Abstract
The Mekong delta is divided into seven divisions in terms of physiographic character relating to rice culture. They are Trans-Bassac Horst, Floodplain, Modern Delta, Coastal Complex, Broad Depression, Plain of Reeds and Western Coastal Zone, and some of them are further subdivided. Trans-Bassac Horst is a slightly uplifted geologic block with flat ground surface. Floodplain is a graven filled up by the Bassac and the Mekong's fluviation. Modern Delta is the downward extension of Floodplain and has deltaic network of rivers of great tidal range. Broad Depression is a blocked-in swamp behind Coastal Complex. These five divisions are important rice growing area of the delta. The last two, Plain of Reeds and Western Coastal Zone, are swampy areas on the margin of the delta and still waiting reclamation. The distributions of the divisions and their subdivisions are given in Fig. 3.
