Grid based flora mapping - how to create grid cells as places?

Dear Folks,

I am involved in a discussion on launching a grid-based flora mapping project. The platform could be iNaturalist but there are questions about handling the geographic grid system. As I understand, for grid-level statistics we need to create each grid cell as a separate Place. Or is there any shortcut to create all cells from a single kml file?
Do you know other grid-based projects using iNat?
Cheers,

Attila

what exactly are you trying to map / analyze? what kind of grid are you thinking of using?

if you’re trying to query the system by grid cell, then one way to accomplish this would be by adding each cell as a place. however, each cell would need to be its own place, and there’s a limit for the number of places a user can create per day, i think. so this probably is not a good approach if you need to add a lot of cells. additionally, depending on the size and shape of your cells, obscured observations may not be picked up properly in your cells / grid.

however, you can also just extract the observations you’re interested in and run whatever sort of analysis you need to do and make whatever sort of visualizations you need to make outside of iNaturalist. it’s a little more work, and there’s a little more setup / lag doing it this way, but this is probably the best way to do something where you need a lot of precision / control over what you’re doing.

iNat also sort of has a built-in grid based on map tiling (UTFGrids), which may or may not be useful for your purposes. i like to use it for quick visualizations involving large numbers of observations in close to real time, but it may not be suitable for more scientifically rigorous applications.

…

if you’re interested in going further down one of these paths, i can provide more guidance once i understand what kind of result you’re trying to achieve.

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This is an auxiliary project of an earlier flora mapping at the country level in which the sampling completeness varied considerably. We plan to identify target grid cells (up to 300, still to be decided), where the earlier survey was critically incomplete and launch an iNat project only on these cells. New data from this auxiliary project will be added to the earlier database stored in a different software environment. So, the main challenge is how to define the target grid cells comfortably.

Places, especially larger ones, create a major load on iNat infrastructure, so any project that involves the creation of a large quantity of new places might be challenging. 300 is a fair amount - if they are fairly small places, this might not be a huge issue. However, if they will be large, it might be best to check with staff to see if this is ok.

KMLs can have multiple shapes within them, but there is a max file size limit for kmls on iNat:

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ok. so you’re trying to make a place or places for a project.

i think the best way to do this is to combine all your sampling cells into one multipolygon feature. (note that it should be 1 feature, not 300 features.) so you’ll get a place that contains all your sampling cells together. how to do this technically depends upon how your cells are defined currently. are they individually defined in some sort of GIS format already? what sort of GIS program(s) do you use? (if you use QGIS and your grid is defined with each cell being its own feature, you can open the advanced editing toolbar, edit your grid layer, select the cells / features you want to combine, and then select “Merge selected features” rom the advanced editing toolbar.)

the benefit of creating a single place that contains all your sampling cells is that there’s much less to manage in iNaturalist. the downside is that you won’t be able to query directly in iNaturalist for a specific cell.

i assume that attilalengyel is working in Hungary, and that country is not so large nor has so many observations that adding a place here should cause any issues. a multipolygon consisting of up to 300 polygons should not be overly complicated either, assuming the cells themselves are not overly complicated. (i’m assuming that a simple grid should mean the cells have relatively simple geometry.)