SWMM 5, Watersheds, Water Quality, Technology, Hydrology, Hydraulics - Watershed

SWMM 4 Rainfall Files

How to Use SWMM 4 Rainfall Files in SWMM 5

If you are using the option

#SWMM4_RAINFALL

Which reads a SWMM 4 Binary Rainfall Interface File and is entered in the dialog Data=>Title/Notes

the SWMM 5 program will read a SWMM 4 Unformattted Rainfall File but it will not know how many GAGES it needs to allocate for the SWMM 4 .RIN file. We cannot put this value in the SWMM 5 input data file because the actual values of the SWMM 5 input data file are not read until AFTER the memory is allocated in the SWMM 5 C code.

We now get around this limitation by entering the maximum number of expected raingages in the SWMM 5 GUI using the command Data=>Options=>Advanced=>SWMM 4 Gages in the Rin File.

The number of entered gages is sent to the SWMM 5 DLL engine by using the swmm_open command:

swmm_open(f1, f2, f3, GlobalRain);

where, f1 = name of input file
f2 = name of report file
f3 = name of binary output file
GlobalRain = number of SWMM 4 Rin Gages

If the number of SWMM 4 Rin Gages (GlobalRain) is 0 then the SWMM 5 engine will allocate and process the raingages as it normally does. This methodology will eliminate the need for multiple SWMM 5 engines and also eliminate the problem of simulating only one out of many raingages if you use the wrong SWMM 5 engine.

if you use the #SWMM4_RAINFALL then only one raingage is defined in the SWMM 5 input file. The File Name should be the name of teh SWMM 4 .rin file. The SWMM 5 engine will read the number of raingage locattions from the SWMM 4 .rin file and allocate enough memory for each gage. The output text file of SWMM 5 will list each of the gages that it found along with the precipitation per gage as shown below.

  ********************
* Raingage Summary *
********************
                                         Data
Name                Data Source         Type
-------------------------------------
GAGE1               C:\Documents and Settings\D
GAGE2               C:\Documents and Settings\D
GAGE3               C:\Documents and Settings\D
GAGE4               C:\Documents and Settings\D
GAGE5               C:\Documents and Settings\D
GAGE6               C:\Documents and Settings\D
GAGE7               C:\Documents and Settings\D
GAGE8               C:\Documents and Settings\D
GAGE9               C:\Documents and Settings\D
GAGE10              C:\Documents and Settings\D
GAGE11              C:\Documents and Settings\D
GAGE12              C:\Documents and Settings\D
GAGE13              C:\Documents and Settings\D
GAGE14              C:\Documents and Settings\D
GAGE15              C:\Documents and Settings\D
GAGE16              C:\Documents and Settings\D
GAGE17              C:\Documents and Settings\D
GAGE18              C:\Documents and Settings\D
GAGE19              C:\Documents and Settings\D
GAGE20              C:\Documents and Settings\D
GAGE21              C:\Documents and Settings\D
GAGE22              C:\Documents and Settings\D

How it works in the SWMM 5 C Code

     // --- count number of objects in input file and create them
    input_countObjects();
    // Nobjects for GAGES should be defined beforehand
    // for reading SWMM 4 .rin files
    // This is now set by the user in the SWMM 5 GUI
    if( GlobalRinStations>0) Nobjects[GAGE] = GlobalRinStations;
    createObjects();
    // Reset Nobjects GAGE to 1 - this will change as the program
    // reads the SWMM 4 .rin file
    if( GlobalRinStations>0) Nobjects[GAGE] = 1;

    // --- read project data from input file
    input_readData();