A geomorphic study of lagoonal landforms

We perform an analysis of the observational morphological structure of a tidal landscape aimed at examining key assumptions on the geomorphological evolution of wetlands, lagoons, estuarine areas and tidal environments in general. The issues addressed pertain to the statistical measures and the morphodynamic implications of topological or metric properties of the observed landforms, in particular their scale-dependent (or invariant) characters that might suggest self-organized dynamical origins. Field surveys and remote sensing are employed here to accurately characterize different morphodynamic features of a lagoonal environment. Of particular novelty and interest is the structure of landscape-forming shear stresses (properly calculated in unchanneled portions of the landscape) which suggests the viability of threshold models of incision for the formation of tidal channel networks. Distinctive geomorphic indicators, suitable for comparative purposes with modeling of the long-term evolution of tidal systems, are also pointed out. We finally discuss space-distributed analyses of ecogeomorphological properties which strongly suggest the dominance of subvertical processes in the control of the distribution of halophytic vegetation, a key morphodynamic factor. Copyright 2005 by the American Geophysical Union.