A remote sensing approach to determine environmental flows for wetlands ofthe Lower Darling River, New South Wales, Australia

A remote sensing approach was adopted to determine environmental flow requi rements for wetlands in the Lower Darling River. The regulation of river fl ows by the Menindee Lakes Storage has altered the natural flow regime in th e river and is likely to be affecting the health of both the river and its wetlands. Landsat Thematic Mapper (TM) images corresponding to four flood e vents (1989, 1990 and two in 1996) were analysed and a relationship between river flow heights and wetland inundation was established. Wetlands were c lassified according to broad commence-to-flow river discharges. The study c oncluded that 13 000 Ml d(-1) (megalitres per day) at Weir 32 would inundat e approximately 50% of the wetlands along the Lower Darling River, this fig ure being 10 000 Ml d(-1) less than estimated in a previous study.