straightline
method is applied for timedrawdown, distancedrawdown and
timedistance drawdown plot analysis. Besides, for some conceptual
schemes the method is used applied to plots of dimensionless
time and dimensionless distance to the pumping wells (e.g. for
bounded aquifers or multiwell tests).
The
"Value"
supplemental window displaying previously selected wells (or
observation points on distancedrawdown plot) together with
parameters estimated by straightline method, appears
simultaneously with the straight line.
The method is
applied wherever the flow equation of the chosen conceptual scheme
allows and is usually appropriate for quasisteadystate section of
the diagnostic curve.
For
normal plots
the
first straight line superposition on the diagnostic plot is made
automatically by minimizing the observation points deviation from
the straight line.
Aquifer test analysis by straightline method.
Key functions for straightline method
LEFT,
RIGHT

Move the
straight line left/right

UP, DOWN

Move the
straight line up/down

HOME, END

Move the
straight line left ending up/down

PgUp,
PgDn

Move the
straight right ending up/down

"1"

Twice reduce the
step width

"2"

Twice increase
the step width

"3"

Return to the
initial step width

"+",
"–"

Maximize/minimize
the straight line

Left mouse click
in the plot field

Move the
straight line left ending to the cursor position

Right mouse
click in the plot field

Move the
straight line right ending to the cursor position

ENTER

Duplication of
the straight line on
the plot

Select the well
in "Value"
dialog box

Switch to
analysis of the selected well. On distancedrawdown plot selected
time points are displayed here

ESC

Escape from the
straightline method analysis

The method can
be supplementary used for parameter estimation by steadystate
intervals of the diagnostic curve (for recharge boundary
conditions, for instance). The straight line is parallel to the
abscissa axis and is moved upward or down, the parameter being
determined by its intercept on ordinate axis.
Example of transmissivity estimation by straight line interval of
the diagnostic curve for a semiinfinite aquifer with a recharge
boundary.
Similar analysis
is available for quasisteadystate flow on the graph plotted
for 2 wells.
