EARTHSC 1G03 Lecture Notes - Lecture 24: Suspended Load, Turbulence
19 Apr 2017
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Document Summary
The hydrologic cycle involves the stages and processes that water undergoes: evaporation, condensation, precipitation. Most precipitation and evaporation occurs over the sea: the precipitation that doesn"t occur over the sea collects in lakes and drains down to groundwater. The majority of water on earth is saltwater: oceans and seas (95. 96%) Water that falls in very dry areas may not drain out to any ocean; instead, it may re-enter the atmosphere through evaporation. Drainage divide: topographic line or boundary separating watersheds. Two types: laminar, very smooth flow, never makes contact with other flows (parallel, turbulent, very varied movement. Rivers tend to turbulent flow as velocity increases: most streams have relatively turbulent flow, this leads to erosion by lifting particles from channel bottom and keeping them in suspension. Discharge: the volume of water moving past a given point per unit time: product of cross-section area and stream velocity, proportionally related; therefore, increasing cross-sectional area or stream velocity will increase discharge.
