How to use topographic maps?

We use topographic map to show every detailes in our site by its cordinates (X,Y,Z) which collect by different survey instruments.

We use grid to show (X,Y) and use contour line to to show (Z) .

 

hello the answer to your question we define a point or a study area by coordinates (x, y, z) that belongs to a system of geodetic coordinates (exp wgs84 ......) or a system of local coordinates (exp north sahara , ........).
topographic map is used to set and track a project these coordinates as (road, bridge, pipeline, building ....) must have positioned the map in the direction of true north.

AutoCAD Land Desktop Auto Civil3d importing topographic maps to the program and start designing for roads, rough, fine grading and infrastructure and also many other uses like ground water wells, railway design .etc and designing on surface imported from the map (x,y,z) from total station survey or google earth depends on the scale of area