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I am using QGIS 2.14 (Essen Version).

I need to create a grid of points within a given area so that each points 500m across the ground from any other point. At these points trail cams will be placed, as part of a research project on biodiversity (i.e. a square with 500 meter sides and cameras placed at each corner of each square).

This terrain is in the mountains of Costa Rica. It is very steep (30 deg slopes and sudden drop-offs are not uncommon), covered in dense vegetation and has many large mudslides sporadically found throughout the area.

We can only reach these sites by foot, so I would like to be as accurate in my plotting as possible to reduce the amount of time spent wandering in the bush.

I have plotted a grid with points using MMQGIS, but it is a “flat-grid” that doesn’t seem to account for the steepness and I’m not sure what to do next.

I am fairly new to GIS and my skill set is limited (particularly when it comes to code). I am also working on a Mac, which can be problematic. I have tried searching the web (as well as this site) for detailed answers, but came up short.

I seek a detailed, step-based answer on how to do this, if it is indeed possible for me to do.

As an aside, the Internet here is unreliable and slow, it took me several days to download QGIS and it failed several times because the internet frequently disconnects. So I prefer an answer that does not involve downloading large files or software.

closed as too broad by PolyGeo Jun 5 '18 at 18:27

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • I'm not sure if you are aware that in a landscape with sudden drop-offs etc. you just won't be able to place evenly distributed squares. The position of each corner will depend on the way you're walking through your investigation area, and depending on the exact form of the terrain you may end up with diamonds instead of squares. So depending on your equipment it could be best to stick to the flat grid and think about best ways to reach those points. If you have a GPS it shouldn't mind the exact waylength between two consecutive corners. How do you orient yourself? – Rudi Uhl Apr 30 '18 at 16:13
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    Maybe this link can help – Moh Apr 30 '18 at 16:30
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    If you use a planar grid (and correctly project 500m), each intersection will be at least 500 m away from any other intersection. Acounting for slope will lead to irregular polygons and there are multiple solutions to it. Sounds ot me quite unusual to segmentate terrain in that way, could you explain your case? – jjmontes May 1 '18 at 19:30
  • I agree with the comments so far. The problem as stated has multiple solutions. Therefore there is not a single solution. A way to tackle the problem is by first determining the route you are going to walk. That way you could just 'walk 500m' and 'drop' a new point. In the direction you are walking that would be a good solution. However in all other directions the distance will not be exactly 500m. – LMB May 7 '18 at 12:14