The influence of neo-tectonics on water dispersal in the northeastern regions of the Okavango swamps, Botswana

Abstract

The Okavango alluvial fan occurs in an extension of the East African Rift system. Changes in water dispersal patterns on the fan have been attributed both to neo-tectonic activity and to sedimentation. Analysis of SPOT satellite imagery in an area where major changes in water distribution are currently taking place indicates that these changes are initiated by neo-tectonic activity, which creates interconnected graben systems which divert water flow. The process of redistribution is accentuated by sedimentation in distributary channels. The graben systems arise due to East-West extension which has produced intersecting, distributary channels. The graben systems arise due to East-West extension which has produced intersecting, conjugate fault sets. Analysis of associated seismic activity indicates that seasonal flooding has no influence on seismicity, which is due entirely to crustal extension.