Aquifer visualization for sustainable water management

Abstract

The purpose of this paper is to develop a three dimensional (3D) geological model, based on geographic information system (GIS), of the Barwon Downs Graben aquifer system in Victoria, Australia, and to visualize the complex geometry as a decision support tool for sustainable water management. A 3D visualization of the aquifer is completed, based on subsurface geological modelling. The existing borehole database, hydrogeological data, geological information and surface topography are used to model the subsurface aquifer. ArcGIS 9.2 is employed for two-dimensional (2D) GIS analysis and for 3D visualization and modelling geological objects computer aided design (GOCAD) 2.5.2 is used. The developed methodology of ArcGIS and GOCAD is implemented for creating the 3D geological model of the aquifer system. Findings - The 3D geomodel of the Barwon Downs Graben provides a new perspective of the complex subsurface aquifer geometry and its relation with surface hydrogeology in a more interactive manner. Considering the geometry, estimated volume of the unconfined Eastern View aquifer is as 0.83 × 1010 m3 and for the confined aquifer is about 1.02 × 1010 m3. The total volume of overlying strata of this aquifer is about 3.09 × 1010 m3. The water resources of the study area are affected by the pumping from this aquifer. This is also significantly influenced by the geometry of the Graben. The 3D model utilises comprehensive and generally available datasets in the public domain. Although the used 3D geomodelling tools are mainly developed for applications in the petroleum industry, the current paper shows its ability to be adapted to hydrogeological investigations.

Full text

Translate

Turn on search term navigation

Special issue from the Environment Research Event (ERE) 2009

Edited by Craig Froome

Introduction

Sustainable water management includes two important concepts: sustainability and management of resources. The [11] Brundland Commission Report (1987) defined sustainability for human and environmental development as where the needs of the present generation are met without compromising the needs of future generations. This definition implies an equitable distribution of the resources not only spatially between users in a region, but temporally between them over time ([23] Harding, 1998). Management includes the allocation and use of the resources. Information is the key to good management. Understanding the demands of the stakeholders, as well as the possibilities and limitations of the resources, is essential for effective resource management ([18] EC (European Commission), 2000). In order to allocate water, managers are guided by conceptual, and numerical models that predict how much water will be available at various times throughout the catchment or groundwater basin ([42] Rivera, 2007). These models depend on good quality data and accurate conceptualisation of the various hydrological processes ([49] Royer, 2004). All these data can now be stored and visualised in interactive 3D geological models, which provide a better environment to process, analyse and communicate information rather than to conceptualize the hydrogeological system ([45] Ross et al. , 2004a).

Geographic Information Systems (GIS) are powerful tools, which allow for spatial analyses and representations of georeferenced data ([58] Tweed et al. , 2007). These tools have proved their usefulness in hydrogeology over many years, but standard multi-layered systems of GIS are quite limited for modelling, visualizing, and editing subsurface data and geological objects and their attributes ([1] Abdul-Rahman and Pilouk, 2008). With general-purpose GIS, geological layers are represented as regular grids or triangulated surfaces that can only be modelled as explicit functions in the form of z = f (x,y ), where x and y are a pair of coordinates defining a location. Therefore, they cannot integrate all the constraints induced by 3D data sets ([35] Mallet, 1998; [50] Soller et al. , 1998). However, in recent years, geomodelling systems have been developed with powerful 3D visualization and property modelling capabilities for the construction and analysis of 3D geological objects in a way that general purpose GIS cannot do ([34], [36] Mallet, 1992, 2002). [34] Mallet (1992) proposed a complete notion of discrete modelling of geological object. With this approach, discrete triangulated surfaces can be built from discrete points, lines, and polygons, and can be modified by applying the Discrete Smooth Interpolation (DSI) algorithm ([34], [36] Mallet, 1992, 2002).

Generally surface water and groundwater components are managed separately ([24] Ivkovic, 2006; [32] Macumber, 1991), which ignores the fact that there is interconnection between these two systems. Surface water in many parts of the world has already become depleted due to increased water use (e.g. for irrigation or urban supply), changes in land use, and increased frequency of drought ([10] Brodie et al. , 2007; [12] Cartwright and Simmonds, 2008; [31] Loa'iciga, 2003). Moreover, because of prolonged drought, groundwater is getting more of a concern in many parts of Australia as an alternative source ([62] Wolock et al. , 1993). In many Australian catchments, aquifers and surface water features are hydraulically connected ([27] Ladson, 2008; [32] Macumber, 1991; [37], [38] NGC, 2003, 2004). Because of geological settings and surface conditions in some cases over exploitation of groundwater will affect the aquatic ecosystem, perennial stream and wetlands especially during the period of prolonged dry time that is common in Australia ([32] Macumber, 1991; [33] Macumber and Fitzpatrick, 1987).

This integrated movement of water can have significant water management and policy implications that cannot be ignored ([2] Alley et al. , 1999). The negative consequences of managing these resources separately are becoming increasingly apparent, for example where groundwater extraction schemes result in declining river flows ([4] Barton et al. , 2006; [9] Braaten and Gates, 2003; [28] Lamontagne et al. , 2003; [59] VCMC (Victorian Catchment Management Council), 2007). Hence, effective management of water quantity and quality issues requires an understanding of the links between surface water and groundwater ([60] Winter et al. , 1998). Whenever groundwater is exploited or likely to become part of any integrated water supply network, the nature of the water flow needs to be modelled.

Investigation of surface water flow is relatively less complex than groundwater flow because surface water flow can be differentiated in different catchments boundaries and it is visible. But groundwater basins are heterogeneous. Groundwater basin boundaries are not necessarily congruent with those of the surface catchments and area not visible ([40] Ransley et al. , 2007; [51] Sophocleous and Perkins, 2000). 3D modelling of the complexity of aquifers may enhance the understanding of the particular hydrogeological context well enough to support the estimation of sustainable yields under various scenarios ([15] Donatis et al. , 2005; [52] Spottke et al. , 2005). Such modelling involves mapping the configuration and characteristics of the aquifers and groundwater flow systems, which requires data about aquifer geometry (such as thickness, gradient, edge and isolation), geological and stratigraphical configurations (such as fold, syncline, Graben, intersections with the faults and facies changes), and hydraulic properties (such as transmissivity and storavity, and recharge and discharge mechanisms) ([3] Artimo et al. , 2003; [25] Jessell, 2001; [26] Kajiyama et al. , 2004; [41] Rhén et al. , 2007; [43] Robins et al. , 2005; [50] Soller et al. , 1998). Once assembled, such models support visualization, which is useful for hypothesis generation and to some extent hypothesis testing as well as for stakeholder consensus building ([46] Ross et al. , 2007). In this context this research will explore the geometry and settings of the water producing Barwon Downs Graben aquifer by using spatial information techniques especially 3D visualization.

Background

The Barwon Downs Graben is situated approximately 70 km southwest of Geelong on the northern flanks of the Otway Ranges. It extends from Gellibrand in the southwest to Birregurra in the east and covers an area of approximately 500km² ([61] Witebsky et al. , 1995). The Graben is within the area obtained by the Corangamite Catchment Authority (see Figure 1 [Figure omitted. See Article Image.]) and divided into two groundwater management units (GMU) - Gellibrand and Gerangamete.

The region has a temperate climate with warm dry summers and cool wet winters. The average daily maximum temperature ranges between 25 to 27°C in summer and 12 to 14°C in winter ([16] DSE (Department of Sustainability and Environment), 2008). A precipitation gradient extends between the North-western zone (the annual average - 1,200 to 1,400 mm) and the north-east (the annual average-600 to 700 mm). The average winter monthly rainfall from June to September is approximately 110 mm, but less than 50 mm falls in the summer between January and March. Potential evaporation exceeds rainfall from December to March. Therefore, the most recharge potential is from May to September in this area ([14] Cox et al. , 2007).

Groundwater investigations have been conducted in the Barwon Downs Graben since the early 1960s. They revealed the presence of extensive high-quality groundwater ([8] Blake, 1978; [30] Leonard et al. , 1983; [53] Stanley, 1991; [61] Witebsky et al. , 1995). For some decades the Barwon Water Corporation has exploited this resource as part of its drought management plan for Geelong ([6] Barwon Water, 2008a). The Barwon Water bore field consists of six production bores with a combined capacity to extract up to 50ML/day ([7] Barwon Water, 2008b). This bore field provided a significant contribution to Geelong's water supply during the periods from 1982 to 1983 and from 1988 to 1990, and in 1997, 2001, 2006 and current years. Barwon Water is licensed to extract 80,000 ml over a ten-year period with a maximum of 12,500 ml in a single year ([39] Petrides and Cartwright, 2006; [61] Witebsky et al. , 1995).

The region is dominated by a series of NE/SW-trending folds and faults that make up the major structural elements of the Graben ([17] Edwards et al. , 1996; [56] Tickell et al. , 1991) and impose significant influence on both surface and subsurface water flows ([39] Petrides and Cartwright, 2006; [53] Stanley, 1991; [61] Witebsky et al. , 1995). This Graben aquifer is a small synclinal structure bounded by the Bambra Fault in the south that separates the Otway Ranges and the Barwon Monocline in the Northwest that separates the Barongarook High. The northern boundary of the Graben is not clear ([61] Witebsky et al. , 1995). The subsurface stratigraphy is characterised by a complex multi-layered suite of Mesozoic and Cainozoic sedimentary members reflecting several distinct depositional and tectonic events ([55] Tickell, 1991). Sediment types characterise the aquifer properties of a layer and mineral content determine the water quality ([30] Leonard et al. , 1983). Multiple subsurface layers of different sediment types form alternating aquifer and aquitard in this Graben, although water quality varies (see Table I [Figure omitted. See Article Image.]).

The Eastern View Formation (lower tertiary) forms the main aquifer system. This formation crops out and is recharged directly in the Barongarook and the Otway Ranges ([17] Edwards et al. , 1996; [21] Geissler, 1989; [30] Leonard et al. , 1983; [55] Tickell, 1991). Changes to the water balance can affect the recharge pattern. Streambed reaches that have base flow due to aquifer discharge during a season may become recharge reaches due to changes in the water balance. In other words the surface water flow will be reduced. The nature of the implied patterns of water flow connectivity depends on the water level both in the aquifer and in the rivers and also on the lithological characteristics of the riverbeds ([20] Freeze, 1983; [60] Winter et al. , 1998).

From the surface it seems the Barwon Downs aquifer is an isolated Graben structure, which might have limited value in the search for sustainable water supply ([39] Petrides and Cartwright, 2006). For instance it has been reported that Barwon Downs bore field pumping during dry time has dried up flow in the nearby Boundary Creek ([61] Witebsky et al. , 1995). Even though this area gets a significant amount of rainfall, the overall water flow of other rivers is reduced ([59] VCMC (Victorian Catchment Management Council), 2007). The volume of water of this aquifer system has varied from one-estimation to another ([29] Leonard, 1988; [30] Leonard et al. , 1983; [54] Teng, 1996; [61] Witebsky et al. , 1995). Typically the estimates are done based on the simplified assumptions of the geological settings and boundary configuration. In this context the specific objectives of this research are to characterize the geometry and heterogeneity of the Graben and estimate the volume and water storage of the Barwon Downs aquifer based on 3D visualization i.e. geomodelling using GIS techniques.

Methodology

Geomodelling was first defined by [34] Mallet (1992) as the set of all mathematical methods allowing modelling the topology, the geometry and the physical properties of geological objects in a unified way while taking into account any type of data related to these objects.

ArcGIS 9.2 is used for two-dimensional GIS analysis. For 3D visualization and modelling Geological Objects Computer Aided Design (GOCAD) 2.5.2 suite is selected which is one of the leading software packages employed in geomodelling. This software, developed by the GOCAD Research Group at the Nancy School of Geology (France) and its partners, is specifically designed to construct and analyse geological objects and their properties ([44], [47] Ross et al. , 2005). The developed methodology of ArcGIS and GOCAD is implemented to model the subsurface. The data transfer between these software components is made through file exchanges. In ArcGIS geological objects are represented by points, lines or polygons which can be directly imported into GOCAD as cultural data like "point and curve objects".

The modelling procedure is subdivided into different steps (see Figure 2 [Figure omitted. See Article Image.]). The first step involves collecting, sorting and importing the usable data into the modelling software. This initial work is very time consuming but is the basic work for the whole modelling process. The borehole information, Digital Elevation Model (DEM) for surface topography, surface geology, geological cross-sections, seismic profiles, and structural elements are the input data for building the geomodel of the Barwon Downs Graben Aquifer. All the input data are collected from the Victorian Spatial Data Infrastructure and other relevant government organizations. One of the main difficulties of using such diverse data in 3D geological modelling is the heterogeneity of descriptions and interpretations. The variable nature and quality of the data means that a data-validation step must be employed. In the validation process, all the collected data are first checked for the consistency in geo-referenced coordinate systems. The GDA 94 MGA zone 54 co-ordinate system is used to project all the data and the DEM is used for referencing elevation. The initial model area covers 1,650km² including the surrounding area of the Graben. But the final 3D model area covers 320km² , which is selected mainly based on the density of the bore log data.

The positions of the data points are validated using spatial query, and deemed accurate, well located and consistent with the surrounding information. From the database the interpreted stratigraphical information is sorted out using the built-in database query function. The data are also carefully checked for the consistency in geological interpretation for each selected bore log and validated through comparison with the surrounding bore log and information about the surface exposures. In the Barwon Downs area 11 stratigraphic layers are sampled from the bore log data. In addition, the descriptions of hydrogeological characteristics of these layers are collected from different published reports ([30] Leonard et al. , 1983; [54] Teng, 1996; [61] Witebsky et al. , 1995). To overcome the inconsistency in the interpretation, broad geological units and hydrogeological characteristics are considered. Based on these characteristics layers are then grouped into six units, which are encoded with numeric values (see Table I [Figure omitted. See Article Image.]). In the 3D environment the imported data are validated using the unit marker points with surface geology.

The second step involves the construction of lithological surfaces and the faults from the validated data. Surface exposure of the geological units (see Figure 3 [Figure omitted. See Article Image.]), faults and lineaments are modelled from the surface geological map. Subsurface extensions of these geological units are modelled from the bore log data and geological cross-sections. Geophysical sections are collected from different published reports ([13] Constantine and Liberman, 2001; [22] GSV (Geological Survey of Victoria), 1995; [57] Tim, 2003). In addition, 35 cross-sections are made from the bore log data. To generate the fault surfaces the azimuth, dip and depth of the fault plane are approximated from different published reports ([17] Edwards et al. , 1996; [55] Tickell, 1991; [57] Tim, 2003). At this step, the surfaces of the other faults are modelled and visualized in three dimensionally and only the offset has been included in the geological units but their integration is more difficult because large uncertainties remain about their dips and extents at depth. After having the correct geometry and contacts of the layers the Discrete Smooth Interpolation (DSI) algorithm is applied. The final lithogical model is shown in Figure 4 [Figure omitted. See Article Image.].

The third step is to make the volume model from the modelled surfaces. The surfaces formed closed volumes that represent the geological objects. The surfaces thus act as "dividing walls" isolating 3D regions ([36] Mallet, 2002). Surfaces must defined closed volumes and these must be "watertight". This requires perfect intersections between the lithological surfaces and the faults or the surface topography. The topology should be consistent, as it allows calculation of volumes, visualization of separated objects and application of grid generation tools that maintain the geometric integrity of the geological model. Further discretization may also be achieved by using advanced grinding tools. The 3D regions and grids are used to create sub-models for visualization of geological settings, generate continuous units and to calculate unit thickness and volumes. The volumetric geological model can be further sliced in different cross sections to check the geometry of the different layers.

After building all the surfaces of geological units, the 3D geological volume model of the Barwon Downs Graben aquifer is constructed as a stratigraphical grid (S-Grid). An s-grid is a curvilinear type of grid, which is deformed (the cells are not regular anymore) to follow the surface geological constraints. The average cell size in the horizontal plan (along x and y ) is around 100m while it is about 5m in vertical direction. The DEM is used as the top surface while the base of unit 6, which is Eumeralla Formation, is used as the bottom of the s-grid. Layers are then built from the base to the top using the lithological surfaces previously built to differentiate separated volumes within the grid. The 3D geomodelling ends with creating a 3D geological volume model of the Barwon Downs Graben aquifer (see Figure 5 [Figure omitted. See Article Image.]) in which, each formation, is represented by a region. Each region is separated by a common surface and these surfaces are free from gaps. This model then allows displaying each formation as a separate geometric volume and also as cross-sections.

Results and discussion

The 3D volume model significantly enhances the visual interpretation and understanding of the complex subsurface settings of different geological units as well as the aquifers of this Graben. This type of representation also helps the non-professionals to understand the subsurface complexity. From the volume model, each of the layers is individualized using their spatial properties. Therefore, the volumes have been calculated to estimate the water availability in each layer. One of the important requirements in groundwater management is to know how much water is available for development (see Figure 6 [Figure omitted. See Article Image.]). Usually, to calculate this, the volume of water bearing strata is generalized considering homogenous thickness and structural settings. But the geomodel provides the layer volume considering the geological settings and visually allows the visualisation of the thickness distribution of each unit and the relations among the units.

Aquifer geometry

The volume model shows that the Graben is bounded in the south by the Bambra Fault, and in the north by the Barwon Monocline, and it also follows the basement (Eumeralla Formation) topography. The margins are steep on both sides of the Graben and this steep gradient may enhance the water flow towards the centre of the Graben. A cross-sectional view of the model (see Figure 7 [Figure omitted. See Article Image.]) reveals that the Lower Tertiary Eastern View aquifer is continuous and exposed in the Barongarook High and Otway Ranges while its depth increases towards the centre of the Graben. The exposed part is considered as the main recharge area. The thickness of this formation in the exposed area is only a few meters and directly lying on top of the Cretaceous Eumeralla Formation (Figure 7 [Figure omitted. See Article Image.]). In this area the Eastern View aquifer is unconfined in nature. The Eumeralla Formation is considered as the basement of the aquifer system and consists of low permeable fractured rock. In the central part the aquifer system becomes confined due to the thick and continuous presence of Demons Bluff and Gellibrand Marl as the confining layer.

One of the important uses of this geomodel is to map the distribution and thickness of the confining layers and also hydrostratigraphy in the recharge area. The depth to the top of the aquifer (see Figure 8 [Figure omitted. See Article Image.]) shows the presence of a subsurface topographic high in the western part of the Gerangamete GMU that divides the Graben into two parts and may act as a groundwater divide of flow from the southwest and to the northeast. The thickness of this aquifer system is not evenly distributed. The 3D volume model shows that (see Figure 9 [Figure omitted. See Article Image.]) in some part of the aquifer layer is absent. This could be due to three reasons:

The layer thickness is less than the modelled vertical resolution that is 5m.

The absence of the aquifer layer in the bore log.

May be the poor distribution of the data points, which constrains the layer boundary during interpolation.

The spatial distribution of the thickness of a layer determines its volume. In that case, the 3D model facilitates the estimation of the volume of a particular layer by considering the spatial distribution of its thickness.

Resource estimation

Table II [Figure omitted. See Article Image.] gives the calculated volume of each layer from the geomodel. The main aquifer, the Easter View Formation, is partly exposed in the surface and considered as the recharge area. From the model, the unconfined or recharge area is estimated to cover 5.14 × 10⁷ m² and the confined aquifer is 1.84 × 10⁸ m² . The volume of the unconfined Eastern View aquifer is estimated as 0.83 × 10⁸ m³ and that of the confined aquifer is 1.02 × 10⁸ m³ .

Estimation of the water volume (elastic storage) of the confined Easter View Formation aquifer is carried out using the following equation ([30] Leonard et al. , 1983) considering 3 × 10^-4 as storage co-efficient: Equation 1 [Figure omitted. See Article Image.]

where, V_w is volume of water (ML), V_c is volume of confined aquifer unit (m³ ) and S_c is storage co-efficient.

The water volume of the unconfined aquifer has been estimated according to [30] Leonard et al. (1983), considering that the unconfined part of the aquifer is fully saturated with average specific yield of 0.2. Equation 2 [Figure omitted. See Article Image.]

where, V_w is volume of water (ML), V_uc is volume of unconfined aquifer unit (m³ ) and S_y is specific yield.

[30] Leonard et al. (1983) estimated the aquifer volume as 4.97 ×10¹⁰ m³ for 250km² area using difference between isopach of the potentiometric surface and the top of the aquifer. Whereas the current geomodel covers 200km² and estimated aquifer volume is 1.02 ×10¹⁰ m³ . The estimated aquifer volume is remarkably different from the previous estimates ([30] Leonard et al. , 1983; [61] Witebsky et al. , 1995) and this also makes the difference in the estimation of water volume (see Table II [Figure omitted. See Article Image.]). This significant difference in volume estimation highlights that 3-D geomodelling of an aquifer should be incorporated for accurate estimation. Besides, the estimation of groundwater volume, the best possible natural settings of an aquifer should be considered to determine the sustainable yield limit. Otherwise extraction from an aquifer might lower the water table and have impact on the surface water flow as well as on the overall water balance. Using the 3-D model an attempt has been made to identify the parts of river, which might be affected by the changed water level due to water extraction from the Eastern View aquifer.

Connectivity between river and aquifer

Based on the thickness of strata overlying the Eastern View Formation, the river parts, which are connected with the aquifer are identified. The thickness of the overlying strata is classified into four classes as shown in Figure 10 [Figure omitted. See Article Image.].

It is assumed that the river parts which are flowing over the minimum or zero thickness class of the overlying strata are directly connected with the aquifer. In the current work, the connected river parts are only identified according to the overlying strata thickness to the Eastern View aquifer system (see Figure 11 [Figure omitted. See Article Image.]). In the study area most of the rivers that are flowing over the exposed aquifer in the Barongarook High and Otway Ranges are directly connected and the rivers in the middle part of the Graben exhibit very low connectivity with the Eastern View aquifer. This part might have connections with other overlying aquifers. Within the model area 23 per cent of the rivers and creeks are identified as having direct connectivity, where the overlying strata of the aquifer layer have a thickness between 0 and 5 m.

Identifying these river parts is important for the sustainable environmental flow management of the rivers and also for the management of the water quality. Changes in the level of both surface water and groundwater will change the water flow direction between river and aquifer. Because of prolonged drought over last few years in the study area, surface water bodies are stressed due to less rainfall and reduced base flow because of pumping ([5] Barton et al. , 2008; [19] Evans, 2007). In the future this model can also be used for groundwater flow modelling to determine the extraction rate that can maintain the base flow towards the rivers. Moreover, it can be used to analyse the different climate scenarios for recharge and discharge phenomena for sustainable groundwater development. This model can be improved in the future by including more geological constraints like faults and lineaments and by incorporating other data such as geophysical, geochemical, and more detail geological information.

Benefits and limitations

3D visualisation offers significant benefits to the understanding and development of the aquifer, including that:

- this is based on the archival data, which is cost effective;

- it can assemble the diverse and complex data sets into a comprehensive and tangible model;

- it provides a basis on which subsequent analytical models can be developed;

- it allows visual inspection of the data in 3d and provides graphical presentations of data for reporting and demonstration and for informing decision makers;

- it can help identify the structural features for analysis by exaggerating the vertical scale;

- it allows the investigation of the relationship between lithostratigraphy and seasonal piezometric surfaces; and

- this can be further used for water flow modelling, vulnerability assessment, environmental analysis, etc.

Besides the promising benefits described previously this model is highly dependent on the input data quality and data density. Model quality also depends on the subjective knowledge. This modelling procedure requires high-end computation capacity and it is often time consuming.

Conclusion

In this paper, a methodology is presented to integrate different types of accessible geological information for 3D geomodelling. For the Barwon Downs Graben aquifer 3D geomodelling offers a new perspective of sustainable water management. This aquifer is an important resource of fresh groundwater and has complex geological and structural settings. Estimation of the water resource based on the generalized aquifer geometry may mislead the sustainable development of this aquifer. 3D geomodelling offers a flexible and interactive platform for incorporating the natural settings and complexity of the aquifer into assessment of the resource. The accuracy of the model depends strongly on the amount of available data, and the nature, quality and distribution of the data over the area of interest. This methodology allows testing and comparing different geological data and identifying the gaps in the data. The geomodel of Barwon Downs Graben aquifer can provide information to complement the development and management policy for sustainable water extraction from an aquifer. The developed volume model can be further used for the water flow modelling, vulnerability assessment and environmental analysis among others.

References

1. Abdul-Rahman, A. and Pilouk, M. (2008), Spatial Data Modelling for 3-D GIS, Springer-Verlag, Heidelberg, p. 290.

2. Alley, W.M., Reilly, T.E. and Franke, O.L. (1999), Sustainability of Ground-Water Resources, US Geological Survey, Denver, CO, p. 1186.

3. Artimo, A., Makinen, J., Berg, R.C., Abert, C.C. and Salonen, V.P. (2003), "Three-dimensional geologic modeling and visualization of the Virttaankangas aquifer, south-western Finland", Hydrogeology Journal, Vol. 11, pp. 378-86.

4. Barton, A., Cox, J., Dahlhaus, P. and Herczeg, A. (2006), "Groundwater flows and groundwater-surface water interactions in the Corangamite CMA region", paper presented at the Regolith 2006 - Consolidation and Dispersion of Ideas, available at http://crcleme.org.au/Pubs/monographs/regolith2006/Halas_L.pdf (accessed 12 December 2008).

5. Barton, A.B., Herczeg, A.L., Dahlhaus, P.G. and Cox, J.W. (2008), "Hydrological and geochemical processes controlling salinity of the groundwater dependent ecosystems in the Corangamite CMA", Project No. WLE/42-009, CSIRO, Canberra.

6. Barwon Water (2008a), Media Release, Reference No. 014/08, Barwon Region Water, Authority, Geelong, January 31.

7. Barwon Water (2008b), Sustainability Report 2006/2007, Barwon Region Water Authority, Geelong.

8. Blake, R. (1978), Groundwater for Geelong: Completion Report on the Hydrogeological Investigation of the Barwon Downs Basin, Department of Mines, Melbourne.

9. Braaten, R. and Gates, G. (2003), "Groundwater-surface water interaction in inland New South Wales: a scoping study", Water Science and Technology, Vol. 48 No. 7, pp. 215-24.

10. Brodie, R., Sundaram, B., Tottenham, R., Hostetler, S. and Ransley, T. (2007), An Adaptive Management Framework for Connected Groundwater-surface Water Resources in Australia, Bureau of Rural Sciences, Canberra.

11. Brundland Commission Report (1987), Our Common Future, Report of the World Commission on Environment and Development, World Commission on Environment and Development.

12. Cartwright, I. and Simmonds, I. (2008), "Impact of changing climate and land use on the hydrogeology of southeast Australia", Australian Journal of Earth Sciences, pp. 1-13.

13. Constantine, A. and Liberman, N. (2001), Hydrocarbon Prospectivity Package for VIC/O-01(1), VIC/O-01(2) and VIC/O-01(3), Eastern Onshore Otway Basin, Victoria, Department of Natural Resources and Environment, Melbourne.

14. Cox, J., Dahlhaus, P., Herczeg, A., Crosbie, R., Davies, P. and Dighton, J. (2007), Defining Groundwater Flow Systems on the Volcanic Plains to Accurately Assess the Risks of Salinity and Impacts of Changed Land Use, Final Report to the Corangamite Catchment Management Authority.

15. Donatis, M.D., Gallerini, G. and Susini, S. (2005), 3-D Modelling Techniques for Geological and Environmental Visualisation and Analysis, available at: http://pubs.usgs.gov/of/2005/1428/pdf/dedonatis2.pdf (accessed 12 December 2008).

16. DSE (Department of Sustainability and Environment) (2008), Climate Change in the Corangamite Region, available at: www.climatechange.vic.gov.au (accessed 12 December).

17. Edwards, J., Leonard, J.G., Pettifer, G.R. and Mcdonald, P.A. (1996), Colac 1: 250 000 Map Geological Report: Geological Survey of Victoria.

18. EC (European Commission) (2000), Towards Sustainable and Strategic Management of Water Resources, Lanham, Luxembourg.

19. Evans, R. (2007), "The impact of groundwater use on Australia's rivers - exploring the technical, management and policy challenges", available at: www.lwa.gov.au (accessed 2 February 2009).

20. Freeze, R.A. (1983), "Regional groundwater analysis in surface and subsurface hydrology", International Conference on Groundwater and Man, Sydney, Vol. 1, pp. 101-19.

21. Geissler, P.E. (1989), "Seismic reflection profiling for groundwater studies in Victoria", Australia Geophysics, Vol. 54 No. 1, pp. 31-7.

22. GSV (Geological Survey of Victoria) (1995), The Stratigraphy, Structure, Geophysics and Hydrocarbon Potential of the Eastern Otway Basin, Report 103, Geological Survey of Victoria, Melbourne.

23. Harding, R. (1998), Environmental Decision-making: the Roles of Scientists, Engineers and the Public, Leichhardt, New South Wales.

24. Ivkovic, K.M.J. (2006), Modelling Groundwater-river Interactions for Assessing Water Allocation Options, Australian National University, Canberra.

25. Jessell, M. (2001), "Three-dimensional geological modelling of potential-field data", Computers & Geosciences, Vol. 27, pp. 455-65.

26. Kajiyama, A., Ikawa, N., Masumoto, S., Shiono, K. and Raghavan, V. (2004), "Three-dimensional geological modeling by FOSS GRASS GIS - using some field survey data", paper presented at the FOSS/GRASS Users Conference, Bangkok, 12-14 September, available at: www.gisdevelopment.net/proceedings/fossgrass/papers/Three-dimensional%20Geological%20Modeling.pdf. (accessed 12 December 2008).

27. Ladson, A.R. (2008), Hydrology: an Australian Introduction, Oxford University Press, Victoria.

28. Lamontagne, S., Herczeg, A.L., Dighton, J.C., Pritchard, J.L., Jiwan, J.S. and Ullman, W.J. (2003), Groundwater-surface Water Interactions Between Streams and Alluvial Aquifers: Results from the Wollombi Brook (NSW) Study (Part II - Biogeochemical Processes).

29. Leonard, J. (1988), Groundwater Recharge Estimates, Basal Tertiary Aquifer System, Barwon Downs Graben, Department of Industry Technology and Resources, Melbourne.

30. Leonard, J.G., Lakey, R.C. and Blake, W.R. (1983), "Hydrogeologial investigation and assessment, Barwon Downs Graben, Otway Basin, Victoria", International Conference on Groundwater and Man, Sydney, pp. 175-83.

31. Loa'iciga, H.A. (2003), "Climate change and groundwater", Annals of the Association of American Geographers, Vol. 93 No. 1, pp. 30-41.

32. Macumber, P.G. (1991), Interaction between Groundwater and Surface Systems in Northern Victoria, Department of Conservation and Environment, Victoria.

33. Macumber, P.G. and Fitzpatrick, C.R. (1987), Salinity Control in Victoria: Physical Options, Department of Water Resources, Victorian Government Printing Office, Melbourne.

34. Mallet, J.-L. (1992), "Discrete smooth interpolation in geometric modelling", Computer-Aided Design, Vol. 24 No. 4, pp. 178-82.

35. Mallet, J.-L. (1998), "Discrete smooth interpolation", ACM Transactions on Graphics, Centre de Recherche en lnformatique de Nancy and Ecole Nationale Superieure de Geologie, Vol. 8 No. 2, pp. 121-44.

36. Mallet, J.-L. (2002), Geomodeling, Oxford University Press, Oxford and New York, NY.

37. NGC (National Groundwater Committee) (2003), Impacts of Land Use Change on Groundwater Resources, NGC, Canberra.

38. NGC (National Groundwater Committee) (2004), Knowledge Gaps for Groundwater Reforms, NGC, Canberra.

39. Petrides, B. and Cartwright, I. (2006), "The hydrogeology and hydrogeochemistry of the Barwon Downs Graben aquifer, South-western Victoria, Australia", Hydrogeology Journal, Vol. 14, pp. 809-26.

40. Ransley, T., Tottenham, R., Sundaram, B. and Brodie, R. (2007), Development of Method to Map Potential Stream-Aquifer Connectivity: a Case Study in the Border Rivers Catchment, Bureau of Rural Sciences, Canberra.

41. Rhén, I., Thunehed, H., Triumf, C.-A., Follin, S., Hartley, L., Hermansson, J. and Wahlgren, C.-H. (2007), "Development of a hydrogeological model description of intrusive rock at different investigation scales: an example from South-eastern Sweden", Hydrogeology Journal, Vol. 15, pp. 47-69.

42. Rivera, A. (2007), "Groundwater modelling: from geology to hydrogeology", available at: www.isgs.uiuc.edu/research/3-DWorkshop/2007/pdf-files/rivera.pdf (accessed 12 September 2008).

43. Robins, N.S., Rutter, H.K., Dumpleton, S. and Peach, D.W. (2005), "The role of 3D visualisation as an analytical tool preparatory to numerical modelling", Journal of Hydrology, Vol. 301 Nos 1-4, pp. 287-95.

44. Ross, M., Aitssi, L., Martel, R. and Parent, M. (2005), "From geological to groundwater flow models: an example of inter-operability for semi-regular grids", paper presented at the ISGS 2005 Workshop-Geological Models for Groundwater Flow Modeling, Salt Lake City, UT, October 15, available at: www.isgs.uiuc.edu/research/3DWorkshop/2005/workshop (accessed 12 September 2008).

45. Ross, M., Martel, R., Lefebvre, R., Parent, M. and Savard, M.M. (2004a), "Assessing rock aquifer vulnerability using downward adjective times from a 3-D model of superficial geology: a case study from the St Lawrence Lowlands", Canada Geofísica Internacional, Vol. 43 No. 4, pp. 591-602.

46. Ross, M., Martel, R., Parent, G. and Smirnoff, A. (2007), "Geomodels as a key component of environmental impact assessments of military training ranges in Canada", available at: www.isgs.uiuc.edu/research/3-DWorkshop/2007/pdf-files/ross.pdf (accessed 12 September 2008).

47. Ross, M., Parent, M. and Lefebvre, R.3-D. (2005), "Geologic framework models for regional hydrogeology and land-use management: a case study from a Quaternary basin of southwestern Quebec, Canada", Hydrogeology Journal, Vol. 13, pp. 690-707.

49. Royer, J.-J. (2004), "3-D modeling and visualization", paper presented at the 9th International CODATA Conference: Data Visualization - Earth and Geoscience, available at: www.codata.org/04conf/papers/RoyerViz.PDF (accessed 12 September 2008).

50. Soller, D.R., Price, S.D., Berg, R.C. and Kempton, J.P. (1998), "A method for three-dimensional mapping", paper presented at the Digital Mapping Techniques '98, US Geological Survey Open-File Report.

51. Sophocleous, M. and Perkins, S.P. (2000), "Methodology and application of combined watershed and groundwater models in Kansas", Journal of Hydrology, Vol. 236 Nos 3-4, pp. 185-201.

52. Spottke, I., Zechner, E. and Huggenberger, P. (2005), "The southeastern border of the Upper Rhine Graben: a 3-D geological model and its importance for tectonics and groundwater flow", International Journal of Earth Sciences, Vol. 94 No. 4, pp. 580-93.

53. Stanley, D.R. (1991), Preliminary Groundwater resource evaluation of the Kawarren sub-region of the Barwon Down Graven, RWC Investigation Branch, Rural Water Commission of Victoria, Victoria.

54. Teng, M.L. (1996), Modelling the Seasonal Variation of Groundwater Recharge and Yield of the Barwon Downs Acquifer, South-Western Victoria, University of Melbourne, Melbourne, unpublished thesis (MSc).

55. Tickell, S.J. (1991), Colac and Part of Beech Forest 1:50 000 Scale Geological Map.

56. Tickell, S.J., Cummings, S., Leonard, J.G. and Withers, J.A. (1991), Colac 1:50 000 Map, Department of Manufacturing and Industry Development, Victoria.

57. Tim, O.B. (2003), "Seismic interpretation and basin analysis of the Eastern Otway Basin-Colac trough area", unpublished thesis (MSc), Monash University, Caulfield East.

58. Tweed, S.O., Leblanc, M., Webb, J.A. and Lubczynski, M.W. (2007), "Remote sensing and GIS for mapping groundwater recharge and discharge areas in salinity prone catchments", Southeastern Australia Hydrogeology Journal, Vol. 15, pp. 75-96.

59. VCMC (Victorian Catchment Management Council) (2007), Catchment Condition Report, VCMC, Victoria.

60. Winter, T.C., Harvey, J.W., Franke, O.L. and Alley, W.M. (1998), Ground Water and Surface Water A Single Resource, Denver, CO.

61. Witebsky, S., Jayatilaka, C.J., Shugg, A.J., Lakey, R. and Lawrence, C. (1995), Groundwater Development Options and Environmental Impacts: Barwon Downs Graben, South-western Victoria, Victoria Department of Natural Resources and Environment, East Melbourne.

62. Wolock, D.M., Mccabe, G.J., Tasker, G.D. and Moss, M.E. (1993), "Effects of climate change on water resources in the Delaware River Basin", Water Resources Bulletin, American Water resources Association, Vol. 29 No. 3, pp. 475-86.

Aquifer visualization for sustainable water management

Content area

Abstract

Full text