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Hydrologic Cycle
Hydrologic Cycle
Sand porosity
and permeability
Fig. 19.06
W. W. Norton
Shallow aquifer
Confining bed/aquitard
Deeper aquifer
Fig. 19.07 a
Unsaturated zone
Fig. 19.11
W. W. Norton
HUMID CLIMATE
Important to identify recharge areas!!!! Do not pollute them!
Gaining Stream
Losing stream
ARID CLIMATE
Fig. 19.13
W. W. Norton
Determine which wayGroundwater flows
Determine location ofRecharge/discharge areas
Cone of depression
Fig. 19.15 a
W. W. Norton
Fig. 19.15 b
W. W. Norton
Fig. 19.15 c
W. W. Norton
Fig. 19.22 a, b
W. W. Norton
South Florida before pumping South Florida after pumping
Fig. 19.06
W. W. Norton
AQUIFER TYPES
Confining bed
Confined/artesian aquifer
Note: aquiclude = confining bed!
Fig. 19.16 c
W. W. Norton
The potentiometric surface is a pressure surface
It’s the level to which water will rise in your well!
Flooding due to subsidence in Indonesia
Fig. 19.09
W. W. Norton
Unit Conversions
Common units used to measure water are:
• cfs (cubic feet per second)• gallons• acre-foot• inches (in precip gage)
Need to be able to convert between them
Acre-foot
1 acre-foot = 43,560 ft2/acre x 1 foot = 43,560 ft3
How many gallons is this???
Cubic feet gallons
• 7.48 gallons = 1 ft3
• 43,560 ft3 x 7.48 gal/1 ft3 = 325,829 gal
Length-Area-VolumeL vs. L2 vs. L3
1 ft2
12 inches
12 inches
12 inches x 12 inches =
144 in2
=1 ft2
Length-Area-VolumeL vs. L2 vs. L3
1 ft312
inch
es
12 inches
12 inches
12 in x 12 in x 12 in = 1728 in3 = 1 ft3
CRATER LAKE
Surface area = 579,348,000 ft2
Avg. ann. Precip = 68 in.
What volume of precip. is added to the lake in acre-feet each year?
1) Need to convert units to makethem consistent. It’s easiest to convert Feet to acre-feet, so let’s convert inches toFeet!68 in x 1 foot /12 inches = 68/12 feet = 5.67 ft
2) Calculate volume of precip. in ft3 by multiplying Surface area of lake x depth of precip.579,348,000 ft2 x 5.67 ft = 3,284,903,160 ft3
3) Convert ft3 to acre-ft 3,284,903,160 ft3 x 1 ac-ft/43,560 ft3 = 75,411 acre-ft/year from ppt.
