A sample of drill core collected from an unconfined sandstone aquifer was tested using a constant head permeameter with a radius of 3cm at 20°C and provided the following data:
Flow rate = 0.18 cm3/min
Distance between manometers = 5 cm
Difference in head between manometers = 2.8 cm
A well in the same aquifer was pumped to a steady state, and the following information measured in a series of observation wells: (refer to attachments)
- Calculate the hydraulic conductivity of the rock sample.
- Use the data from the well pumping test to calculate the hydraulic conductivity of the aquifer as a whole.
- Suggest possible reasons for the differences in the results of your two calculations, and discuss the relative advantages and disadvantages of field and laboratory permeability tests.© BrainMass Inc. brainmass.com August 17, 2018, 5:02 am ad1c9bdddf
Calculate the hydraulic conductivity of the rock sample.
Q= flow rate, K= hydraulic conductivity, i= hydraulic gradient = change in hydraulic head/change in distance, A = cross sectional areas
(2) A= r^2pi
A = (3 cm)^2 x pi = 28.27 cm^2
rearranging equation (1), isolate for K, hydraulic conductivity
(3) K = Q/iA
K = 0.18 cm3/min / (2.8cm/5cm)*28.27 cm^2
K = 0.0114 cm/min
Use the data from the well pumping test to calculate the hydraulic conductivity of the ...
The distances between manometers for hydraulic conductivity is examined.