1. Global hydrological cycle and water resources

Question 1

Hydrology

Answer 1

Science concerned with the origin, circulation, distribution of water on earth (freshwater)

Question 2

Percent of saltwater vs freshwater

Answer 2

97.5% vs 2.5%

Question 3

The water cycle (def)

Answer 3

Conceptual model describing the storage and movement of water between the biosphere, atmosphere, lithosphere and hydrosphere.

Question 4

Precipitation

Answer 4

Water condensed in clouds that falls on land as rain, sleet, hail or snow

Question 5

Evaporation

Answer 5

Liquid water in lakes, oceans, rivers and soils heated by the sun that is converted to a gas (water vapor) and returned to the atmosphere

Question 6

Infiltration

Answer 6

Water that moves from the above-ground to the subsurface

Question 7

Storage

Answer 7

Water held in contained areas for a given amount of time (e.g. in soil as soil moisture, in snow and ice caps)

Question 8

Runoff

Answer 8

Water that moves away from a terrestrial location via surface/subsurface flow processes

Question 9

River discharge

Answer 9

Flow of water within a river channel

Question 10

Interception

Answer 10

Water that is prevented from reaching the ground by plant leaves and brances

Question 11

Transpiration

Answer 11

Liquid water from plant leaves and stems that is converted to water vapor and returned to the atmosphere

Question 12

Evapotranspiration

Answer 12

Combination of evaporation and transpiration

Question 13

Percolation

Answer 13

Water that moves vertically through the soil toward the water table

Question 14

Recharge

Answer 14

Water that is added to the water table

Question 15

Groundwater flow

Answer 15

Water that is flowing below the water table

Question 16

Water table

Answer 16

Subsurface boundary below which the ground is completely saturated with water

Question 17

Water cycle: Fluxes in (4)

Answer 17

• rainfall
• snowmelt
• ground water inflow
• irrigation

Question 18

Water cycle: Fluxes out (3)

Answer 18

• evapotranspiration
• runoff
• groundwater outflow

Question 19

Water cycle: Typical storages (5)

Answer 19

• surface water
• soil moisture
• groundwater storage
• glaciers
• biomass

Question 20

Residence time (def + eq)

Answer 20

Average time spent by a water molecule in one of the reservoirs of the hydrological cycle
Tr=Vol/ Q where Q is the rate at which water exits the reservoir

Question 21

Water budget equation (broad aka no details)

Answer 21

Input - Output = Change in storage

Question 22

Steady state assumption

Answer 22

Input - Output = 0
such that change in storage = 0

Question 23

Transient state

Answer 23

Change in storage doesn’t equal 0

Question 24

Detailed water budget equation

Answer 24

Δ(M,G,S) = P - (Q+E+I)
- M = soil water storage
- G = groundwater storage
- S = channel and surface water storage
- P = precipitation
- Q = river discharge
- E = evapotranspiration
- I = interception

Question 25

Evaporation in arid, semi-arid and humid climates. Place in order of most evap to least evap

Answer 25

Arid > Semi-arid > Humid

Question 26

COMPARING INTERCEPTION
Flatwoods (forest) vs Urban vs Agricultural land
(most to least)

Answer 26

Flatwoods > Urban = Agr

Question 27

COMPARING TRANSPIRATION
Flatwoods (forest) vs Urban vs Agricultural land
(most to least)

Answer 27

Flatwoods > Agr > Urban

Question 28

COMPARING INFILTRATION
Flatwoods (forest) vs Urban vs Agricultural land
(most to least)

Answer 28

Flatwoods > Agr > Urban
(but flatwoods can be variable such that sometimes agr could beat)

Question 29

COMPARING SURFACE RUNOFF & SUBSURFACE RUNOFF
Flatwoods (forest) vs Urban vs Agricultural land
(most to least)

Answer 29

SURF: Urban > Agr > Flatwoods
SUBSURF: Flatwoods > Agr > Urban

• Flatwoods: surf < subsurf
• Urban: surf > subsurf
• Agricultre: surf = subsurf

Question 30

Green water

Answer 30

Soil and plant water: Unsaturated water storage (soil moisture) and evapotranspiration fluxes

Question 31

Blue water

Answer 31

Liquid water: saturated storage, and groundwater flow, and surface water fluxes