The interface has been designed to provide plenty of working space for the schematic and map model while maintaining easy access to the hydrologic objects and their associated parameters. The layout consists of various sections as explained in the text below. Most of the windows can be docked to selected location. In the case that a window is closed, it can be re-opened through the Windows drop-down list in Home tab.

1) Toolbox: Gives the user access to all the hydrologic objects (e.g. Hydrographs, Routing Routines) for the respective project type. Each object is categorized for ease of access and is represented by an icon in the Toolbox.

2) Toolbar: Provides easy access to common program features found in all Windows pro-grams (e.g. New, Open, Save, etc), as well as VO’s own program features (e.g. Resource Library, Hydrograph, etc.). There can be up to three ribbon tabs (Home, GIS and Simulation).

3) Project Manager: Shows the user the names of all the hydrologic scenarios within the open project. This window also provides a simple way of modifying those scenarios (e.g. Add, Delete) and it holds the climate data used in the simulation.

4) Properties Window: Provides the user with the main form for inputting hydrologic object parameters (e.g. catchment area, slope, length). This window is where the bulk of the data entry takes place.

5) Map View: The geospatial representation of the same model. Each hydrological object is assigned to a geometry either from manual drawing or from existing GIS data. Hydrological objects of different type are in different layers. For more information, please refer to Chapter 7.

6) Schematic View: Where the user builds their model schematic from the hydrologic objects in the Toolbox. Objects are dragged from the Toolbox and dropped on the Designer Canvas. Links are generated by dragging the centre of a glyph to the centre of another. For more information, please refer to Chapter 6.

7) Parameter Tables: Lists all parameter values in tables. It provides a spreadsheet-like environment for data editing.

8) Hydrograph Results / Water Balance Results: This is where the simulation results are summarized. For single-event simulation, it has peak flow and runoff volume. For continuous simulation, average annual water balance components are summarized.

9) Error List: Violations are categorized to warnings and errors which are categorized on the Error List. The model is constantly checked for compliance with the established rules. Models with errors can’t run a simulation.