Erosion and sediment transport in the upper Tana catchment with special reference to the Thiba basin

Abstract

This thesis examines erosion and sediment transport problems in the Upper Tana Catchment which covers an area of 9250 km. It is based on a four-year field and laboratory study of erosion and sedimentation processes in the drainage system. The subject matter includes the assessment of hydrologic and geomorphic processes responsible for soil erosion and sediment transport within three land use types in the Upper Tana Catchment. These include undisturbed forested areas, the cultivated regions and the predominantly grazed areas. The study demonstrates how fundamental the physical and human factors are to the operation of these processes • Although a considerable number of studies of erosion and sediment transport have been carried out in various parts of the world, very few such measurements have been carried out in tropical countries. No detailed work of this kind has been carried out in Kenya so far and certainly not in the Upper Tana Catchment. The study does not only deal with these processes but also demonstrates a methodology that can be utilized in the assessment of sediment production rates in r catchments and on hill slopes.