AQUA TERRA Consultants


Scenario Generator For Enhanced Use Of Watershed Models

When using complex watershed models to evaluate impacts of changes in land use, land-use management practices, and water management operations, analyzing and managing the high volumes of input and output associated with model application becomes a major task. For some model applications input sequences alone may require thousands of lines of inter-related information.

Over the past nine years AQUA TERRA Consultants has developed a program known as GenScn, a System for the Generation and Analysis of Model Simulation Scenarios. GenScn provides the ability to change an input sequence interactively, run the model, and analyze results graphically. GenScn is a generic product that can be tailored to a certain region as desired.

GenScn is currently being used by the U.S. Geological Survey, the U.S. Environmental Protection Agency, numerous States and consultants. Notable applications include those to the Truckee-Carson River Basin; the Connecticut drainage to Long Island Sound; the Patuxent River Basin; DuPage County, Illinois; and Dekalb County, GA.

A scenario translator for urban drainage systems has been developed for the Seattle area, providing specific features required for urban drainage analysis. Other scenario translator modules can be inserted into GenScn as needs arise.

Three special types of statistical analyses include comparing two time series over a range of class intervals, constituent duration analysis, and frequency analysis. Animation provides a means of viewing time-series data on a map over a specified time span, allowing the user to see where, when, and how long critical conditions exist. Animated profile plots are also enabled.

To date the GenScn application shell has been applied in a stand-alone capacity to the EPA/USGS Hydrological Simulation Program - Fortran (HSPF) and to a linked modeling system including HSPF and the FEQ dynamic surface water routing model. GenScn is also "bundled" with the EPA BASINS 3.0 software to provide post-processing capabilities for the HSPF model, the Soil and Water Assessment Tool (SWAT) and for archived water quality data. For these applications, a scenario translator module within GenScn provides a less sophisticated HSPF user with a subset of HSPF parameters of interest to a particular application.