I am making a map for an orienteering class at the environmental education center that I work at. In order for us to easily calculate the distance between orienteering points, I need the scale to be 1 cm = 100 meters. I am not sure how to set this under the map item properties in the print map composer. I thought that it would be a 1:10 000 ratio, but in the print map composer this is way too zoomed in to possible be correct. Once I have this scale set is there some way to lock it in place so it does not change again?
Also, on my working map in QGIS, the project CRS is set to WGS 84 with on the fly projection enabled. When I switch the map units from decimal degrees to meters, it appears to be incorrect. Distances that I know to be approximately 100 meters in real life appear to be thousands of km apart on the map when I am using the measuring tool. I also get an error message that says
"This map is defined with a geographic coordinate system (latitude/longitude) but the map extents suggests that it is actually a projected coordinate system (e.g., Mercator). If so, the results from line or area measurements will be incorrect. To fix this, explicitly set an appropriate map coordinate system using the Settings:Project Properties menu."
What am I not understanding here!? Please help!