ACTGOV Hydrogeological Landscapes (HGL)

The focus of this dataset is the Australian Capital Territory (ACT). It contains digital spatial data developed to assist in land management decision making in the ACT. The dataset contains hazard ratings for land salinity, stream salt load and stream EC as well as overall salinity hazard for each HGL unit. Information about landscape functions and appropriate salinity management strategies are also listed. Hyperlinks to full management descriptions for each HGL unit are provided. The Hydrogeological Landscape (HGL) concept provides a structure for understanding how differences in salinity are expressed across the landscape. A HGL spatially differentiates areas with similar salt stores and pathways for salt mobilisation. The process of delineating a HGL relies on the integration of a number of causative factors: geology, soils, slope, regolith thickness, and climate; an understanding of the different modes of salinity development; and the impacts of salinity within landscapes (land salinity, salt load and salt concentration in streams due to salt contributions from base flow and runoff ). Information sources such as soil landscape maps, site characterisation, salinity occurrence maps, hydrogeological data, surface water and groundwater data are incorporated into standardised unit descriptions.Updates: By mid-2017, this dataset will be updated to align HGL boundaries with the final ACT Soil Landscape linework. After that, the dataset will be static, but could be updated as required if new or better mapping becomes available.Fit for purpose: This dataset was captured at 1:25,000 scale. This dataset is fit for use as a tool for assessing land management issues at the paddock-scale in the ACT, but this does not negate the need for site assessment at a scale suitable to any potential land use or development under consideration. The mapping was mapped in ‘GDA1994 MGA Zone 55s’ and transformed to GDA2020 MGA Zone 55s.Credits: Rob Muller (NSW OEH), Wayne Cook (NSW OEH), Allan Nicholson (NSW DPI), Alie Cowood (UC)Disclaimer: While all care is taken to ensure accuracy, the ACT Government does not warrant that the map is free from errors. © ACT Government