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Hydrologic Cycle
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Solar-powered movement of water between the sea, air, and land
Follows water as it evaporates from the earth’s surface, forms clouds, and then falls back to the surface as precipitation
Cycle is continuous with no beginning or end
Basic Steps:
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Condensation
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Precipitation
Infiltration
Runoff
Evapotranspiration

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Provide examples for the following terms:
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Condensation
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Precipitation
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Infiltration
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Runoff
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Evapotranspiration

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Water available for use:
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97.2% salt water
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2.8% fresh water
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2.2% is in glaciers and ice caps
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0.6% is groundwater
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0.01% in lakes, rivers, and streams
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0.001% is water vapor

Water Availability
Salt Water
Glaciers and Ice Caps
Groundwater
Lakes and Rivers
Atmosphere

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Uses of Fresh Water
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Agriculture
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69% for irrigation
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Industrial
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15% for power plants, refineries, manufacturing
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Household
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15% for drinking, cooking, sanitation, gardening, etc.
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Recreational
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Environmental

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What steps of the water cycle can we get our water from?
For each use of water, identify if you use it directly (D), indirectly (I), or not at all (N/A).
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Agriculture
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Industrial
Household
Recreational
Environmental

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Estimated only 0.34% of all water on earth is available for human use
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Fresh water supply decreasing due to pollution:
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Point Pollution
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Landfills
Industrial waste
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Power plants
Smoke stacks
Leaking pipelines or storage tanks
Livestock waste
Non-Point Pollution
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Sewage/Combined Sewer Overflow (CSO)
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Road salt
Fertilizer/pesticide runoff
Litter

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Water Pollution
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Any chemical, biological, or physical change in water quality that has a harmful effect on living organisms or makes water unsuitable for desired uses
Major Pollutants
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Fecal Coliform
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Disease causing bacteria
Non-point toxic chemicals
Discharges of untreated sewage
Discharges of industrial wastes

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Non-degradable wastes
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Toxic lead, arsenic, fluoride are permanent pollutants
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Slowly degradable wastes
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Ex. DDT
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May be there for decades, centuries, or longer

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Compare and contrast point and non-point pollution.
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Consider runoff. Is this a bigger concern for point or non-point pollution?
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Explain why slowly degradable and nondegradable water pollution is such a concern.