I checked the intermediate_outputs and found that flow_direction_ndr is good, but flow_accumulation_ndr is completely black. The final outputs p_surface_export_ndr and n_surface_export_ndr are all NaN. I have tried multiple times, and the results are still the same. Please help me figure out what the problem is.
This question has recently been asked on the forum. Please see this thread, which points to User Guide information and other forum posts that might help explain your results. If these do not help, let us know.
Check the stream.tif output and see if streams are being created. If the flow accumulation raster doesn’t show a stream network, then stream.tif should also show no streams. If that is the case, then the model will produce maps with no valid values. As the User Guide says:
If you see areas of NoData in these outputs that can’t be explained by missing data in the inputs, it is likely because they are not hydrologically connected to a stream on the map. This may happen if your DEM has pits or errors, if the map boundaries do not extend far enough to include streams in that watershed, or if your threshold flow accumulation value is too high to recognize the streams. You can confirm this by checking the intermediate output what_drains_to_stream.tif, which indicates which pixels drain to a stream.
So, along with looking at stream.tif, look at what_drains_to_stream.tif and see if it shows any pixels connected to a stream, or if none of them are.
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