Geomorphology and sedimentology of the implications to coastal zone management Mombasa - Diani area

Abstract

The overall objective of this thesis was to identify coastal zone management problems within Mombasa— Diani area. The study of sedimentological processes and geomorphic features have been used to solve these problems. Other objectives included evaluating the effectiveness of the existing control measures and identifying response strategies for the affected areas. The methods used were divided into field and laboratory methods. Sediments were investigated using grain size distribution analysis, carbonate content determination and microscopic study. Beach profiling, beach gradients and beach y width measurements together with wave and current measurements and aerial photo interpretation facilitated the interpretation of geomorphic results. The results of sedimentological wort showed erosional beaches to occur at Kikambala, Kanamai, Mtwapa, Shanzu, Bamburi, Kenyatta and Black Cliff Point. Nyali , Tiwi, Galu and Kinondo were found to be stable beaches while Likoni, Diani and Gazi were considered depositional beaches given no induced erosion. Geomorphological 1y, coastal dunes and beach f ridges, cliffed coasts and backshore areas could be developed but with proper set back lines so as not to induce erosion. Coastal erosion, over development and lack of coastal zone management system, and construction of stabilizing structures along the beaches were identified as major problems within the project area. From these results it is concluded that there is an urgent need for a coastal zone management system and to enact a legislation which would protect coastal resources and environment for their sustainabi1ity. Stabilizing structures should be constructed only for highly developed areas. Keeping in mind the future sea level rise. beach hotels should bp put about 1 km landward of the shoreline.