This column, explain details on steps by steps of OSD spreadsheet computation.
Step 1:- Open ESM (OSD) spreadsheet.
Step 2:- Change design ARIs value.
[Refer to table 1.1 in MSMA (2011).]
Step 3:- Change Coefficient value for lambda, kappa, theta and eta.
[Refer to table 2.B2 in MSMA (2011).]
[Refer to table 14.3 for area smaller than 0.4 hectare. For area larger than 0.4 hectare, please used formula stated in chapter 14.]
Step 5:- Insert area and runoff value for impervious and pervious area.
[Refer to table 2.5 in MSMA (2011) for runoff coefficients value.]
Step 6:- The PSD & SSR value will be automatically calculated for you.
[Please choose type of OSD that you want to design and select the maximum value for SSR value.]
Editor:- Dilah – 11 Feb 14