Atlas of Australian Acid Sulfate Soils: recent developments and future priorities.

Abstract

The Atlas of Australian Acid Sulfate Soils (AAASS) is a web-based hazard assessment tool with a nationally consistent legend, which provides information about the distribution and properties of acid sulfate soils (ASS) across Australia. This tool is available on ASRIS (Australian Soil Resource Information System: www.asris.gov.au) and every polygon or mapping unit is attributed with information pertaining to: (i) 4 classes of “probability of occurrence”, (ii) 4 levels of confidence relating to the quality of data source, and (iii) 10 additional descriptors such as desiccation cracks. In Australia, ASS occupy an estimated 215,000 km2 of which 58,000 km2 is coastal ASS and 157,000 km2 is inland ASS (Fitzpatrick et al. 2008a). In the coastal zone, 41,000 km2 are exposed at some point during the tidal cycle, with the remaining 17,000 km2 being permanently subaqueous. More than 126 km2 of coastal ASS with sulfuric material have been mapped, however this is a significant underestimate, which will be modified with future work. Being web-based the Atlas is a constantly evolving national map of available ASS information, which also includes priority case studies at a range of localities across Australia. With ongoing recent field investigations and acquisition of more detailed local spatial data sets, especially in the Lower Lakes region in South Australia, resolution and accuracy of the inland ASS component are being continually improved from its current, first cut “broad brush” depiction. Future priorities are to constantly integrate ASS data from any new regional ASS investigations to enhance, update and refine the AAASS and new case studies.