How to show streams in the produced final results in the SDR model


I am trying to use the SDR model to produce avoided erosion and avoided export maps, but in the resulting maps, there are no data fields where streams should be. From what I could understand by reading other questions here, it is supposed to happen (Also, the same thing happened in the test file provided while installing InVEST).
But I wanted to ask what I should do if I want to show the watershed as a whole (including streams) in the avoided erosion and avoided export maps.

Thank you in advance

Hello @Atul, and welcome to the forum!

Can you clarify what exactly you want to visualize with the streams? Since the output maps do not have data in streams, by default these areas will not have any color symbology in a GIS. If you want to fill the streams in with some sort of value (perhaps to highlight that they have no data, or maybe just to fill them in with blue so they’re not empty), you can do that in a variety of ways. One way is to give a color to the NoData values, but then that will color outside of the watershed too. Another way is to give a color to the watershed polygon and layer it underneath the avoided erosion/export raster.

~ Stacie

Thank you for the quick reply @swolny

I was just wondering what the right approach would be for showing the erosion/export of the whole watershed. The thing is that the streams (NoData values) are relatively higher than my waterbodies/streams LULC classification. So should I just mention that the NoData values are streams or should I fill the NoData values in the erosion/export raster with the some values?

Thank you for the help

When I visualize these results, I usually leave the streams as NoData (with blank/no symbology on the map) and note that no model output is produced in streams because the model does not include in-stream processing. Another option would be to make them, say, gray (while perhaps the other raster symbology is brown or green or something), which would allow you to add the “NoData” (or whatever) to your legend, increasing the clarity of the result.

I would not recommend assigning them a value that could be mis-interpreted as valid model data. For example, a value of 0 is a valid model value, and it is not true that the model calculated a value of 0 avoided export within streams.

If you want to provide a sum total of erosion/export for the whole watershed, you can sum the output raster pixels within the watershed to get a total value. Again, there is the caveat that this total only represents overland erosion, so does not include what’s going on within streams.

~ Stacie

Okay, I got it now. Thank you so much for clarifying my doubts.

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