Water Hydrology and Streams Flashcards Preview

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Flashcards in Water Hydrology and Streams Deck (49)
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1

Hydrologic cycle

movement of water between hydrosphere (ocean), atmosphere (air), and lithosphere (land)

2

Hydrologic processes (5 points)

-Evaporation
-precipitation
-infiltration
-evapotranspiration
-runoff (streams)

3

runofff

part of precipitation that does not infiltrate or re-evaporate, that is collected by stream.

4

Annual water balance

-stream runoff (mm/annum)= imput-losses
(imput=rain and snow, losses=evapotranspiration)
-storage (changes in volume of soil, or lake/river water

5

steady state

imput=output
no increase in reservoir size

6

Residence time

volume/imput

7

1 km^2= xm^2?

1 km^2 = 1*10^6 m^2

8

Examples f residence times:

H2O in atmosphere: A few days
H2O in lake ON: 6.4-9 yrs
Ground H2O in deep aquifer: 100s-1000s of yrs
Sea water in ocean: ~3200 yrs

9

What happens when imput is greater than output? (2 points)

-flooding
-ships can carry more cargo without grounding

10

What happens when loss is greater than precipitation imput? (5 points)

-drop in water levele
-increase in salinity
-soil dries up
-wind born soil transport increases
-agricultural failure

11

Define stream

-any flowing body of water
-most important eroding agent and main function of sediment transport

12

Define river

major branch of a stream system

13

Importance of streams

-major agents of change in landscapes
-provided pathways for colonists
-most cities are buit around a river (source of drinking water)
-agriculture
-recreation

14

Stream System components

-Drainage basin
-tributary
-drainage divide

15

Drainage Basin

total area drained by stream and its tributaries

16

Tributaries

Small stream flowing into larger (small stream conTRIBUTES to larger)

17

Drainage divide

ridge of high ground dividing one drainage basin from another

18

Largest Drainage basins in North America?

1) Mississippi (3.2 million km2)
2) Mackenzie (1.8 million km2)

19

Largest Drain Basin globally?

The Amazon river (6 million km2)

20

Define headwaters and mouth

-headwaters=source
-mouth is where river enters open water

21

Stream system components

-Valleys: sloping area around stream
-channel: bottom of valley where water flows
-floodplains: flat area in valley level with top of channel. (can be flooded)

22

Define Gradient (L)

change in height/distance (cm-m/km)
-decreases as you go downstream

23

Define Discharge (Q) (m3/s)

=velocity (U) (m/s)/area (m2)
-increases downstream due to collection from tributaries

24

Depth (d) and Width (w)

channel size INCREASES downstream
-increased area (A)= decresed friction; larger streams have greater velocity (U)

25

velocity (U) (m/s)

U increases downstream; less bed roughness, higher Q, larger channels

26

What is the purpose of a stream?

plane out relief via channelized flow (most efficient)

27

How does a stream plane out relief via channelized flow? (3 things)

1) erosion
2) transport
3) deposition

28

What controls erosion, transport, and and deposition? (3 things)

1) hydraulic parameters:
-flow velocity, discharge, viscosity
(volume of water flowing through channel and the velocity at which it does so)
2) morphology
(ie. Fast flowing cascade in mountains vs long, sinuous river in plains
3) material (that its eroding into or transporting)
(ie. eroding into granit vs loose sediment; transporting large boulders vs sand)

29

modes of sediment transport (4)

-Bedload (along the bed)
-Saltation (periodically lifts off into flow)
-suspension (in the flow)
-solution (dissolved in flow)

30

True or False: Grain size transported by stream is directly proportional to stream velocity

true