Unit V

Earth Systems &Resources

Water Resources

• Properties of Water– 2 parts Hydrogen and 1 part Oxygen

(H2O)

– Water is never completely pure in nature.

• Many substances water dissolves and causes water pollution

• Contents of Sea Water

Hydrologic Cycle• The same water has been recycled

through the atmosphere since the earth’s beginning!

• Evaporation

• Condensation

• Precipitation

Hydrologic Cycle

• Transpiration

• Respiration/Perspiration

A drop of water could spend as little as 9 days in the

atmosphere or as much as 40,000 years in the ocean

before being recycled.

Distribution of Water

• Ocean Water– 97.5% of planet’s water

• Cover 75% of the planet’s surface

• Freshwater– Remaining 3% divided

between rivers, lakes, groundwater, aquifers

– greatest amount is in glaciers and polar ice

– only ~0.5% is available freshwater

Water Terminolgy

• Surface Water

• Runoff

• Watershed (drainage basin)

• Groundwater

• Aquifer

Aquifers

Water Bodies• Rivers

• Lakes

• Seas

• Oceans– Can you name all 5 oceans?

Water Supply Issues• 3 basic categories:

– Too much water– Too little water– Poor quality/contamination of water

• Balanced water budgets have equal amounts of water coming in as going out in all locations.

• Situations Create Changes

Water Usage• Water Uses

– World Uses• Irrigation ~ • Energy ~• Domestic Use ~

Too Much Water!• Flooding

– Both natural and human induced

Too Little Water• Causes:

• Aquifer depletion:

Problems in US• Overall, US has plentiful

water

Problems in US• Water shortages in West and

Southwest

• Mono Lake (Eastern CA)

• Colorado River Basin

Aquifer Depletion

Aquifer Depletion

• Ogallala Aquifer

Global Problems• Water Budgets aren’t Balanced!

– Climate Change

– Drinking Water

Global Problems– Population Growth

– Sharing Water Resources

Dams & Reservoirs• Benefits: • Disadvantages

Dams & Reservoirs• Disadvantages

Water Diversion Projects

• Water diverted to areas deficient– California Aqueduct Project

Other Water Supplies• Desalinization

– Removal of salt from sea water

– Two methods:– Distillation

– Reverse Osmosis

– Very Expensive

• Cloud Seeding– Saturation of existing clouds to promote rain.

Irrigation Issues• Irrigation is largest user

of water in the world.

• Gravity Flow

• Center Pivot

Irrigation Issues

• Drip Irrigation

Water Conservation• Reduction of Industrial Water Waste

• Reduction of Municipal Water Waste

Soil Resources• Soil

– Controls the distribution of rainfall, regulates biological activity, and filters water, air, and nutrients.

– Soil Forming Factors

Soil• Not just dirt!

• Mixture of eroded rock, minerals, inorganic nutrients, decaying organic matter, water, air, and living organisms.

• Soil Composition– % mineral matter

• weathered rock– % organic matter

• detritus– %water– % air

Soil

Soil Layers• Horizons

– soil forms in horizontal layers called horizons

– most plant roots are in the first two layers

– O Horizon

– A Horizon

Soil Layers– E Horizon

– B Horizon

– C Horizon

– Bedrock

Soil Layers

Soil Structure• Clay

– smallest particle size

• Silt– medium sized particles

• Sand– relatively large particle size

Soil Structure• Gravel

– largest particle size

• Loam

Soil Structure

Soil Quality• Porosity

• Structure

• Sorting

• Permeability

Soil Quality• Conductivity

• Nutrient Retention

• Stability

• pH

Erosion• Removes soil and ruins surface water

where the soil is deposited.• Causes

• Accelerated by poor agricultural practices

Erosion• Great Dust Bowl of 1930s

– severe drought• 1930-1937

– poor agricultural practices• no natural vegetative roots to

hold soil in place

Agricultural Degredation• Soil Salinization

Agricultural Degredation• Desertification

Increasing Crop Production• Fertilizer Methods/Types

– Organic Fertilizers• Animal manure

• Green manure

• Compost

– Inorganic Fertilizers

Soil Conservation• Erosion Reduction Methods:

– Conservation Tillage Farming

– Crop Rotation

– Contour Farming

Soil Conservation• Erosion Reduction Methods:

– Terracing

– Strip Cropping

Strip Strip CroppingCropping

TerracinTerracingg

Soil Conservation• Erosion Reduction Methods:

– Alley Cropping/Agroforestry/Shelterbelts

Soil Conservation Laws• Soil Conservation Act of 1935

– authorized formation of Soil Conservation Service, now called Natural Resource Conservation Service (NRCS)

– assess soil damage and develop BMPs to improve soil

• Food Security Act (Farm Bill) 1985– farmers with highly erodible soil had to change

their farming practices– instituted Conservation Reserve Program

• pays farmers to stop farming highly erodible land

Soil Conservation Laws• 1872 Mining Law

– Forces government to sell public land leases to private investors at bargain prices

– Requires companies to return site to as good of condition, if not better, when completion of mining activity

• companies can (and have) abandon site or file for bankruptcy.

– leaves taxpayers with the clean-up bill– some sites cost several million dollars to

remediate

Mineral Resources• Minerals

– Naturally occurring elements or inorganic compounds found in Earth’s crust.

• Elements or compounds of elements that occur naturally in the Earth’s crust.

– Rocks

– Ores

Minerals• Unevenly distributed throughout the world

• Discovery of new reserves

Mining• Surface Mining

– extracts ~ of minerals in US ( of coal)– Open-Pit Mining

– Strip-Mining/Mountain Top Mining

• Subsurface (Traditional) Mining

Open Pit Mine

Ore Processing

• Smelting– process in which ore is

melted at high temps to separate impurities from the molten metal

Mining Effects• Disturbs large area

• Uses large quantities of water

• Acid Mine Drainage (AMD)

Mining Effects• Mill Tailings

• Smelting plants

Mining Restoration• Goals

• prevent further degradation and erosion of land, eliminate local sources of toxins and make land productive for another purpose

• Creative Approaches– Wetlands

– Phytoremediation

Minerals• Reserves

– mineral deposits that have been identified and are currently profitable to extract

– Highly developed countries

– Developing countries

Minerals

Other Mineral Reserves• Antarctica

– no substantial mineral deposits identified to date– Antarctica Treaty of 1961

• limits activity to peaceful uses– Madrid Protocol of 1990

• Moratorium on mineral exploration

• Deep Ocean– may provide us with future supplies

• extracting minerals from seawater

• mining seafloor

– manganese nodules

Manganese Nodule Deposits

Mineral Conservation

• Reduce– the amount of materials you use

• Reuse– lunch boxes, sandwich bags, grocery bags,

soda bottles, diapers

• Repair– instead of replace

Mineral Conservation• Recycle

– Paper is the most recycled item

Four “R’s”• Recycle

– USE THE BINS!– Paper is the most recycled item– Primary/Closed Loop Recycling

• Waste is recycled into new products of same type

– old cans into new cans, old newspaper into new newspaper

– Secondary/Open Loop Recycling• Convert waste materials into different products

– Newspapers into cellulose insulation

– Preconsumer/Internal Wastes• wastes from manufacturing process

– Postconsumer/External Wastes• wastes generated by the consumer