SIMULATION OF GROUNDWATER INTERCEPTION AT LAKE RANFURLY, VICTORIA, INCORPORATING VARIABLE-DENSITY FLOW AND SOLUTE TRANSPORT

The movement of salt from Lake Ranfurly West towards the River Murray and the associated groundwater interception scheme has been modelled i n cross-section using the SUTRA model, Recharge from irrigation areas, and saline seepage from the lake have been taken into account. Owing to the salinity contrast between Lake Ranfurly West and groundwater, i t was considered appropriate to simulate density-dependent flow behavi our. concentration profiles in the aquifers and salt loads to the rive r under various management scenarios were computed under conditions of both density-dependent and non-density-dependent flow. The model simu lations have shown that the salt load to the river is (1) dependent on the rate of pumping from interception bores, (2) dependent on the aqu ifer(s) in which groundwater is intercepted, and (3) marginally greate r (11-15%) for density-dependent flow behaviour at less than full inte rception compared with calculations which neglect density-dependent fl ow.