CZM applications of argus coastal imaging at the Gold Coast, Australia

Abstract

A video-based ARGUS coastal imaging system is being used at the northern Gold Coast, Australia to monitor and quantify the regional-scale coastal response to sand nourishment and construction of the world-first Gold Coast artificial (surfing) reef. This automated monitoring system is used to obtain hourly daylight images from four cameras that combined provide continuous coverage of 4.5 km of the coast. Digital image processing techniques are then applied on a routine (weekly to monthly) basis to extract a range of CZM information from the growing image database. Analyses include: the mapping of changing shoreline position (and hence beach width); the measurement of three-dimensional inter-tidal morphology and resulting changes in sub-aerial sand volume; and the comparison of wave breaking frequency at the reef and adjacent nearshore bars, to quantify enhanced recreational surfing opportunities at the reef site. Based upon the results of image analysis, to date (January 2003) an additional 20-30 m of net beach width was achieved along the approximately 2 km of nourished coastline, relative to the adjacent unnourished beaches to the north and south. Due to a regional net accretionary trend during this same period, in January 2003 the nourished beach at Surfers Paradise was some 50-80 m wider than at the commencement of the video monitoring program in mid 1999.