1. School of Engineering; University of KwaZulu-Natal; PO Private Bag, X01 3201 Scottsville South Africa
2. Centre for Water Resources Research; University of KwaZulu-Natal; PO Private Bag, X01 3201 Scottsville South Africa
3. Division of Environmental Mechanics, DPEM; MMUST; PO Box 190-50100 Kakamega Kenya