Three dimensional modelling of earth science data has expanded rapidly over the last decade, but further research and case studies are needed on how to best visualise multiple data sets and to characterise the uncertainty in our interpretation of the available information. The construction of these models is a blend of geological knowledge with computer science.

Traditionally, geologists and hydrogeologists have worked with 2D maps and cross sections between boreholes, to establish the distribution of geological layers and properties between the boreholes. How we collate and visualise data dramatically influences the way we perceive the world. Traditional 2D maps limit our capacity to visualise the complexity of our 3D world. Advances in 3D geological modelling software and data availability now enable the analysis and communication of complex geological and hydrological data sets in a visually interactive 3D environment.

Whether characterising the hydrogeology of a catchment or determining the extent of contaminated soil or water on an industrial site, 3D geological models combined with geostatistical methods can provide the hydrogeologist with methods to determine the most likely value of a property at non-sampled locations, quantify the uncertainty in that estimate, and subsequently guide the placement of additional boreholes or optimise expenditure on site characterisation.

Earth science information for geological mapping and resource characterisation is obtained from many sources including satellite, land and airborne geophysical surveys, geological field mapping and borehole logging. Due to variations in the scale of data collection (including the density of the samples and the volume of the samples), original survey objects and measurement errors, data sets rarely combine cleanly in 3D space to give a unique interpretation of the hydrogeology.

The Connected Waters Initiative (CWI) are researching how to integrate all disparate earth science data relating to the hydrogeology of catchments in order to build improved frameworks for catchment water balance modelling. These 3D geological models will also lead to better scientific understanding of the processes surrounding coupled surface and ground water interactions.

Advances in 3D geological modelling software and numerical methods have provided hydrogeologists with a toolbox of flexible methods to improve our capacity to estimate the value of physical and chemical properties in space at non-sampled locations. We are also better positioned to quantify the uncertainty in our estimate. Questions that we often need to answer include:

In the earth sciences we will never have enough data to eliminate uncertainty, but we can improve the way that we quantify the uncertainty and acknowledge that uncertainty in the way we manage an aquifer, or remediate contaminated land. Our research goals, led by Associate Professor Bryce Kelly, include:

Capturing the true 3D distribution of aquifer sediment types and their associated hydraulic properties is critical when coupling water chemistry and ecological processes to the movement of water movement through a catchment. The 3D models will yield improved insights on recharge pathways, groundwater contributions to river baseflow, the impact of irrigation extraction, water quality characterisation and the possibility of examining climatic variability and change on groundwater availability.

Another valuable aspect of collating all the data into a single 3D environment is that it acts as a quality control method. This quality control is particularly important when data have been collected over several decades, using different coordinate systems, or information has been transferred between different data storage formats, in particular when data have been manually entered into databases.

For more information contact A/Prof Bryce Kelly.