Based on phytosociological data, a polythetic divisive classification technique resulted in the delineation of eight broad vegetation types in the back-swamp areas of the Maunachira River Systems of the Okavango Delta. A detrended correspondence analysis indicated that water depth was the major environmental factor influencing the distribution of submerged, floating-leaved and tall, emergent species dominated communities. The remaining communities were of short emergent species assemblages rooted in peat deposits with a water depth of less than 0.7 meters. Hydrology.