to the zone of saturation, becoming groundwater.
By comparing the age of groundwater obtained from different parts of the Great Artesian Basin, hydrogeologists have found it increases in age across the basin.
Groundwater contamination can occur from a number of sources.
The interaction of groundwater contamination with surface waters is analyzed by use of hydrology transport models.
Most rivers, lakes, and wetlands are fed by, and (at other places or times) feed groundwater, to varying degrees.
Groundwater feeds soil moisture through percolation, and many terrestrial vegetation communities depend directly on either groundwater or the percolated soil moisture above the aquifer for at least part of each year.
Over-use of groundwater, known as overdraft, can lead to depletion and cause major problems to human users and to the environment.
Hyporheic zones (the mixing zone of streamwater and groundwater) and riparian zones are examples of ecotones largely or totally dependent on groundwater.
Research has demonstrated that evaporation of groundwater can play a significant role in the local water cycle, especially in arid regions (Hassan 2008).
By year 500, this had reduced to 0%, signalling complete death of the groundwater-dependent vegetation.
When groundwater is removed from aquifers by excessive pumping, pore pressures in the aquifer drop and compression of the aquifer may occur.
Two key issues facing groundwater reserves are (1) depletion of groundwater; and (2) contamination.