Version 3.4 - October 30, 2007
Revised Runoff algorithm for impervious surfaces. Runoff coefficients specified on the Watersheds screen apply to storms with cumulative rainfall + snowmelt <= the "breakpoint" specified on the 'Edit General ' screen. A runoff coefficient of 1.0 is assumed when the cumulative rainfall + snowmelt exceeds the specified breakpoint, regardless of the value specified on the watershed screen. The default breakpoint value (0.8 inches) is consistent with SLAMM calibrations. The breakpoint is automatically set to 0.8 inches when an input file created in Versions <=3.2 is read. This change impacts runoff simulations from watersheds with specified runoff coefficients < 1. While it is likely to provide more accurate simulations, setting the breakpoint to 999 will maintain consistency with previous versions. Setting the watershed runoff coefficient to 1.0 will produce conservative results for typical urban watersheds
Runoff algorithm modified to include indirectly-connected impervious areas (draining to pervious areas that in turn drain to watershed outlet). Previous versions assumed that indirectly-connected impervious areas were considered by the user in estimating the Curve Number for pervious areas. In the current version, the Curve Number reflects pervious areas only (function of soil type & cover) and the indirectly connected impervious fraction is estimated independently.
Impervious area runoff
parameters (depression storage, runoff coefficient) consistent with runoff volumes predicted by the Source Loading
and Management Model (SLAMM) for Wisconsin watersheds are provided in the
documentation.
Added several options for swale/buffer hydraulics . These allow depth-dependent Manning's n according to various published relationships for grassed swales & treatment wetlands.
Enhanced Stage/Discharge output table to include additional hydraulic variables relevant to BMP design (e.g., hydraulic load, hydraulic residence time, flow per unit width, manning's n).
Interface settings for output destination (Excel, Text, Notepad) and output window (devices, particles, water quality components) are saved with the case file so that they don't have to be reset each time the case is read.
Additional guidance on street sweeping routine. The default particle files (NURP50 & NURP90) contain revised values for sweeper efficiency, which apply only to vacuum sweepers. Current information indicates that the efficiency of broom sweepers is negligible for particles in the size range typically found in runoff.
The file format for importing and
exporting watershed data
from Excel or ASCII files is modified relative to that used
in Version 3.2. Import files created for Version 3.2 files will have to be
re-formatted for use with Version 3.4. See 'File Watersheds Import/Export'.
Access to an online help file is provided from the menu. This contains the same information as the local help file distributed with the program.
Various repairs & minor enhancements
to previous versions.
Limited testing with Windows VISTA and/or Excel 2007. n VISTA installations, the default program location specified in the setup procedure: "C:/Program Files/P8 Urban Catchment Model..." must be moved outside of the "/Program Files" directory, e.g. to "C:/P8/..."
Version 3.2 -
June 30, 2007
Various repairs & minor enhancements.
Added procedures for importing and exporting watershed data from Excel or ASCII files. See 'File Watersheds Import/Export'.
Added procedure for listing watershed data in the import/export format; see 'List Inputs Watersheds'
Added option to select air temperature and precipitation files from disk on the General Inputs screen.
The maximum number of watersheds has been increased to 250. The maximum number of devices has been increased to 75.
In previous draft windows versions, the default input file (read each time P8 starts), there was an error in the 5-day antecedent precipitation values used in simulating runoff from pervious areas. These are entered on the 'Edit ET/Snowmelt' screen. Values for the growing season and non-growing season were reversed in the default input file, which is loaded automatically each time P8 starts up. This is corrected in Version 3.2. Any new cases created using previous windows versions and starting from the default input file should be corrected accordingly. See the 'Edit ET/Snowmelt' help screen or the current default input file for the correct values. If case watershed loads are primarily from impervious surfaces or if the input file was converted from the DOS version, this issue should not have a significant impact on results.
Users are advised to test sensitivity of results to the integration step size. Start with at least 4 steps per hour. See further discussion .
Check out the EPA CEAM website as potential source of rainfall & temperature data http://www.epa.gov/ceampubl/tools/metdata/us_met.htm These data formats are not directly supported but can be imported via Excel (see Air Temperature Data and Precipitation Data )
This version seems to work with Windows VISTA and Excel 2003. It does not work with Excel 2007. That will be supported in a future release.
Version 3.1 - February 28,
2007
General repairs.
Added date range checks for input precipitation files.
Version 3.0 - Nov 17, 2006
Utility added for importing precipitation data from Excel worksheets. (File Translate Precipitation)
Utility added for importing temperature data from Excel worksheets. (File Translate Temperature)
Added output table 'List Tributary Areas' . Lists watershed areas tributary to each device. Total and scaled vs. device dimensions.