http://www.ajol.info/index.php/wiojms/article/view/85875
The prevailing northward longshore drift of beach sand on the northern part of Msasani Bay, north of Dar es Salaam, is interrupted at Kunduchi by the tidal flushing of Manyema Creek, a mangrove ecosystem partially developed for salt production. Shoreline changes around the creek mouth in recent decades have eroded coastal land and destroyed buildings, prompting stakeholders to construct protective groynes and revetments. Sand is transported across the delta by the interaction of two forcing processes – currents that flush the creek in response to tidal variation and, more generally, those generated by monsoonal wind-driven waves. A study of the sand morphology of the creek and delta platform together with time-series satellite imagery permitted demarcation of the respective sand transport pathways and morphodynamic changes in the delta over the last decade. The sand transport regime has promoted erosion of the shore to the south of the creek mouth, and has resulted in intermittent delivery of sand to beaches north of the channel. Attempts to stabilise the shore around the creek mouth are described and their effectiveness evaluated.