Mapping concepts ... getting started...

In additionto my earlier entries about plan or map features (point, line and polygon)... there are other technical factors that define them for users (i.e. engineer, surveyor, urban planner etc). These include scale, resolution, accuracy and projection.

Map Scale - to diplay these map features (point, line and polygon) that represent object on the earth surface (i.e. waterpipe valves, roads and buildings) the area must be reduced. The extent of reduction is expressed as a ratio. For example 1 cm = 2000 m is also defined as 1:2000. Map scale indicates how much the given area was reduced. For the same size map, features on a small scale map (1:100000) will be smaller than on a large scale map (1:1500). Each scale represents what you can and cannot see in a plan or map. You can see more details in a large scale map than in a small scale map.

Map Resolution - this refers to how accurately the location and shape of map features can be depicted for a given map scale. Of course... in other words... scale affects resolution. In larger scale maps, the resolutions matches closer to ground survey. The minimum sizes and dimensions are sometimes called minimum mapping units.