Abstract
The Mekong delta is divided into five landform units, namely, the floodplain, the coastal complex, the broad depression, the old alluvial terrace, and the hills-mountains, and some of them are further subdivided (Fig. 2). These landform units are discernible from LANDSAT imageries, topography, properties of sediment and agroecology. Except for the old alluvial soil, which was formed during the Tertiary to late Pleistocene period, the landforms were shaped by transgression and regression in the Holocene period. Stratigraphic properties of sediments were examined in terms of chemical characteristics and pollen content, and seven depositional environments were ascertained: fan wash-out into littoral, transitional, marine, lagoonal, tidal flat, intertidal, and riverine.