Definitions Related to Drainage Engineering


The process of removal of excess surface or ground water from land by means of surface or sub-surface drainage.

Hydraulic Properties of Soil:

The Properties which are involved in water retention and transmission in soil i.e. specific water capacity (c), hydraulic conductivity (k)and soil water diffusivity (d).

Diffusivity of Water (d):                                                                                                  

It is the radio of the hydraulic conductivity to the specific water capacity and its also a function of water content expressed in cm2/sec.

Hydraulic Conductivity ( k):

It is the flux of water per unit gradient of hydraulic potential which is demoted as k and expressed in cms/hour.

Dareylaw V= KI
:.               K = V/I
Where, V= effective velocity of flow, cm/hr
K= coefficient of permeability cm/hr
I= hydraulic gradient

Hydraulic Gradient:

The hydraulic head drop per unit distance in the direction of flow (dh/dl) is called as the hydraulic gradient.

Infiltration Rate:

It is the flux or (rate of movement) of water passing through the soil surface and moving laterally on down ward into the soil.

1 ATM = 76cm.Mercury =1033 cm water 
1 Bar= 1000 cm water.


These are deep black soil containing > 30% clay and 0 to 50 cm profile, having swell, shrink property which result in the development of gi/gai micro relief and 1 cm wide crack upto 50 cm soil depth.


Muhammad Ramzan Rafique
Muhammad Ramzan Rafique

I am from a small town Chichawatni, Sahiwal, Punjab , Pakistan, studied from University of Agriculture Faisalabad, on my mission to explore world I am in Denmark these days..

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