Page 11 - soil-plant-water relationship and water requirement

SOIL-PLANT-WATER RELATIONSHIP AND WATER REQUIREMENT

Figure 1-1: Hydrological cycle

Precipitation is the primary mechanism for transporting water from the atmosphere to the
surface of the earth. There are several forms of precipitation, the most common of which for
Malaysia is rain. Other forms of precipitation include; hail, snow, sleet, and freezing rain.

Rainfall distribution and intensity will affect:
a. water in the soil,
b. rate of water loss from the root zone and
c. the rate of erosion on the soil surface.

There are three terms used to describe the characteristics of rainfall intensity,
total rainfall and frequency.

Rain intensity
 rainfall rates within a certain period of time.
 The unit used is mm / hr. Changing the intensity of rainfall during the rainy period
 The relationship between rainfall intensity and time, the rainfall is ideal as
depicted in graph below:

Total rainfall
 Total rainfall is Accumulated rainfall at one place, whether for a single rain or for
a certain period. (monthly, anually total rainfall) .
 In mm unit

Rainfall frequency
 The frequency of rain is min. of rain for certain period in which rainfall intensity
and amount determined expected to be occured

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