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• Rapid geomorphological evolution occurred in the erodible lithology and semiarid climate of southern Italy. • A deposition phase during the Little Ice Age (LIA) was the last global cold climatic phase. • Badland incision occurred during Mediaeval Warm Period and continued in stably alternating phases until 1700 CE. • Valley aggradation ended early in 1850 as a phase of historic arroyo cutting began. • Geomorphological evolution around Basilicata during the LIA was very rapid and controlled by extreme surface process sensitivity to climate change. There is a general consensus that the increased frequency of extreme climatic events will quickly change the morphology of the landscapes in the Mediterranean area. Knowing and understanding the expected changes becomes crucial for defining future adaptive strategies. This paper deals with the very rapid geomorphological evolution in an emblematic Mediterranean area, the Basilicata region of southern Italy, during the last 300 years. The results show that the landscape evolution was mainly controlled by the extreme sensitivity of surface processes to climate change. Landslides, a new cycle of the formation of badland landforms such as calanchi and biancane, and an aggradation/incision phase in the main river valleys have completely reshaped the landscape of the Bradanic Trough, whereas fresh eroded material was moved to the coast. New data on valley-fill alluvium in the Basento River and one of its main left tributaries, the Vella stream, show ages ranging from 1700 to 1850. This deposition phase coincides with the Little Ice Age, an epoch of global climate variability. Previous literature showed that the alluvium of this age consists of a mappable stratigraphic unit outcropping in all the large alluvial valleys of the Basilicata and Mediterranean regions. Palaeoclimate and high-resolution palaeoflood data indicate that valley-fill alluviation occurred during a long humid period. Valley aggradation ended in approximately 1850 with the beginning of a new phase of historic arroyo cutting, mainly due to high magnitude-low frequency rainy events within prolonged drought periods. The stream incision drew the terminal dissection of the clayey slopes into biancana rounded morphologies. These data seem to be confirmed by the comparable heights of about 3 m, both of the biancane and of the fluvial terraces. [ABSTRACT FROM AUTHOR]

This paper presents the results of geomorphological investigations carried out in Basilicata region (southern Italy) from the most external thrust front of the Apennines, where the town of Craco is located, to the adjacent sector of the Apennines foredeep (Fossa Bradanica; Pisticci area). The importance of the chosen area mostly resided in the presence of really diffuse running-waters and gravity-induced landforms which strictly affect urban areas. The geomorphological processes are linked with the Quaternary tectonic uplift affecting the Apennine front-Bradanic foredeep sectors. Series of field surveys, supported by aerial photo-interpretation, have led to the production of a geomorphological map at 1:16,000 scale which outlines the main processes and related landforms recognized in the study area. The latter are the result of the complex interplay of structural, gravitational and fluvial processes. Particular attention was devoted to the recognition, identification and mapping of landslides which affect the slope of the main villages (Craco and Pisticci), locally giving rise to hazardous conditions. [ABSTRACT FROM AUTHOR]

Abstract: Piping (tunnelling) appears to be one of the more significant methods of erosion in the badlands in the Plio-Pleistocene marine-sourced clays of the Basilicata area in Southern Italy. A detailed field investigation of the pedological, textural, mineralogical and geochemical properties of the clay-rich terrains widely outcropping in two selected badland field sites (the Fossa Bradanica area and the Bacino di Sant''Arcangelo) was undertaken to further elucidate process variability across the complex site. Paralleling findings from other piped badlands, certain physico-chemical properties of the clays were found to influence the different erosional processes in fundamental ways. The very dispersive nature of the materials enhances pipe enlargement so that subsurface flow rapidly becomes the dominant process, causing pipe enlargement by a process of positive feedback. The paper speculates on the progressive role of surface and subsurface processes in the genesis of all evolutional badland forms (calanchi, calanchi mammellonari and biancane). In an early stage, the calanchi mammellonari are produced, as slope mounds become increasingly separated by a dense network of small inclined pipes in the intermediate part of the slopes, a site which is presumed to favour elevated subsurface flow. When the overburden collapses, many cones are isolated in these portions of the slope. A second stage follows in which overland flow dominates, with the water canalizing into small gullies generated by the collapsed crust. At the base of many slopes, this same mechanism produces biancane as residual cones. Because of the structural weakness of piped materials, mass movements cannot be ruled out. In a few locations, landsliding may be involved, especially in the formation of calanchi mammellonari. In this case the intersection of the vertical pipes with the impermeable substratum focuses subsurface flow, and collapse of the surface along this failure plane. Subsequent remodelling occurs by surface processes, since the ‘catchment volume’ for large pipes no longer exists. This interpretation differs from that of others who have argued that in other locations the biancane formation is linked to the development of large vertical pipes along tectonic joints. [Copyright &y& Elsevier]