Are you a sports teacher and would like to introduce your students to orienteering? Here are some tips for creating a map easily. In this article, we will give you tips and tricks to develop the base map (on which you will take the readings). Together, we will develop a simple orienteering race map.
Creating a base map: where to start?
Starting surveys directly on a blank sheet of paper would be a considerable waste of time. Here are 3 types of support that you can find for free online:
The IGN map
The IGN map is available for a fee in paper form, but on sites such as Géoportail or Open Runner, you will find all IGN maps online free of charge (subject to conditions of use). On Open Runner, these are bastard scales, but on Geoportal, you can choose the scale of the map on the screen. The area you will have to map may be larger than the area of the map visible on your screen. In which case you will have to learn how to assemble IGN map screenshots, the IGN map is an essential support if you want to copy the contour lines onto your map.
The aerial view
On Google map or Geoportal, you will easily find an aerial view of the area you want to map. As soon as this area is discovered, you will be able to do most of the work on your computer. The best for mapping a park for example. The scale is also strange, I advise you to print the area and calculate the scale in relation to a fixed or known distance (ex: stadium, track).
It seems that all cadastres have been online for free for some time. Otherwise, simply ask the town hall for the plot you are interested in. This is the most accurate base you can use to start a map! To retrieve the cadastre, you can also use the Geoportal. Here, we explain how to assemble it and put it on the right scale.
Open Cycle Map
Open Cycle Map are Open Source mapping projects. At high zoom levels, OCM and OSM provide very accurate information and thus create a solid mapping base. Read also: plot a route with Open Cycle Map
The more basic supports you group together (IGN maps, aerial photos, cadastre etc etc.), the more you will be able to create a precise base map with a maximum of information. The aerial view can already place elements that are exposed, the IGN map can be used to draw contour lines and main paths. The land registry will allow you to place houses or monuments, draw streets… etc etc. etc.. Each of these base maps will be templates under OCAD (your software to draw a map)
Choose the scale of your map
For a park or school yard, you can therefore determine the scale so that it occupies your A4 sheet to the maximum. To do this, download OCAD. It is a mapping software with which you will be able to open your models as background maps. The latest versions are not free, but version 6 is free, you can download it here. Opening the model with OCAD means making it a layer and drawing on it with symbols and colors.
Open ocad, (file > new > CO card 10.000)
Change the map scale (Extra > change scale). Make sure that the area you want to cover fits on an A4 sheet)
Open template: Options > Open template.
Adjust the scale of your model to the scale of the map. In this tutorial, we explain how to load a model on OCAD and how to adjust it to your map
Once your model is loaded on OCAD, draw paths, contours and buildings on your map. Anything that can serve as a reference point is also good to place. If you were mapping a park or schoolyard, you wouldn’t have to worry about drawing the buildings with your hands up. But if you have a village or neighborhood to map, we invite you to read our tutorial: Importing houses with one click on OCAD.
Then print your base at a scale twice as large as you expected[if you want to make a 1/4000 map (1cm =40 m), print it at 1/2000 to take the readings]. You will be much more precise when drawing. In theory, the models above are oriented to the north, but it is necessary to check better beforehand. (you can only be sure once you are in the field, compass in hand). Your base is ready, print it out and go into the field for the first readings.