WATER

Chapter 5, pages 86-94

Relationships of Land and Water• The Earth may be 70% water, but water interacts with

land A LOT!• Precipitation falls on land. Rain, snow, hail, etc.• Evaporation of lakes and rivers takes place on land.• Watersheds are on land—watersheds are large land

areas in which water from rain and snow drain into rivers or lakes or get absorbed into the soil to form groundwater.

• When water gets absorbed into the soil, it forms a water table. As it sinks even deeper into the rock layers below, an aquifer is formed. The largest aquifer is the Ogallala Aquifer that is actually beneath us (the central Plains of the US)

Aquifers• Aquifers are VERY VUNERABLE to pollution. They

cannot be cleaned, without a HUGE cost. (In order to clean them, water would have to be pumped up through pipes, cleaned, and then pumped back down—EXPENSIVE!)

• If we pump the water out of the groundwater faster than it is replenished by new precipitation that is sinking through the soil, then the aquifer could be drained.

• A LOT of communities rely on aquifers for their drinking water.

Groundwater Basics

• See the green box on page 92.• (know it!)

More details about watersheds—flooding!

• Plants/trees help slow down the flow of water across land. Therefore, you find more flooding occurring (usually) in urban areas rather than in forested areas.

• If the land is frozen, snow and rain have a hard time absorbing into the soil, so you get run-off and flooding.

Marshes and Wetlands

• Some of the most valuable resources in nature are marshes and swamps (wetlands).

• These help to remove contaminants from surface waters.

• Animals make their home there (ducks, geese, etc.)

Indicator Species

• Sensitive organisms that show the state of an environment’s overall health.

• The four categories of indicator species in water are fish, aquatic invertebrates (aquatic insects, snails, etc.), algae, and aquatic plants.

• A pollutant in the water might cause indicator species to die off or become unhealthy, OR pollutants may make it so that only species that can tolerate pollution live in that stream or river.

Assignment

Essay questions: 1-4, 7, 9, 10, 12, 13 and Multiple Choice questions: 1-8,

10-12Turn in when done….and if not done

by the end of the hour, it is homework and due at the beginning

of class on Monday.