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Wetlands and Groundwater. 11.3. Types of Wetlands. 3types: Marshes – low moist grassy areas surrounding fresh or salt water Swamps – Trees or shrubs growing on wet or water covered land – usually found in warm moist low lying areas - can be fresh or salt.
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Types of Wetlands • 3types: • Marshes – low moist grassy areas surrounding fresh or salt water • Swamps – Trees or shrubs growing on wet or water covered land – usually found in warm moist low lying areas - can be fresh or salt. • Bogs - low lying moist, acidic areas covered with mostly mosses – found in cooler climate areas – fresh water wetlands formed by glaciers during last ice age
Importance of Wetlands - wildlife • Provides shelter and food for a wide diversity of organisms • Provides temporary rest and food for migratory animals ( on the flyway) • Provides habitat for endangered animals and plants
Importance of wetlands - people • Spreads out excess water to limit flooding and erosion especially on coasts • Absorbs and neutralizes some pollutants – both plants and silt do this • Traps silt and mud in plant roots – building up new land. • Provides habitat for hunting and sporting
Groundwater • Aquifer – permeable rock that collects and holds groundwater. • Water table is the uppermost surface of water in an aquifer – When it is above ground, a spring forms as water bubbles out of cracks in the rock. • Outcrops of the aquifer on the surface serves as a recharge zone where precipitation replenishes water in aquifer. • Groundwater can travel long distances and stay underground for thousands of years.
Wells • Water can be brought to the surface from an aquifer by drilling a well below the water table. • Heavy use on an aquifer can lower the water table as can building over the recharge zone • Water can be pumped to surface – it lowers water level near well, but it will recharge in time • Water trapped between 2 layers of impermeable rock are put under pressure and when drilled form artesian well where water flows freely to surface due to pressure within aquifer.
Springs and geysers • In areas with geothermal activity – water heated below surface can be put under pressure due to heat and bubble to surface through cracks in the bedrock – This forms hot springs • Geysers form when heated water underground is forced up due to hot gases and steam. Pressure builds and eventually forces water and gases to erupt above ground as a fountain through small passageways in the rock.