Deltaic and estuarine environments and their Late Quaternary dynamics on the Sunda and Sahul shelves

Deltaic and estuarine environments have been, and continue to be, some of t he most rapidly changing environments. Those associated with the Sunda shel f generally receive large volumes of sediment and were characterised by a d iverse and productive vegetation before much of it was cleared and converte d for agriculture, silviculture or urban development. By contrast estuaries in northern Australia receive far less sediment supply, and record a much less modified pattern of landform change during the Holocene. Three periods of change are discussed: first, the long-term geological development and r esponse of deltaic-estuarine plains to eustatic cycles of sea-level change, particularly postglacial sea-level rise to present; second, Holocene devel opment of deltaic-estuarine environments, dominated by patterns of coastal progradation and distributary migration, under relatively stable sea level; and third, the impact of human modifications. These observations provide a framework within which response of the deltaic-estuarine environments to f uture, anticipated environmental change can be assessed. (C) 2000 Elsevier Science Ltd. All rights reserved.