Difference between revisions of "Infiltration - Hood Infiltrometer"
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(New page: ==Parameter to be measured:== ==Method:== ==Equipment:== ==Advantages:== ==Disadvantages:== ==What to watch out for:== ==Problems/Questions:== ==Links== Projects that used th...) |
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| Line 1: | Line 1: | ||
==Parameter to be measured:== | ==Parameter to be measured:== | ||
| − | + | Infiltrability, hydraulic conductivity | |
==Method:== | ==Method:== | ||
| − | + | Tension-infiltrometer (UGT IL-2700): Measures infiltration rate within a hood that is placed onto soil surface. Hydraulic head within hood can be adjusted between 0 (=saturated conductivity) and bubbling pressure by means of a Mariotte-bottle, optional data interface and software (I haven't worked with these) | |
==Equipment:== | ==Equipment:== | ||
| − | + | * main reservoir (with combined) Mariotte-bottle | |
| + | * hood (various sizes), steel rim | ||
| + | * connecting tubes, manometer (e.g. U-style), hand pump | ||
| + | * datasheets, stop watch, sand (for sealing hood rim with soil surface) | ||
| + | * scissors for clipping vegetation | ||
| + | * spade (if levelling or deeper measurements are necessary) | ||
| + | * large water vessels for supply | ||
==Advantages:== | ==Advantages:== | ||
| + | * in-situ measurement, no analysis of disturbed soil samples in lab | ||
| + | * no contact layer with soil required (as with ceramic plates) | ||
| + | * works with reasonably uneven surfaces and original vegetation | ||
| + | * no need to drill neat holes (as with a constant head permeameter like the Amoozemeter) which is problematic in stony soils | ||
==Disadvantages:== | ==Disadvantages:== | ||
| − | + | * heavy, comes in huge metal suitcase (17 kg) | |
| + | * large water consumption with sandy soils | ||
| + | * many pipes and valves - requires practice and understanding to recognise errors, set-up time | ||
| + | * lots of potentially leaky connections and many parts to loose in the field | ||
| + | * measurement in different depths of soil profile is complicated, though possible when digging pits | ||
| + | * price | ||
==What to watch out for:== | ==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 | ||
| + | * inequivocal identification of stationary flow | ||
| + | (worksheet of H. Elsenbeer) | ||
| + | * insolation and temperature related problems | ||
==Problems/Questions:== | ==Problems/Questions:== | ||
| Line 21: | Line 45: | ||
==Links== | ==Links== | ||
| + | UGT [http://www.ugt-online.de/neu_englisch/Produkte/14_Hydraulische_Pneumatische_L/142000.html] | ||
| + | no-frills-instruction (in German) | ||
| + | [http://brandenburg.geoecology.uni-potsdam.de/projekte/sesam/download/fieldwork/haube_fuer_dummys.pdf] | ||
| + | |||
Projects that used the above equipment: | Projects that used the above equipment: | ||
| − | + | SESAM [http://brandenburg.geoecology.uni-potsdam.de/projekte/sesam/index.php] | |
Other related web sites: | Other related web sites: | ||
| Line 28: | Line 56: | ||
==References== | ==References== | ||
| + | Gardner, W.R., 1958. Some steady-state solutions of unsaturated moisture flow equations with application to evaporation from a water table. Soil Science 85, 228-232. | ||
| + | |||
| + | Wooding, R.A., 1968. Steady infiltration from a shallow circular pond. Water Resources Research 4, 1259-1273. | ||
| + | |||
[[Category:Equipment]] | [[Category:Equipment]] | ||
Revision as of 11:08, 29 March 2007
Parameter to be measured:
Infiltrability, hydraulic conductivity
Method:
Tension-infiltrometer (UGT IL-2700): Measures infiltration rate within a hood that is placed onto soil surface. Hydraulic head within hood can be adjusted between 0 (=saturated conductivity) and bubbling pressure by means of a Mariotte-bottle, optional data interface and software (I haven't worked with these)
Equipment:
- main reservoir (with combined) Mariotte-bottle
- hood (various sizes), steel rim
- connecting tubes, manometer (e.g. U-style), hand pump
- datasheets, stop watch, sand (for sealing hood rim with soil surface)
- scissors for clipping vegetation
- spade (if levelling or deeper measurements are necessary)
- large water vessels for supply
Advantages:
- in-situ measurement, no analysis of disturbed soil samples in lab
- no contact layer with soil required (as with ceramic plates)
- works with reasonably uneven surfaces and original vegetation
- no need to drill neat holes (as with a constant head permeameter like the Amoozemeter) which is problematic in stony soils
Disadvantages:
- heavy, comes in huge metal suitcase (17 kg)
- large water consumption with sandy soils
- many pipes and valves - requires practice and understanding to recognise errors, set-up time
- lots of potentially leaky connections and many parts to loose in the field
- measurement in different depths of soil profile is complicated, though possible when digging pits
- price
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
- inequivocal identification of stationary flow
(worksheet of H. Elsenbeer)
- insolation and temperature related problems
Problems/Questions:
Links
UGT [1] no-frills-instruction (in German) [2]
Projects that used the above equipment: SESAM [3]
Other related web sites:
References
Gardner, W.R., 1958. Some steady-state solutions of unsaturated moisture flow equations with application to evaporation from a water table. Soil Science 85, 228-232.
Wooding, R.A., 1968. Steady infiltration from a shallow circular pond. Water Resources Research 4, 1259-1273.