Getting Started

Typical Procedure for Defining New Cases

• Review this help file , the 1990 model development report , and user manual  to obtain a basic understanding of P8 structure, calibrations, and limitations.
• Visit the P8 web site to get the most recent information on the model, updates, applications, references, etc.
• Assemble reference materials for site (maps, engineering reports).
• Construct schematic diagram illustrating linkage of watersheds & devices.
• Assign a unique name to each watershed. Write these on your schematic.
• Tabulate basic watershed characteristics needed for model input.
• Assign a unique name and type to each device.  Write these on your schematic.
• Obtain a regional hourly precipitation file  (or use one of the sample files provided).
• Obtain a regional daily air temperature (or use one of the sample files provided).
• Obtain regional monthly climatologic data used for evapotranspiration, snowmelt, and runoff computations. Some of these inputs are need only if you are simulating snowmelt or aquifers.
• Enter the case input data by editing the default case that is automatically loaded when P8 is run or by selecting 'File New'.  Enter the device input values before the watershed input values.
• Load the desired particle file ('Edit Particles Read' ) or use the default file NURP50.PAR.  Several particle files are supplied with the program.
• Review input values using the 'List Inputs ' procedures.
• 'Run Model' to start the simulation.
• Review any error messages and correct input values accordingly.
• Save case input values 'File Save'.
• Select output destination (text box, notepad, or Excel) from the 'Options' menu.
• Explore model output using the 'Explore' tab on the left of the menu screen or the 'Output Tables' procedures .
• 'Run Traced ' to obtain hourly or daily output for a specified device
• Review traced time series using the ' Charts' procedure.
• If you are using P8 for BMP design, select the ' Run Design Tune ' procedure to rescale any device to achieve a specified removal efficiency for TSS or other water quality component.  Review the rescaled device to ensure that it conforms with typical engineering guidelines for each device type. (e.g. Schuler, 1987).
• Use the 'Run Sensitivity ' procedure to identify the input values that have the largest impact on the predicted removal efficiencies.  Review those values to ensure that they have been accurately specified within the limitations of existing information.