Post by Ex_Nuke_Troop on Apr 22, 2014 21:59:34 GMT
USGS : GROUND WATER RESOURCES FOR THE FUTURE
THIS ARTICLE SHOULD SCARE THE LIVING CRAP OUT OF YOU !!!
Ground water is among the Nation's most important natural resources. It provides drinking water to urban and rural communities, supports irrigation and industry, sustains the flow of streams and rivers, and maintains riparian and wetland ecosystems. In many areas of the Nation, the future sustainability of ground-water resources is at risk from overuse and contamination. Because ground-water systems typically respond slowly to human actions, a long-term perspective is needed to manage this valuable resource. This publication is one in a series of fact sheets that describe ground-water-resource issues across the United States, as well as some of the activities of the U.S. Geological Survey that provide information to help others develop, manage, and protect ground-water resources in a sustainable manner.
A recent U. S. Geological Survey (USGS) report (Galloway and others, 1999) shows that sustainable development of our land and water resources depends on improved scientific understanding and detection of subsidence. The report features nine illustrative case studies that demonstrate the role of subsurface water in human-induced land subsidence (http://pubs.usgs.gov/circ/circ1182). More than 80 percent of the identified subsidence in the United States is a consequence of human impact on subsurface water, and is an often overlooked environmental consequence of our land and water-use practices. The increasing development of our land and water resources threatens to exacerbate existing land-subsidence problems and initiate new one (fig.1).
Land subsidence is a gradual settling or sudden sinking of the Earth's surface owing to subsurface movement of earth materials. Subsidence is a global problem and, in the United States, more than 17,000 square miles in 45 States, an area roughly the size of New Hampshire and Vermont combined, have been directly affected by subsidence. The principal causes are aquifer-system compaction, drainage of organic soils, underground mining, hydrocompaction, natural compaction, sinkholes, and thawing permafrost (National Research Council, 1991). Three distinct processes account for most of the water-related subsidence--compaction of aquifer systems, drainage and subsequent oxidation of organic soils, and dissolution and collapse of susceptible rocks.
Mining Ground Water
Figure 2. Approximate location of maximum subsidence in the United States identified by research efforts of Dr. Joseph F. Poland (pictured). Signs on pole show approximate altitude of land surface in 1925, 1955, and 1977. The site is in the San Joaquin Valley southwest of Mendota, California.
The compaction of unconsolidated aquifer systems that can accompany excessive ground-water pumping is by far the single largest cause of subsidence. The overdraft of such aquifer systems has resulted in permanent subsidence and related ground failures. In aquifer systems that include semiconsolidated silt and clay layers (aquitards) of sufficient aggregate thickness, long-term ground-water-level declines can result in a vast one-time release of “water of compaction” from compacting aquitards, which manifests itself as land subsidence (fig. 2). Accompanying this release of water is a largely nonrecoverable reduction in the pore volume of the compacted aquitards, and thus a reduction in the total storage capacity of the aquifer system. This “water of compaction” cannot be reinstated by allowing water levels to recover to their predevelopment status. The extraction of this resource for economic gain constitutes “ground-water mining” in the truest sense of the term.
READ MORE HERE water.usgs.gov/ogw/pubs/fs00165/
THIS ARTICLE SHOULD SCARE THE LIVING CRAP OUT OF YOU !!!
Ground water is among the Nation's most important natural resources. It provides drinking water to urban and rural communities, supports irrigation and industry, sustains the flow of streams and rivers, and maintains riparian and wetland ecosystems. In many areas of the Nation, the future sustainability of ground-water resources is at risk from overuse and contamination. Because ground-water systems typically respond slowly to human actions, a long-term perspective is needed to manage this valuable resource. This publication is one in a series of fact sheets that describe ground-water-resource issues across the United States, as well as some of the activities of the U.S. Geological Survey that provide information to help others develop, manage, and protect ground-water resources in a sustainable manner.
A recent U. S. Geological Survey (USGS) report (Galloway and others, 1999) shows that sustainable development of our land and water resources depends on improved scientific understanding and detection of subsidence. The report features nine illustrative case studies that demonstrate the role of subsurface water in human-induced land subsidence (http://pubs.usgs.gov/circ/circ1182). More than 80 percent of the identified subsidence in the United States is a consequence of human impact on subsurface water, and is an often overlooked environmental consequence of our land and water-use practices. The increasing development of our land and water resources threatens to exacerbate existing land-subsidence problems and initiate new one (fig.1).
Land subsidence is a gradual settling or sudden sinking of the Earth's surface owing to subsurface movement of earth materials. Subsidence is a global problem and, in the United States, more than 17,000 square miles in 45 States, an area roughly the size of New Hampshire and Vermont combined, have been directly affected by subsidence. The principal causes are aquifer-system compaction, drainage of organic soils, underground mining, hydrocompaction, natural compaction, sinkholes, and thawing permafrost (National Research Council, 1991). Three distinct processes account for most of the water-related subsidence--compaction of aquifer systems, drainage and subsequent oxidation of organic soils, and dissolution and collapse of susceptible rocks.
Mining Ground Water
Figure 2. Approximate location of maximum subsidence in the United States identified by research efforts of Dr. Joseph F. Poland (pictured). Signs on pole show approximate altitude of land surface in 1925, 1955, and 1977. The site is in the San Joaquin Valley southwest of Mendota, California.
The compaction of unconsolidated aquifer systems that can accompany excessive ground-water pumping is by far the single largest cause of subsidence. The overdraft of such aquifer systems has resulted in permanent subsidence and related ground failures. In aquifer systems that include semiconsolidated silt and clay layers (aquitards) of sufficient aggregate thickness, long-term ground-water-level declines can result in a vast one-time release of “water of compaction” from compacting aquitards, which manifests itself as land subsidence (fig. 2). Accompanying this release of water is a largely nonrecoverable reduction in the pore volume of the compacted aquitards, and thus a reduction in the total storage capacity of the aquifer system. This “water of compaction” cannot be reinstated by allowing water levels to recover to their predevelopment status. The extraction of this resource for economic gain constitutes “ground-water mining” in the truest sense of the term.
READ MORE HERE water.usgs.gov/ogw/pubs/fs00165/
so whats happening in the Solomons, is haarp missing its mark?