Infiltration of soil

Purpose

The purpose of the lab work was to examine the infiltration of the soil and measure its infiltration rate.

Introduction

Water penetrates in the soil and to measure its capacity to absorb water, infiltration is incorporated. The measure is influenced by many factors. For example how moist the soil is what is its texture and what is its structure. The infiltration is united in the length of infiltration in inches or millimetre in each hour. The device used is called infiltrometer.

Following apparatus is used for the soil test:

A silicon, a stop watch or chronometer, wood block, 197-W-Turf Tec Heavy Duty Double infiltration rings (6 to 12 inch) diameter for soft soil and 197-W-Turf Tec Heavy Duty Double infiltration rings (10 to 24 inch) diameter for soft soil, shovels and an infiltrometer.

The following procedure is followed:

First of all apply the silicon to the ring blades and place them on the soil. Then vertically check soil by pushing the blades about 2 inches down. If the soil is hard, hammer can be used to push blade. Now we the soil had to be covered with the centre ring. The erosion of the soil can be avoided by covering the soil between the two rings of the splash guards. Liquid is then poured using a pail into the rings. The splash guards can be removed. Over flow is prevented by measuring the volume of the liquid continuously.

The measurement of the infiltration is recorded for the first 15 minutes in the first hour and then after 30 minutes for the second hour and is continued till a contestant rate can be obtained.  The final decision about the structure of the soil is made by observing the infiltration rate at different times. After the test, the apparatus is recovered and the blades are cleaned with silicon.


 

Following are the observations that were recorded during the test

 

Inner ring Time min Water Level
 

Start

7:33 pm 0.0 3.7’’
  7:43 pm 10:00 3.2’’
Finish 7:59 pm 15:00 2.99’’
Add

 

 

1250 m2
Outer ring Time min Water Level
Start 7:50 pm 0.0 3.6’’
Finish 8:00 pm 5:00 3.2’’

 

Following calculations correspond to the readings above.

In case of the inner ring

The formula used is: V1R =

Let’s put in the values in the formula.

ΔV1R = 60.6321-52.4386/10*1250

= 0.000658

In case of the outer ring

The formula remains the same i.e. V1R =

Let’s put the values in the formula

ΔV1R = 58.6321-52.4386/10*1250

= 0.000788

Result

Third interval was where the soil volume got constant during the infiltration calculation.