Water Resources. Chapter 14. Why is water so important?. All organisms are made up mostly of water Plays a key role in; -sculpting the earth’s surface -moderating climate -diluting pollution. I. WATER’S UNIQUE PROPERTIES. High Heat of Evaporation Great Dissolving Power
-sculpting the earth’s surface
A. Water into the atmosphere
B. Water out of the atmosphere
C. Water over and through the soil
High temperature = increased moisture
Low temperature = decreased moisture
All forms of moisture out of the atmosphere
Rain Shadow Effect:
Air sweeps up the windward side of a mountain, pressure decreases, and the air cools.
1. Runoff or Surface Water:
-Water that flows directly over the surface into streams that form rivers which make lakes and eventually run into the oceans.
Watershed or Drainage Basin:
-The land area that drains a particular waterway
Example: Ohio River Watershed is where we live
Infiltration is the process of water seeping through the various layers of soil.Infiltration:
Porous layers of sand, gravel, or rock lying below the water table
Pressurized aquifer where water flows without pumping. (Examples: seeps and springs)
Areas where water infiltrates into an aquifer
Evaporation and transpiration
Well requiring a pump
Less permeable material
such as clay
Confirming permeable rock layerGround Water
-97% of water is found in the oceans
-3% freshwater - most locked up in glaciers or too deep to obtain.
-0.014% is available for use
Readily accessible freshwater
Fig. 13.2, p. 296
Water may reside briefly in one compartment or stay there for eons.
Glaciers, Ice, and Snow
Rivers and Streams
Lakes and Ponds
United States evaporates.
Acute shortage evaporates.
Metropolitan regions with population greater than 1 million
Personal Water Usage evaporates.
According to the experts there are four causes of water scarcity…
1. Dry climate
4. Water stress
WORLD WATER STRESS evaporates.
There are six ways to increase the supply of freshwater in a particular area:
B. Transferring Surface Water
C. Withdrawing Groundwater
E. Cloud Seeding
F. Decreasing Water Waste
-Capture and store runoff that can be released as needed.
-Worldwide they have increased available runoff by 1/3.
-Increase water for irrigation and recreation
-Decrease water flow
Downstream cropland and evaporates.
estuaries are deprived of
Flooded land destroys forests or cropland and
of water through
Downstream flooding is reduced
Reservoir is useful for recreation and fishing
Can produce cheap electricity
Migration and spawning of some fish are disruptedUsing Dams and Reservoirs to Supply More Water
- Often associated with dams and reservoirs
-Moving water from rich to depleted areas
- California Water Project
Oroville Dam and
San Luis Dam
C. Withdrawing Groundwater evaporates.
-Removal of water from AQUIFERS
-In U.S.; 50% of drinking water and 43% of irrigation water come from the ground.
-Decrease water table
-Draw chemicals/salt water
-Cone of Depression
-Available all year
Major irrigation evaporates.
D. Desalination: evaporates.
-Removal of salts from ocean or brackish water
Reverse Osmosis evaporates.
E. evaporates.Cloud Seeding
-Creating rain by dumping chemicals into the atmosphere
-Can’t be used in extremely arid regions
-Introduce large amounts of chemicals into the soil/water
1. Commercially: evaporates.
F.Decreasing Water Waste
A. Improving manufacturing processes
B. Improving irrigation techniques
Center Pivot evaporates.
(efficiency 80% with low-pressure
sprinkler and 90–95% with LEPA sprinkler)
Water usually pumped from
underground and sprayed from
mobile boom with sprinklers.
(efficiency 60% and 80% with surge valves)
Water usually comes from an
aqueduct system or a nearby river.
Above- or below-ground pipes
or tubes deliver water to
individual plant roots.
A. Reduce losses due to leakage evaporates.
2. Home, Businesses
B. Reform water laws
C. Water efficient landscaping (XERISCAPING)
D. Water efficient appliances
-Natural phenomena with spillage intoFLOOD PLANS
-Renew and replenish
-Aggravated by human activities
Over $1 trillion in real estate in USA flood plains
1. CHANNELIZATION: Deepen, widen, and straighten waterways
2. ARTIFICIAL LEEVES: evaporates. Walls to prevent water into floodplains
3. FLOOD CONTROL DAMS
Levee Failures During Katrina evaporates.
Extremely severe evaporates.
FLOOD PRONE AREAS
A. SURFACE WATER
-Anyone whose land adjoins a stream has the right to use H2O as long as some remains
-1st come, 1st served
-Later users are cutoff to satisfy early users