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Hydrologic modelling practice notes

River system models, developed by Basin states, MDBA and Snowy Hydro Limited, have been used to inform development and implementation of key water management policies across the Murray–Darling Basin for over 40 years. There are more than 20 of these models, developed using different methods and software. This makes it difficult to link the models for whole of Basin assessments and requires specific software and model expertise for each valley. To overcome these issues, MDBA and the States, together with CSIRO and many others in the Australian water sector, contributed to the development of a common hydrological modelling platform through the eWater CRC between 2005 and 2012. This platform, called Source, is identified in the Murray-Darling Basin Plan as the standard software to use for models underpinning water resource plans in the Basin.

More recently, MDBA, CSIRO and Basin states have worked together to develop a set of practice notes to facilitate the transparent, consistent, and efficient implementation of the Source modelling platform across the Murray-Darling Basin. The content for these practice notes comes from material provided by MDBA and jurisdictions and has been consolidated by MDBA and CSIRO, with the aid of a jurisdictional advisory group.

Some of the practice notes describe agreed modelling conventions, for example, general principles for naming nodes and links. Others describe recommended practices for methods, for example for flow routing and residual inflow estimation. Where practices differ and where the practice has an effect on model results (e.g. flow routing method), a practice based on scientific research is recommended.

The notes do not aim to be overly prescriptive. They aim to provide high-level principles for modellers to follow when undertaking a particular modelling task. It is anticipated that the practices will be adopted and adapted over time as the benefits of working together using agreed conventions are realised. The development of the practice notes has provided a successful forum for jurisdictions to work with the MDBA to facilitate consistency and good practice in building models to support water resource planning.

While the notes address river system models developed using the eWater Source modelling platform, they are relevant and applicable to model development and application in other modelling environments.


Practice notes
Naming nodes and links

Recommended conventions for naming of nodes and links in river system models used in the Murray–Darling Basin

Naming and storing functions and variables

Recommended conventions for naming and storing of functions and variables in river system models used in the Murray–Darling Basin

Flow structure and file types for time series data

Recommended conventions for naming and storing of time series input data sets with examples of implementation

Climate data

Recommendations for sourcing and quality assuring climate (rainfall and evaporation) data with examples of different sources and practices used by jurisdictions.

Flow data

General principles to be followed when assessing the availability and quality of observed flow data. It summaries flow data sources and the quality assurance checks that are used by different jurisdictions in the Basin.

Demands (Diversion) Data

General principles and recommended practices for representing key demands in Source river system models; the sourcing, and quality assurance, of the data used to represent these key demands.

Data requirements for modelling reach losses

General principles and recommended practices for sourcing of data to model known reach losses in Source river system models with examples of implementation.

Infilling and extension of streamflow data

General principles to be followed when infilling and extending streamflow data to cover the period of a model run in a Source river system model.

Modelling a reach water balance

General principles and advice on what components of the water balance should be considered during reach calibration, how to derive acceptable values for modelled reach water balance components (e.g. residual inflows) and links to more detailed general principles and documentation currently used by the MDBA and State/territory jurisdictions

Modelling urban demands

General principles and practices for modelling of urban water demands in Source river system models.

Reach Conceptualisation - Identification of key fluxes

Describes the general principles that should be followed when conceptualising the reach water balance.

Estimation of Unmetered Irrigation Diversions

Describes the general principles and a suggested method for estimating the total unmetered irrigation diversions from floodwaters.

Calibration of Crop Water Models

Describes the general principles and a high-level method that should be adopted when irrigation demands are to be estimated via crop water models that maintain a soil moisture account.

Related resources and references
Explanatory summary for floodplain harvesting practice notes

This explanatory summary provides a background to the development of the practice notes, including an overview of the first two practice notes to be published. These are the Reach conceptualisation – Identification of key fluxes and Modelling a reach water balance. Find out more Compliance and enforcement documents


Updated: 05 Jan 2021  •   MDBA reports