Week 1: Introduction, Water Cycle Basics & Rainfall

Question 1

Hydrology

Answer 1

The branch of science concerned with the properties of the earth’s water, and especially its movement in relation to land.

Question 2

Reservoir

Answer 2

A reservoir is a large natural or artificial lake used as a source of water supply.

Question 3

Water footprint

Answer 3

The amount of fresh water utilised by a particular person or group.

Question 4

Catchment area

Answer 4

The area from which rainfall flows into a river, lake or reservoir. It is a distinct hydrological unit and defines the area of land that contributes to all the flow past a particular point of reference.

Question 5

Drainage basin

Answer 5

The area drained by a river and all its tributaries. Same as a catchment area.

Question 6

Discharge

Answer 6

The volume of water flowing through a river cross section in a unit of time.

Question 7

Runoff coefficient

Answer 7

Runoff coefficient = runoff / (rainfall x area)

Question 8

Water balance

Answer 8

A water balance equation describes the flow of water going in and out of a system.

Question 9

Rainfall genesis mechanisms
-Convection
-Convergence
_Forced Uplift

Answer 9

Convection: rising moist air cools, resulting in condensation and the formation of clouds.

Convergence: a cold air mass pushes under a warm air mass while rotating in the opposite direction, causing wave cyclones. This occurs at a regional/continental scale.

Forced uplift:

a) Orographic lifting: air is forced up by terrain, if moist it condenses.
b) Cold fronts: similar to convergence but no rotation. Cold, heavy air forces warm, moist air up.