Description

Topographic survey is simply the recording of coordinates and height data for a particular survey area. This data can be used to create spot height maps, contour maps, or more complex terrain models of the surveyed area.

The purpose of the first type of topographical survey is to establish, on a horizontal plane, the position of one or more points in relation to the position of one or more other points. To do this, you will measure horizontal distances and horizontal angles or directions. You will use a method called plan surveying, which will be explained in this chapter.

Topographical surveys will help you to make plans or maps of an area that show:
-The main physical features on the ground, such as rivers, lakes, reservoirs, roads, forests or large rocks; or the various features of the fish-farm, such as ponds, dams, dikes, drainage ditches or sources of water;
-The difference in height between land forms, such as valleys, plains, hills or slopes; or the difference in height between the features of the fish-farm. These differences are called the vertical relief.