Water- A Fragile Resource
You Wanna be a Hydrologist? Deals w/ properties, distribution, and circulation of H 2 O on and below earth's surface and in air.
Hydrologic cycle: movement of water from atmosphere, to terrestrial areas, and back. Evaporation/Transpiration Condensation Precipitation Runoff/Groundwater Replenishment Remember: Cute Video!
Average Residence Time Time a molecule of H 2 O spends in ocean before evaporating and rejoining H 2 O cycle = 3000 years
1) Surface Water Glaciers, snow, rivers & streams, lakes & ponds, wetlands, oceans Replenished by runoff Watershed - area drained by a river
Los Angeles Watersh ed Drained by LA River. Emptied in LBC. DMHS
Malibu Watershed Malibu Lagoon-Base
Mississippi River Watershed
Areas where a river would flood. Yet, we build there? Watershed Flood Plains
Glaciers, Ice and Snow 75% of fresh water= ice or snow Antarctic glaciers: 85% of all ice in world
Muir Glacier, Alaska: 1941 and 2004
So. Cascade Glacier, Wash
Rivers and Streams Carry water to ocean (runoff) Discharge – how much water passes a pt. in a given time period. 16 largest rivers carry 50% of runoff
Name the world’s largest rivers…Come up with as many as you can with your partner!
Ponds: small, shallow temp or perm water w/surface plant growth Lakes: inland depressions holding water year-round; up to 5000ft deep Echo Park Pond?
Oligotrophic vs Eutrophic Lakes
Wetlands AKA Bogs, swamps, marshes Base of watershed Benefits: Slows H 2 O, enhances infiltration into aquifers Ballona Wetlands
Benefits: Fish breeding grounds.
Benefits: Home to migratory birds
Oceans 97% of all liquid water: 3 % salinity Moderates earth’s temps
2) Groundwater Systems Stored water from percolation forms aquifers (pools under ground). 40% of fresh water in U.S. Aquifers: recharged by rain/snow melt
Unconfined Aquifer Porous rock above, clay below Replenished by surface H 2 O
Confined (artesian): Groundwater between impermeable layers of rock, Trapped, under pressure: SLOWLY recharged by water far away
Infiltration Video Clip