Groundwater
Lab Help
The textbook describes groundwater
with text and figures on pages 388-392. Problem 1: Interactions between
groundwater and the surface are described in the textbook on page 394. Problem
3: Read the discussion on aquifers in the textbook on pages
388-92. (Look at
the figs. on pages 388-391.) Problem
4: The textbook discussion of groundwater and aquifers and the
figures on pages 388-392 will help you understand the terminology.
(p. 382 will be especially helpful.)
- read
http://www.eserc.stonybrook.edu/cen514/info/LI/Groundwater.pdf
- d. Saltwater may intrude by
seeping into the ocean floor.
- f. The contour lines on map 11.9b
(lab book)
show the elevation of the water table surface. The groundwater
divide marks the ridge in the water table and would connect the
highest points.
- i. "Lithologic
character" refers to the consistency of the rock unit. Is
it uniform or highly variable?
Problem 5: This map (on the bottom of
page 83) shows both the elevation of the ground surface and the "potentiometric
surface" of a confined aquifer. See example here.
- See Figure 12.10 on page 390 of the
textbook and the discussion of confined aquifers on p. 389.
Pressure can build in a confined aquifer and a water in a well drilled
in such an aquifer may rise above the ground surface, resulting in a
well that flows without being pumped!
- a. The map at the bottom of page 84
(lab book) shows
ground surface elevations using solid tan contour lines. The
dotted lines show how high water will rise in a well drilled into a
confined aquifer. By comparing the two elevations, you can
determine how high water will rise. See example here.
- b.& c. Where will the water
rise the highest above the ground surface. Subtract the surface
elevation from the groundwater elevation to determine the height above
the surface.
- d. Where will the water be the
farthest below the ground surface. Subtract the groundwater
elevation from the surface elevation to determine the depth below the
surface.
- e. & f. Groundwater flows from
a high elevation to low elevation. Look at the surface
represented by the dotted lines.
- g. It's up to you, but justify
your choice.
Problem 6: Use the equation
below.
- volume = width x depth x permeability x
gradient
- Be sure that all the units are the same
(don't mix feet and miles).
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