| || || Chand, Prerna Bharti|
| || || Identifying and analyzing coastline changes along Coral Coast, South West Viti Levu, Fiji Islands, via multi-temporal image analyses|
Author: Chand, Prerna Bharti
Institution: University of the South Pacific.
Subject: Coast changes -- Fiji, Shorelines -- Fiji, Beach erosion -- Fiji
Call No.: pac GB 455 .62 .F5 C532 2010
Copyright:Under 10% of this thesis may be copied without the authors written permission
Abstract: This research identifies the nature of temporal coastline changes along the Coral Coast area in Fiji Islands. Prograding, resilient and eroding coastlines were identified by comparison of historical aerial photographs and satellite images. For this study 1967 aerial photographs and 2002 IKONOS satellite images were compared to observe and classify the coastline changes over the 35 year period. Subsequently, a ground truthing exercise along the Coral Coast was carried out to re-evaluate the results obtained from the desktop study of historical aerial photographs and satellite images. The desktop comparison did not reveal any prominent coherent coastline change patterns. However, a slight pattern is evident; the far west (Fijian Resort area) and the far east (Naboutini Village area) sides of the study area generally indicate resilient and prograding coastlines. Along the shoreline in the central region it was found that stretches of prograding coastlines alternate with resilient and eroding coastlines. The rates of coastline change for prograding and eroding coastlines were quantified in terms of area (in square meters) and maximum distance (in meters) of landward and seaward movement. For prograding coastline segments the area advancement ranged from 1 564 ± 6 m2 to 97 285 ± 6 m2 and the maximum distance of progradation ranged from 13 ± 3 m to 400 ± 3 m. For eroding coastline segments the area recession ranged from 840 ± 6 m2 to 21 487 ± 6 m2 and the maximum distance of coastline recession ranged from 14 ± 3 m to 40 ± 3 m. The area and maximum distance values for progradation and erosion indicate that the Coral Coast coastline change is influenced more by progradation than erosion. However, the ground truthing exercise revealed only two sections of the study area to be naturally prograding; the region at the head of Sovi Bay and Namatakula Village front. All other prograding and resilient coastlines had been fortified by coastal engineering structures; indicating artificial progradation and foreshore reclamation. Beach erosion was prominent on most of the beaches with fortified coastlines. iii The wave energy along the Coral Coast, set up by the dominant southeast trade winds is relatively high. Since this area only possesses a narrow fringing reef system, interrupted by numerous channels, the wave energy does not dissipate significantly upon reaching the shore. Hence, the Coral Coast coastline is a “High Energy Coastline”. Due to fortification of the coastline by the construction of seawalls, a large portion of the Coral Coast coastline is showing signs of artificial progradation. Coastal processes, erosion, progradation and resilience are depended on the local wind, wave and geomorphological characteristics of an area. Therefore, the dominant coastal process at any given area would be specific to that area, respective to the local characteristics.