4 Outputs from conceptual modelling

4.1 Outputs for product 2.3 (conceptual modelling)

Table 4 outlines the main content to include in product 2.3 (conceptual modelling):

  • Section 2.3.1 provides an overview of the high-level method, cross-referencing this submethodology and identifying deviations. Details of generally developing the conceptual model of causal pathways are presented here, but the details of methods for landscape classification, hazard analysis, etc., are included instead in the appropriate section.
  • Section 2.3.2 summarises how the bioregion or subregion works, synthesising the information from product 1.1 (context statement, which covers geology, hydrogeology and surface water hydrology) and product 2.5 (water balance assessment).
  • Section 2.3.3 describes the ecosystems in a bioregion or subregion in terms of landscape classes.
  • Section 2.3.4 outlines the potential change that might occur in a bioregion or subregion by describing and documenting the baseline and coal resource development pathway (CRDP) that underpin the BA. A summary of the water management for coal resource developments follows.
  • Section 2.3.5 concludes product 2.3 (conceptual modelling) by presenting a summary of the hazard analysis and the causal pathways, from coal resource developments through to hydrological changes, for both baseline and CRDP. See Table 5 for an example table that is recommended to be included.

Product 2.7 (receptor impact modelling) extends the causal pathways from the hydrological changes to potential risk on assets via qualitative models and conceptualisations of landscape classes and their dependency on surface water and groundwater.

In writing product 2.3 (conceptual modelling), it is important to note that more detail will sit in other products and that a key role of product 2.3 is to synthesise and summarise to preface the impact and risk analysis that follows. Ask the question: is this piece of information essential for this role? If it is then it should be in product 2.3 (conceptual modelling). If, on the other hand, it is not, then leave the detail elsewhere. For instance, while it is necessary to summarise the geology, particularly as relevant to water pathways, the details about any geological model developed for BAs should sit instead in product 2.1-2.2 (observations analysis, statistical analysis and interpolation).

Throughout product 2.3 (conceptual modelling), acknowledge knowledge gaps, uncertainties and alternative formulations that may exist. The synthesis in a conceptual model can reflect alternative hypotheses or understanding of interaction pathways if it represents uncertainty or gaps in the extent of the knowledge base. As more data or information is collected, conceptual models should be updated and refined. This will happen through the BAs where Component 2: Model-data analysis, Component 3: Impact analysis and Component 4: Risk analysis will clarify the importance of some links and dependencies in the conceptual model.

Table 4 Recommended content for product 2.3 (conceptual modelling)

Section number

Title of section

Main content to include in section



Summary Background and context Developing causal pathways


Summary of key system components, processes and interactions

Summary Scope and overview

  • define spatio-temporal boundaries of the conceptual model on the basis of the preliminary assessment extent (PAE) and coal resource development pathway (CRDP). Focus on a smaller area within the PAE if the CRDP (and the resulting conceptual model of causal pathways) localises the area of interest Geology and hydrogeology

  • summarise the two- and three-dimensional representations and cross-sections of the geology and hydrogeology in the bioregion or subregion, including a representation of the coal‐bearing sediments, aquifers and aquitards, as well as hydrodynamics
  • summarise the major stratigraphic units, faults and other hydrogeological features, such as distribution of hydraulic conductivity and porosity, trends in groundwater level and flow characteristics, and assumptions about interconnectivity of strata
  • summarise groundwater conceptual model (from product 2.6.2 (groundwater numerical modelling), including groundwater divides and the current knowledge of groundwater inflows and outflows. Surface water

  • identify boundaries of river basins
  • summarise surface water inflows and outflows to a bioregion or subregion, noting large-scale climate gradients and resulting gradients in hydrological systems
  • identify dominant mechanisms and locations of recharge, discharge, flows and surface water – groundwater interactions Water balance

  • summarise the water balance, including other consumptive uses (note that detail should instead sit in product 2.5 (water balance assessment)) Gaps



Summary Landscape classification

  • describe the method and approach used for the landscape classification
  • define a set of landscape classes that represent the main biophysical and human systems for the bioregion or subregion at the surface. It is likely to be a hybrid classification where the aquatic ecological components will covered by classifications such as the Australian National Aquatic Ecosystem (ANAE) or River Styles, and other terrestrial or human systems picked up by vegetation, land use or other classifications. See companion submethodology M03 for assigning receptors to water-dependent assets (O’Grady et al., 2016) for additional detail on landscape classes
  • document how the landscape classes are constructed
  • describe the dependence of those landscape classes on surface water and/or groundwater, and the internal heterogeneity in the landscape class
  • detailed conceptual models for landscape classes are not required at this stage and will only be examined through the receptor impact modelling (product 2.7) and impact and risk analysis (product 3-4) for any landscape classes that are potentially impacted
  • summarise the results of the landscape classification in maps and tables Gaps


Baseline and coal resource development pathway

Summary Developing the coal resource development pathway

  • describe the methods, process and literature sources used to construct the CRDP
  • justify the CRDP decisions for all developments listed in Section 1.2.4 of product 1.2 (coal and coal seam gas resource assessment). Comment on the approval process, workshops and external facilitation
  • describe baseline activity
  • table of coal resource developments (in baseline and additional coal resource development (ACRD), which together are the developments in the CRDP)
  • map of developments (baseline and ACRD, which together are the developments in the CRDP)
  • timeline of developments (baseline and ACRD, which together are the developments in the CRDP)
  • describe any limitations and further research Water management for coal resource developments

  • describe process to identify water management rules and the data and literature sources used
  • summarise water management practices for coal and coal seam gas (CSG) developments in the baseline and the CRDP. Details of the water management are instead reported in product 2.1-2.2 (observations analysis, statistical analysis and interpolation). Specific implementation rules for the numerical modelling are instead reported in product 2.6.1 (surface water numerical modelling) and product 2.6.2 (groundwater numerical modelling). Gaps


Conceptual model of causal pathways

Summary Methodology

  • describe the methods and the process undertaken to identify, construct and test the causal pathways for a subregion or bioregion
  • describe Impact Modes and Effects Analysis (IMEA) (refer to detail in the subregion- or bioregion specific hazard report) and describe process for aggregating hazards to causal pathways and considering spatial and temporal context
  • summarise the workshops held for hazards and for causal pathways Hazard analysis

  • summarise the hazard identified for coal mines and CSG operations
  • emphasise the hazard scope and handling Causal pathways

  • describe the causal pathways for coal mines and CSG operations
  • represent the causal pathways graphically (e.g. using influence diagrams)
  • summarise causal pathways for the baseline and CRDP
  • identify potentially impacted landscape classes Gaps

Table 5 Example table: all causal pathway groups arising from open-cut mines and coal seam gas operations in the Gloucester subregion

Example only; do not use for analysis. This is an early draft of a table published in Dawes et al. (2016). See Dawes et al. (2016) for full explanation and interpretation of the final results, which might vary from that shown here.

Type of coal resource development

Causal pathway group

Baseline coal resource development

Coal resource development pathway

Potentially impacted landscape class

Open-cut mines

Subsurface depressurisation and dewatering



Intermittent – gravel/cobble streams

Forested wetlands (GDE landscape group)

Perennial – gravel/cobble streams

Subsurface physical flow paths



Operational water management



Surface water drainage



Coal seam gas operations

Subsurface depressurisation and dewatering


Intermittent – gravel/cobble streams

Subsurface physical flow paths


Operational water management


Surface water drainage


4.2 Outputs for other products

Product 2.3 (conceptual modelling) and product 2.7 (receptor impact modelling) fully describe the potential causal pathways between coal resource development and possible impacts on water and water-dependent assets. Product 2.3 focuses on the causal pathways from the coal resource development to the hydrological changes (represented by the hydrological response variables), with less focus on the links through to the ecological and human-dominated systems at the surface (landscape classes). Following the outputs from the numerical modelling (product 2.6.1 (surface water numerical modelling) and product 2.6.2 (groundwater numerical modelling)) and identifying locations of potential hydrological change, product 2.7 (receptor impact modelling) considers only those potentially impacted landscape classes and creates qualitative, or signed digraph, models that describe the impacted landscape classes; the functions, processes and interactions within them; and their dependency on specific attributes of groundwater and surface water. Thus product 2.7 completes the causal pathways, from the hydrological changes to the impacts (represented by the receptor impact variables, which are linked to the landscape classes and assets).

Table 6 describes the specific role for conceptual modelling in all products and their links to product 2.3 (conceptual modelling).

Table 6 Role of conceptual modelling and links to product 2.3 (conceptual modelling) by product

Product code




Context statement

The context statement summarises the geography, geology, hydrogeology, groundwater, surface water and ecology of a bioregion or subregion. Product 2.3 (conceptual modelling) provides a further and more integrated representation of the key systems, components and processes identified initially in product 1.1 (context statement).


Coal and coal seam gas resource assessment

The catalogue of identified coal and CSG resources in Section 1.2.4 provides the basis for the decision on the coal resource development pathway (CRDP) that is described in detail in product 2.3 (conceptual modelling).


Description of the water-dependent asset register

Assets feature indirectly in product 2.3 (conceptual modelling) through the landscape classification, where assets may be used to provide context for individual landscape classes.


Observations analysis, statistical analysis and interpolation

No conceptual modelling is required in this product but analysis conducted here may be important to summarise the science and provide the evidence base for conceptual models. In some cases the development of the three-dimensional geological model is reported here.


Current water accounts and water quality

The water balance is summarised qualitatively in product 2.3 (conceptual modelling), but more details are provided in product 2.5 (water balance assessment). Some conceptual representation is required for assessing the movement of water and salt between stores within key system components, and assessing the variability and changes over time.


Water balance assessment


Surface water numerical modelling

The hydrological conceptual model (Section in product 2.6.1 (surface water numerical modelling) that underpins the development of the surface water model is a key part of product 2.3 (conceptual modelling).


Groundwater numerical modelling

The hydrogeological conceptual model (Section in product 2.6.2 (groundwater numerical modelling)) that underpins the development of the groundwater model development is a key part of product 2.3 (conceptual modelling).


Receptor impact modelling

Receptor impact models will be underpinned by fine-scale conceptual models that characterise, in more detail, landscape-scale conceptual models and link receptor impact variables and hydrological response variables at receptor locations. Whereas product 2.3 (conceptual modelling) describes the pathway from coal resource development through to hydrological change (represented by hydrological response variables), product 2.7 (receptor impact modelling) details the pathway from hydrological change to impacts (represented by receptor impact variables).


Impact and risk analysis

Product 2.3 (conceptual modelling) plays a critical role in framing the impact and risk analysis, by determining the hazards (through the Impact Modes and Effects Analysis), dependencies and the causal pathways that need more detailed analysis in product 3-4 (impact and risk analysis). While qualitative in nature in the conceptual model, Component 3: Impact analysis and Component 4: Risk analysis use the results from numerical hydrological modelling and the receptor impact modelling to make quantitative assessments of the potential impacts, and their severity and likelihood. At the end of product 3-4 (impact and risk analysis), the conceptual model of causal pathways is updated to reflect the modelling, impact and risk analyses.



4.3 Bioregion- and subregion-specific considerations and workflow

While there are some differences in the nature of BAs across bioregions and subregions, product 2.3 (conceptual modelling) is a consistent product, though it is only developed where there is an agreed CRDP.

The potential causal pathways identified in product 2.3 (conceptual modelling) are extended to a detailed consideration of landscape classes that the groundwater and surface water modelling results suggest might be affected. Where receptor impact modelling is undertaken, conceptual models for these landscape classes are reported in the product 2.7 (receptor impact modelling). Where receptor impact modelling is not undertaken, these conceptual models will be described in product 3-4 (impact and risk analysis). In either case, these conceptual models will underpin some of the essential narrative around impacts and risks.

Last updated:
26 October 2018