River Details Flashcards
Roles of a river/stream
-Erosion
-Transport
-Deposition
Main processes of erosion
-Hydraulic action
-Corrasion/Abrasion
-Attrition
-Solution/Corrosion
Types of load
-Solution load
-Suspension load
-Saltation load
-Traction load
Main types of erosion
-Vertical erosion
-Lateral erosion
Agents of erosion
-Wind
-Water
-Ice
-Gravity
Formula for discharge
Cross-sectional area × velocity
Discharge is measured in…
cumecs(cubic metres per second)
Features of rivers in an upland valley
-River flows quickly over steep ground
-Main process is vertical erosion
-Low capacity but high competence
Features of rivers in a lowland valley
-River flows more slowly over flatter ground
-Large capacity but low competence
-Main process is lateral erosion
-Deposition is the main process in times of flooding
Factors which influence the shape of a river valley
-Rate of vertical erosion
-Rate of lateral erosion
-Geology of the valley
-Climate of the valley
-Time
Describe the creation of waterfalls over horizontal hard rocks
-Water wears away the softer rock downstream faster
-Harder rock overhangs softer rock, forming a waterfall
-Overhang breaks off and falls into plunge pool
-Waterfall ‘retreats’ downstream, forming a gorge
Describe the creation of waterfalls over vertical hard rocks
-Water erodes soft downstream rock in front of the vertical hard rocks
-Waterfall is created
Impacts of flooding
-Loss of housing
-Lower house prices but higher insurance costs
-Loss/diversion of transport routes
-Loss of social, environmental and economic amenities
-Stress, injuries and death
Opportunities from rivers
-Water for domestic use
-Water for industrial use
-Water for irrigation
-Water for transport
-Water for generating electricity
-Water for leisure/tourism
Opportunities from river-made valleys
-Flat flood plain for building
-Fertile soils
-Flat, straight transport routes for roads/railways
Hard engineering techniques(examples)
-Dams
-Barriers/flood walls
-Enbankments/levées
-Dredging/straightening channels
Soft engineering techniques(examples)
-Afforestation
-Controlling where water overflows to(ie. sacrificing less valued land for more valued land)
-Controlling the location of buildings near the river
Procedures to protect people/land from floods
-A store of sand/sandbags(for emergency use)
-A system of sirens and warnings/Evacuation procedures
-Temporary moveable metal barriers
