Geomorphology Flashcards
Abrasion
Particles of sand and silt that are carried by the river scratch an wear aqua the bed and sides of the channel
Abstraction
Process whereby the watershed becomes lower and its position shifts
Aerated zone
Part of crust above the water table where there are open air spaces
Alluvium
fertile silt deposited by a river
Attrition
Small particles bump against one another and become smaller, rounder and smother
Antecedent drainage pattern
After the river formed, folding and faulting occurred, but the river maintained is pattern, cutting a gorge/ poort/ gap through the land that has been uplifted
Baseflow
Ground water that seeps into a river
Braided streaks
Rivers that have multiple channels and islands of alluvial sediment in between those channels
Captive stream
Less energetic river that was captured by the captor river
Captor stream
More energetic river that eroded through the watershed and captured another river
Catchment areas
The are that feeds water into a river system
Channel flow
Water flowing in a river channel
Confluence
Point where one river in the network joins another
Corrosion
Acids in the water can dissolve the rock particles
Delta
Depositions feature that forms when a river enters the sea or a still body of water
Direct runoff
Water flowing over earth in river channels
Discharge
Amount of water flowing in a river channel past a point in a given time
Drainage basin
And area drained by a river and its tributaries
Drainage density
The total length of all the streams and rivers in at raise drainage basin (KM) divided by the total area of the drainage basin (KM squared)
Elbow of capture
Point where capture occurred; The captive changes direction and flows into the captor
Entrenched or incised meanders
A meander that has cut (vertically) deep into the crust
Episodic rivers
Rivers that hardly ever flow because they are in low rainfall areas and the water table is always a load of riverbed
Erosion
The wearing away and removal of weathered rock material from the river channel
Exotic rivers
Rivers found in low rainfall areas but flow all year round because they are fed by tributaries in high rainfall areas
Floodplain
Flat valley floor
Gorge
Deep-steep sided valley
Graded river
A river that has just enough energy to carry it to load; neither erosion nor deposition is taking place resulting in a smooth, concave longitudinal profile
Groundwater
Underground water
Groundwater flow
Water flowing through underground rocks
Headward erosion
A river lengthens itself by cutting back towards it source
Hydraulic action
The force of water hitting the side and the bed off the river will break pieces off
Impermeable rock
Rock which does not allow water to pass through it
Indirect runoff
Water feeding into rivers through base with
Ingrown meanders
A meander that cuts sideways into the bank so that there is slight overhang above the stream
Interfluves
Ridges of high ground between individual channel