Lesson 2 - Properties of Water

Question 1

What are some charateristics of water

Answer 1

• very strong
• Asymmetric

Question 2

What happens to water when it freezes

Answer 2

Increase in volume
decrease in density –> expansion of water molecule at freezing allows ice to flow

Question 3

Water molecules in gas phase

Answer 3

Highly charged with engergy
–> high energy state reduces likelihood of bonds between indiviual molecules

Question 4

Answer 4

Question 5

Two fundamental approaches to quantifying hydrology of landscapes:

Answer 5

Question 6

General Water Balance Equation:

Answer 6

Quantitative (arithmetic) expression of the hydrologic cycle
Inputs – Outputs = Change in Storage
I - O = ∆S

Where:
I = Area inflows
O = Area outflows
∆S = Area Storage

Question 7

Precipitation is defined as

Answer 7

 The addition of fresh water to the earth’s surface from atmospheric water vapour in the
form of rain, snow, frost, fog, dew, etc.
 Rain and Snow are the primary forms of precipitation
 In the Okanagan Basin 80 to 90% of precipitation enters the basin as snow

Question 8

Evapotranspiration Phase (ET) is defined as:

Answer 8

The total loss due to evaporation, interception and transpiration.
ET = E +It + T

In rough terms, about 60% of the total rainfall never reaches the soil due to Evaporation and transpiration in forested or grassland areas.

Question 9

Evaporation (E) is defined as:

Answer 9

 The transfer of water from the ground surface and from surface waters to the atmosphere resulting from solar radiation, temperature and wind velocity.

Question 10

Interception total (It) is defined as:

Answer 10

 The portion of rain that remains on above ground objects until its return to the atmosphere through evaporation.
 Acts as temporary storage.
 It = Ic + Ig

Question 11

Transpiration (T) is defined as:

Answer 11

 A biological evaporation process by which water within plants and vegetation, drawn through the root systems from the soil, is evaporated from the pores of leaves into the atmosphere.
 Is dependent on weather conditions including temperature, wind, solar radiation, type of
vegetation
 Is seasonal

Question 12

Storage Phase (S)

Answer 12

Precipitation can be stored in a variety of ways including:
 Surface waters
 Snow and ice
 Groundwater
 Soil moisture
 Depression storage
All of these types of storage are key components of the overall hydrological cycle.

Question 13

Depression storage (Ds) refers to:

Answer 13

 Precipitation which reaches the ground, is open to the atmosphere but does not immediately infiltrate or run off.
 Lakes, rivers, ponds, puddles
 Is described in terms of volume (m3, ft3, hectare metres, acre inches)

Question 14

Runoff Phase (Q)

Answer 14

Runoff describes the amount of water from a watershed or drainage area resulting from precipitation, less evaporation and storage.
The end destination for all runoff is the oceans.
Components of Runoff:
Qtotal = Qsro + Qssro

Question 15

Surface Runoff (Qsro) is described as

Answer 15

all flows over the earth’s surface

Question 16

Subsurface Runoff (Qssro) is described as

Answer 16

all water that infiltrates and flow below the earths surface either above the saturated soil or below the water table.

Question 17

Infiltration (If) is described as:

Answer 17

 The vertical flow or movement of water from the surface of the ground into the soil mass itself to become soil moisture and then groundwater.
 Described in mm/hour or inches/hour
 Important consideration in the design and/or understanding of:
o Sewage infiltration
o Recharge of aquifers
o Storm runoff infiltration facilities
o Soil condition after fire (water repellant soils)

Question 18

Infiltration is dependent on?

Answer 18

 The vertical flow or movement of water from the surface of the ground into the soil mass itself to become soil moisture and then groundwater.
 Described in mm/hour or inches/hour
 Important consideration in the design and/or understanding of:
o Sewage infiltration
o Recharge of aquifers
o Storm runoff infiltration facilities
o Soil condition after fire (water repellant soils)