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SWMM Computational Methods

SWMM is a physically based, discrete-time simulation model. It employs principles of conservation of mass, energy, and momentum wherever appropriate. This section briefly describes the methods SWMM uses to model stormwater runoff quantity and quality through the following physical processes:     Surface Runoff The conceptual view of surface runoff used by SWMM is illustrated in Figure 3-7 below. Each subcatchment surface is treated as a nonlinear reservoir. Inflow comes from precipitation and any designated upstream subcatchments. There are…

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SWMM Non-Visual Objects

In addition to physical objects that can be displayed visually on a map, SWMM utilizes several classes of non-visual data objects to describe additional characteristics and processes within a study area. Climatology Temperature Air temperature data are used when simulating snowfall and snowmelt processes during runoff calculations. They can also be used to compute daily evaporation rates. If these processes are not being simulated then temperature data are not required. Air temperature data can be supplied to SWMM from one of the following…

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SWMM Visual Objects

Visual objects can be displayed on a map in the SWMM workspace.   1  Rain Gages Rain Gages supply precipitation data for one or more subcatchment areas in a study region. The rainfall data can be either a user-defined time series or come from an external file. Several different popular rainfall file formats currently in use are supported, as well as a standard userdefined format. The principal input properties of rain gages include: rainfall data type (e.g., intensity, volume,…

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Demand input method in GISpipe

If you create a pipe network with GISpipe, you can enter the number as “meta:demand customer number” in the category of Demand Categories based on EPANET. The reason for leaving this information is to change the demand later so that we can simulate it. Demand input is 1) Click the Distribute Demand button to analyze the pipe network. 2) Open the excel demand data file and select the customer number field and the demand field. 3) Click the Run…

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epanet3 is published on github.

site address is  https://github.com/OpenWaterAnalytics/epanet-dev The new features of EPANET3. Pressure Dependent Demands EPANET 3 offers four different ways of handling consumer demands at network nodes through its DEMAND_MODEL option: 1.FIXED – demands are fixed values not dependent on pressure. 2. CONSTRAINED – demands are reduced so that no net negative pressures occur. 3. POWER – a node’s demand varies as a power function of pressure. 4. LOGISTIC – a node’s demand varies as a logistic function of pressure. Pipe…

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Supported formats in GISpipe

  Description The File Extension ESRI Shape File shp AutoCAD DXF File dxf Epanet File inp   The file name defined in the GISpipe. Type File Name Water Pipe WTL_PIPE_LM.shp WTL_PIPE_LS.shp  Supply Pipe  WTL_SPLY_LS.shp Service Reservoir  WTL_SERV_PS.shp  Valve WTL_VALV_PS.shp Pressure Gauge WTL_PRGA_PS.shp Flow Gauge WTL_FLOW_PS.shp Water Meters WTL_META_PS.shp Flow Gauge WTL_FIRE_PS.shp Block boundary WTL_BLSM_AS.shp

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