Water stress, more or less?
World Water Day on 22 March 2020 has a focus on climate change, specifically how water is linked to climate change. With such a ‘hot topic’ it is understandable that there are numerous articles on climate change covering a vast range of topics. One topic that is of interest is the observed impacts on water resources.
Precipitation replenishes surface and groundwater water sources, as well as assists to improve water quality. Modelling completed by climatologists1 showed that there is either an increase or decrease in precipitation (that includes both rainfall and snowfall) depending where you are on our blue planet. This is based on physics, where air can hold more moisture at an increase in temperature (noting that an increase of 1C allows air to hold 7% more moisture).
Larger water bodies (the oceans and large lakes) evaporate quicker with an increase in atmospheric temperatures, increasing moisture in the air above and influencing the precipitation depths and frequencies locally as well as moisture within the global wind belts. It is observed that droughts are more severe in drought prone areas, and that rainfall depths increased in some tropical rainfall areas 2. Analysis of the October to April rainfall for northern Australia show an increase in long term trends, whereas the south-western and south-eastern Australia show a decrease 3.
Water stress is therefore expected in regions where reduced rainfall overlays areas with increasing population and locations where water dependant agriculture and industries are clustered.
Furthermore, water stress will increase in areas where water quality is directly linked to rainfall depth resulting in decreasing available fresh water resources and increasing reliance on water treatment and water supply networks.
Noting that these systems have limitations and that increasing either treatment (which might include upgrading the treatment process to deal with changing inflow water qualities), storage or transfer capacities will require planning and construction time.
The price of water will likely increase when water availability decreases, which is a deciding factor for most industries and agricultural activities to continue. Reducing production or closing of one business can have a domino effect on smaller businesses, which can affect the viability of remaining businesses to pay rates for upkeep of the water systems.
Taking a proactive approach in developing waterless technologies or increasing water efficiencies are becoming a growth area. Mining companies are actively looking for opportunities to reduce the intake of fresh water, and reusing mine affected water. The agricultural industry, which uses substantial more water than other industries4 is looking at innovative ways to reduce water use or increase effectiveness5.
Farmers in arid areas have developed similar systems, however these systems are costly and require modifications if used for a different produce. Funding to implement water saving initiates are available, such as the On-Farm Irrigation Efficiency Program (OFIEP) that is part of the Sustainable Rural Water Use and Infrastructure Program6. However, the effectiveness of these initiatives will be less when water resources become limited.
It is likely that water stress in existing water stressed areas will increase and that some areas might become water stressed.
Learn more about how Cardno is making a difference to people and communities around the world. #Cardno75years