Hi @Deri ,
Thanks for writing in to the forum with your question about the Sediment Delivery Ratio (SDR) model.
Which version of InVEST are you using? Please upload your log file to this post so we can take a closer look at what’s happening.
InVEST version 3.14.0 was recently released and it includes a major change to the SDR model in terms of how the LS-factor is calculated, resulting in significantly lower values for USLE and export than previous versions would output. You can read a discussion about the details of these changes on GitHub. If you have not updated to InVEST version 3.14.0 yet, I strongly recommend doing so. Download the latest installers from our site, here. Then, try running the model again and check if the results are more sensible.
-Jesse