Gradient of a line
To calculate the gradient between two points:
a) Find the elevation difference: Subtract the Reduced Level (RL) of the first point from the second point. If the difference is negative, it indicates a down gradient, and if positive, it indicates a rising gradient.
b) Calculate the distance: Multiply the total number of foresights and intermediate sight readings by the constant distance between consecutive stations.
c) Determine the gradient: Divide the distance by the elevation difference to obtain the gradient of the line:
Gradient = Distance/ Difference in Elevation
- For more advanced calculations, corrections for curvature, refraction, and reciprocal levelling are applied.