The Inflow Dependence Likelihood grid indicates the likelihood that landscapes are accessing water in addition to rainfall on a scale from 1 to 10 (low to high), where 10 indicates landscapes that are most likely to access additional water sources. The additional water source may be soil water, surface water, or groundwater. Values of 6 or more indicate that the landscape is more likely to be inflow-dependent and accessing an additional source of water than it is to be relying solely on rainfall. Values of 5 or less are unlikely to be inflow-dependent.

The likelihood grid is one of the key datasets in the Groundwater Dependent Ecosystems (GDE) Atlas: http://www.bom.gov.au/water/groundwater/gde/map.shtml as it can be used as an indicator of GDEs.

The grid was constructed using data from multiple satellite sensors, namely MODIS and Landsat. While MODIS estimates evapotranspiration from land surface (van Dijk et al., 2011), the Landsat measures vegetation dynamics sustained during a prolonged dry period (Barron et al., 2012). The two sources were combined by converting these metrics into a standard scale. Within different landscapes, rules were applied to determine the combination of MODIS and Landsat data to develop a continental likelihood grid at 25 m resolution.