CE En 547 - Midterm Exam #1 KEY

Fall Semester 2017

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Short Answer

Click here to access the Equation Sheet.

14. (2 pts) (modflow) The package typically used to simulate lakes and reservoirs in MODFLOW is called the
package.

15. (2 pts) (head-darcy) In groundwater models, total head is a combination of head and head.

16. (1.75 pts) (head-darcy) For flow parallel to the layering, the equivalent hydraulic conductivity is generally dominated by a layer with a value of k.

17. (2 pts) (modflow) In MODFLOW, the array is used to classify cells as inactive, specified head, or variable head.

18. (head-darcy) The water level in an observation well A is measured at 3785.4 ft. At a point 1238 ft downgradient from that point, the water level in a second well (B) is measured at 3629.3 ft.

a. (3 pts) What is the hydraulic gradient between the well A and well B?



b. (2 pts) Assuming that the hydraulic conductivity is 3.0 ft/day and the effective porosity is 0.3, what is the seepage velocity between the two points?

[ft/day]

c. (1.5 pts) How long would it take for a particle to travel from point A to point B?

[days]

19. (2 pts) (gw-concepts) Tweaking the model inputs until the model outputs match field observations is called .