Lecture 28

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Bouwer and Rice Method

 

Fetter 7.5.4

 

Uses Theim’s Equation-

 

rc - radius of well casing(L)
R - radius of gravel envelope (L)
Re - effective radial distance over which head is dissipated(L)
Le - length of screen
H0 - drawdown at t = 0
H - drawdown at t = t
t - time since H = H0

 

 

Bouwer and Rice established way for getting Re/R

 If Lw < h (saturated thickness) partially penetrating-

ln =
 ln =
A, B, C are dimensionless from curve of Bouwer.

 

 

Figure 7.24 Geometry and symbols for a slug test on a partially

penetrating screened well in an unconfined aquifer with a gravel

pack around the screen.

Figure 7.25 Dimensionless parameters A, B, and C plotted as a

function of Le/rw. These parameters are used in the determination

of ln (Re/R).

 

Graphical Method

 

 

Methods of Determining Values of Selected Hydraulic Parameters

 

Method

Parameter

Grain size Analysis

Lab permeameter

Slug

Test

Pumping

Test

Flow

Net

Kh

X

X

X

X

X

Kv

X

s

T

X

X

X

X

S or Sy

X

s

X

K’

X

X

X

 s = some test methods

 

Uncon-fined

Confined

Natural

Anthro-pogenic

Short-lived

Diurnal

Seasonal

Long term

Climatic

Ground-water

Recharge

X

X

X

X

Air trapped during recharge

X

X

X

X

ET and plant use

X

X

X

X

Bank-storage effects

X

X

X

X

Tidal effects

X

X

X

X

Atmospheric pressure effects

X

X

X

X

X

Earthquakes

X

X

X

G-w pumping

X

X

X

X

Deep-well injection

X

X

X

Artificial recharge

X

X

X

Agricultural irrigation

X

X

X

X

Geotechnical drainage of mines, ...

X

X

X

 

 

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