Profile Leveling by Rise and Fall Method

Procedure:

The field procedure and booking of staff reading is done in the same way as explained in the height of instrument method (each reading is entered on a different line in the appropriate column, except at a change point, where a FS and BS occupy the same line). However the data booking is performed as shown in the Table below.

Tabulation:

Calculations:

1. The difference in elevation between any two successive points (say A and B) can be calculated as:  Elevation difference between A and B = first reading at A – second reading at B 

2. NOTE, for any two successive staff readings: 

• Second reading smaller than first reading represents a Rise (The sign of elevation difference is positive). 
• Second reading greater than first reading represents a Fall (The sign of elevation difference is negative). 

3. If the elevation of the first point is known, then the elevation of the second point can be calculated as: Height of B = height of A + rise (in rise case) or Height of B = Height of A – fall (in fall case) 

Check:

∑BS - ∑FS = ∑Rise - ∑Fall = RL of last point – RL of first point

Video link: 
 https://youtu.be/QvSr8jQ8UYQ