Saline wetland extents and tidal inundation regimes on a micro-tidal coast, New South Wales, Australia

Abstract

The microtidal coast of New South Wales (NSW), Australia contains a broad range of estuary types that can be classified according to their internal geomorphology and entrance hydraulic conditions. We present an analysis of intertidal wetland area and the proportion of mangrove and saltmarsh, and investigate the variety of tidal inundation regimes in NSW estuaries. Our work hypothesizes that regional patterns in wetland extent and tidal inundation regimes are related to estuary type, through controls on intra-estuary geomorphology and modification of the open-coast tide. Several styles of tidal inundation regime are identified, which display markedly different combinations of the average frequency, duration and depth of inundation events for a specified elevation in the tidal frame. The regional-scale patterns in saline wetland extent and the tidal inundation regimes identified herein are potentially representative of microtidal estuaries more broadly, including similar estuary types in South Africa and Brazil.