Multiple Scale Morphodynamic Mapping: Methodological Considerations and Applications for the Coastal Atlas of Andalusia

Mapping of dynamic variables is an ideal tool for coastal scientists and managers; however, cartographic tools often offer limited capabilities when complex nearshore and dynamic processes are to be included. The characterisation of beach morphodynamic states has been among the most successful attempt for beach classification schemes in the last 30 years, since beach behaviour can be interpreted using somewhat simple methods at local scale. The main limitation lies in the application of such a method to is robust and operative for both local (beach) scale as well as for regional scale (in the case study over 800 kms long). In this contribution the authors present a prototype in the construction of a variable scale method based on a GIS that enable distributed web services of fully flexible morphodynamic beach state mapping. The complex scaling up and down to the high resolution needed for testing individual beaches is solved using a stepwise procedure of nested bathymetric models of large coastal segments combined with highly detail "project scale" DEMs in which land and sea are integrated to generate the geometric variables of the system. Dynamic variables (mostly related to wave hydrodynamics) are provided by simulations using the SWAN wave propagation model which takes recoded wave data from off shore to nearshore environments. Input to the model include spectral wave records, winds and currents and output yield the necessary input to construct the morphodynamic indicators, such as the surf scaling parameter. Maps are then generated by combining the data layers in the GIS. The overall outputs of calculated morphodynamic states are output for integrated format within the combined coastal atlas and provided via Web Feature Services.