River Definitions Flashcards
Water Cycle
Continuous circulation of water between air, land and sea
Drainage Basin
land drained by river and all of its tributaries
Precipitation
Moisture in atmosphere (rainfall, snow, sleet, fog)
Interception
Precipitation is prevented from falling onto the ground by plants. It slows down runoff and reduces risk of flash flooding
Surface runoff
Water moving through surface of the land
Infiltration
Movement of water from surface to soil
Throughflow
Movement of water from soil to bedrock
Groundwater flow
Water moving horizontally through bedrock towards river/sea
Evapotranspiration
Water is (transferred from land to atmosphere) evaporated from surfaces [EG: lakes and transpiration from plants]
Watershed
Boundary between drainage basins (often a ridge of high land)
Source
Starting point of a river [can be lake, glacier, marsh etc)
Tributary
A smaller stream flowing into a large river
Confluence
2 rivers’ meeting spot xxx
River mouth
End of river where it meets sea, lake or ocean
Gradient
Slope where river loses height
Depth
Distance from river surface to river bed
Width
Measurement from one river bank to the other across a river channel
Load
Sediment carried by river
River discharge
Amount of water in a river which passes a certain point in a certain time. It is measured in CUMECS [cubic metres per sec]
Erosion
Wearing away of landscape by ice, wind and water
Attrition
Erosion where transported particles hit each other making the particles smaller and more rounded
Abrasion
Grinding of rock fragments carried by river against bed and banks of river
Hydraulic Action
Erosion caused by force of moving water. It undercuts riverbanks on outsides of meanders and forces air into cracks in exposed rocks/waterfalls
Solution
Water chemically reacts with soluble materials in rock and dissolves them (chalk, lime, softer materials etc)
Transportation
Movement of material across Earth’s surface
Suspension
Transportation of the smallest load suspended by water (EG sand, clay, fine particles etc)
Saltation
Bouncing of medium sized load along river bed (EG stones, pebbles…)
Traction
Rolling of boulders and pebbles along river bed
Deposition
Dropping of material on Earth’s surface
River Landforms
Large scale features found along the profile of a river’s course. [EG: waterfalls, meanders….]
Waterfalls
Steep fall of river water where its course crosses between different rock types resulting in different rates of erosion
Meander
River landform where there is a sweeping curve of bend in river’s course
Slip-off slope
Smalll feature seen on the outside of some meander bends high is caused by erosion of river bank
River cliff
The outside bank of a water channel (stream) that continually undergoes erosion
Floodplains
Area of low lying ground adjacent to a river formed by river sediments. (Subject to flooding)
Levees
Raised banks along a river that reduce flood risk
Flooding
Temporary covering by water of land which is normally dry
River Management Strategy
Aims to control rivers and reduce risk of flooding
Hard Engineering Strategy
Aims to control natural river hazard with methods that do not blend into natural surroundings
Dams
A barrier [made of earth, concrete of stone] built across a valley to interrupt river flow and create reservoirs that store water and controls discharge of river
Flood walls
Stone/brick/cement walls built alongside rivers to protect nearby areas from flood
Levees
Raised banks along a river that help reduce flood risk
Soft Engineering Methods
Strategies to control natural hazards that blend into environments and surrounding whilst often remaining sustainable
Washlands
River allowed to flood these areas [usually farmland/recreational land close to settlements
Land use zoning
Areas prone to flooding are protected from urban development
Afforestation
Planting trees in areas that havent yet been forested
