Question

Mention features of a grid system of a topo sheet.

Answer 1

1. The lines that run vertically are called eastings and those that run horizontally are called northings.
2. Eastings and northings cross each other to form a square called as a grid square.
3. The starting point or the reference point is the exteme south-west grid or the one at the bottom left corner.
4. The numerical value of eastings increases eastwards beginning from the south-west corner. Similarly, the numerical value of northings increases northwards.
5. Eastings and northings are always given in two digit numbers. Even 0 is read as 00. (For example, 01, 02, 03, 98, 99.)
6. When referring to a grid, eastings are always stated first.
7. Eastings and northings on a topo sheet drawn on a scale of 1 : 50,000 are always 2 cm apart, which means they represent a distance of 1 km on the ground. So, the area of 2cm × 2cm on the map represents 1 km × 1 km on the ground.
8. There are two types of grid references, the four-figure reference and the six-figure reference.