Fitzroy and Margaret rivers likelihood of groundwater inflow

Brief description

This data set contains polygons as shape files identifying the reaches of the main river channel in the Fitzroy and Margaret rivers (Western Australia) where there is a likelihood of groundwater inflow. The shape files are symbolised to represent different categories of the likelihood of groundwater inflow (i.e. low, medium or high) and are based on the results and interpretation of a longitudinal surface water environmental tracer and chemistry sampling survey. The purpose of the data set is to map the spatial occurrence and likelihood of groundwater inflow to reaches of the Fitzroy and Margaret rivers in Western Australia, to graphically communicate groundwater – surface water connectivity.

Lineage

The polygons as shape files were created based on the spatial occurrence and composition of surface water chemistry and environmental tracers. More specifically, surface water pH, electrical conductivity (EC) major and minor ion composition, stable hydrogen and oxygen isotope composition, as well as radon (222Rn) and Helium-4 (4He) concentrations. The field sampling sites for the survey were identified using an analysis of 25 years of Landsat data for the six month dry-season period (1st May to 31st October) to map in-stream pool persistence across the Fitzroy and Margaret rivers in the Fitzroy catchment Western Australia. Surface water samples were collected from 80 sites across 300 km of the Fitzroy River and 80 km of the Margaret river. Samples were collected from in stream pools and reaches, as well as off-channel pools and wetlands by helicopter in June 2017 when the rivers were exhibiting base flow conditions. The locations of the sampling were recorded using Universal Transverse Mercator coordinates and the polygons projected as GDA_1994_MGA_Zone_51. The polygons highlight the location of reaches of the main river channels where groundwater inflow is occurring with the data symbolised by colour representing a category of the likelihood (i.e. low, medium, high or nil) of groundwater inflow.