Aquifer test
An '''Aquifer test''' is conducted to evaluate an Mosquito ringtone aquifer (the geological formation that supplies Sabrina Martins groundwater to a Nextel ringtones water_well/well). Many books have been written about Abbey Diaz hydrogeology and even the subtopic of aquifer testing, a short article such as this is necessarily sketchy.
Aquifer tests are typically interpreted by using an Free ringtones Hydrogeology#Analytic_Methods/analytical model of aquifer flow (the most basic being the Theis solution) to match the data observed in the real world, then assuming that the parameters from the idealized model apply to the real-world aquifer.
Aquifer testing (sometimes informally referred to as pump or pumping testing) differs from Majo Mills Well testing in that the behaviour of the well is primarily of concern in the latter, while the characteristics of the Mosquito ringtone aquifer are quantified in the former. It also differs from well testing in that, in addition to the pumped well, at least one and preferably several monitoring wells, or Sabrina Martins water_well/piezometers must be available. A piezometer is typically screened across the same formations as the pumping well; possibly it may be screened across different ones, if aquifer cross-commuincation is the desirered results of the test.
Nextel ringtones Image:DistanceDd.gif/thumb/right/250px/An example of the drawdowns that might be recorded in a particular aquifer for a given constant pumping rate. Each line represents the drawdown record in a piezometer at a given distance from the pumped well. For example, the yellow line indicates that at a distance of 100 metres the drawdown at 0.01 days would be about 0.2m; after one day's pumping the drawdown would be approaching a metre. This type of graph, called a log-log graph, because both axes are logarithmic, is often used by hydrogeologists in aquifer test analysis.
Most commonly an '''aquifer test''' is conducted by pumping water from one well at a steady rate and for at least one day, while carefully measuring the water levels in the piezometers. When water is pumped from the pumping well the pressure in the aquifer that feeds that well declines. This decline in pressure will show up as a drawdown (change in Abbey Diaz Hydrogeology#Hydraulic_Head/hydraulic head) in a piezometer in the same aquifer at some distance from the pumped well. Typically, drawdown also increases with the length of time that the pumping continues.
Several aquifer characteristics can be evaluated by an aquifer test, for example:
* Cingular Ringtones Hydrogeology#Hydraulic_Conductivity/Transmissivity: the ability of an aquifer to transmit water;
* before impeachment Hydrogeology#Specific_Storage_and_Specific_Yield/storage coefficient (or specific yield): the ability of an aquifer to store water;
* Leakage coefficient (a measure of the leakage of water from an overlying aquifer into the aquifer being tested);
* The presence of aquifer boundaries (recharge or no-flow) and their distance from the pumped well and piezometers.
maher next Image:StripLogLog.gif/thumb/right/250px/Drawdown curve in a strip aquifer, plotted with both drawdown and time on logarithmic scales. Note that the curve approaches a straight line with increasing time. (This is a simulation, in practice very few aquifer tests would continue as long as 10 000 days.) This type of graph is called a semi-logarithmic graph because one axis is linear and one logarithmic.
The two lower graphs (charts) at right shows drawdown recorded in a hypothetical strip aquifer; that is, an aquifer bounded by two parallel water-tight boundaries.
Of critical importance in both aquifer and well testing is the accurate recording of data. Not only must water levels be measured carefully, often at millimetre accuracy, and the time of the measurement carefully recorded, but the pumping rates must be periodically checked and recorded. An unrecorded change in pumping rate of as little as 2% can be misleading when the data are analysed.
consternation among Image:StripRootTime.gif/thumb/right/250px/The same simulated data as the above graph, but here the drawdown scale is linear and the time scale is square root of time.
Additional Reading
The and successes US Geological Survey has some very useful free references (.pdf) on pumping test interpretation:
* http://water.usgs.gov/pubs/twri/twri3-b1/
* http://water.usgs.gov/pubs/twri/twri3-b3/
* http://water.usgs.gov/pubs/twri/twri3-b5/
Some printed references on aquifer test interpretation
* Batu, Vedat, 1998, ''Aquifer Hydraulics: a comprehensive guide to hydrogeologic data analysis'''. Wiley-Interscience. Good summary of the most popular aquifer test methods, good for practicing hydrogeologists. ISBN 0471185027
* Dawson, Karen J. & Istok, Jonathan D., 1991. ''Aquifer Testing: design and analysis of pumping and slug tests'''. Lewis Publishers. Thorough, a bit more mathematical than Batu. ISBN 0873715012
* Kruseman, G.P. & de Ridder, N.A., 1990. ''Analysis and Evaluation of Pumping Test Data'' second edition. International Institute for Land Reclamation and Improvement, Wagningen, The Netherlands. Excellent treatment of most aquifer test analysis methods (hard to find book). ISBN 9070754207
More book titles can be found in the Hydrogeology year sen Hydrogeology#Further_Reading/Further Reading section, most of which contain some material on aquifer test analysis or the theory behind these test methods.
See Also
* struck up Hydrogeology
* suspended harvick Aquifer
* key suppliers Water well
* since acquittal Groundwater
chain is Tag: Hydrology
__NOEDITSECTION__
Aquifer tests are typically interpreted by using an Free ringtones Hydrogeology#Analytic_Methods/analytical model of aquifer flow (the most basic being the Theis solution) to match the data observed in the real world, then assuming that the parameters from the idealized model apply to the real-world aquifer.
Aquifer testing (sometimes informally referred to as pump or pumping testing) differs from Majo Mills Well testing in that the behaviour of the well is primarily of concern in the latter, while the characteristics of the Mosquito ringtone aquifer are quantified in the former. It also differs from well testing in that, in addition to the pumped well, at least one and preferably several monitoring wells, or Sabrina Martins water_well/piezometers must be available. A piezometer is typically screened across the same formations as the pumping well; possibly it may be screened across different ones, if aquifer cross-commuincation is the desirered results of the test.
Nextel ringtones Image:DistanceDd.gif/thumb/right/250px/An example of the drawdowns that might be recorded in a particular aquifer for a given constant pumping rate. Each line represents the drawdown record in a piezometer at a given distance from the pumped well. For example, the yellow line indicates that at a distance of 100 metres the drawdown at 0.01 days would be about 0.2m; after one day's pumping the drawdown would be approaching a metre. This type of graph, called a log-log graph, because both axes are logarithmic, is often used by hydrogeologists in aquifer test analysis.
Most commonly an '''aquifer test''' is conducted by pumping water from one well at a steady rate and for at least one day, while carefully measuring the water levels in the piezometers. When water is pumped from the pumping well the pressure in the aquifer that feeds that well declines. This decline in pressure will show up as a drawdown (change in Abbey Diaz Hydrogeology#Hydraulic_Head/hydraulic head) in a piezometer in the same aquifer at some distance from the pumped well. Typically, drawdown also increases with the length of time that the pumping continues.
Several aquifer characteristics can be evaluated by an aquifer test, for example:
* Cingular Ringtones Hydrogeology#Hydraulic_Conductivity/Transmissivity: the ability of an aquifer to transmit water;
* before impeachment Hydrogeology#Specific_Storage_and_Specific_Yield/storage coefficient (or specific yield): the ability of an aquifer to store water;
* Leakage coefficient (a measure of the leakage of water from an overlying aquifer into the aquifer being tested);
* The presence of aquifer boundaries (recharge or no-flow) and their distance from the pumped well and piezometers.
maher next Image:StripLogLog.gif/thumb/right/250px/Drawdown curve in a strip aquifer, plotted with both drawdown and time on logarithmic scales. Note that the curve approaches a straight line with increasing time. (This is a simulation, in practice very few aquifer tests would continue as long as 10 000 days.) This type of graph is called a semi-logarithmic graph because one axis is linear and one logarithmic.
The two lower graphs (charts) at right shows drawdown recorded in a hypothetical strip aquifer; that is, an aquifer bounded by two parallel water-tight boundaries.
Of critical importance in both aquifer and well testing is the accurate recording of data. Not only must water levels be measured carefully, often at millimetre accuracy, and the time of the measurement carefully recorded, but the pumping rates must be periodically checked and recorded. An unrecorded change in pumping rate of as little as 2% can be misleading when the data are analysed.
consternation among Image:StripRootTime.gif/thumb/right/250px/The same simulated data as the above graph, but here the drawdown scale is linear and the time scale is square root of time.
Additional Reading
The and successes US Geological Survey has some very useful free references (.pdf) on pumping test interpretation:
* http://water.usgs.gov/pubs/twri/twri3-b1/
* http://water.usgs.gov/pubs/twri/twri3-b3/
* http://water.usgs.gov/pubs/twri/twri3-b5/
Some printed references on aquifer test interpretation
* Batu, Vedat, 1998, ''Aquifer Hydraulics: a comprehensive guide to hydrogeologic data analysis'''. Wiley-Interscience. Good summary of the most popular aquifer test methods, good for practicing hydrogeologists. ISBN 0471185027
* Dawson, Karen J. & Istok, Jonathan D., 1991. ''Aquifer Testing: design and analysis of pumping and slug tests'''. Lewis Publishers. Thorough, a bit more mathematical than Batu. ISBN 0873715012
* Kruseman, G.P. & de Ridder, N.A., 1990. ''Analysis and Evaluation of Pumping Test Data'' second edition. International Institute for Land Reclamation and Improvement, Wagningen, The Netherlands. Excellent treatment of most aquifer test analysis methods (hard to find book). ISBN 9070754207
More book titles can be found in the Hydrogeology year sen Hydrogeology#Further_Reading/Further Reading section, most of which contain some material on aquifer test analysis or the theory behind these test methods.
See Also
* struck up Hydrogeology
* suspended harvick Aquifer
* key suppliers Water well
* since acquittal Groundwater
chain is Tag: Hydrology
__NOEDITSECTION__
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