Presentation on theme: "Precipitation The process of depositing moisture in the form of rain, snow…"— Presentation transcript:
Precipitation The process of depositing moisture in the form of rain, snow…
We know it starts with condensation, but what does it take for condensation to occur?
Condensation requires Humidity The right air pressure Particles in the atmosphere
Types of precipitation: Rain ….See they really do look like buns….
Types of precipitation: Snow
Types of precipitation: Hail Of course there are also dew, fog, sleet…
What controls the fate of precipitation once it falls? Climate Geomorphology Infiltration Vegetation
Infiltration: Where does the water go? here/subsurface_water_1.html
Why does water infiltrate some land more than other land ? Topography Steep verses gentle slopes Soil/Land Surface Type Vegetation
Geomorphology and Run-off Topography The general configuration of a land surface or any part of the Earth's surface, including its relief and the position of its natural and man-made features Slope Also known as “gradient” when referring to streams Drainage Patterns Channel Shape
For surface-water systems, the greater the likelihood that water will run off the land surface, (that is, the higher the slope), the higher the rating applied on a scale of 1 to 10
What is soil? Soil- a natural body of solids, liquid, and gases with either horizons, or layers and/or the ability to support rooted plants.
O – Organic Horizon A- Zone of leaching B – Zone of Accumulation C – Broken-up bedrock R – Regolith – hard bedrock (not soil) See Fig Text
What soil zones do you see here?
How does the type of soil or the lack of soil affect infiltration? Porosity Permeability Pervious verses Impervious Surfaces Soil cover verses bare rock Soil verses concrete and asphalt
The type of material in the unsaturated zone influences whether precipitation runs off or infiltrates into the subsurface. The greater the likelihood that water infiltrates into the subsurface, the higher the rating applied on a scale of 1 to 10.
The hydraulic conductance is related to permeability and represents the ability of the unsaturated zone to transmit water. The higher the conductance of the unsaturated zone, the higher the rating applied on a scale of 1 to 10
How does vegetation affect runoff? Provides a physical barrier and decreases the rate at which water enters a stream Roots loosen soil and provide conduits for water Plants absorb water What happens when vegetation is removed for building?
For surface-water systems, the greater the likelihood that water runs off the land surface, the higher the rating applied on a scale of 1 to 10
Confused about water terminology? Check out the on-line water dictionary at index.htm
Stream Restoration at NCSU extension_engagement.html Achieving a balance between run-off and infiltration