Earth Science 5

Front 1

Hydrological cycle

Back 1

97% of earth's water is stored in ocean, evaorated then precipated on land - some soaks in (infiltration) some flows over land as streams (runoff), some evaorpates back into the atmosphere and is transpired by plants, some stored in glaciers, but most return to ocean by streams

Front 2

streamflow

Back 2

stream erodes, transports according to its velocity and channel shape

Front 3

gradient

Back 3

slope of stream chanel over its length; cross-sectional shape determines how much of the channel contacts water, slowing it down, rougher more friction

Front 4

discharge

Back 4

volume of water flowing thorugh the stream's cross section per second; if discharge increases, stream usually gets wider, deeper and faster downstream

Front 5

erosion

Back 5

by abrasion using partilces in transport as cutting tools to scour channel walls and in circular eddies to cut potholes into the channel floor

Front 6

transport

Back 6

4 types of sidements

Front 7

dissolved

Back 7

ions in solution from cheical weathering and ground water

Front 8

suspended

Back 8

sediment that remains above the bed

Front 9

bed load

Back 9

particles sliding and rolling along the channel floor

Front 10

saltation

Back 10

jumping and skipping of particles that alternate between bed and suspended loads

Front 11

deposition

Back 11

occurs when stream can no logner carry its load and particles fall to the bed; can form a channel deposit of sand and gravel bars or floodplain deposit of mud beyond the channel

Front 12

stream valleys

Back 12

a stream cuts vertically but its banks cave in by mass wasting to develop narrow V-shaped valleys with waterfalls and rapids in rough channels

Front 13

wide valleys

Back 13

form on gentle gradients and cut sideways forming floodplains as the stream shifts back and forth across the valley leaving a thick fill of sediments

Front 14

meanders

Back 14

bends on floodplains where a stream erodes the outsides of bends at cut banks deposits on the insides at point bars

Front 15

drainage patterns

Back 15

determined by the network of tributaries ffeeding the stream; pattern of a basin depends on rock types and structures

Front 16

dendritic

Back 16

uniform bedrock where channels follow local slopes

Front 17

radial

Back 17

fro volcano or rock dome

Front 18

rectangular

Back 18

streams flows over joints or a fault system with right angle bends

Front 19

artificial levees

Back 19

built along stream banks to increase the volume that stream can hold

Front 20

flood control dams

Back 20

built to store water than let it out slowly, flood valleys, displace wildlife, drown forests