Following are the definition and equation of porosity, void ratio, water content, and degree of saturation:

## 1. What is Porosity (n)

The porosity of a given soil sample is the ratio of the Volume of voids (**Vv**) to the total volume (**V**)of the given soil mass. It is generally expressed as a percentage and denoted by ‘**n**‘ It is also termed as percentage voids.

**Thus,** **n = Vv/V**

## 2. What is Void Ratio (e)

The void ratio of a given soil sample is the ratio of the volume of voids (**Vv**) to the volume of soil solids (**Vs**) in the given soil mass. It is generally expressed as a fraction and denoted by ‘e’.

**Thus, ** **e = Vv/Vs **

## 3.Water Content or Moisture Content (w)

The water content or moisture content (w) is defined as the ratio of the weight of water (**Ww**) to the weight of solids (**Wd**) in a given soil mass. It is denoted by m or w. It is generally expressed as a percentage.

**Thus, ** w = (**Ww/Wd** ) * 100 %

## 4. What is the Degree of Saturation (Sr)

The degree of saturation is defined as the ratio of the volume of water (**Vw**) present in a given soil mass to the total volume of voids (**Vv**) in it. It is denoted by (**Sr**). It is generally expressed as a percentage and is also known as per cent saturation.

**Thus,** **Sr **=** Vw / Vv**

*Read More: *

**What is Bulk, Submerged, Dry and Saturated Density & Density of Solids of Soil**

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