Synthesizing Subsidence Research in Coastal Louisiana

Subsidence in coastal Louisiana has been associated with enhanced storm and flooding risk to nearby communities, degraded ecosystem health, and land loss in recent years. In response, the processes driving subsidence have received considerable attention from the scientific community. The increased breadth of research on subsidence, though productive, has raised several fundamental questions about the applicability of the different methods which subsidence is measured. Collectively, the body of current subsidence research defines rates spanning an order of magnitude and attributes different, often contradictory, causal mechanisms. These discrepancies must be reconciled as policy makers begin to project and plan for the effects for coastal subsidence in the next 50 years.

The numerous processes contributing to subsidence vary, in terms of rate and relative contribution, at different spatial and temporal scales. The methods used to measure subsidence vary, in terms of accuracy, at different spatial and temporal scales. Proper analysis of coastal subsidence must account for these variations by examining subsidence processes with measurement methods of a complementary scale as well as by defining and communicating the scale limitations of the analysis. In this regard, it becomes increasingly important that researchers fully comprehend the properties of the measurement methods available. This poster explores the utility and limitations of the different methods in which subsidence is measured (chronostratigraphy, geodetic survey, tide-gauge analysis, etc.) as well as the practical scales of their use and analytical interpretation. It is part of a larger project to build a holistic conceptual model of subsidence along the Louisiana Gulf Coast that differentiates processes by their competent spatial and temporal scale. This model will offer utility to coastal resource managers who require the ability to select and abstract only the information relevant to the scales of their management concerns.