Interface Implementation and Science Model

Interface

This section describes the WEPS 1.0 User Interface program implementation and how it interacts with the WEPS science model. The WEPS 'science' model refers to the computer code and executable program that performs the actual calculations of field conditions and erosion processes for a simulation run. A simple flow diagram of the WEPS science model and User Interface is shown in Figure 5.1. A detailed description of how to operate the WEPS 1.0 User Interface is described elsewhere in the WEPS User's Guide in a chapter titled 'Interface Reference'.

A simplified description of the science model is provided later in this chapter. The inputs to the science model reside in a series of ASCII input files. These input files are: a Windgen file (*.win), a Cligen file (*.cli), an initial field conditions file (*.ifc), a management file (*.man), and a run file (weps.run). The science model can be executed from the command line or through the interface. When WEPS is executed, the science model reads the input files, calls each submodel performing daily time-step simulations, and writes output files. The output is written to one or more ASCII files. Building input files by hand, executing the model on the command line, and interpreting the output files can be time consuming and confusing; the WEPS 1.0 User Interface simplifies this process.

The WEPS 1.0 User Interface is written in Java. The interface can be thought of as a 'shell' or 'wrapper' around the science model, which does not affect the execution of the science model. Through the interface program, the user can easily enter the information necessary to create and edit the input files. A description of how to enter this information is given elsewhere in the WEPS User's Guide in a chapter titled 'Interface Reference'. Once the field, location, soil, and management are described, pressing the 'Run' button performs a series of commands to execute the science model. The interface first calls the CLIGEN and WINDGEN weather generators, which create the WINDGEN and CLIGEN files for the simulation. Then the WEPS science model is called and executed as described earlier. When the science model is finished, the interface reads and displays the output.