23-02-2013, 10:07 AM
SALT WATER INTRUSION
[attachment=51537]
INTRODUCTION
Almost two thirds of the world's population lives within 400 km of the ocean shoreline; just over half live within 200 km, an area only taking up 10% of the earth's surface (Hinrichsen, 2007).
Most of these coastal regions rely on groundwater as their main source of fresh water for domestic, industrial and agricultural purposes.
As the world's population continues to grow at an alarming rate, fresh water supplies are constantly being depleted, bringing with it issues such as saltwater intrusion and increasing the importance of groundwater monitoring, management, and conservation.
Saltwater intrusion
Saltwater intrusion is a major concern commonly found in coastal aquifers around the world.
Saltwater intrusion is the movement of saline water into freshwater aquifers.
Most often, it is caused by ground-water pumping from coastal wells, or from construction of navigation channels or oil field canals.
Saltwater intrusion occurs in virtually all coastal aquifers, where they are in hydraulic continuity with seawater.
causes
Saltwater intrusion happens when saltwater is drawn in (from the sea) into fresh water aquifers .
This behavior is caused sea water has a higher density (which is because it carries more solutes) than freshwater.
IMPACTS
Salt-water intrusion from rising sea levels will reduce the quality and quantity of freshwater supplies as it is happening along Atlantic and Gulf coasts.
This is a major concern, since billions of people already lack access to freshwater.
Salt water intrusion leads to the loss of fresh water vegetation
Spread of mudflats into previously vegetative areas.
GHYBEN-HERZBERG RELATION
The first physical formulations of saltwater intrusion were
made by W. Badon-Ghijben(1888,1889) and A.Herzberg
(1901), thus called the Ghyben-Herzberg relation.
They derived analytical solutions to approximate the
intrusion behavior , which are based on a number of
assumptions that do not hold in all field cases.
conclusion
Monitoring well networks allow continuous observation of the saltwater interface, after management strategies have been put in place.
This provides early warnings of saltwater intrusion and tracks the effectiveness of the strategy. Overall, proper groundwater monitoring techniques and groundwater management, combined with groundwater conservation are needed to keep saltwater intrusion under control, and ensure fresh water supplies are sustained for future generations.
[attachment=51537]
INTRODUCTION
Almost two thirds of the world's population lives within 400 km of the ocean shoreline; just over half live within 200 km, an area only taking up 10% of the earth's surface (Hinrichsen, 2007).
Most of these coastal regions rely on groundwater as their main source of fresh water for domestic, industrial and agricultural purposes.
As the world's population continues to grow at an alarming rate, fresh water supplies are constantly being depleted, bringing with it issues such as saltwater intrusion and increasing the importance of groundwater monitoring, management, and conservation.
Saltwater intrusion
Saltwater intrusion is a major concern commonly found in coastal aquifers around the world.
Saltwater intrusion is the movement of saline water into freshwater aquifers.
Most often, it is caused by ground-water pumping from coastal wells, or from construction of navigation channels or oil field canals.
Saltwater intrusion occurs in virtually all coastal aquifers, where they are in hydraulic continuity with seawater.
causes
Saltwater intrusion happens when saltwater is drawn in (from the sea) into fresh water aquifers .
This behavior is caused sea water has a higher density (which is because it carries more solutes) than freshwater.
IMPACTS
Salt-water intrusion from rising sea levels will reduce the quality and quantity of freshwater supplies as it is happening along Atlantic and Gulf coasts.
This is a major concern, since billions of people already lack access to freshwater.
Salt water intrusion leads to the loss of fresh water vegetation
Spread of mudflats into previously vegetative areas.
GHYBEN-HERZBERG RELATION
The first physical formulations of saltwater intrusion were
made by W. Badon-Ghijben(1888,1889) and A.Herzberg
(1901), thus called the Ghyben-Herzberg relation.
They derived analytical solutions to approximate the
intrusion behavior , which are based on a number of
assumptions that do not hold in all field cases.
conclusion
Monitoring well networks allow continuous observation of the saltwater interface, after management strategies have been put in place.
This provides early warnings of saltwater intrusion and tracks the effectiveness of the strategy. Overall, proper groundwater monitoring techniques and groundwater management, combined with groundwater conservation are needed to keep saltwater intrusion under control, and ensure fresh water supplies are sustained for future generations.