Morphodynamic Classification of Morocco's Steep Coasts using multivariate methods and remote data

Abstract

The Moroccan coastline extends for 2,130,80 km on the East Atlantic an Western Mediterranean coasts. It shows a high diversity of estuaries, bays, beaches and steep coasts. Despite its ecological, economic, and recreational importance, Morocco does not have a comprehensive inventory of its coastal landscapes. This study attempts to develop a primary classification of Moroccan steep coasts, based on a descriptive inventory of these landscapes, using 12 morphodynamic criteria that we mainly measured on satellite images. To achieve the said classification, we organized the steep coasts and the criteria in a binary matrix, which we treated with the hierarchical ascending classification method (CAH) and Factorial Correspondence Analysis. The results of this treatment provides a clustering scheme where we distinguish six different groups of cliffs, each of them being subdivided to 2 or 3 subgroups. Three categories of criteria appear as determinant in this classification: morphometric (length, area, and elevation), geologic (dominant rock and geologic eras), hydrodynamic (swells), and aerodynamic (wind). However, the two first criteria have the most significant influence on the classification. This classification, mainly based on satellite data, remains preliminary and requires improvements such using some field data. Finally, the raw and compiled data collected in this study constitute database composed of 175 cliffs, described using parametric criteria; this database is a contribution to the national wetlands inventory and is essential to promoting their conservation as well as management.