The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. http://http://dspace.unitus.it:80 2013-05-22T08:12:53Z 2013-05-22T08:12:53Z Rulli, Maria Cristina Nardi, Fernando Santini, Monia Petroselli, Andrea Grimaldi, Salvatore http://hdl.handle.net/2067/1416 2011-06-27T17:38:31Z 2006-12-31T23:00:00Z

Title: Flow routing algorithms and landslide modelling Authors: Rulli, Maria Cristina; Nardi, Fernando; Santini, Monia; Petroselli, Andrea; Grimaldi, Salvatore Abstract: The physical processes governing shallow landslide triggering can be ascribed to hydrological and geomechanic forcings. Modelling shallow landslide triggering via hydrogeomorphic spatially distributed model requires to extract for any location in the river basin the geomorphic and hydrologic attributes. The Digital Elevation Models allow an easy quantification of several morphologic and hydrologic landscape properties e.g.primary attributes such as slope, aspect, plan and profile curvature, flow path lengths and secondary attributes such as topographic index and drainage area per unit contour length. Although all of these attributes are used when assessing the hydrological forcings to shallow landslide triggering, it has to be stressed that the flow direction and accumulation algorithm plays a significant role in the accurate physical representation of those waterdriven slope instability phenomena. In this study three flow direction algorithm (D8, D8- LTD and D ) are applied in conjunction with two DEM correction techniques for the treatment of pits and flat areas (ArcInfo standard approach and PEM4PIT), in order to determine the terrain attributes needed as input for the hydrogeomorphic model Shalstab. Quantitative results corresponding to the implementation of the different hydrogeomorphic terrain analysis algorithms on different case studies provide an objective framework for testing the accuracy and performance of the different schemes in relation to the DEM-based hydrogeomorphic prediction of shallow landslides.

2006-12-31T23:00:00Z Santini, Monia Grimaldi, Salvatore Petroselli, Andrea Nardi, Fernando Rulli, Maria Cristina http://hdl.handle.net/2067/1427 2011-06-27T19:01:04Z 2008-12-31T23:00:00Z

Title: Pre-processing algorithms and landslide modelling on remotely sensed DEMs Authors: Santini, Monia; Grimaldi, Salvatore; Petroselli, Andrea; Nardi, Fernando; Rulli, Maria Cristina Abstract: Terrain analysis applications using remotely sensed Digital Elevation Models (DEMs), nowadays easily available, permit to quantify several river basin morphologic and hydrologic properties (e.g. slope, aspect, curvature, flow path lengths) and indirect hydrogeomorphic indices (e.g. specific upslope area, topographic wetness index) able to characterize the physical processes governing the landscape evolution (e.g. surface saturation, runoff, erosion, deposition). Such DEMs often contain artifacts and the automated hydrogeomorphic characterization of the watershed is influenced by terrain analysis procedures consisting in artificial depression (pit) and flat area treatment approaches combined with flow direction methods. In shallow landslide deterministic models, when applied using topographic dataset at medium scale (e.g. 30 m of resolution), the choice of the most suitable DEM-processing procedure is not trivial and can influence model results. This also affects the selection of most critical areas for further finer resolution studies or for the implementation of countermeasures aiming to landslide risk mitigation. In this paper such issue is investigated using as topographic input the ASTER DEMs and comparing two different combinations of DEM correction and flow routing schemes. The study areas comprise ten catchments in Italy for which hydrogeomorphic processes are significant. Aims of this paper are: 1) to introduce a parameter estimation procedure for the physically-based DEM correction method PEM4PIT (Physical Erosion Model for PIT removal); 2) to investigate the influence of different terrain analysis procedures on results of the slope stability model SHALSTAB (SHAllow Landsliding STABility) using remotelysensed ASTER DEMs; 3) trying to assess which of terrain analysis methods is more appropriate for describing terrain instability. Description: L'articolo è disponibile sul sito dell'editore http://www.sciencedirect.com/

2008-12-31T23:00:00Z