Hydraulic Conductivity

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Description

These functions are used to calculate a soil's hydraulic conductivity from standard laboratory tests (kConstant for the constant head test and kFalling for the falling head test), and to calculate the equivalent horizontal and vertical hydraulic conductivity for layered soil deposits (kx and kz, respectively).

Usage

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kConstant(V, t, h, L, As = NA, Ds = NA)
kFalling(h0, hf, t, L, As = NA, Ap = NA, Ds = NA, Dp = NA)
kx(thk, k)
kz(thk, k)

Arguments

t

time of flow

L

length of soil sample

As

cross-sectional area of the soil sample

Ds

diameter of soil sample

V

volume of water collected (constant head test)

h

head difference between inflow and outflow (constant head test)

h0

head difference at beginning of test (falling head test)

hf

head difference at end of test (h0 > hf; falling head test)

Ap

cross-sectional area of the standpipe (falling head test)

Dp

diameter of the standpipe (falling head test)

thk

vector of layer thicknesses

k

vector of hydraulic conductivities

Details

  • Either English or metric units can be used, but they must be consistent.

  • Either the areas or the diameters of the soil sample (or standpipe) need to be specified.

Value

  • kConstant calculates the measured hydraulic conductivity from the constant head test

  • kFalling calculates the measured hydraulic conductivity from the falling head test

  • kx calculates the equivalent hydraulic conductivity in the horizontal direction for a layered soil deposit

  • kz calculates the equivalent hydraulic conductivity in the vertical direction for a layered soil deposit

Author(s)

James Kaklamanos <kaklamanosj@merrimack.edu> and Kyle Elmy <ElmyK@merrimack.edu>

See Also

wellHydraulics

Examples

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##  Example code for Hydraulic Conductivity from Constant head test
##  k in units of cm/s
kConstant(V = 800, t = 100, h = 200, A = 40, L = 50)

##  Example code for Hydraulic Conductivity from Falling head test
##  k in units of cm/s
kFalling(h0 = 12, hf = 2, L = 10, Ds = 20, Dp = 2, t = 100)