Pathways and Processes • Evaporation • Transpiration • Condensation • Precipitation • Surface Runoff • Infiltration Evapotranspiration
Why is the water cycle important ? • Essential for Life • Transportation • Drinking Water • Irrigation • Industrial Processing
Surface Water Running Water Base Level and Graded Streams Stream Erosion Transport and Deposition of Sediments Drainage Networks Stages of Valley Development
Running Water (streamflow) 1. Laminar Flow- particles flow in a straight-line path, parallel to the stream channel 2. Turbulent Flow- water moves in an erratic fashions characterized by swirling, whirlpool-like eddies Controlled by: velocity of flow and roughness of the channel bottom
Running Water (streamflow) Discharge- the amount (volume) of water passing a certain point in a given amount of time. m3/sec, MGD, cfs, gal/min.
Base Level and Graded Streams Gradient- the vertical drop of a stream over a fixed distance Base level - The downward limit of stream erosion
Base Level and Graded Streams Headwaters Mouth
Base Level and Graded Streams Graded Stream - a stream with the correct slope and other characteristics necessary to maintain just the velocity required to transport the material supplied to it Any change in base level will cause a corresponding readjustment in stream activity.
Stream Erosion 1. Lifting poorly consolidated particles 2. Abrasion 3. Solution - less significant
Stream Erosion by Abrasion Potholes
Transport and Deposition of Sediments Transportation- stream transport provides a mechanism by which solid particles of various sizes are separated(SORTED). Deposition - well-sorted material deposited by streams is called(ALLUVIUM).
Transport and Deposition of Sediments Channel Deposits Bars- temporary channel deposits of sand, gravel, and coarser components of the stream’s load. Point Bars- bars which occur on the inside of a bend.
Transport and Deposition of Sediments Meander – a looplike bend in the coarse of a stream
Alluvial Fans– develop where a high-gradient stream leaves a narrow mountainous valley.