Estimate the radius of influence of a well

get_ROI(..., method)

Arguments

...	Variable parameters, depending on the method used. Single numbers or vectors (of equal length)
method	String containing the name of the desired method

Value

A numeric value indicating the horizontal radius of influence of the well.

Methods

The methods below are taken from Fileccia (2015). Acque Sotterranee - Italian Journal of Groundwater (http://www.doi.org/10.7343/AS-117-15-0144). The following strings can be input for the method variable, and must be accompanied by the corresponding variables as part of the ... input:

"cooper-jacob":

\(R=\sqrt{2.25 Tr t / S}\), for confined aquifer after short pumping period. (Cooper and Jacob, 1946)

"aravin-numerov":

\(R=\sqrt{1.9 Ksat h t / n}\), for unconfined aquifers (Aravin and Numerov, 1953)

"sichardt":

\(R=3000 s \sqrt{Ksat}\), Sichardt formula for unconfined aquifers (Cashman and Preene, 2001)

Where:

R = radius of influence [m]
Tr = transmissivity [m^2/s]
t = time [s]
S = storage
h = height of the water table above substratum [m]
n = effective porosity
Ksat = saturated hydraulic conductivity [m/s]
s = drawdown in the borehole [m]

These inputs can be single numbers or vectors of equal length.

Examples

get_ROI(Tr=0.01,t=3600*12,S=1,method="cooper-jacob")
#> [1] 31.17691
get_ROI(Ksat=0.0001,h=50,t=3600*12,n=0.4,method="aravin-numerov")
#> [1] 32.03123
get_ROI(Ksat=0.0001,s=10,method="sichardt")
#> [1] 300