1 / 22

Hydrosphere

Hydrosphere. Only planet with correct atmospheric pressure and temperature to allow water to exist in all its phases 97% water held in ocean basins 2% water frozen Only 1 % water fresh *. Figure 2-11 (Merritts et al., 1998). Image ID: corp1893, NOAA Corps Collection

adanna
Télécharger la présentation

Hydrosphere

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Hydrosphere • Only planet with correct atmospheric pressure and temperature to allow water to exist in all its phases • 97% water held in ocean basins • 2% water frozen • Only 1 % water fresh* Figure 2-11 (Merritts et al., 1998)

  2. Image ID: corp1893, NOAA Corps Collection Location: Alaska Southeast Photo Date: August 1991 Photographer: Commander John Bortniak, NOAA Corps

  3. The Hydrologic Cycle • Water continuously circulates from the ocean to the atmosphere to the land and back to the ocean. • Regardless of its physical form-solid,liquid, or vapor-every molecule of water eventually moves through the hydrologic cycle. Water sources for Earth included 1) water from icy comets, 2) volcanoes, and 3) minerals.

  4. (Press and Siever, 1986)

  5. Hydrosphere residence times • Oceans = 3,100 years • Atmosphere = 9 days • Continents = 403 years • Rivers 12 - 20 days • These residence times are significant for evaluating environmental issues.

  6. Water budget for the U.S. • ~15.9 trillion liters/day fall on the U.S. • 66% returned to atmosphere by evaporation and transpiration • 3% seeps into groundwater • 31% as runoff to rivers and lakes

  7. Water Reservoirs • Rivers • Lakes • Wetlands • Groundwater • Oceans • “cryosphere” (glaciers)

  8. Rivers: sources of flow • Rain falling on the surface of the Earth may infiltrate (to groundwater), runoff (to rivers), or evaporate/ transpirate (to atmosphere).

  9. River discharge • Amazon, South America 212,400 m3/s • La Plata, South America 79,300 m3/s • Congo, Africa 39,600 m3/s • Yangtze, Asia 21,800 m3/s • Brahmapututra, Asia 19,800 m3/s • Ganges, Asia 18,700 m3/s • Mississippi, North America 17,300 m3/s • Colorado River, North Am. 300 m3/s

  10. Large rivers of the U.S.

  11. Rivers: Human influences • Commerce • Transportation • Irrigation • Waste disposal • Dams diversions

  12. Lakes • Basins that collect water • Location of basins defined by geologic setting, presence of water based on climate (local or regional) • Most of the world’s freshwater resides in lakes

  13. Lakes: Human influences • Pollution • Water diversion • Exotic species

  14. Wetlands • Wetlands are usually inundated by water during some part of the year, are poorly drained, have low relief, and have high soil moisture. • Wetlands may appear along coasts as swamps or marshes (i.e. salt marshes) or in the continental interior as marshes, wet meadows, or prairie potholes, or peat moss bogs http://www.epa.gov/owow/wetlands/

  15. http://www.epa.gov/owow/wetlands/

  16. Natural wetlands have distinct ecosystem functions to which society can assign a “value.” • nutrient storageremoval of fertilizing nutrients helping farmers to attain compliance with water quality targets • accumulation of organic material for fuel or agriculturestorage of carbon, source of peat • filtering of solids from waterswastewater and sewage treatment, trapping sediment

  17. Natural wetlands have distinct ecosystem functions to which society can assign a “value.” • animal habitatsfishing, wildfowl hunting and fish and shrimp hatcheries. In addition, Wetlands are a home to a third of the nation’s threatened and endangered species. • plant habitatsforestry, agriculture • regulating water outflowflood and erosion protection • all functionsrecreation, research, and education

  18. Wetland losses in the U.S.In the 1660’s, 220 million acres of wetlands were thought to exist in the U.S. By 1980, only 103 million acres remained. • Drainage • Dredging • Stream channelization • Diking, damming • Tilling • Logging • Levees, • Mining •  nutrient levels • Pollution • Nonnative species http://www.epa.gov/owow/wetlands/

  19. Groundwater • Water enters the ground as excess surface water • Water then seeps downward due to gravity and the porous nature of soil, rock, and sediment • Water ultimately seeks it’s base level (usually sea level)

  20. Groundwater Depletion • Overdraft • Subsidence • Saltwater intrusion Groundwater Pollution • Contaminant transport

  21. Environmental problems related to water usually involve problems with water quantity or water quality.

More Related