Mask to specific waterbody extent

[NickSievert]

If I'm interpreting the documentation correctly, I believe the estimates are derived from all water pixels within the 2000 meter bounding box. In many cases (when working with small waterbodies) multiple, distinct, waterbodies may fall within the bounding box associated with a single point. Is it possible to apply a masking functionality so that rather than returning results for all cells within the bounding box only values associated with a specific, defined waterbody are returned?

[ejm714]

I believe the estimates are derived from all water pixels within the 2000 meter bounding box

@NickSievert yep you are correct this is a current limitation and is especially impactful for smaller water bodies near other water bodies. One option is to limit to contiguous water pixels though this gets tricky because some neighboring water pixels may have cloud cover. I think a more robust option is to mask to pixels within the water body boundary as you suggest. It would be useful if we had a fixed asset that defined water body boundaries across the U.S. (since that's where all the training data is from). From a cursory search, ARCGIS has a USA Detailed Water Bodies shapefile but I'm not sure if that will be accurate down to the river and reservoir level.

I'm curious where you're looking to use CyFi and if you have boundaries for your water bodies of interest?

[NickSievert]

Thanks for your prompt response. I've been using CyFi to develop a historical dataset and monitoring program for waterbodies managed by the Missouri Department of Conservation (my employer). As you mentioned in your response, many of the waterbodies we manage are quite small (but large enough to be resolved with Sentinel 2 imagery), and near enough to one another that multiple waterbodies fall within a single 2000 meter bounding box placed at a given waterbody centroid.

We have boundaries for all of our waterbodies of interest, however the dataset we use is specific to the state of Missouri. At a national level the National Hydrography Dataset has a waterbody layer that would provide a useful, universal (USA only) waterbody polygon layer. (This wouldn't capture rivers/streams unfortunately, however that could potentially be addressed with incorporation of the NHDArea layer).

https://hydro.nationalmap.gov/arcgis/rest/services/nhd/MapServer/10

The layer should be viewable on the national map:
https://apps.nationalmap.gov/viewer/

Really appreciate your help!