GIS-Based Analysis and Modeling of Coastline Advance and Retreat Along the Coast of Guyana

This research utilized a Geographical Information System (GIS)-based approach to analyze, map and model coastline advance and retreat. A time series (1941-1987) of empirical advance and retreat data from the coast of Guyana was used. Coastlines were also extracted from 1987, 1990 and 1992 Landsat TM images, and 1999, 2002, 2004 and 2006 Landsat ETM+ images. The historical data were used to calculate advance and retreat (AOR) rates and sediment volume changes. Distinct periods of advance and retreat matched corresponding periods of sediment gains and losses. The Digital Shoreline Analysis System (DSAS) was used to predict rates of coastline change. Graphical plots of DSAS results identified spatial and temporal phase shifts of the coastline. Recurring episodes of accretion and erosion could be associated with the presence or absence of mudbanks along the coast.