Areas and Volumes
Always the land is bought and sold on the basis of cost per unit area. For railways and road land is to be acquired on the basis of area. In the designing of bridges and bunds catchment area of nalla and river are required. Thus finding areas is the important part of surveying. It may be noted down that area to be found is the projected area. For finding areas Units used are square metres, square kilometre and hectare. Relation among them is
Hectare = 100 m × 100 m = 1 × 104 m2
Square kilometer = 1000 m × 1000 m = 1 × 106 m2 = 100 hectare
Volume of earth work involved similarly in projects like rail, road and canal are to be found by surveying. Also the Capacity of reservoir needs volume calculations.