My graduate student Jackie Monge recently completed a thesis that examined the similarities in dune topography among different barrier island morphologies. We found that dune topography tends to converge around two basic forms (top graphic), an overwash-reinforcing topography associated with microtidal barrier island dune topographies. and an overwash resisting topography characteristic of mesotidal barrier islands. This convergence held up over a range of cluster groupings of barrier island morphology (middle graphic). Dune topography was compared on the basis of lidar-derived indices of landscape patch structure of elevational ranges, directional spatial autocorrelation structure of elevation, and frequency distribution data for elevation (bottom graphic, lidar for a site on Sapelo Island). Her thesis can be accessed here.![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjvh69n6eY8h0uvIGTIfqlKwDnj83LUyPdbtY9pv2dZaW_N0acXlk64bafADW-qf4eZ72DXwMWykLSesC7m4Oh2SJaM8VmliPtBjEWwn7iaQNmjywpcejFO35jxHSKf5nBI2ST254NMiHbU/s1600/Fig+7+PCoA+dune+state+space.jpg)
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