Some Erosional Features Due to Piping and Sub-Surface Wash with Special Reference to the Sudan

Abstract

Movement of water through the interstices of near-surface unconsolidated materials is a significant factor in erosion and in certain landforms. In the Central Sudan water movement underground results in collapse features which may be important micro-relief landforms in some plainland areas. Concentrated sub-surface movement of water above incised stream heads also causes surface collapse and is a means of headward extension of the incised channel.