Introduction to Hydrology

 INTRODUCTION TO HYDROLOGY

Hydrological cycle Comprises of

1. Precipitation

2. Evaporation

3. Transpiration

Precipitation & Evaporation are the two most important elements of the water cycle for hydrologists.

The water cycle is

1. A closed system

2. No water being created or lost, just moved around.

3. Its a Finite resource – but renewable if quality controlled.

Components of a Hydrologic Cycle is as shown in the figure

A Typical flowchart of a Hydrologic Cycle is as shown in the figure below

Precipitation: All forms of moisture being released from the atmosphere.

Rainfall and evaporation are measured by depth (usually millimetres)

One cubic metre (m3) = 1000 litres

One millimetre depth over one hectare = 10 m3 

10cm depth over one hectare = 1000 m3 = 1 Megalitre (ML)

Rainfall and evaporation are also by rate (mm/hour,  mm/day,  mm/year)