Control of climate and local topography on dynamic evolution of badland from southern Italy (Calabria)

• Precipitations and topography have a crucial role in the evolution of calanchi.
• Calanchi physical-chemical properties are controlled by climate and topography.
• Calanchi clay mineralogy is a feature sensitive to climate regime changes.
• Local climate changes are responsible of the peculiar calanchi clay mineralogy.

This work deals with an integrated geomorphological and chemical–physical study of “calanchi” landforms in site (Caulonia) of SE Calabria (southern Italy), developed on of Late Pliocene–Quaternary clay deposits.The aim of this paper is to investigate how topography and rainfall quantity may affect runoff and slope processes in “Calanchi” landforms by influencing the physical, chemical and mineralogical properties of clayey sediments.To this purpose a comparison has been made among the physical, chemical and mineralogical features of calanchi materials sampled after a rainy period precipitation (mean annual rainfall of ~ 709.6 mm; wet year) with those sampled after relatively dry period (mean annual rainfall of ~ 431.4 mm; dry year) and in different topographic settings (opposite flanks of a catchment exhibiting different steepness and lengths i.e. W- to NW-facing and E- to NE-facing slopes). Using a multivariate statistic approach – which adopts the principal component analysis (PCA) method to extract factors – it has been possible to make a hypothesis of the main processes responsible for dynamic evolution of the study area. The rainfall quantity coupled with topography has to be considered as the main control factor inducing changes in the physical–chemical–mineralogical parameters.