Difference between revisions of "Hydraulic Conductivity - Amoozemeter"
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==Method:== | ==Method:== | ||
| − | Constant head permeameter: Measures infiltration rate within an auger hole up to a depth of 2 m and with extension set up to a depth of 4 m. A constant hydraulic head is kept in the auger hole . | + | Constant head permeameter: Measures infiltration rate within an auger hole up to a depth of 2 m and with extension set up to a depth of 4 m. A constant hydraulic head is kept in the auger hole which must be H/r >= 5 and the infiltration rate will be monitored until steady state flow is attained. Hydraulic conductivity will be calculated with the equation of Glover (Amoozegar, 1989b, 1993) |
==Equipment:== | ==Equipment:== | ||
| Line 12: | Line 12: | ||
* in-situ measurement, no analysis of disturbed soil samples in lab | * in-situ measurement, no analysis of disturbed soil samples in lab | ||
* measurement in different depths of soil profile | * measurement in different depths of soil profile | ||
| − | * easily transportable for | + | * easily transportable for monitoring at any location |
* less water consume | * less water consume | ||
| Line 19: | Line 19: | ||
* price | * price | ||
* exact geometry of auger hole as specified in the equation is not often realised | * exact geometry of auger hole as specified in the equation is not often realised | ||
| − | * in depth up to 70 cm the measurment is complicated because of | + | * in depth up to 70 cm the measurment is complicated because of controling water level |
| + | * soils with high content of gravels and boulders would be problematic because of realsing the correct geometry of the auger hole | ||
==What to watch out for:== | ==What to watch out for:== | ||
| Line 41: | Line 42: | ||
==References== | ==References== | ||
| − | + | Amoozegar, A. (1989a), A compact, constant-head permeameter for measuring saturated hydraulic conductivity of the vadose zone, Soil Sci. Soc. Am. J., 53, 1356–1361. | |
| − | + | Amoozegar, A. (1989b), Comparison of the Glover solution with the simultaneous equations approach for measuring hydraulic onductivity, Soil Sci. Soc. Am. J., 53, 1362–1367. | |
| + | Amoozegar, A. (1993), Comments on ‘‘Methods for analyzing constanthead well permeameter data’’, Soil Sci. Soc. Am. J., 57, 559– 560. | ||
| + | Elrick, D. E., and W. D. Reynolds (1992), Methods for analyzing constanthead well permeameter data, Soil Sci. Soc. Am. J., 56, 320– 323. | ||
| + | Sobieraj, J. A., H. Elsenbeer, R. M. Coelho, and B. Newton (2002), Spatial variability of soil hydraulic conductivity along a ropical rainforest catena, Geoderma, 108, 79– 90. | ||
[[Category:Equipment]] | [[Category:Equipment]] | ||
[[Category:Hydraulic Conductivity]] | [[Category:Hydraulic Conductivity]] | ||
Revision as of 14:19, 17 December 2008
Parameter to be measured:
Hydraulic conductivity
Method:
Constant head permeameter: Measures infiltration rate within an auger hole up to a depth of 2 m and with extension set up to a depth of 4 m. A constant hydraulic head is kept in the auger hole which must be H/r >= 5 and the infiltration rate will be monitored until steady state flow is attained. Hydraulic conductivity will be calculated with the equation of Glover (Amoozegar, 1989b, 1993)
Equipment:
Advantages:
- in-situ measurement, no analysis of disturbed soil samples in lab
- measurement in different depths of soil profile
- easily transportable for monitoring at any location
- less water consume
Disadvantages:
- many pipes and valves - requires practice and understanding to recognise errors, set-up time
- price
- exact geometry of auger hole as specified in the equation is not often realised
- in depth up to 70 cm the measurment is complicated because of controling water level
- soils with high content of gravels and boulders would be problematic because of realsing the correct geometry of the auger hole
What to watch out for:
potential problems with
- hydrophobic soils
- heterogenous water content of soil before measurement
- strong effects from preferential flowpaths
- strong swelling/shrinking of soil
- effects of impermeable layers before stationarity is achieved
- inclined, uneven surfaces
Problems/Questions:
Links
Projects that used the above equipment:
Other related web sites:
References
Amoozegar, A. (1989a), A compact, constant-head permeameter for measuring saturated hydraulic conductivity of the vadose zone, Soil Sci. Soc. Am. J., 53, 1356–1361. Amoozegar, A. (1989b), Comparison of the Glover solution with the simultaneous equations approach for measuring hydraulic onductivity, Soil Sci. Soc. Am. J., 53, 1362–1367. Amoozegar, A. (1993), Comments on ‘‘Methods for analyzing constanthead well permeameter data’’, Soil Sci. Soc. Am. J., 57, 559– 560. Elrick, D. E., and W. D. Reynolds (1992), Methods for analyzing constanthead well permeameter data, Soil Sci. Soc. Am. J., 56, 320– 323. Sobieraj, J. A., H. Elsenbeer, R. M. Coelho, and B. Newton (2002), Spatial variability of soil hydraulic conductivity along a ropical rainforest catena, Geoderma, 108, 79– 90.