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.