3D Down-under – What are the Australians up to in 3D Hydrogeology

Bruce Gill and Don Cherry

Three-Dimensional Geological Mapping for Groundwater Applications Workshops

2009 GSA Annual Meeting, Portland, Oregon. October 17, 2009

Talk Outline

• Current Groundwater situation in Australia

• Victorian Study area descriptions

• Victorian study objectives and method

• Some findings to date

• Completing this study

• Other Australian Studies

Current Groundwater situation in Australia - Rainfall

Continental average=455mm/yr

Current Groundwater situation in Australia – Major river basins

Current Groundwater situation in Australia – Groundwater Management• Water is the responsibility of the state and

territory governments.• Realized in the late 1970s that licensed volumes

in the Murray Darling Basin exceeded available supply

• Nationally, about 50% of total groundwater abstraction is for irrigated agriculture, but 65% in Victoria and NSW and is highest in SA at 80%

Current Groundwater situation in Australia – Groundwater Management (cont’d)

• Groundwater exploitation has risen in tandem with competition for surface water resources.

• In NSW and Victoria, groundwater use has tripled between 1983/84 and 1996/97

• Recent dry decade has really focussed national attention on all water resources

• Groundwater management seeking improved methods and reliability to underpin allocation decisions, management and water trading

• 3D hydrogeology methods should help

Victorian Study Objectives• State and Federally funded 3 year study to explore

the potential of 3D technologies in groundwater studies

• Research how to apply the types of 3D visualisation tools routinely used in mining and oil industry to groundwater resource needs

• Investigate the capability of GIS based 3D aquifer mapping to enhance landscape analysis and groundwater interactions

• Campaspe 733km2

• North flowing, part of the Murray system• Significant surface and groundwater usage

for towns, agriculture and rural communities

• Moderate data level• Simple geology – narrow valley setting

with Ordovician aged metasedimentary bedrock, thick sequence of Paleocene to Recent terrestrial sediments, minor Quaternary aged basalt, interbedded clay aquitards

Campaspe Deep Lead WSPA

Southern Campaspe Plains GMA

Study area background

Study area background (cont.)

Groundwater declines in the Campaspe Management Area

Permissible Consumptive Volume: 47,252ML

Licensed allocation: 46,267 ML

Metered usage (2007) 34,762ML,

(50% of license in 2008 due to WL decline)

• Loddon 2174km2

• North flowing, part of the Murray system• Significant surface and groundwater usage

for towns, agriculture and rural communities

• High data level• Complex geology – Ordovician

metasedimentary and Devonian –aged granite bedrock, thick sequence of Paleocene to Recent terrestrial sediments, thick Quaternary aged basalt, interbedded clay aquitards

Spring Hill WSPA

Upper Loddon WSPA

Mid Loddon WSPA

Study area background (cont.)

Study area background (cont.)

Groundwater declines in the Upper Loddon (Spring Hill) Management Area

Permissible Consumptive Volume: 55,910MLLicensed allocation: 55,508 MLMetered usage (2007) 29,251ML,(50% in some parts in 2008 due to declines)

• Moorabool 3208km2

• South flowing to the ocean• Availability and quality of data is

considered low• Complex geology - Ordovician

metasedimentary and Devonian –aged granite bedrock, thick sequence of Paleocene to Recent marine & terrestrial sediments, blanketing Quaternary aged basalt, interbedded clay aquitards

Bungaree WSPA

Study area background (cont.)

National & state geological data

National & state geological data

Regional geological data

Regional geological data

Regional geological data - geophysics

Regional geological data – drilling data

Methodology

• Multiple databases (MS, web-based, custom etc)• Multiple formats (relational, spreadsheets etc)• Missing information (logs, coordinates)• Incorrect information (translation errors etc)• Poor or varying interpretation

Some outputs to dateImage showing impact of unreliable bore hole data on 3D surface construction

Some outputs to dateRight – early 3D object of basalt in Campaspe study area

Left - voxel constructed block of part of the Moorabool study area

Some outputs to date

Several images of the Campaspe area - alluvial aquifer (brown) and basalt flow (orange) in bedrock valley.

Some outputs to date

Upper Loddon voxels of Basalt aquifer (brown) and Deep Lead Aquifer (green) with cross cutting faults (blue)

Completing our study

• Adding groundwater chemistry• Exploring volumetric methods from mining / oil

industry applied to quantify aquifers• Hydrogeology theory applied to 3D aquifers?

(specific yields, groundwater management issues)• Outputting 3D model objects to numerical models

(eg MODFLOW)• Field testing 3D visualisation to groundwater users

and managers

Groundwater chemistry (salinity)

Salinity variation in part of the Upper Loddon Deep Lead aquifer

Other Australian Studies:

Other Australian Studies• Queensland University of Technology ( Malcolm Cox et al)• Groundwater Visualisation System (GVS): A software framework for

developing low-end, scalable and robust software for 3D visualisation and animation of groundwater conceptual models

• GVS Used in several site studies

Figure 1: Example visualisation in 2.5D using DEM with draped geology and a 3D block with drillholes

Other Australian Studies• University of New South Wales (Bryce Kelly,

Beatrice Giambiastiani et al)• 3D Hydrograph Analysis for Constraining the

Construction of Hydrogeological Models• 3D temporal analysis of surface and

groundwater interactions• The need for better 3D conceptual models of

aquifers

Other Australian Studies• GeoScience Australia (Alison Kirkby et al. and Pauline English et al.)• Eromanga Basin 3D (below) and Toowoomba, Qld

Toowoomba

Hodgson Creek catchment

Kings Creek catchment

Great Dividing RangeToowoomba

Hodgson Creek catchment

Kings Creek catchment

Great Dividing Range

Figure 3. A perspective view of the 3D map of the Eromanga Basin, a) showing all units, and b) view from the top of the Cadna-Owie Formation.

Other Australian Studies• Department of Water - Western Australia (David Schafer et al)• Aquifer mapping, regional models and stratigraphic analysis• Perth Basin on PETREL (right)• Leederville formation ( below)

Other Australian Studies• Southern Rural Water

Authority, Victoria & Sinclair Knight Merz (Terry Flynn and Andrew Harrison)

• 3D hydrogeology mapping for groundwater resource management – southern half of Victoria

• First Australian 3D Hydrogeology Workshop held 31 Aug-1 Sept had 22 presentations

• Extended abstracts and presentations available at :www.ga.gov.au/??????

Conclusions• Early success in identifying errors, aquifer

geometries and alignment of geological interpretations.

• 3D geological modelling is essential in the process of understanding the geological and hydrogeological features of an aquifer.

• Significantly improves the capacity of models to interpret aquifer dimensions and connectivity.

• Feed into groundwater management numerical models.

• For public engagement

Any Questions?