Greetings fellow SWMMers,
I am working on my masters project and I am struggling to get the output of my model to match with the precipitation data I have.
My precipitation data indicates that I should have about 50 inches of cumulative rainfall for the year 2008. However, the output of my model, using the assoicated precipitation values as input for my time series, indicates that there is only about 20 inches of precipitation. I have set the units as inches and cumulative precipitation, with my subcatchments imperviousness set to 100%, as well as specifying LID parameters (dedicated entire subcatchment area to area of LID; rain barrel height, outlet, etc.)
Does anyone have any suggestions as how to go about fixing this issue?
Some context: My project invovles rainwater harvesting using the LID capabilities within SWMM. I have precipitation data from NOAA for several rain gauges in Nan, Thailand - a rural, mountainous province. The precipitation data is 24 hour amounts, but I have calculated cumulative precip (which I am using as input since the 24 hour values yield about 7 inches of annual precip). I am looking into using the rooftops of the homes, which are primarily corrugated steel sheets, to capture the precipitation.