Erosion rate evaluation and slope morphology evolution in badland areas represent very important scientific and practical problems. In this work detailed geomorphological investigation has been carried out in some areas of Southern Tuscany (Italy) characterized by very rapid morphological evolution. The Pliocene marine claystones outcropping in this area have been uplifted during the Quaternary up to 750 meters above sea-level, and they are now undergoing particularly intense erosion, leading to considerable badland formation. Detailed geomorphological field surveys have been made and some slopes, chosen as sample-areas, have been monitored. These slopes represent experimental field laboratories , where short-term evolution and seasonal change of landforms generated by fluvial and hillslope processes have been accurately studied, and where the erosion rate is directly measurable. Morphographic and morphometric analyses carried out in special measurement stations evidence that the values of erosion rate on the slopes range from 5 to 7.5 cm/year. Slope features, because of intense landslide and sheetwash action, changed from rectilinear to concave-convex, to convex becoming rectilinear again in the winter 2000 – winter 2005 short period,. The comparison between 1976 and 1994 digital elevation models (DEM), obtained using a digital video plotter (DVP, Leica) and the aerial photographs of EIRA (1976) and Tuscany Region (1994) flights, allows to draw a “difference map”, showing the changes that the topographic surface underwent in a nineteen years period. Furthermore this made possible to calculate the mean erosion rate in the chosen area and to analyse the slope morphology evolution due to erosion and accumulation processes.
Erotion rate and slope morphology evolution in some badlands areas of southern Tuscany (Italy)
SALVATORE, MARIA CRISTINA
2005-01-01
Abstract
Erosion rate evaluation and slope morphology evolution in badland areas represent very important scientific and practical problems. In this work detailed geomorphological investigation has been carried out in some areas of Southern Tuscany (Italy) characterized by very rapid morphological evolution. The Pliocene marine claystones outcropping in this area have been uplifted during the Quaternary up to 750 meters above sea-level, and they are now undergoing particularly intense erosion, leading to considerable badland formation. Detailed geomorphological field surveys have been made and some slopes, chosen as sample-areas, have been monitored. These slopes represent experimental field laboratories , where short-term evolution and seasonal change of landforms generated by fluvial and hillslope processes have been accurately studied, and where the erosion rate is directly measurable. Morphographic and morphometric analyses carried out in special measurement stations evidence that the values of erosion rate on the slopes range from 5 to 7.5 cm/year. Slope features, because of intense landslide and sheetwash action, changed from rectilinear to concave-convex, to convex becoming rectilinear again in the winter 2000 – winter 2005 short period,. The comparison between 1976 and 1994 digital elevation models (DEM), obtained using a digital video plotter (DVP, Leica) and the aerial photographs of EIRA (1976) and Tuscany Region (1994) flights, allows to draw a “difference map”, showing the changes that the topographic surface underwent in a nineteen years period. Furthermore this made possible to calculate the mean erosion rate in the chosen area and to analyse the slope morphology evolution due to erosion and accumulation processes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
