1. 9: Running Water
Basins: land area that contributes water to a river system
Divide: separates different drainage basins
Ex. Drainage basin of Mississippi River

2. Stream Flow Factors that determine velocity:
Gradient (slope); channel characteristics
Shape, size, roughness
Discharge: water vol. in stream [ft3/sec]
Profile: cross-sectional view used for study
Profile usually a smooth, concave up curve
Gradient decreases from head to mouth
Factors that increase downstream:
Velocity, discharge, channel size
Factors that decrease downstream:
Gradient, channel roughness

3. Erosion Load: material transported by a stream
Types: dissolved load (in solution), suspended load
Bed load: slides or rolls on bottom
Load related to stream’s competence and capacity
Competence: max particle size transported
Capacity: max load stream can carry
Capacity is related to discharge
Deposition caused by:
Decrease in velocity, reducing competence
Sediment drops out as water flow slows.
Sediments: alluvium, well-sorted deposits
Base level: lowest point eroded by stream
Sea level: ultimate base level
Adjustment in base level due to changing conditions
Change causes readjustment of stream
Increases deposition and erosion
Figure 5.14: Resistant rock layer acts as
temporary base level.

4. Depositional Features
Features produced by deposition:
Deltas: exist in oceans or lakes
Natural levees: form parallel to stream channel
Back swamps: area behind a levee
Yazoo Tributary: runs parallel to mainstream
Yazoo does not directly join main stream
Figure: Erosion and deposition along a meandering stream
Figure: Characteristic meandering on flood plain in wide-stream valley; also cutoffs, oxbow lakes can be included
Figure: Continued erosion and deposition widens the valley
Meander loop in Colorado River

5. Drainage Patterns and Floods
Stream networks form patterns
Types: Dendritic, radial
Rectangular, trellis
Floods are a common hazard
Caused by weather
Caused by stream interference
Engineering efforts:
Artificial levees, flood-control dams
channelization
Flood Plains, (2:38)