Gura watershed SDR

Regarding this project I have some questions:

  1.    The USLA erosion rates are ranging between 0-110 t/pixel/year, considering that the pixel size is 15 x 15 m (225m2), then the erosion rates would be ranging from 0 - 110*10000/225 = 0 – 48888 t/ha/year ?
    
  2.    The aggregated results by the software are in t/year, is
    

1392511,75

  1.    The aggregated results in t/ha/year, l could be simply transformed by dividing results with the Gura’s area in (ha), Gura watershed: 10810,2149 ha
    

usle tot: 1392511,75/10810 t/ha/year?

  1.    Finally, if I want to modify any map e.g. sed_export to t/ha/year I just need simply to calculate pixelvalue*10000/225 ?
    

I am waiting for your response.

Welcome to the forum @Dimitris!

The USLA erosion rates are ranging between 0-110 t/pixel/year, considering that the pixel size is 15 x 15 m (225m2), then the erosion rates would be ranging from 0 - 110*10000/225 = 0 – 48888 t/ha/year ?

Yes, that calculation looks correct to me, and we note that conversion equation in the User Guide. For what it’s worth, we are in the process of updating the SDR (and other) models to output values per hectare instead of per pixel, so they will do this calculation for us in the future.

The aggregated results in t/ha/year, l could be simply transformed by dividing results with the Gura’s area in (ha), Gura watershed: 10810,2149 ha usle tot: 1392511,75/10810 t/ha/year?

If you want to calculate the total USLE value per hectare within each watershed, then yes, that seems a correct calculation.

Finally, if I want to modify any map e.g. sed_export to t/ha/year I just need simply to calculate pixelvalue*10000/225 ?

Yes. Again, this calculation is noted in the SDR Interpreting Results section of the InVEST User Guide.

~ Stacie