Water resources and availability in Australian croplands

We used BRTSim to conduct a mechanistic analysis of the soil-water dynamics across Australia for the climate projections of the Coupled Model Intercomparison Project 6 (CMIP6). We modelled the historical soil water dynamics from 1981 to 2018 at various depths within and below the root zone to generate the "current conditions". We then investigated the potential impact of the future climate projections on croplands and native ecosystem. We found that Australia is projected to undergo a substantial soil water loss in both top soil and root zone in the next three decades, with the 2030 decade projected to experience the greatest soil water loss. Such loss can affect native ecosystem, especially shrublands and savannas that are projected to suffer from a moisture decline between 16% to 7%. Our analysis also shows that about 40% of the croplands undergo to a 7% decline in soil moisture within the root zone.

The animation in the Figure below shows the weekly forecasts of soil saturation at various depths within and below the root zone across Australia from 2020 to 2050, the anomalies to the current conditions (years 2009-2017) for the three decades and the percolation from the root zone and the capillary rise to the root zone. More details can be found in PUBLICATIONS.