Sources of Water that enter Rivers/Streams
    groundwater: rainfall or snowmelt soaks into earth, saturating the ground.  4 stars****
        rivers and lakes form where topography intersects the water table-varies w/ seasons
        groundwater recharges lakes and streams in summer when no rainfall
    overland flow: runoff directly into stream over land; soil must be saturated first
    glacial melt:  ice melts throughout year but mostly in summer, very important in WA
    tributaries:  smaller streams that enter the larger one, part of stream network

River/Stream Channel:  trough shaped depression that holds running surface water
    parts of channel:  bed/bottom of river, banks/edges of channel, flood plain on sides
    size of river/channel measured by width across and average depth of water
            average width x depth = cross sectional area through channel
            speed/velocity of water; velocity increases with depth, decreases with roughness
       Discharge = volume of water passing by a point per time = width x depth x velocity
            can't measure discharge directly so measure cross sectional area and velocity

Transport of Sediment aka "Load":  rivers carry 3 different types of sediment/load
    Dissolved Load:  ions carried in solution; invisible.  "fresh" water has plenty of ions.
    Suspended Load:  mud carried in suspension.  mud of flood plains--deltas--ocean.
    Bed/Bottom Load: gravel and sand carried along the bottom/bed, mostly during floods
        large bits can't be carried, so must be rolled, bounced or slid along river bottom

Flooding and Flood Plain:  the river's way of dealing with too much water for the channel
    flood plain:  flat areas adjacent to stream that are flooded periodically
        flooding frequency: about every 2-3 years for most streams, floods not rare events
        flood plains affect the width, average depth and average velocity of stream
    ave. depth and velocity decrease during flooding, width increases dramatically
    deposition of suspended sediment to form flood plains; terraces & ancient flood plains

Drainage Basins and River Erosion:  rivers are very efficient at erosion and transport
    drainage basins separated by drainage divides (e.g. continental divide)
    drainage patterns and stream networks/systems; fractal distribution of streams
    sideways (lateral), downward, and headward erosion along stream channel
    evolution of landscapes during stream erosion and transport

River Deposition: landforms produced from constantly shifting river deposits
    sand and gravel bars; point bars at meanders, mid-channel bars, braided streams
    meander bends: deposition on the inside (point bar), erosion on the outside (cutbank)
        migration of meander bends, meander loops, cutoff meanders, oxbow lakes
    terraces: ancient flood plains.  Ancient glacial streams and flood plains in Washington
    deltas (rivers dump mud in lakes and oceans) and alluvial fans

Rivers and Humans
    Modification and habitation of natural flood plains; floods; levees and dikes
    Water for agriculture, industry, municipalities.  Water quality and quantity
    Hydroelectric power in the Pacific Northwest; role of glacier runoff
    Rivers as ecosystems; rivers and salmon; logging and rivers, the silt controversy

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