Flow of variable-density formation water in deep sloping aquifers: minimizing the error in representation and analysis when using hydraulic-head distributions

摘要: Abstract Although not fully adequate, freshwater hydraulic heads have been used historically to represent and analyze variable-density flow in sloping aquifers sedimentary basins. The use of environmental is valid only for strictly vertical unconfined aquifers, while using contravenes Darcy's law. the hydraulic-head surfaces simplest quickest means analysis interpretation, preceding other methods such as numerical modeling, it introduces some errors that should be assessed minimized order provide most accurate representation. A first error introduced when approximating potential buoyancy components along aquifer slope flow-driving force with their projections onto horizontal plane. This probably negligibly small undisturbed basins, but may significant dipping at a angle, folded strata. second representation analysis, neglecting component force. significance this can by performing Driving Force Ratio (DFR) analysis. There no single or critical value DFR, below which alone negligible, above acceptable anymore; rather, decision regarding acceptability made on case basis. hence direction magnitude, any given an optimum reference density calculations areally-weighted average formation water aquifer. In analyses based potentiometric surfaces, actually maximizes neglect because either low end density-variation spectrum outside it.