geography - key vocab

• Suspension is material carried along in the rivers channel, usually fine particles.
• Traction is heavy material usually big boulders that are rolled along the river bed.
• Transportation is when the river moves material as bedload, suspended load or dissolved load (in solution).
• Bedload can be moved by saltation or traction.
• Tributary is a small river that joins a larger one.
• Upper course is the highest stage of a river near to its source, characterised by large boulders and turbulent water.
• V shaped valley is usually found in the upper course of the river where the water has considerable erosive power.
• Vertical erosion leads to the bed getting deeper.
• The valley sides become unstable and weakened by weathering and eventually collapse creating this.
• Waterfalls form where the river meets a band of softer rock after flowing over an area of more resistant material.
• Waterfalls progressively cut back, leaving a gorge.
• Watershed is the high land marking the boundary between two drainage basins.
• Weathering is the breaking down of rock by chemical, biological, freeze thaw or onion skin processes.
• Hydrological Cycle is the movement of water around the water system.
• Evaporation is when water is heated by the sun, it turns to vapour (gas) and rises (because it is lighter than the surrounding air as molecules spread out through heating).
• Transpiration is when water is lost through the leaves (stomata) of plants into the atmosphere.
• Condensation occurs when water vapour cools and changes from gas to liquid.
• Precipitation is the ways in which water moves from the atmosphere to the ground.
• Infiltration is when water passes down into the ground.
• Percolation is when water moves down through soil.
• Surface runoff, also called overland flow, occurs when water cannot sink into the ground.
• Interception is when water is prevented from reaching the ground by vegetation.
• Ground water flow is when water passes through rocks in the ground.
• Groundwater storage is when water is held in rocks underground.
• Surface Storage puddles, ponds and lakes are all examples of this store.
• Channel flow is water that is moving in the river.
• Store is when water is stationary in the water cycle e.g. clouds, groundwater storage, surface storage etc.
• Flow is when water is moving in the water cycle.
• Lag time is the time between peak rainfall and peak discharge.
• Peak Discharge is the maximum amount of water held by a river after a storm.
• Base flow is the normal discharge of a river.
• Hydraulic Action is when the force of the water washes away rocks, a bit like when you wash the car with a hose.
• Delta is a land form made of sediment that is deposited where a river flows into an ocean or lake, usually when waves are not strong enough to take it out to sea.
• Catchment is an area from which a river system or lake derives its water.
• Prevailing wind is the direction in which the wind most often blows.
• Water cycle is the continuous flow of water between the Earth's surface and the atmosphere.
• Porous is a rock, such as chalk and sandstone, which has many tiny gaps (pores) within it, which allow it to store water.
• Soft engineering is an alternative method of reducing floods by, for example, planting trees, creating areas along river banks to flood naturally or importing beach material along coasts.
• Undercutting is a type of erosion at the base of a river cliff, sea cliff or waterfall.
• Transpiration is water loss from plants through pores in the leaves.