Topographic insights in the Frome-Callabonna system and the elevation of a newly surveyed highstand shoreline

ABSTRACT

Lakes Frome, Callabonna, Blanche and Gregory are playa lakes on the eastern and northern sides of the Flinders Ranges, South Australia. Between 2007 and 2019 we surveyed key topographic features of the lakes, including shorelines, lake floors and the alluvial sills that separate the lakes with differential GPS (DGPS). We combine these observations with the analysis of a hybrid DEM that blends data from multiple sources. The lowest elevation of the Frome-Callabonna system based on the hybrid DEM is −8.33 m Australian Height Datum (AHD) at Lake Callabonna but −5.42 m AHD based on DGPS field data. Both values are considerably lower than previous estimates based on spot heights and contours. The DGPS data for Lake Callabonna support the Shuttle Radar Terrestrial Mission (SRTM) estimates of lake-floor elevations but with a mean difference of 1.7 m in elevation. There are larger differences in elevation between the hybrid DEM and the DGPS data for the floor of Lake Frome (mean difference of 4.25 m). We also report on a newly topographically surveyed high shoreline at Lake Callabonna between 20.1 and 20.8 m AHD, the highest to date.

KEYWORDS:

• Playa lake
• digital elevation model
• DEM
• Lake Callabonna
• Lake Frome
• shoreline

Acknowledgments

We wish to acknowledge the deep and continued connection held by the First Nations peoples of Adnyamathanha and Arabunna, to the country in and around the Frome-Callabonna lakes and Kati Thanda-Lake Eyre. We thank Paul Hesse and an anonymous reviewer, for helping to improve the clarity of the manuscript, and Professor Gerald Nanson for leading the earlier phase of this research. We also thank Gerard and Karina Sheehan of Moolawatana homestead for their hospitality and access to the sites. This work was supported by the Australian Research Council (ARC) Centres of Excellence Scheme (Project Number CE170100015) and the ARC Future Fellowship scheme (FT180100524) to TJC.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Australian Research Council [CE170100015 FT180100524 and FT130100195].