Transcript HydrolCycle9

Hydrologic Cycle
Pat Ellsworth, ITEP
&
Robert K. Hall
USEPA Region IX
[email protected]
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Hydrologic Cycle
 “Hydrologic cycle”—circulation and conservation of earth's
water
 Begins with evaporation of water from earth (20%) and
ocean (80%) surface
 As moist air rises, it cools, and water vapor condenses to
form clouds
 Moisture is transported around globe via oceanic gyres
(N and S hemispheres) until it returns to surface as
precipitation
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Hydrologic Cycle (cont.)
 Once water reaches the ground
 Evaporates back into atmosphere
 Runs off into streams and lakes, eventually
back to ocean
 Penetrates surface, becomes groundwater
 Groundwater will
 Seep into lakes, rivers, streams
 Return to atmosphere through transpiration
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Earth’s Water Budget
(0.001%)
(2.4%)
(97.5%)
Diagram adapted from: Peixoto and Kettani (1973). http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/hyd/home.rxml
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Condensation
Condensation
(rain, hail, sleet, snow, freezing rain)
Convection
Evaporation 80%
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Hyporheic Zone
 Region beneath and lateral/adjacent to stream bed
 Mixing of shallow groundwater and surface water
 Hyporheic flow is important for
 Surface water/groundwater interactions
 Fish spawning
 Benthic macroinvertebrate distribution and community
structure
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Hyporheic Zone (cont.)
Hyporheic
Flow
Adapted from National park Service
(http://www.nps.gov/archive/sitk/Natural%20Resources/Stream%20Ecology/Stream/hyporheic.htm)
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Ecological Function
 Natural riparian-wetland areas characterized by
interactions of vegetation, soils, hydrology
 Riparian-wetland areas function properly with
adequate vegetation, landform, or large woody debris
 Dissipates stream energy associated with high waterflows
 Reduces erosion, improves water quality….
 Changes in ecological function result from alterations
(e.g., fire, invasive species, anthropogenic activity)
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Ecological Function (cont.)
 Human influences accelerate changes in
ecosystem character
 Over time, ecosystems develop spatial
patterns characteristic of human
disturbance and alterations
 Necessary to recognize
 Different geographic patterns and
 How they respond to alterations and resourcemanagement activities
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Illustration by Tom Schultz www.buffer.forestry.iastate.edu/Photogallery/...
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Riparian Function
Functional
Nonfunctional
Functional at Risk
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Impacts: Watershed Morphology and Invasive
Species Classification: Humboldt River, NV
Area shown is part of the Special Recreation Management Area Near Elko, NV
Source: BLM Nevada State Office and BAE Systems Advanced Technologies Inc.
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Conclusion
 Hydrologic Cycle
 Impacts to the Hydrologic Cycle
 Preservation
 Tribal-oriented Best Management Practices (BMPs) to
achieve ecological function
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