hydrology and fluvial geomorphology

Question 1

evaporation

Answer 1

the process of liquid changing into water vapour from puddles and streams.

Question 2

transpiration

Answer 2

water is drawn up from the soil by the plant and leaves the plant as water vapour through tiny pores on the underside of the leaves known as stomata

Question 3

river discharge

Answer 3

water that flows into the sea, or that moves within channels water enters the channel as direct channel precipitation or other flows

Question 4

interception

Answer 4

precipitation is caught and stored by vegetation before it reaches the ground

Question 5

surface water

Answer 5

when the infiltration capcity is exceeded, water builds upon the surface

Question 6

ground water

Answer 6

water that has percolated into bedrock. is a store of freshwater

Question 7

channel stoarge

Answer 7

all water stored in river streams and drainage channels

Question 8

field capacity

Answer 8

amount of water held once excess has drained away

Question 9

thorughfall

Answer 9

leaves and twigs become saturated so water drips from them. precipitation can also fall through gaps in vegetation cover

Question 10

stemflow

Answer 10

precipitation is intercepted by vegetation, then runs down the branches and main trunk

Question 11

overland flow

Answer 11

when soil is saturated, or precipitation exceeds infiltratoni rate, surface runoff occurs, where water flows over the surface

Question 12

channel flow

Answer 12

movement of water in channels such as streams and rivers

Question 13

infiltration

Answer 13

precipitation soaks/ is absorbed into soil

Question 14

infiltration capacity

Answer 14

maximum rate that precopitation can be absorbed can be absorbed by soil in given conditions

Question 15

percolation

Answer 15

slow movement of water downwards through the soil into bedrock under gravity. fast in carboniferous limestone

Question 16

throughflow

Answer 16

water flows through the soil in natural pipes or percolines occurs above bedrock

Question 17

groundwater

Answer 17

water that had infiltered the ground, entered the phreatic zone and discharged into the channe

Question 18

phreatic zone

Answer 18

part of an aquifier below the water table where all pores are permanently saturated

Question 19

baseflow

Answer 19

where groundwater seeps into the rivers bed and contributes to discharge. very slow transfer from bedrock and very deep throughflow. takes anywhere between several months to a couple of years

Question 20

aquifers

Answer 20

permeable rocks that contain significant quantities of water. water inside moves slowly and maintains stramflow, by absorbing or releasing water in wet/dry periods

Question 21

springs

Answer 21

water flow reaches the surface, making a spring. might be substantial enough to become a source. usually where percolating water reaches an impermeable layer or the saturated zone

Question 22

annual hydrograph

Answer 22

to study responses of the river to its environment; highlights seasonal characteristics, therefore biggest influencer is climate

Question 23

storm hydrogragh

Answer 23

shows variations of river discharge over a short time period.includes both discharge and rainfall on the y-axis

Question 24

cumecs

Answer 24

cubic meters per secon. unit of discharge

Question 25

approach segment

Answer 25

discharge prior to storm

Question 26

rising limb

Answer 26

shows quick rise in discharge

Question 27

bank full discharge

Answer 27

channel full. any further increase in discharge = flood

Question 28

peak discharge

Answer 28

maximum river discharge

Question 29

lag time

Answer 29

time between max rainfall and max discharge

Question 30

receding limb

Answer 30

less steep than rising, shows discharge decline after peak discharge

Question 31

stormflow

Answer 31

streram dishcharge after rainstorm

Question 32

quickflow

Answer 32

surface runoff reaches channel quickly

Question 33

drainage density

Answer 33

low drainge density causes a long lag time, as water only has a few paths to take

Question 34

porosity

Answer 34

a measure of the void (empty) spaces in a material

Question 35

permeability

Answer 35

the ability of a rock or soil to allow fluids like water to pass through it

Question 36

abrasion

Answer 36

riverbed and bank eroded by the river's load. it is the mechanical impact produced by debris rubbing on the river's sides. abrasion with velocuty and effectiveness depends on energy, hardness and concentration of particles

Question 37

corrasion

Answer 37

the erosive action of particles carried by the river

Question 38

solution

Answer 38

the dissolving of rocks by removing chemical ions.

Question 42

hydraulic action

Answer 42

direct force of air and water on the rivers banks that casues chunks to break away. eddies in the water compress water into bank cracks, and explosion of air bubbles cause the cracks to weaken

Question 43

cavitation

Answer 43

the force of air exploding, with acceleration, pressure drops in fluids, causing air bubbles to form. cavitation is when these bubbles implode and produce tiny water jets, cutting rocls

Question 43

attrition

Answer 43

collision of sediments that wears down both particles. produces smaller, rounder particles

Question 44

traction

Answer 44

large particles that are rolled along the riverbed by theforce of water. spend all/most of times on the riverbed

Question 45

saltation

Answer 45

gravel and small stones hop along the riverbed, as a fast eddy picks them up, and a slower one causes them to fall back downs

Question 46

suspension

Answer 46

slits and clays are held up by the water. gives rivers a cloudy appearance, especially close to the mouth

Question 47

solution

Answer 47

dissolved calcareous rocks