Rivers Definitions Flashcards
Precipitation
any form of water(eg. dew, fog, frost, hail, mist, sleet, snow, etc.) falling on the Earth’s surface from the atmosphere
Discharge
the amount of water flowing across the width of a river at any given point
Drainage basin
the area of land drained by a river and its tributaries(streams)
Watershed
the boundary of a drainage basin
Evaporation
the change of water(liquid) into water vapour(gas) in a water body
Transpiration
the loss of water in the form of water vapour through the stomata of plants
Evapotranspiration
the loss of water in the form of water vapour through plants and in water bodies
Condensation
the change of water vapour(gas) back into water(liquid)
Infiltration
the movement of water into the ground from the surface
Percolation
the movement of water through the soil itself
Overland flow
the movement of water over the land
Through-flow
the flow of water under permeable ground
Groundwater flow
the movement of water underground(below the soil)
Saturated
full of water
Permeable
capable of soaking up water
Wetted perimeter
length of the wet part of the channel’s cross-section containing flowing water
Velocity
the speed at which the river is flowing
Erosion
the wearing away and removal of rocks through the action of the agents of erosion(wind, water, ice and gravity)
Deposition
the laying down of solid material(eg.mud, sand, etc.) on the seafloor and river or lake beds
Network
a collection of all the paths formed by every tributary of the river in its drainage basin
Tributaries
streams that feed into a larger stream, river or other water body
Source
the original point from which the river flows
Confluence
the point at which two rivers meet
Interception
the process of interrupting the movement of water in the water cycle leading to water bodies(or the ground)
Capacity
the total amount of sediment or load that a stream or river can carry at any one time
Competence
the maximum size of a particle that a stream or river can carry
Flood plain
an area next to a river that would be affected by flooding if the river overflowed its banks
Distributaries
a stream or river channel resulting from the division of a larger stream channel(often found in deltas)
Delta
a landform(often triangular in shape) which develops where a river meets a slow body of moving water such as a lake or ocean(sediment builds up above the water level forcing the river to split into distributaries to form a delta)
Levée
a natural or artificial wall that blocks water from going to certain areas
Gorge
a deep, narrow valley with steep, rocky sides often with a stream or river flowing through it
Vertical erosion
the process in which a stream or river flowing quickly down a steep gradient in an upland area wears away the bed at a faster rate than the valley sides, leading to a V-shaped valley
Lateral erosion
the process in which a stream or river wears away the sides and banks on each side of the channel
Hydrograph
a graph which shows the pattern of a river’s discharge(measured in cubic centimetres per second(cumecs) over a period of time)
Hydraulic action
the process by which the force and impact of flowing water removes material from the bed and banks of a river
Corrasion/Abrasion
the effect of the load grinding away at the bed and banks of a river like sandpaper(the most effective process of river erosion)
Attrition
the process in which material such as rocks or stones carried by waves hit and knock against each other, wearing them down, and resulting in them becoming smaller and more rounded
Solution/Corrosion
the process in which some rocks are dissolved in the presence of water in the river
Load
the material carried by a river
Solution load
the materials/minerals that are dissolved in the river and carried through it
Suspension load
the very light materials that are carried near the surface of the river(giving it its colour)
Saltation load
the small pebbles and stones that are bounced along the riverbed
Traction load
the heavy boulders and rocks that are rolled along the riverbed(this takes the most energy)
Plunge pool
a deep depression in a riverbed at the base of a waterfall which is formed by erosion
Interlocking spurs
a series of ridge-like projections which protrude out on alternate sides of a V-shaped valley around which a river winds its course
Meander
a bend in a river channel
Oxbow lake
a U-shaped lake that is formed when a wide meander of a river is cut off, creating a free-standing body of water
Base flow
the low level of water that is always in the river throughout the year
Peak discharge
the maximum amount of water in the river due to rainfall
Bankful discharge
the maximum amount of water in the river just before it is about to flood over its banks
Time lag
the time between the peak rainfall and the peak discharge
Hard engineering
the construction of costly, permanent structures that will affect river flow, prevent the damage caused by floodwater, or even prevent the flooding completely
Soft engineering
the use of relatively cheap methods or structures that work with the river and do not involve permanent structures or lots of construction
Dredging
the process of clearing the bottom of a riverbed by removing material(eg. weeds, silt) from it
