Simulating Australia's water systems
Water is one of our most precious resources. All Australians depend upon it for our wellbeing, healthy ecosystems and economy.
We use water monitoring data and computer models to understand and predict water availability, conditions and use. These models simulate Australian water systems, using mathematical equations to represent the movement of water in the environment (hydrology).
To improve our water information and prediction services, we:
- analyse and use water resources monitoring data with weather and climate model predictions
- develop and apply hydrological models at multiple spatial scales – from river catchments to Australia-wide
- combine results from computer models with observations data – a process called data assimilation
- run models many times, with slightly different conditions. This is called ensemble forecasting. It's used to better understand and communicate uncertainties in models and forecasts.
Developing water models
We're developing models that help us understand and predict the movement of water on and through the Earth's surface (for example, streamflow).
The models underpin our water information services and forecasts. These services support decisions in many sectors of the Australian economy including water, agriculture, environment, emergency management, transport, energy and resources.
National water model
Our national model to predict water in Australia was developed in partnership with the Commonwealth Scientific and Industrial Research Organisation (CSIRO).
The model is used to provide services including:
- historical conditions – for example, daily gridded outputs of rainfall, soil moisture, runoff and deep drainage from 1911 until yesterday
- forecasts – for example, seasonal forecasts (1–3 months) of root-zone soil moisture, evapotranspiration and runoff – updated monthly
- long-term projections for Australia – including projections of changes in rainfall, soil moisture, evapotranspiration and runoff for multiple time slices to 2100.
These outputs are available from the Australian Water Outlook.
Land surface model
The national water model is being updated with the next generation hydrological model. This will provide an improved land surface model for use in our numerical weather predictions.
We're working with the United Kingdom Meteorological Office and other international partners on this project.
To tailor the model, it will use vegetation and soil water observations from satellites for Australia. This will ensure that future water products are:
- more accurate at finer spatial and temporal scales – providing more accurate detail for an area, across smaller steps in time
- moving towards comprehensive water balance modelling for 1 km2 grids across Australia
- consistent with weather forecasts generated through Earth system modelling.
Other models
We're also working on:
- a routing scheme that transforms the runoff into streamflow running at about 1 km resolution Australia-wide
- future flood risk maps down to meter (gauge) scale for selected areas
- an update of hydrological projections for Australia based on the latest generation of climate model data
- better understanding ecosystem dependencies and how surface water and groundwater interact.
Water forecasting
We're continuing to improve our:
- 7-day and seasonal streamflow forecasts
- short-term and seasonal forecasts, and long-term projections, of our national water balance.
Information from many sources
We combine weather and climate predictions, hydrological science and models to:
- provide seamless forecasts across time and space
- understand uncertainty in forecasts and projections.
We also use data assimilation techniques and data sources that give us the best snapshot of the environment at any given time. For information, view the Earth system models research page.
Our water balance model uses water and vegetation data from satellites. This means we can provide predictions for areas of Australia where there are no gauges.
Delivering impact and value
Working closely with partners, we're quantifying the impact and value of hydrological predictions to support:
- emergency services
- water resources and environmental asset management
- agriculture productivity
- transport management.
Our scientific expertise helps to guide use of prototype forecasting products. This includes how these products are used in applications and other models.
Water and climate
Climate is our average weather pattern over a long time – many years. We aim to understand climate change impacts and predict changes in water availability, quality and use over these longer periods.
To do this, we quantify trends and identify significant changes in historical observed data. This involves analysing rainfall, river flows and the water levels of storages and groundwater.
We also assess the future impact of climate change on water and related variables such as soil moisture, evaporation and streamflow. This includes assessing the uncertainty of future projections.