This command creates a hydrograph for the runoff of one drainage area. The Use TR-20 toggle in the upper left chooses between using TR-20 and using the SCS method from A Method for Estimating Volume and Rate of Runoff in Small Watersheds. The hydrograph is stored in a file with a .h1 extension that can be drawn with the Draw Hydrograph command. Storm types include 24-hour, 48-hour and emergency 6-hour.
Calculate Hydrograph Dialog
Select Hydrograph File Dialog
Pulldown Menu Location: Watershed
Keyboard Command: calchgrf
Prerequisite: None
File Names: \lsp\calchgrf.lsp, \lsp\poly3d.arx, \lsp\hydro.dcl, \exec\tr20.exe