Earth 2W03

Front 1

Evaporation

Back 1

Water molecules move from liquid to gaseous state

Front 2

What is r.h?
What happens when r.h = 100%?

Back 2

R.H = Relative Humidity
It rains when r.h = 100% because then the air is completely saturated with wata

Front 3

Condensation

Back 3

Water molecules move from gaseous to liquid or frozen state

Front 4

Precipitation

Back 4

Occurs when r.h= 100% and cooling occurs

Front 5

Adiabatic Cooling

Back 5

Warm air rises, expands and cools
- air cools as it moves away from the Earth's surface

100% r.h + cooling = condensation = clouds!

Front 6

Three physical loops of the water cycle

Back 6

1. Evapotranspiration loop
2. Surface water loop
3. Groundwater loop

* Humans have managed to compromise every facet of each loop (WHOOPS!)

Front 7

Be able to draw the water cycle diagrams in Ch 1

Back 7

This is a star question

Front 8

What are some human impacts on the water cycle?

Back 8

Urbanization: reduced infiltration and increased runoff due to paving/ cement
- Pollution
- Withdrawal for use

Front 9

What industry uses the most water?

Back 9

Agriculture!

Front 10

Know the water balance equations

Back 10

Lecture 1, slide 18

Front 11

Climatic Indices:
- Runoff Ratio
- Index of Dryness
- Potential Evaporation Ratio

Back 11

Runoff Ratio: Q/P
Index of Dryness: Eo/P
Potential Evaporation Ratio: Eo/E

Front 12

What are the two main factors of global precipitation?

Back 12

1. Global convection currents
2. Rain shadow effect

Front 13

Know Global Air Circulation diagrams from L2 Slide 4

Back 13

A-OK

Front 14

What is the rain shadow effect?

Back 14

A rain shadow is a dry area on the lee (back) side of a mountainous area.
- The mountains block precipitation systems and cast a "dry shadow" upon it's other side

How it works:
1. Warm + moist air is pulled to the top of the mountain by prevailing winds (and condenses as snow before reaching the top)
2. The air is relieved of moisture and travels down the other side of the mountain

Front 15

Orographic Precipitation

Back 15

- Systematic increase with elevation on windward slope
= low precipitation in rain shadow area
Occurs when warm + moist air travelling across the ocean is forced to rise when it encounters large mountains
- Produces a rain shadow!

Front 16

Convectional Precipitation

Back 16

Results from the heating of the Earth's surface. Localized + limited in areal extent

How it works:
1. The sun heats the ground, which in turn heats the air molecules right above it
2. As the air molecules become warmer, they rise up into the atmosphere (which is cold), which causes the air to condense into clouds

*Common in the Prairies + Ontario

Front 17

Cyclonic Precipitation

Back 17

A warm + moist air mass (warm front) meets a cool + dry air mass (cool front)

- Warm air is forced up over cool air
- As it rises, it condenses to form clouds + precipitation results

* Common in Atlantic Canada

Front 18

Why does precipitation vary around the world?

Back 18

- Different areas of the world have different topography, latitude, longitude, and altitude (which all affect climate)

Front 19

What are the four types of rain gauges discussed in lecture?

Back 19

1. Tipping-bucket
2. Weighing-recording gauge
3. Optical precipitation gauge
4. Ground based radar

Front 20

What are some factors that affect measurement accuracy for rain gauges?

Back 20

- Size + orientation of gauge orifice
- Gauge height above ground surface
- Wind effects (some have a wind shield)
- Gauge location (proximity to trees, buildings)
- Water splashing out (force of droplets)
- Evaporation

Front 21

What is the equation for an estimate of snow density?

Back 21

ps= w/v

w= weight of snow
v= volume of snow

Front 22

What is the equation for Snow Water equivalent?

Back 22

SWE: (ps/p)d

p= density of water (1000kg/m3)
d= mean snow depth (mm)

Front 23

Know how to do Arithmetic Mean + Theissen Polygon Diagrams

Back 23

HOW? -> FIND OUT!

Front 24

What are the Merits + Shortcomings of the Arithmetic Mean method?

Back 24

Shortcomings
- Assumes uniformity + flat topography

Merits
- Easy + fast

Front 25

What are the Merits + Shortcomings of the Theissen Polygon Method?

Back 25

Merits
- Easier for quick assessment

Shortcomings
- Not as accurate

Front 26

What are the merits + shortcomings of the isoheytal method?

Back 26

Merits
- The most accurate (takes topography into account)

Shortcomings
- Takes longer to calculate

Front 27

What is snowfall interception affected by?

Back 27

1. Snow characteristics (density, cohesiveness)
2. Geometry of vegetation (type of trees/ plants, season)
3. Transportation of intercepted snow (Wind transport, weight of snow, sublimation)

Front 28

What are the three areal methods for obtaining rainfall?

Back 28

1. Arithmetic mean
2. Theissen Polygon
3. Isoheyt

Front 29

Cold content (Cc)

Back 29

The amount of energy required to raise the snow temperature to 0 degrees
Cc = -ci p(SWE)(Ts-Tm)

ci: ice heat capacity ( = 2102 J kg-1 oC-1)
p: 1000 kgm-3
Ts: average temperature of snow (°C) Tm: melting point temperature (= 0 °C) d: average snowpack depth (m)

Front 30

How is heat transfered in snow?

Back 30

1. Air circulation (convection)
2. Water vapour diffusion
3. Radiation penetration

Front 31

Snowmelt estimation equation (think of that stupid snowmelt lab!)

Back 31

M= Qm/[(lambda)p]

M= snowmelt (m/s)
Qm= energy available for melting
lambda= : latent heat of fusion(333 kJ kg-1)
p: density of water (1000 kg m-3)

Front 32

What is the equation for Qm?

Back 32

Qm= Q* + QH + QE + QG + QR

Generally only Q* is used

Qm: energy available for melting
Q*: net radiation
QH: sensible heat flux (convective transfer) QE: latent heat flux (condensation transfer) QG: ground heat flux (negligible)
QR: energy flux from rainfall

Front 33

What is the equation for Q*? (Radiation Melt Eq)

Back 33

Q* = (1-a)K\/ + (L^ - L\/)

The main source of radiation is affected by the albedo (depends on snow characteristics)

a: snow surface albedo
K\/: incoming short-wave radiation L: long-wave radiation
L\/:

Front 34

Sensible heat

Back 34

Driven by temperature

Front 35

Latent heat

Back 35

Driven by changes in pressure

Front 36

What is the Degree-Day method?

Back 36

Used for estimating snowmelt
Relies on temperature
- Deviation of 1 deg from a given temperature over a 24-h period (How much deviation has occurred in 1 day?)
- Only for non-rainy days (it can be used for rainy days but will not be as accurate)

Temperature index method (non-rainy days)
M = a + b(Ta-To) Ta: air temperature
: reference temperature (32oF) o:
a: constant (often set to zero)
b: melt per degree-day

** APPLICATION OF THIS (L3 Slide 13)

Front 37

What is the latent heat of vapourization?
(lambdav or lambdaa)

Back 37

The amount of energy needed to break the hydrogen bonds in water in order to evaporate it

= 2.5 MJ/Kg

Front 38

What is the reason for modifying the Penman Combination equation for dry areas?

Back 38

- When the air + plant are dry, the stomata of the plant are super trying to hold onto the water
- apply the "stomata resistance" in order to properly estimate PE (Potential evaporation)

Front 39

What are some evaporation approximations?

Back 39

- Dalton approximation/ eddy correlation method
- Energy Budget/ Bowen Ratio
- Preistly + Taylor
- Penman Combination (Potential Evaporation)
- Temperature/ Heat index methods (Thornwaithe)

Front 40

What is the stage of a river?

Back 40

The depth: can be recorded continuously

Stage records can be converted into discharge series using the station rating curve

Front 41

What is the discharge/ flow rate?

Back 41

The volume of water that passes a specific point in a unit of time

Front 42

What are some methods for calculating discharge?

Back 42

- Dilution method (chemical tracer)
- Velocity-area method (cross-section)
- Float-area method (surface velocity)

Front 43

What are some key tidbits of information for the Dilution methods?

Back 43

- Tracer must be readily soluable in water and able to travel through the water
- Tracer must not be harmful to the environment

Front 44

What are advantages of the dilution method for finding discharge?

Back 44

- Better measure in mountainous rivers
- Good for streams with high turbulence
- No need for regular profile

Front 45

Be sure to be able to know how to calculate the discharge tables (Star question) from L6-7 slide 10

Back 45

Cooly cool

Front 46

What is the role of Infiltration?

Back 46

- Replenishes soil moisture
- Recharges aquifers
- Supports streams during dry periods
- Contaminant leaching

Front 47

What are some factors that influence infiltration rate?

Back 47

- Type + extent of vegetation cover
- Surface crust conditions (hardpan, frozen ground, ect)
- Temperature, rainfall intensity
- Physical properties of soils (CHANNEL 2B03)
- Volume of water below ground

Front 48

What is porosity?

Back 48

Volume of void spaces where water can travel through
- Fine grained soils have a lower porosity than coarse grained soils

Front 49

What is the specific yield of a soil (infiltration)

Back 49

The amount of water that can be taken away (think the amount of water that will drain out in order for the soil to reach field capacity)

Front 50

What is the specific retention of a soil?

Back 50

The water left after drainage

Front 51

Horton's Infiltration Model

Back 51

f = fc+(fo-fc)exp(-kt)

fc: final or equilibrium capacity (or ultimate infiltration capacity)
fo: initial infiltration capacity (mm/h)
k: constant representing the rate of decrease in f

fc: What is the maximum infiltration rate that can be reached in an area? When is the soil reaching saturation?

Front 52

What is a Hadley cell? Why are they important?

Back 52

Warm/moist air rising
- air cools and dry air moves downwards

Hadley cells are responsible for global precipitation patterns

Front 53

Water is driven in motion by

Back 53

1. Radiation energy (upward transfer of vapour)
2. Earth's rotation
3. Gravitational pull

Front 54

Mass curve

Back 54

A graph of the cumulative values of a hydrological quantity (ex: runoff) plotted against time

Front 55

Tipping-bucket rain gauge

Back 55

Consists of paired buckets which tilt on a pivot
- As rainwater fills one bucket, it tips, empties the water + generates an electrical pulse
- Each tipping is calibrated to represent 0.25mm of rain
- The number of tips within a time period (multiplied by 0.25) will reveal the amount of rain that fell

Front 56

What is a snowbelt?

Back 56

A snowbelt is an area which persistently receives lake effect snowfall in winter

Front 57

What is lake effect snowfall?

Back 57

- Water bodies are warmer than adjacent land in winter (b/c water has a higher heat capacity)
- Open water conditions may occur at some large lakes
- The air blowing over open water is warmed, which increases it's moisture capacity
- When the warmer air mixes with cold air it will produce snow

Front 58

Name two reasons why snow becomes stratified:

Back 58

1. Differences in freshly fallen snow
2. Melts between snowfall events

Front 59

Constructive metamorphism of snow

Back 59

The growth of new ice crystals

Front 60

Destructive metamorphism

Back 60

Destruction of the original shape of ice crystals, mainly through rounding of the particles

Front 61

Firnification

Back 61

Refreezing if the rounded crystals to form an increasingly dense ice mass

Front 62

Snow ripening

Back 62

a form of snow metamorphism in which the loose, dry and sub-freezing snow changes to closely packed, wet and almost isothermal condition at 0 deg

Front 63

What are some ways that heat is transferred in snow?

Back 63

1. Conduction between ice grains (air is a poor heat insulator, therefore high porosity reduces heat conduction)
2. Convection
3. Water vapour diffusion carries heat with the vapour transfer
4. Percolation and refreezing of meltwater
5. Radiation penetration

Front 64

Transpiration

Back 64

The vapourization of water through the stomata pf plants

Front 65

Lysimeter

Back 65

A container filled with soil and the same vegetation as its surrounding
- Checks the amount of water evaporated

Front 66

What are the limitations of the Eddy-correlation method?

Back 66

- Need to sample very quickly (highly sensitive + costly instruments)
- Need to be sampled on terrain not affected by upward/downward drafts

Front 67

T/F: The Penman Combination model combines the energy balance with mass transfer to eliminate the need for surface temperature data

Back 67

True

Front 68

Volumetric water content

Back 68

The ratio of water volume to soil volume

Front 69

Gravimetric water content

Back 69

The ratio of water weight to dry soil weight

Front 70

Bulk Density

Back 70

The weight of the soil/ volume of soil

Front 71

Degree of saturation

Back 71

The amount of pores that contain water

Front 72

Where does Hortonian Overland Flow occur?

Back 72

- High intensity rain areas (semi-arid/ arid)
- Impermeable areas (asphalt)
- Frozen soil
- Compacted soils

Front 73

What should be taken into account when choosing a hydrometric station?

Back 73

- Accessible under all weather conditions
- Cover the full range of flow
- Not subject to disturbance by humans/ animals
- Stable stage-discharge relationship

Front 74

What is a stable stage-discharge relationship?

Back 74

- River flows in a single channel
- Bed + banks are sable
- no backwater from major tributaries/ tide

Front 75

What should be taken into account when selecting a discharge measurement site?

Back 75

- Safe to carry out measurements (even in floods)
- Straight stretch, possible with segment length more than 5x the width
- No large tributaries nearby
- Preferably parabolic cross section

Front 76

Weir

Back 76

An obstruction built across an open channel over which the stream flows

Front 77

What are the advantages + disadvantages of weirs?

Back 77

Advantages
- Inexpensive + easy to install
- Rating equations for standardized weirs

Disadvantages
- Applicable only to small streams
- Impounded water may be lost to infiltration

Front 78

Flume

Back 78

An artificially shaped open channel flow section which provides a restricted flow area to induce an increase in velocity

Front 79

What are the advantages + disadvantages of flumes?

Back 79

Advant
- Can operate with a smaller loss of head than weirs
- Accuracy is not dictated by varying approach velocities

Disad
-More expensive than weirs

Front 80

What does the dramatic change in slope of a mass curve allude to?

Back 80

- The measurement station might have been moved (due to changes in precipitation/ runoff)

- It can also indicate a change in climate pattern (maybe a changing of seasons?)

Front 81

What is runoff ratio?

Back 81

The portion of water which does not immediately infiltrate after a precipitation event

Front 82

What is the index of dryness?

Back 82

Potential evaporation (how much water can be evaporated in a given area without any limitations/ restrictions

Front 83

What is the main source of energy available for melting?

Back 83

Net radiation!
If you look at the equation,
M= Qm/(lambda)p, you will notice that Qm basically equals Q*, and the formula for Q* is
Q*= (1-a)K - (Longwave net)

K= incoming shortwave radiation

Front 84

What is the dewpoint?

Back 84

Temperature at the point of condensation (100% r.h)

The temperature when the air is completely saturated with water

Front 85

Turc Method

Back 85

Temperature/ heat index approach to evaporation estimation
- Mean annual temperature and precipitation is needed

Front 86

Current-meter method

Back 86

- Device with a rotating part
- Place it into the water and see how fast the velocity of the water turns the turbine
- Preform measurements every 2 m

Front 87

Velocity-Area method

Back 87

Take measurements of the stream and add them up
- Water moves faster at the surface than at the bottom= take 2 measurements (top + bottom) and use the average of the two as the velocity
Q=wdv
(width x depth x velocity)

Make measurements for each of the little cross sections
Add up the discharges to get the full discharge

Front 88

What is the main assumption of Darcy's Law? What is wrong with this assumption?

Back 88

Main assumption is that the water is flowing through an unobstructed column (like an artificial pipe)

This is wrong because in nature, there are no artificial pipes, and water is only able to flow through small pores in soil

Front 89

What is a Unit Hydrograph? What are they used for?

Back 89

A time plot of discharge (Q)
- Gives knowledge of magnitude and time distribution of streamflow
- The hydrograph is a predictor of rainfall/ discharge

* You can multiply any amount of net rain to the UH and get the DRH for that amount

- Used for designing dams, reservoirs, ect

Front 90

What factors influence the shape of the hydrograph?

Back 90

- Rainfall intensity (spatial + temporal)
- Topography
- Land cover
- Soil condition
- rate of snowmelt
- hydraulics of streams
- geology + soil characteristics

Front 91

What is the time of concentration? What can it be used for?

Back 91

- The time it takes for every area of the watershed to contribute to 100% of runoff (when even the most remote area of the watershed has been drained)

Tc= end of direct runoff - end of effective rain

- Important to know for contaminant transport in a flood situation (good for quick decision making)

Front 92

When does Hortonian Overland Flow occur?
(what is the equation)

Back 92

- It occurs when the ground is fully saturated (exceeded infiltration capacity)
- This happens when all of the pores are so filled with water that the soil acts as an impermeable surface

qo= w- (f+d)-E >0

Front 93

How can you measure peak discharge with only knowing peak rainfall?

Back 93

Qp= CIA

(What does CIA stand for?- look in ccw p52)

Front 94

Which method is best for estimating evaporation when air is saturated?

Back 94

Priestly + Taylor method

Front 95

Draw a discharge hydrograph and indicate:
- Time of Rise
- Rising Limb
- Falling Limb
- Lag time

Back 95

Draw it

Front 96

Indicate three types of precipitation

Back 96

- Orographic
- Frontal
- Cyclonic

Front 97

What is matrix flow? What are macropores? What are their significance?

Back 97

Matrix flow is the flow of water in the pores of soil.
- Macropores are the large pores between soil peds. They are important because they are the most influential to matrix flow + air flow through soils

Front 98

If you have a three hour storm that produces 2 inches of net rain, what will be the DRH?

Back 98

Use Sherman's Assumption:
- (equal storm duration) DRH = p(x-h UH) p is net rain

DRH= 2(3-h UH)

Front 99

If you have a two hour storm that produces 5 inches of net rain, what will the DRH be?

Back 99

DRH= 5(2-h UH)

Front 100

What is volumetric water content?

Back 100

The amount of water/ volume of soil

Front 101

How is snowmelt calculated? What are the different sources of energy that contribute to snowmelt?

Back 101

Qm= Q* + Qe + Qh + Qg + Qr

Q* is the most influential (it is net radiation)

M= Qm/λρ

Front 102

What is the cold content?

Back 102

The amount of energy needed to raise the snow to melting level

Front 103

How can you estimate the amount of rainfall received under a canopy?

Back 103

Pnet= P –P(intercepted)

Front 104

Derive a 2-hr UH from a 1Hr- UH using the S-hydrograph method method

Back 104

CCW pg 60

Front 105

What is ER?

Back 105

ER: Effective Rain/ net precipitation
- What contributes to the DRH

Front 106

What is the difference between baseflow and subsurface flow?

Back 106

Baseflow is the amount of water that is flowing when there is no rain events
Subsurface flow is the water that flows through the ground directly under the river

Front 107

What would the DRH of a small river vs. a large river look like?

Back 107

- A small river DRH will be peaky
- A large river DRH will be smooth

Front 108

What is the base time of the DRH?

Back 108

The duration of the DRH
- How long it took to go up and down

Front 109

What is the lag time of the DRH?

Back 109

The time lag between the net rain event and the peak of the hydrograph

Front 110

What happens if peak flow exceeds 100% over a short amount of time?

Back 110

- Flooding will occur
- Can find this from the Tc (Time of concentration) graph
- Good to know ahead of time so people in the path of the flood can be warned

Front 111

What is the phi index?

Back 111

The difference between the precipitation and runoff
- The difference is the amount that infiltrates
- Good to know for those who are interested in groundwater recharge (Mexico City)

phi: (P-Q)/D

: Precipitation- Runoff (Basin Recharge)
D: Duration of rainfall

Front 112

T/F: ERH (Effective Rain Hyetograph) is the same as DRH (Direct Runoff Hydrograph)

Back 112

True!

Effective rain is what produces the DRH

Front 113

What is the UH?

Back 113

The unit hydrograph: how long it takes to produce 1 inch of rain.
It can have any x(time) so you can have a crazy long hydrograph
(5 hours), or a very short one (a very heavy rain for 10 minutes)

Front 114

How does one make an S-Lagged Hydrograph (method?)

**** QUESTION- KNOW THIS

Back 114

- Allows for the construction of any hydrograph

Procedure:
To find any t-Unit Hydrograph (t-UH):

Front 115

What are the key assumptions of the UH?

Back 115

- Uniformity of Effective rainfall in time + space
- Constant duration of DRH
- Hydrograph reflects all physical characteristics in basin
- For ER of different intensities but similar duration, the magnitude of runoff at any time is proportional...

Front 116

What are three types of hydrographs?

Back 116

Natural Hydrographs
Synthetic Hydrographs
Unit Hyrdograph

Front 117

What are the advantages of UH?

Back 117

Advantages
- Establishes a useful relationship between ERH and DRH
- Can obtain flood hydrograph for extreme rainfall magnitude
- Allows for extension of flow records based on rainfall data
- Can be used for flood forecasting

Front 118

What are the limitations of UH?

Back 118

- Assume uniform distribution of rainfall
- Will not work for basins over 5000 km2
- Must assume linear rainfall-streamflow relationship
- Most assumptions rarely jive in a real ecosystem

Front 119

Why would the Ministry of Natural Resources be interested in baseflow?

Back 119

In order to give out permits to make small power generation stations, they need to know the baseflow so that they know how much water can be taken from the river

Front 120

What are 5 applications of hydrographs?

Back 120

- Streamflow regime analysis
- Baseflow estimation
- Environmental flow determination
- Water resources estimation
- Hydraulic structures design

Front 121

What is the difference between flood routing and flow routing?

Back 121

there is none! tricked ya

Front 122

What is hydrograph routing useful for?

Back 122

- Predicting temporal and spatial variations in flow
- Predict flood stages before severe storm
- Calculate the size of spillways for dams (all large dams have spillways for safety reasons -prevents possible flooding)

Front 123

What are all flood hydrograph techniques based on?

Back 123

- The continuity equation

I-O = ds/dt

This is the difference between inflow (I) and outflow (O)

ds/dt = rate of change in storage

Front 124

What does the storage in a stable river depend on (Equation?)

Back 124

- Depends on inflow (I), outflow (O) and hydraulic characteristics (k = wave travel time)
S = k[xI + (1-x)O]

x is the weighting factor

Front 125

Advantages of the Bowen Ratio Method

Back 125

- As long as there are good measurements of saturation vapour pressure, vapour pressure of the air, and the temperatures of the water surface + air, this method is very accurate

Front 126

Disadvantages of the Priestly + Taylor Method

Back 126

- Subject to large variation due to the a coefficient (varies over topography/ temperature)

- Dependent on soil moisture
- Can only be used in humid climates because there must be an abundant supply of water for the plants

Front 127

Advantages of the Priestly + Taylor Method

Back 127

A more simple version of the Penman-Monteith equation
- Doesn't rely on wind speed, or relative humidity, but does depend on soil moisture

Front 128

Disadvantages of Bowen Ratio Method

Back 128

- Will not yield very accurate results for arid climates where water stress is high

Front 129

What may affect the response of a drainage basin to a precipitation event?

Back 129

- Vegetation (interception)
- Soil structure/ texture (permeability/ infiltration)
- Size/ topography of catchment area (speed of drainage)

Front 130

How does the Muskingum Method solve the problem of flow routing?

**** STAR QUESTION

Back 130

- It assumes uniform flow using the continuity equation
- The continuity equation shows the difference between inflow and outflow (storage), which is particularly important for estimating peak flow
- Setting equal time increments and assuming a linear relationships is important to obtain an accurate graph + value of k

Front 131

What are Chezy and Manning Equations used for?

Back 131

For flow routing, when inflow and outflow aren't available, wave velocity has to be estimated as a function of average velocity with the C + M equation

Front 132

What is an example of conditional probability?

Back 132

What is the probability that it will rain two days in a row?
- What is the probability that it will rain if there is no rain the day before?

Front 133

What is a flood frequency analysis?

Back 133

-Collection of historical records of observations of peak flows
- Statistical analysis of the records (mean, variance, skewness)
- Fit an appropriate form of probability distribution to the records
- The best-fit distribution serves as a model for the flood frequency analysis

Front 134

What is the return period of a flood event? (T)

Back 134

How frequently will we see this event?

T=n+1/r

A flood that occurs at least once every 100 years: T=100

Front 135

Why might small streams be most influenced by hillslope processes?

Back 135

They have a small baseflow, so any rise in runoff into the stream will create a big jump in the hydrograph

Front 136

Study Discharge calculations!

Back 136

* ccw pg 56( or 48)
- This may not be on the zam since it was on the midterm, but study anyways

Front 137

What are Q*, Qh, Qe, Qg, and Qr?

Back 137

Q*= Net radiation
Qh= sensible heat flux
Qe= latent heat flux
Qg= heat from ground
Qr= heat from rain

Front 138

Name the common distributions used for:
- Drought Freq
- Daily Precipitation
- Low Flows

Back 138

Drought: Gumbel, Weibull, Log-Pearson
Precip: Exponential
Low flows: Exponential

Front 139

During infiltration, why should Fc (final cumulative infiltration) be a smaller number than F? (Lab7: Infiltration +Discharge)

Back 139

B/c the final cumulative infiltration happens when the soil is fully saturated, therefore it will not hold the same amt of water

Front 140

T/F: Raising temperature and lowering precipitation has relatively the same affect on evaporation rate as lowering temperature and raising precipitation.

Back 140

True!
The two are both influencing factors (From lab 6)

Front 141

What is a practical problem with obtaining throughfall? (P=P-Pint)

Back 141

They are useful for estimations, but may not be able to provide a completely accurate estimation of throughfall. This is due to the fact that every site has different characteristics that will affect the amount of water intercepted. Furthermore, evaporation and transpiration both depend on temperature and r.h, which varies widely over topography. Moreover, undergrowth in the forest may lead to 2 or more levels of interception, which will greatly affect the eq.

(Lab 6)