Rivers and Flooding 2 Flashcards
Types of Drainage Networks
- Dendritic
- Radial
- Rectangular
- Trellis
Stream Characteristics
- cross section (depth X width)
- Velocity
- Stream Gradient(dh/dx)
- Discharge(area X velocity)
- Roughness
- Longitudinal Profile
- Base Level
Discharge
-amount of water that flows through a given point
Longitudinal Profile
are an indicator of processes acting along the river course: deviation from the equilibrium profile testify recent forcing in the evolution of the landscape
Base Level
the lowest elevation to which a river can flow. It is ultimately represented by sea level, but it can be locally by a lake. Changes in base level can change the longitudinal profile and create phases of erosion and/or deposition
what do stream terraces show there was?
-a change in base level
Dam Impact: Upstream
Reduced: natural function, water quality, oxygen, turbid flow, circulation,
Increased: pollutant accumulation, stratification, temperature, and algae blooms
Loss of: natural transport processes of sediments, nutrients and debris self-sustaining nature
Dam Impact:Downstream
Reduced: Water Quality and riverbed elevation
Altered: Flow Regime and Temperatures
Starved of: sediment, nutrients and debris
Processes of Running Water
- erosion
- transportation
- sedimentation
Stream Load Parts
- Bed Load
- Suspended Load
- Dissolved Load
Velocity is greatest where?
-in the center
Inertia moves what to where?
- high velocity
- to outside of the bend
Meander Parts
- point bar
- cutbank
meanders are What?
- dynamic
- they change through time
Braided Streams Occur When?
when the sediment load is high
