Hey @Tp09,
Thanks for sharing your data. I think everything looks in working order and if I’ve wrapped my mind around the problem I’m pretty confident in those low volume values. The reason those values are so low is because, as you pointed out, the pixel size of 1m x 1m.
If we drop 27mm of rain on a 1 x 1 pixel and the retention ratio is 0.62, we would expect a little more than half of that to be retained volume. 27mm to meters is 0.027m, and since the pixel size is 1m x 1m, that will be our retention volume for that pixel. That’s a 0.027 cubic meter retention on a pixel (which is 1m x 1m).
The sample data has higher values because it’s looking at 27mm per meter for a 30m x 30m area. So 0.027m x 900sqm = 24.3m_3. That’s a 24.3 cubic meter retention on a pixel (which is 30m x 30m).
So the confusion might be, the 27mm of storm depth is “dropped on the landscape” per meter and NOT per pixel. The model is designed to convert that to an output of volume per pixel.
Does that make sense? Sorry if that attempted explanation was confusing. So yes, I’m not an expert in the science development of the model, but the values seem reasonable.
Doug