Waves of Sand: Erosion and Accretion Across Multiple Coastal Cells

Abstract Remote sensing analysis along a section of the coast of central Chile was used to quantify coastal evolution. The results at a single beach were contrasted with simple linear superposition models to identify parameters that could correlate to the observed change, including tectonic-induced vertical change, climatic indices, wave parameters, and riverine discharges. It was found that riverine discharges were significant contributors to this linear model. Next, the coastal evolution analysis was conducted over a large section of the coast, encompassing several watersheds. The shoreline change showed a mesoscale pattern of propagating erosion, that was interspersed by river discharges, although the trends were similar across cells. It is speculated that these observations point to mesoscale and watershed processes to be relevant and ought to be considered in assessing and forecasting coastal evolution.