Oscillations in the Water Level

In some tests, the water level may oscillate in the well resulting in negative head values. Although none of the test analysis methods in Super Slug specifically analyze oscillating data, the data can still be entered. The arithmetic and semi-log graphs will display the negative head values.

Slug test analysis methods implemented by Super Slug can not accommodate the oscillations. When the test is run, negative head values will be ignored. A negative head value will result in a negative head ratio. Any graph that displays the log of head ratio will not be able to display negative head values, because the log of a negative number will cause an error.

See the pre-loaded example file Oscillating Water Level from File | Example Data Sets for an example of a data set with oscillating water levels. Several examples included with Super Slug also contain data oscillations.

Here is example data from LF2MW03.SLG showing how oscillations result in negative drawdown.

Measured Adjusted Measured Head Head

Time Time Drawdown Change Ratio

(seconds) (seconds) (meters) (meters)

0 0 0.206 0.206 1

0.498 0.498 0.12 0.12 0.585

0.996 0.996 0.0201 0.0201 0.0978

1.5 1.5 0.000914 0.000914 0.00444

2 2 -0.00274 -0.00274 -0.0133

2.5 2.5 -0.00183 -0.00183 -0.00889

3 3 0.000914 0.000914 0.00444

4 4 0.000914 0.000914 0.00444