CE En 547 - Midterm Exam #1 KEY

Fall Semester 2017

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Short Answer

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

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?


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


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