Dear InVEST users and experts,
In the user guide, the unit for SDR results is either tons/pixel or tons/watershed. However, in many papers ton·ha−1·yr−1 has been used. Which one is correct? ton·ha−1·yr−1 or tons/pixel for sediment export and soil erosion?
The unit is tons/watershed, it is rational for a watershed. Those units in the papers as ton·ha−1·yr−1 has Benn converted from the original result of the Model.
Thank you, but in the user guide the unit for USLE is ton·ha−1·yr−1 and tons/pixel. It confused me.
Hi @marye_belete -
As @hilu202 said, the USLE and sediment export results from the model have units of tons/pixel. This can be easily converted to tons/ha, based on the size of the pixel, and we often do this when post-processing model results.
~ Stacie
@swolny To get the Total soil loss in (t/yr) for sub-watersheds, do we first convert the USLE output (t/pixel/yr) to (t/ha/yr), and then use zonal statistics tool to get the sum of each watershed which will be (t/yr)?
Yes @Nametso, that’s a good way of getting the total USLE/soil loss for each sub-watershed.
~ Stacie
For example, my raster resolution is 30×30 m and the result for SDR is 600 tons/pixel. If converted into hectares, is it 600/0.09=6666.67 tons/ha? @swolny