Mapping and characterising springs for understanding groundwater-surface water interactions in the Upper Burdekin Region, north Queensland

The Upper Burdekin region in north Queensland consists of basaltic, alluvial and fractured rock aquifers. In addition to stock and domestic water use, the basalt aquifers sustain wetlands and provide baseflow to streams. Demand for water in the region is predicted to increase, with potential impacts on water availability for natural ecosystems. Understanding the mechanisms and dynamics of groundwater and surface water system interactions is required for the protection and management of groundwater dependent ecosystems. The Basalt Provinces in the Upper Burdekin region contain springs in numerous locations. Springs have been identified as both local discharge features, occurring as small seeps, and as regionally significant discharge features that drive permanent flow in many streams, including the Upper Burdekin River. These springs have differing temporal dynamics and hydrochemical signatures that reflect their combination of groundwater sources, positions in the landscape and phenology. Springs in the Upper Burdekin region have been mapped and characterised by a variety of methods. To complement the more traditional hydrochemical and topographic approaches for understanding groundwater-surface water interactions, remote sensing approaches have also been applied. Remote sensing products provide spatial and temporal datasets that are particularly useful for the current study due to the large area, restricted access and limited availability of time-series hydrological data. Tasselled cap algorithms have been applied to Landsat series spectral data (available through Digital Earth Australia) to identify springs that contribute flow to surface water systems and understand the seasonal response of water in the landscape over multi-decadal time periods. Presented at the 2018 Australian Geoscience Council Convention (AGCC)