River Hydrology And Fluvial Morphology

Front 1

Erosion

Back 1

carrying away or displacement of solids (sediment, rock, other particles) by agents of currents like wind, water or ice due to downward slope movement in response to gravity
- the physical breakdown of rocks

Front 2

Transport

Back 2

Eroded materials carried away along the river (through traction, saltation, solution and suspension)

Front 3

Deposition

Back 3

Transported sediment being deposited by the river on the river banks (due a loss in competence and capacity in the river)

Front 4

Hydraulic action

Back 4

Immense weight and force of the flowing water removing material from the sides and beds of the channel (upper-course of the river; waterfalls; causes undercutting etc)

Front 5

Corrasion

Back 5

Form of erosion, when rocks are abraded by the river bed and river banks; causing pebbles to swirl in caveties in the bed drill downwards forming circular potholes

Front 6

Corrosion

Back 6

When water reacts with chemicals in the rocks which are carried away in solution

Front 7

Solution

Back 7

Method of river transportation whereby chemical ions are dissolved in water (calcium carbonate etc)

Front 8

Attrition

Back 8

Method of river erosion, the collision of larger angular rocks cause them to physically disintegrate into smaller rounder rocks (occurs at the upper-course of the river)

Front 9

Traction

Back 9

Method of river transportation; bedloadis rolled and pushed along the river bed (upper-course of the river) due to strong drag forces therefore instigating attrition

Front 10

Saltation (leap-frog motion)

Back 10

Method of river transportation; large sand grains bounce along the stream bed due to the ballistic effect

Front 11

Suspension

Back 11

Method of river transportation:
suspended load (sand, silt, clay) are carried in suspension

Front 12

Silt

Back 12

Sedimentary material consisting of very fine particles intermediate in size between sand and clay

Front 13

Rapids

Back 13

River feature formed by alternating bands of resistant and less resistant rock (occurs in the upper-course of the river)

Front 14

Waterfalls

Back 14

Formed at the upper course of the river as a result of undercutting of less resistant rock under a layer of hard resistant rock whereby the hydraulic action instigates hammering and vertical erosion; creates slip-off slope, natural step for river to flow vertically. Potholes and eddies at the bottom

Front 15

Potholes

Back 15

Deep circular depression found at the upper-course of a river;
worn out by abrasion from lose stones in strong rapids/waterfalls (due to turbulent flow)

Front 16

Meanders

Back 16

Feature in the lower-course of the river (lateral erosion).

Front 17

Ox-bow lake

Back 17

Feature formed when the loop of a meander becomes too tight due to heavy deposition causing the meander neck to break off from the main channel

Front 18

Delta

Back 18

Found at the mouth of the large rivers. when a river deposits its load faster than the sea can remove its matterial). A result of "flocculation"

Front 19

Levee

Back 19

A formation of course sediments (sand) that are deposited immediately on the river banks

Front 20

Floodplain

Back 20

Plain bordering a river and subject to flooding

Front 21

Braiding River

Back 21

A series of diverging and converging river channels

Front 22

Flocculation

Back 22

When salt water and fresh water mix, creating an electric charge causing clay particles to coagulate and settle on the river bed.

Front 23

Cavitation

Back 23

Implosion of gas bubbles in turbulent flow causing shock waves to weaken rive banks and accelerate bank caving

Front 24

Entrainment

Back 24

A river's ability to transport material (velocity line between erosion and transportation)

Front 25

Zone of Aeration

Back 25

The subsurface sediment above the water table containing air and water. Also known as unsaturated zone; vadose zone; zone of suspended water.

Front 26

Helicoidal flow

Back 26

cork-screw motion occuring in the middle course of a river

Front 27

Flooding

Back 27

-overbankfull discharge

Front 28

Bifurcation Ratio

Back 28

The ratio of number of stream segments of one order to the number of the next higher order.

Front 29

Wetter Perimented

Back 29

Total perimeter in contact with water

Front 30

Hydraulic radius

Back 30

Cross-sectional area of river / Wetter perimeter?

Front 31

Pools

Back 31

Deeper areas of water occuring along meanders with higher erosion due to turblulent flow

Front 32

Rifles

Back 32

Shallow areas of water occuring along meanders

Front 33

Sinuoisity

Back 33

How sinuous a river is
Actual channel width / straight line

Front 34

Through fall

Back 34

Vertical transfer in the hydrological cycle whereby water falls from the surface of leaves on to the ground

Front 35

Headward erosion

Back 35

Backward river erosion occuring at the upper-course of rivers

Front 36

Thalweg

Back 36

Maximum line of velocity in a river (found in meanders), circular moton - occuring in tubulent water.

Front 37

Bluff Line

Back 37

A bluff line is a prominent slope marking the edge of a flood plain.

Front 38

Braided river channel

Back 38

A diverging series of converging and diverging segments due to a drop in a river's competence and capacity instigating high deposition.

Front 39

Alluvial Fan

Back 39

Form of deposition whereby the fastest flowing stream, slows down and is flattened. A fall in the river's capacity causes the river to change direction and gradually build a slight mound/conical shape.

Front 40

Aquiclude

Back 40

A formation of impermeable rock (boundary to an aquifer)

Front 41

Aquifers

Back 41

A formation that stores groundwater/sub-surface water

Front 42

Phreatic Zone (Zone of Saturation)

Back 42

PERMANENTLY SATURATED ZONE WITHIN SOLID ROCK AND SEDIMENTS (all pore spaces filled with water)

Front 43

Vadose ; (Zone of Aeration)

Back 43

SEASONALLY FILLED PORE SPACES - AT THE SUB-SURFACE AREA