Hydrologic Cycle. Water Cycle. Groundwater

Transcription

1 Water Cycle, Groundwater, Water Pollution Hydrologic Cycle Distribution/Cycle Animation Water Cycle 86% of evaporation from sea surface 14% of atmospheric moisture from EVAPOTRANSPIRATION 78% of precipitation on sea surface 22% of water precipitated falls on land Water Cycle Water Cycle Less that 3% of Earth s water is on land Over ¾ of that is in glacial ice Most of the rest is stored as groundwater (some groundwater is saline) Water Distribution Groundwater Precipitation infiltrates Earth s surface Largest reservoir of liquid fresh water Drinking water source for half of U.S. Water sources in Oregon Groundwater Surface water 1

2 Groundwater Contributes to stream flow Universal solvent Dissolves some rock types Limestone (CaCO 3 ) Salts (NaCl, KCl) Gypsum (CaSO 4 ) Groundwater Source First becomes soil moisture Plants use it Some evaporates directly Some sinks down Infiltration Groundwater is stored Groundwater Terms Zone of saturation Water table Zone of aeration Groundwater terms diagram Groundwater Storage Porosity of rock Spaces between sand grains Cracks in crystalline rock Dissolved cavities Permeability Allows water to move Interconnection of pore spaces Groundwater Storage Stored in AQUIFER Porous and permeable rock Trapped by AQUITARD Impermeable rock Clay, shale Groundwater Movement Very slowly Small openings High surface tension Pressure forces water to areas of lower pressure Hydraulic gradient Hydraulic head Groundwater movement diagram Springs Where water table intersects ground surface 2

3 Photo of cliff springs Carlsbad Caverns Arecibo, Puerto Rico: Radio Telescope in Sinkhole Karst drainage of manmade lake in Missouri Karst towering buttes 3

4 Thailand Karst Towers Hot Springs Water heated by hot rock (cooling magma) Temperature increases solvent capabilities May contain acids from magmatic water Geysers Special type of hot spring Pressure of water column suppresses boiling Heat added eventually overcomes pressure Sudden rise of water, increase pressure release on rising Old Faithful photo Old Faithful webcam link yell/oldfaithfulcam.htm Geyser Eruption Geyser eruption stages Wells Wells after drawdown Artesian wells 4

5 Ogallala supported agriculture Ogallala Aquifer Exploited in Great Plains agriculture Water table dropped Recharge rate low San Joaquin Valley subsidence Not able to recover due to aquifer compaction Water Drop Contaminated Groundwater Groundwater purification Agriculture sources of groundwater contamination Landfill leachate contamination Drinking Water Standards 5

6 ppm Change 1,000,000 mg to liters Parts per Million 1 mg 1,000,000 mg 1 g 1 ml 1 L 1,000,000 mg = 1 L 1,000 mg 1 g 1,000 ml 1 mg 1 ppm = 1 L Sewage treatment Primary sewage treatment Secondary sewage treatment Natural substances in water Impurities in Runoff Atmosphere Dissolved substances Silt, etc. Radon Organic byproducts in water Contamination of Water Micro-organisms Decay products Plant nutrients Petroleum compounds Acid Industry Mining Drinking water standards 6

7 Pollution Sources Raw Sewage discharge Plant nutrient pollution Agricultural Runoff Oil pollution Mine leachate Water Pollution Water Pollution Prevention Drinking water standards 7