Unit 8 just the Rivers & Groundwater (I)

river system

a river and its tributaries

headwaters

the source of a stream or river

river mouth

the point where a river enters a lake or sea

river meander

A large bend in a river

velocity

another name for the speed of the current in a river

discharge

the amount of water flowing through a river in a given amount of time calculated as cross-sectional area x velocity

Deposition

Process in which sediment is laid down in new locations.

zone of aeration

above the water table where pores in the rock/sediment are not filled with water

zone of saturation

below the water table where all the pores in the rock/sediment are filled with groundwater

water table

the level below which the pores in the rock/sediment are saturated with groundwater.

cone of depression

lowering of the water table around a pumping well

aquifer

A body of rock or sediment that stores groundwater and allows the flow of groundwater.

porosity

The percentage of the total volume of a rock or sediment that consists of open spaces.

permeability

Ability of rock or sediment to allow water to flow through it

impermeable

not allowing water to flow throw it

well

hole drilled into the ground to reach groundwater

spring

A flow of groundwater that emerges naturally at the ground surface

stalactite

A rock that hangs like an icicle from the roof of a cave

stalagmite

A cone-shaped rock that builds up from the floor of a cave

cave

a large underground chamber made in limestone by groundwater

sinkhole

a depression formed when the roof of a cave collapses

river

water that flows downslope in a channel

trunk stream

the primary river of a river system, the one that empties at the mouth

tributary

A river that flows into a larger river

distributary

When a river branches off of the trunk stream at the mouth of the river, and is located in the delta.

delta

A landform made of sediment that is deposited where a river flows into an ocean or lake

watershed (drainage basin)

the land area bordered by divides that contributes water through runoff and groundwater to a river system

divide

a high point or ridge that determines the direction that water flows, separating two drainage basins

continental divide

mountain ridge that separates drainage basins flowing toward opposite sides of a continent, in the US it is toward the Atlantic Ocean and the Pacific Ocean

point bar

a crescent-shaped accumulation of sand and gravel deposited on the inside of a meander

cutbank

eroded stream bank on the outside of a meander curve

oxbow

A meander that has been cut off from the river

neck

the narrow strip of land separating two meanderloops that will cut-off to form an oxbow

cut-off

the shortcut with a steeper gradient that a river takes betweem two meanders

gradient

slope of a land surface

suspended load

the small sediment carried within the current of flowing water

dissolved load

The stream load of dissolved materials such as sodium and calcium.

bedload

the larger sediment carried along the bed of the river

youthful stream

a stream flowing down a steep slope with a straight channel, v-shaped valley, with some rapids and uneven drops, erosion dominates

mature stream

a stream that flows down a medium slope or a medium valley, most of the rocks that cause waterfalls have been eroded away. the stream starts to erode more along its sides forming small meanders, while transportation dominates there is both erosion and deposition occuring

old age stream

a stream that is flowing over a very gentle slope and large discharge with primarily side-to-side erosion, many exaggerated meanders, and meander scars, a floodplain, oxbow lakes, delta, deposition dominates

waterfall

a vertical drop in a river that water flows over

River pothole

holes carved in a bedrock channel by sediment in a youthful river

Floodplain

a flat area along a river that forms from sediments deposited when the river overflows its banks

natural levee

raised river bank that parallels the channel that results when a river deposits its heavier sediment along the river bank as it floods into the floodplain

backswamp

a poorly drained area on a floodplain that results when natural levees are present

yazoo tributary

a tributary that flows parallel to the main stream because a natural levee is present

meander scar

Dried up oxbow

V-shaped valley

a valley with a relatively narrow bottom, formed by a river, usually with a steep gradient

capillary fringe

region above the water table with water drawn up by capillary action partially filling the pores and cracks in the zone of aeration with water

artesian well

a well created by drilling a hole into a confined aquifer. It will flow on its own without pumping if the well top is lower in elevation than the water table in the confined aquifer.

river channel

The depression in the land created through lifting, dissolving and or abrasion by running water through which a river flows. It is covered by the river water.