The role of landscape evolution & hydrostratigraphy in dryland salinity development and control in south-west Western Australia

Abstract

This paper proposes new conceptual models of groundwater flow systems, depending on the elevation ranges of south-west catchments. We now recognise that ANCIENT landscapes comprising Tertiary sediments have persisted further west within a largely REJUVENATED and forested south-west Western Australia. Widespread inset-valley sedimentary profiles, rather than eroding completely, remain variously dissected and show some common hydrostratigraphic attributes. Their lithology, age and elevation are also factors in these landscapes responding differently to key salinity and catchment management actions. For example, reforestation in the REJUVENATED landscape can raise stream salinity by reducing streamflow that is diluting large salt loads from these ANCIENT landscapes.