The Water Cycle

Question 1

What does the term “Natural Hydrologic Cycle” describe?

Answer 1

It describes the continuous (natural) movement of water (moisture) within our environment.

Question 2

From a civil/resources persective, The Natural Hydrologic Cycle can be viewed as a method or approach to keeping track of what?

Answer 2

Where water…
1 - originates from
2 - is temporarily stored
3 - is ultimately travelling to

Question 3

What two components is the Hydrologic Cycle broken into?

Answer 3

1) Elements - physical entities that store or transmit the water
2) Processes - actions by which the water travels through the cycle

Question 4

Name 5 elements of the Hydrologic Cycle.

Answer 4

1. Atmosphere
2. Surface of the Earth
3. Soil Moisture Zone/Vadose Zone
4. Groundwater zone/Phreatic Zone/Zone of Saturation
5. Channels, Lakes, and Oceans

Question 5

Name as many processes of the Hydrologic Cycle as you can.

Answer 5

1 - Precipitation (P)
2 - Surface Retention or Initial Abstraction (Ia)
3 - Infiltration (F)
4 - Inter-flow (inter-Q)
5 - Percolation (Perc)
6 - Groundwater Flow (GW)
7 - Direct Runoff (DR)
8 - Total Runoff (TR) - the sum of surface runoff and interflow
9 - Streamflow (Q)
10 - Evaporation (E)
11 - Transpiration (T)

Question 6

Surface Retention/Initial Abstraction (Ia) consists of what two things?

Answer 6

i - Interception by vegetation

ii - depressional storage in shallow surface puddles

Question 7

Total Runoff is the sum of what?

Answer 7

Surface runoff + Interflow

Question 8

Describe Transpiration

Answer 8

(Process)

moisture taken up by the plant from its root zone for its development, and released back into the atmosphere.

Question 9

What is transpiration often lumped with?

Answer 9

Transpiration is often lumped together with evaporation, which is collectively called Evapo-Transpiration (ET)

Question 10

What is Direct Runoff?

Answer 10

(Process)
water that travels across the topographic surfaces (downhill) and represents the water resulting from precipitation that was in excess of:

1 - water taken up by surface retention
2 - the infiltrated water

Question 11

What is Streamflow (Q)?

Answer 11

(Process)

• The movement or transmission of water to lower water level elevations further downstream
• ultimately making its way to ocean basins.

Question 12

Describe Evaporation (E)

Answer 12

(Process)
- Resulting from an exchange of energy (thermal, solar) between water and its surrounding environment.
-

Question 13

Describe Goundwater Flow (GW)

Answer 13

(Process)

• The contribution of water from the groundwater zone to nearby water bodies
• Only applicable if the watertable is above nearby water bodies
• very slow process
• aka Baseflow in streams, creeks, rivers

Question 14

Describe the process of Precipitation (P)

Answer 14

• the return of moisture from the atmosphere back to Earth’s surface due to condensation

Question 15

What are two types of rapid or super-cooled rain particles?

Answer 15

Glaze, rime

Question 16

How can ‘Hydrology’ be defined?

Answer 16

a science dealing with the occurrence, movement, and storage of water on the surface, above the surface and, below the surface of the earth

Question 17

What are some smaller sub-topics Hydrology can be broken into?

Answer 17

eg. groundwater hydrology, urban hydrology, snowmelt hydrology

Question 18

How can ‘Hydraulics’ be defined?

Answer 18

The science dealing with the influence and behavior of water in channels, lakes, reservoirs, dams, pipes, culverts and other conduits and structures

Question 19

Is Hydrology or Hydraulics considered more precise?

Answer 19

Hydraulics

Question 20

As part of watershed analysis, does a hydraulic analysis or hydrology study come first?

Answer 20

A hydrology study comes first