eq1 - physical factors affecting drainage basin

Question 1

what is the drainage basin

Answer 1

an open system that is an area of land that is drained by a river and its tributaries

Question 2

what are the 3 types of inputs affecting the hydrological cycle

Answer 2

1. convectional- ground warms causing evaportation which casues intense weather
2. orographic- warm moist air forced to rise overupland areas causing rainfall
3. frontal- moist air meets colder polar ari forming rain

Question 3

what are the physical factors affceting the drainage basin

Answer 3

1. interception
2. infiltration
3. percolstion
4. direct runoff
5. saturated overland flow
6. infiltration excess overland flow
7. growndwater flow

Question 4

what is intercerption

Answer 4

raindrops are prevented from from falling directly onto the ground surface due to the layer of vegetation

vegetation prevents the rate of precipitation

Question 5

what is infiltration

Answer 5

where water is absorbed

Question 6

what is percolstion

Answer 6

similar to inflitration however involves deeper transfer of water into permeble rock

Question 7

what is direct runoff

Answer 7

water flowing over the surface of the ground

Question 8

what is saturated overland flow

Answer 8

occurs when water accumulates in the soil and cannot absorb any more water. This causes water to run off the surface.

Question 9

what is infiltration excess overland flow

Answer 9

occurs when rainfall intensity exceeds
the infiltration capacity so excess water flows over the ground surface

Question 10

what are the 3 physical factors affceting the driange basin outputs

Answer 10

1. evaporation
2. transpiration
3. channel flow
   4.

Question 11

what is channel flow

Answer 11

water that has been collected to flow in a river or stream

Question 12

what

what is evapotranspiration

Answer 12

The total amount water removes from the drainage basin by the process of transpiration and evaporation

Question 13

name the 5 factors whihc determine the importance of the flows outputs and inputs

Answer 13

1. climate
2. soils
3. veg
4. geology
5. relief

Question 14

vegations contibution

Answer 14

transpiration increases deu to more vegeation
vegetaion with a low albedo wiill reflect will absorb more solar rad meaing increased evaporation

Question 15

climates contribution

Answer 15

– influences
amount of rainfall and
vegetation growth.

Question 16

soils contribution

Answer 16

nfluences rate of infiltration
and throughflow.

Question 17

geologys contibution

Answer 17

affects
percolation and
groundwater flow

Question 18

relief conribution

Answer 18

➢ Relief – steeper gradients
of land will encourage faster
rates of surface runoff

Question 19

name the 4 human disruptions of the drainage basin

Answer 19

cloud seeding
urbanisation
dam construction
groundwater abstraction

Question 20

what is cloud seeding

Answer 20

this is the attempt to change the amount or type of preciptation by dispersing substances into the air.

Question 21

what is urbanisationan and what does it create

Answer 21

urbanisation creates impermeable surfaces that reduce infiltration adn increase surface runoff

Question 22

what are the increases and decreases of dam construction

Answer 22

dams increase surface water stores
adn evaporatioon
and reduce downstream river discharge

Question 23

what

what is groundwater abstarction

Answer 23

groundwater is abstacted from some aquifers faster than it is replaced

removing water from an underground source

Question 24

h

what is a water budget

Answer 24

shows the annual balance bewteen inputs(precip)and outputs(evapotranspiration, channel flow).

Question 25

what is a river regime

Answer 25

the annual variation in the dischareg of a river

Question 26

what is the watershed

Answer 26

boundary of the drainage basin

Question 27

how has defroestation affcted the amazonian river

Answer 27

-has lowered humidity’s -less precipitation -more surface runoff -more evaporation, less transpiration -more soil erosion and slit being fed into the rivers.

Question 28

decribe the features fo the amazonian rainforest

Answer 28

1. 6308 km long 2. drains a basin of nearly 6 million km2 3. humid tropical climate 4. peak discharge in may, lowest in september

Question 29

what is the discharge of a river

Answer 29

the volume of water flowing through a river channel

Question 30

describe the features of the yukon river

Answer 30

1. 3540 km long 2.drainage basin area of 850,000 3.tundra climate 4.peak dischareg in may, lowest in decemeber 5.

Question 31

describe the features of the river nile

Answer 31

1. changed deu to the aswan dam 2. flow was reduced by 65% 3. flood peaks in september 4.

Question 32

what does a stormhydrograph show

Answer 32

variations in rivers discharge at a specific point over a short period of time

Question 33

what are the main features of a storm hydrograph

Answer 33

-the rising limb -peak discharge -lag time -falling/ recessional limb -base flow

Question 34

rising limb

Answer 34

where the discharge starts to rise after the rainfall starts

Question 35

peak discharge

Answer 35

reached after the peak rainfall -its the greatest vol of water-flooding may occur

Question 35

base flow

Answer 35

where the rivers dischareg eventually returns to normal

Question 35

lag time

Answer 35

the interval between the peak rainfall and the peak discharge

Question 36

falling limb

Answer 36

once the rainfall starts to decrease so deos the discharge

Question 36

what the two ways a storm hydrograph can be described

Answer 36

flashy and subdeud

Question 37

what is a flashy hydrograph

Answer 37

very steep limbs(rising) 1)high peak discharge 2) short lag time

Question 38

what is a subdued hydrograph

Answer 38

hydrographs with gently inclined limbs 1)low peak discharge 2)long lag time

Question 39

# de describe the drainage basin size of a flashy and subdued hydrograph

Answer 39

f=small basin s=large basin

Question 40

# describe the drainage basin shape of a flashy and subdued hydrograph describe the drainage basin shape of a flashy and subdued hydrograph

Answer 40

f-circular basin s-enlongated basin

Question 41

describe the drainage basin relief of a flashy and subdued hydrograph

Answer 41

f-steep slope s-gentle slope

Question 42

describe the soil type of a flashy and subdued hydrograph

Answer 42

f-clay soils, thin, low porosity-water infiltrates slowly s-sandy soils and thick soils-high porotity-more infiltration

Question 43

describe the rock type of a flashy and subdued hydrograph

Answer 43

f-imperable rock-increases surfaec runoff s-permeablel rocks

Question 44

describe the rock type of a flashy and subdued hydrograph

Answer 44

f-imperable rock -increases surface runoff s-permable rock-

Question 45

describe the drainage density of a flashy and subdued hydrograph

Answer 45

f-high drainage density s-low drainage density

Question 46

describe the natural vegetation of a flashy and subdued hydrograph

Answer 46

f-thin grass-intercepts little water s-forests and woodland-intercepts water-high evaporation rates

Question 47

describe the land use of a flashy and subdued hydrograph

Answer 47

f-urban surfaces-harder surfaces-carry water more rapdily to water sources s-rural-vegetated surfaces-intercept water-allow interception-travel slower to water sources

Question 48

describe the preciptation intensity of a flashy and subdued hydrograph

Answer 48

f-high intensisty- s-low intensity

Question 49

describe the preciptation duration of a flashy and subdued hydrograph

Answer 49

f-prolonged-water table rises and soil becomes saturated s-short duration-

Question 50

describe the snowfall of a flashy and subdued hydrograph

Answer 50

f-fast snowmelt s-slow snowmelt

Question 51

describe the evapotranspiration of a flashy and subdued hydrograph

Answer 51

f-low rates-fewer losses from the drainage basin s-high rates- high evapotranspiration losses will reduce discharge into the river channel