This isn't going to be easy to do with FME unless anyone has done it before and can share their work. However the two articles listed under 3D Analysis here might help. https://community.safe.com/s/article/how-do-i-do-that-in-fme

Thanks.. Came across that and went down a rabbit hole without any success... Hoping someone has a solution.

Not a remote sensing master, but i created a workspace that extracts lake polygon from raster imagery....I think that's what you were asking for...? also not a master in hydrology.

Essentially, I extracted pixels in band 3 that were in range from 0 to 45--based on the logic that bands higher in electromagnetic spectrum tend to be absorbed by water, therefore rendering pixel value near 0.

All you need is (1) known point x,y within lake wanting to extract and (2) polygon around region of interest.

cheers,

Really interesting process there. Has given me some ideas but unfortunately I can't adapt it to what I'm doing. I'm wanting to calculate the "uphill" catchment boundary. Not sure how to explain it but i know the ESRI and Global mapper tools work well. Will keep at it and report back.

add dem layer to the workflow.

Hi @simid​ , did you find a solution on how to create watersheds/ catchment boundaries from a set of points in FME?

Hi @mdohm​, do you have a DEM of the area you would like to build your watershed for?

Hi Jenna, thanks for picking this up. Indeed we have LiDAR data available that could be used to create a DEM.

Though scenario specific, this article should help you get started with the process. I imagine you would need some trial and error with your scenario and your points that you want to use. I would recommend starting a new thread with your question.