Aquaculture Engineering

Methods of sloping ground - Direct Method

Unit 1- Surveying

Chaining on uneven or sloping ground
To get the horizontal distance in sloping ground, there are two methods

• Direct method
• Indirect method

Direct method or stepping method

In this method the distance measured in small horizontal stretches or steps. The follower holds the zero end of the tape at A, the leader select any suitable length l₁ of the tape and moves forward. The follower directs the leader for ranging. The leader pulls the tape tight, make it horizontal and the point 1(one) is transferred to the ground by plumb bob or by using drop arrow. The procedure is repeated. The total length “D” of the line is then equal to l₁+l₂+l₃+……………………It is more convenient to measure down-hill than to measure uphill. The lengths l₁, l₂ etc., to be selected depend on the steepness of the slope. Steeper the slope, lesser the length and vice versa.