Movement of water within the spaces of porous material due to adhesion, cohesion, and surface tension
capillary action
You want to know how much energy is required to increase the temperature of a substance by a certain amount
Q = mcΞT
the specific heat capacity of water
1 cal/gΒ°C
Latent heat and sensible heat
Latent heat is associated with PHASE, sensible heat is associated with TEMPERATURE
What are the two ways to change relative humidity?
change the amount of water vapor molecules, or change the temperature
A land area that channels rainfall and snowmelt to creeks, streams, and rivers, and eventually tooutflow pointssuch as reservoirs, bays, and the ocean
a watershed
You want to know how much energy is taken from the environment when a mass of water evaporates
Q = mHv
what is dew point
the temperature to which a air parcel would have to drop for condensation to occur
vapor pressure vs. saturation vapor pressure
vapor pressure is the amount of water vapor in the air, saturation vapor pressure is the amount of water vapor the air can "hold"
What are the four lifting mechanisms that lead to cloud formation?
orographic uplift, convection, frontal lifting, convergence
the pressure exerted by the water vapor molecules in a given volume of air
actual vapor pressure (or just vapor pressure), e
The water budget for a control volume NOT at steady state
ππ/ππ‘= π + ππππ + πΊπππ β ππππ’π‘ β πΊπππ’π‘ βπΈπ
Which is higher and why? PET or ET?
PET (potential evapotranspiration) because it is how much evaporation would occur if the water supply were unlimited
What happens with precipitation at about 0 degrees latitude versus about 30 degrees latitude and why?
When does the water year start in the US and why?
October 1 - after all the snow melt, before snow begins to fall
What is SWE? Why is it important?
Snow water equivalent - tells you how much water will contribute to water budget
The water budget for a control volume at steady state
π + ππππ + πΊπππ = ππππ’π‘ β πΊπππ’π‘ βπΈπ
What is head and what are its units?
Measure of energy per unit weight, units of length (m, ft, etc.)
The three components of head in the Bernoulli equation
elevation, velocity, pressure
A hose with a cross sectional area of 10 cm2 is connected to a hose with a cross sectional area of 5 cm 2. If the velocity through the wider hose is 10 cm/s, what is the velocity through the narrower hose?
20 cm/s
A bar graph showing precipitation over time
hyetograph
You want to calculate relative humidity
Rh = e/esat
What is the continuity equation? What are the generic units of each term?
Q = U * A
Q = discharge = L3/t,
U = velocity = L/t
A = area = L2
How does increasing hydraulic radius affect velocity and why?
With a lower hydraulic radius (flatter channel), there is more friction, so velocity decreases.
What are interception, stemflow, and throughfall?
INTERCEPTION: rainfall that is trapped on leaves or other plant surfaces, lost to evaporation before reaching the ground
THROUGHFALL: rainfall that drops through vegetation
STEMFLOW: rainfall that falls on vegetation and is directed along plant parts to the ground