The major inputs to IQQM are as follows:

• Rainfall – continuous sets of time series rainfall data that represents the rainfall across the basin
• Potential evapotranspiration – continuous sets of time series of potential evapotranspiration data that represents the potential evapotranspiration across the basin.
• Open water surface evapotranspiration – continuous sets of time series open water surface evapotranspiration data that represents the open water surface evapotranspiration across the basin.
• Flow gaugings – daily flow values for the gauging stations that are to be calibrated against.
• Catchment area – this is used to convert inputs and outputs between flow and depth of run-off.
  

Note: Various time series formats are supported within IQQM. Some of these include:

• text time series format
• IQQM daily time series format (hourly, daily, monthly and yearly formats)
• Hydsys (hourly, daily and monthly formats)
• Hymos daily format
• Metaccess daily format

Statistical tools
A module for statistical comparison of observed and simulated daily, monthly or annual time series data are available which provides the following statistics:

• Mean,
• Standard deviation,
• Skewness,
• Coefficient of determination, and
• Coefficient of efficiency.

When operating with daily data it can provide statistics for the whole sequence and on a month by month basis.

Graphs

An advanced graphical display module can be used for visual comparison of simulated and observed data and many other applications. The following graphs are available:

• Continuous line (eg linear and semi-log. time series plots),
• Histogram,
• Cumulative (eg double mass),
• Ranked (eg flow duration curves, reliability diagrams),
• Frequency,
• Residual mass,
• Normal and log normal probability, and
• Scatter Plot.

The time interval of input data can be hourly, daily, monthly or yearly. The time series data can be displayed at different time spans to the input data. Over one hundred years of daily data can be graphed for up to five parameters. There are zoom facilities provided to focus on areas of interest. There are also on-line statistics provided to determine volume, mean, standard deviation and skewness of data displayed in the graph window. All graphs may be saved to file or printed directly on a variety of printers and plotters.

The accuracy of river simulation models, such as IQQM, is largely dependent upon the representativeness and accuracy of the input data. It is strongly recommended that a very thorough review of input data is undertaken prior to calibrating IQQM. Some tools are included in IQQM to help users to fill gaps in time series data, extend data records, check the basic statistics of input data and to detect inconsistencies. Other specific verifications may have to be performed prior to using IQQM on a case-by-case basis. The first stage in setting up IQQM is understanding the catchment and what needs to be modelled. Care should be taken in identifying and modelling the dominant processes in catchments.

• IQQM is an extremely complex model that contains many parameters that require calibration. To obtain a robust calibration it is important that the calibration be undertaken in a staged manner such that uncertainty and sensitivity of parameters is understood.
• Care should be taken in the calibration to ensure that the model is calibrated during a period that represents sufficient climatic variability to improve the robustness of the model