Investigating fluvial sediment transport within a steep forested coastal catchment in southern Viti Levu, Fiji Islands
Arishma R. Ram
Time: 11-12 noon
Venue: M107 Lecture Theatre, Marine Campus
Marine productivity in the Fiji Islands is threatened by land-based activities that increase soil erosion and fluvial sediment delivery to coasts. The majority of Fiji’s coastal hinterlands are occupied by small steep catchments with a low retention capacity for sediments. Coral reefs adjacent to such catchments are unadapted to periodic exposure to high sediment loads, and may suffer long-term degradation. Unfortunately, the absence of information on fluvial suspended sediment transport prevents the identification of vulnerable areas and hinders the implementation of procedures to restore these catchments. This study investigates fluvial sediment dynamics in Votua Creek, a naturally forested, steep coastal catchment on the Coral Coast, in order to provide a baseline against which comparisons may be made for adjacent areas where land-use activities are more intense. The turbidity of Votua Creek was continuously monitored over an eight-month period from October 2009 to June 2010 in response to catchment rainfall events. Part of the study involved using the Universal Soil Loss Equation (USLE), combined with GIS, to visualise and quantify potential areas of long-term soil erosion risk in the catchment.
