I can see that our original elevation measurements have been scaled in some way and would like to confirm the calculation to create the slope % (Field 59). Currently, we have scored assessments with these scaled elevations, but "0.00" for the slope.
Is the following formula correct?
Structure Slope (%) = [ Inlet Invert Elevation (ft) - Outlet Invert Elevation (ft) ] / Structure Length (ft)
Field 59 = [ Field 52 - Field 55 ] / Field 58
Is it standard practice to provide these values as a negative number or a positive number?
You have the formula correct. We are planning on batch calculating slopes when we have the time, using the formula you laid out. Please feel free to calculate any slopes you wish to, whether offline or in SADES, and we will fill in any blanks when we have the time.
Slopes are typically provided with the sign the calculation results in - positive (higher inlet invert) when positive, negative (lower inlet invert) when negative.
Hope this helps,