Hydrosphere Flashcards
Source
The place a river begins
Drainage basin
The area surrounding a river from which water drains into a river.
Mouth
The place where a river enters a lake, larger river or ocean
Precipitation
The fall of rain, hail, snow or sleet
Evaporation
Water is heated, turned to a gas and rises
Interception
Precipitated that are stopped from getting to the ground by vegetation
Surface Runoff
The flow of water occurring on the ground surface
Infiltration
The process by which water on the surface enters the soil
Throughflow
The lateral unsaturated flow of water in soil
Percolation
Process of a liquid slowly passing through a filter in this case usually rock
Groundwater flow
Water that flows or collects beneath the Earths surface
Groundwater Storage
The storage of water underground in permeable rock strata
Channel Storage
The water held in a river or stream channel
Channel flow
The movement of water within the river channel
Ways in which human activity can affect the hydrological cycle
Removal of vegetation, replacement with concrete, deforestation, fewer trees=less evapotranspiration, water removed, irrigation channels
Formation of a V-Shaped Valley
Rivers begin high up in the mountains so the flow quickly downhill eroding the landscape vertically.
The river cuts deep down into the landscape using hydraulic action when the sheer force of the water gets into small cracks and breaks down the side of the river valley.
Corrasion/abrasion also occurs which is when the riverbed and banks are eroded by the load hitting against them. another type of erosion that happens is corrosion when the river water dissolves minerals from the rocks and washes them away. As the river erodes downwards the side of the valley are exposed to freeze thaw weathering. This loosens the rocks and steepens the valley sides.
any rocks that have fallen into the river assist the process of corrasion and this leads to further erosion.
The river transports the rocks downstream the channel becomes wider and deeper creating a V shaped valley between interlocking spurs.
Waterfall (Uppercourse)
Waterfall is formed when a river flows over a band of hard rock lying on top of soft rock.
The soft rock which lies on the down Riverside is more easily eroded producing a steep face or cliff over which the water falls.
The soft rock at the bottom of the waterfall is eroded to form a plunge pool.
Over a long period of time the waterfall retreats upstream to leave a steep sided valley called a gorge.
Meander (middle course, lateral)
straight river channels are unstable so rivers adjust to find a form which sediment can be transported efficiently.
Pools (deeper areas) and riffles (shallow areas) can form in the river as the water twists to move around objects
Water flows fastest and has more energy on the outside bend leading to more erosion this can be by the process of abrasion where stones and pebbles great at the river bed and banks as well as hydraulic action - this is where the force of the water pushes air into cracks in the bank blasting them apart. This creates a river cliff.
On the inside band D position occurs and this is because the river has a slower current and less energy so cannot carry its mode it drops it creating a river beach.
This can also be assisted by helicoidal flow this is a corkscrew actions where the water move materials from one cliff and deposit it at the next beach
Overtime continual erosion deposition causes the meander to become more extreme
Ox-bow Lake - Lower Course
before explaining an oxbow lake explain the process of meanders
Meander neck gets narrower due to hydraulic action and abrasion
During a flood the river will break through and create a new channel
The river takes the shortcut and the position fills the meander neck as the river is flowing more slowly
The meander water loses energy and the river flows fastest on the cut off
Isolated horseshoe shaped pool of water is cut off from the river channel and forms the oxbow lake.
Factors influencing hydrography
Area, type of rock, soil type, urbanisation, afforestation, drainage density, number of streams, storage capacity
