2.1.5.1.2 Locations of wetlands and relationship to geological characteristics

Analysis of surface water – groundwater interactions is an integral part of understanding the distribution, function and response of wetlands and groundwater‐dependent ecosystems (GDEs). Geological structures such as faults can form pathways for inter-aquifer and inter-aquitard connectivity or for groundwater discharge to the surface, which can be manifested by the presence of wetlands or springs. For example, where aquifers are juxtaposed against low-permeability strata on opposing sides of a fault, this may induce inter-aquifer connectivity or upwards discharge of groundwater to the surface. In addition, geometric characteristics of aquifers and aquitards such as abutments of aquifers against basement highs or against the basin margin can also have a significant influence on aquifer and aquitard connectivity. The Clarence-Moreton bioregion is characterised by a complex geology, with many structural features such as faults which can form conduits that link aquifers, or create links between aquifers and the surface.

Observed datasets include mapped wetlands and GDEs, which are the surface expression of groundwater discharge. For the different river basins of the Queensland part of the Clarence-Moreton bioregion, GDEs can be accessed via the interactive WetlandInfo website (DEHP, 2014). In NSW, recent mapping of GDEs in coastal river basins including the Clarence river basin and Richmond river basin is available from NSW Government (2014). The identification of wetlands within the Assessment was conducted in close collaboration with state government agencies, as discussed in more detail in companion product 1.3 for the Clarence-Moreton bioregion (Murray et al., 2015). The connectivity between surface water and aquifers will be considered in more detail in subsequent companion product 2.3 (Raiber et al., 2016).