Rain over a vineyard in Griffith, NSW.

Understanding how climate change affects water supply

The Water for a Healthy Country Flagship is improving understanding of longer-term climate variability to better manage water resources.

• 26 February 2010 | Updated 14 October 2011

Overview

• Climate determines water supply
• Better climate forecasting and projections

The Water for a Healthy Country Flagship is working toward better management of water resources from climate risk associated with climate variability and climate change. 

Climate determines water supply

Climate is a fundamental driver of the water cycle. It determines how much water is available (supply) and how much water we need (demand) in the short and long term.

In the short and medium term, weather patterns determine variability in water supply and demand on a day-to-day and season-to-season basis – the weather one year may be drier or wetter than the last.

In the long term climate, that is the average of the weather over a period, differs from decade to decade. This alters our perception of what we regard as the normal climate. In eastern Australia the period from 1900-40 was generally drier, while the period from 1940-80 was generally wetter. In recent decades it has been generally drier. 

In addition to natural variability, increased concentrations of greenhouse gases are leading to climate change, inducing a long term trend which superimposes on the natural variability, as is the case with a winter drying trend over south-west Western Australia since the late 1960s.

The sustainability of water systems, irrigation systems, farming systems and dryland landscapes is dependent on climate variability and their future viability may be threatened by climate change.

Better climate forecasting and projections

Research into the risk posed by climate variability and change is being integrated into all of the projects across the Water for a Healthy Country Flagship through:

• observations and analyses
• model simulations
• seasonal water outlooks
• climate scenario constructions
• assessment of hydrological sensitivity of catchments
• interpretive tools.

Improved understanding of long-term climate variability and change is being applied to:

• assist practice and productivity in irrigated and dryland agriculture and grazing
• facilitate improved urban water supply systems
• maximise opportunities for sustainable management of ecosystems such as rivers and landscapes
• design water resource management options and policy response.  

Together with CSIRO Climate, this cross-cutting program delivers directly to clients through collaborative projects with external partners such as:

• the Australian climate change science program
• Indian Ocean climate initiative
• South-East Australian climate initiative. 

Find out more about our research in Water for a Healthy Country Flagship.