UTILIZACIÓN DE TÉCNICAS DE FOTO-RECONSTRUCCIÓN 3D AUTOMATIZADA EN GEOMORFOLOGÍA: EJEMPLOS PARA DIFERENTES MORFOLOGÍAS Y ESCALAS

Three-dimensional photo-reconstruction methods based on Structure from Motion (SfM) and MultiView-Stereo techniques (MVS) are tested for measuring, monitoring and quantifying three different geomorphological features: i) the Corral del Veleta rock glacier and ii) five small gully headcuts in Spain and iii) Calanchi type badland in Italy. Results about the accuracy, usefulness and applicability of these techniques are presented here. The results of these analyses showed centimeter-level accuracies with average distances to the benchmark models ranging from 0.009 m to 0.42 m.

Water erosion assessment and modeling in two calanchi areas in Sicily, Italy

I badlands sono forme di erosione localizzate principalmente nelle regioni aride e semi-aride e sono formati da una complessa combinazione di processi morfogenetici. La loro origine coinvolge processi di erosione idrica ma anche tunnel erosion e movimenti di massa. Inoltre, tali forme possono anche essere correlate a fenomeni di erosione accelerata che hanno luogo laddove le azioni antropiche disturbano l'equilibrio naturale tra processi morfogenetici e suolo. I badlands, con i loro versanti ripidi, sono spesso inseriti all’interno di paesaggi più dolci, in mezzo a colture o bosco, localizzati in aree dove i processi responsabili del loro modellamento sono di solito piuttosto attivi determi…

Gully erosion in a small experimental catchment in SW Spain

GIS-MORPHOMETRIC ANALYSIS OF BADLANDS IN SICILY (ITALY)

Sicily is affected by severe erosion processes, locally causing large volumes of soil loss and high denudation rates. The effects of intense water erosion phenomena are testified by the occurrence of badlands that constitute a common landscape particularly in the central and southern areas of the Island, where slopes are frequently underlain by clay-rich deposits. This paper presents the first results of an investigation carried out in a badlands site located in the head sector of the Imera Meridionale river basin, where geometry of several erosion channels has been characterized. Since length of linear erosion landforms such as rills, ephemeral gullies and permanent gullies, has been prove…

Morphometric characterization of a calanchi inventory in Sicily, Italy

Calanchi are a frequent type of badland landscape of Sicily (Italy), usually located in the middle of crops or forests. They are characterized by heavily dissected terrains with unvegetated slopes, knife ridge edges, V-shaped valleys and channels with a dendritic pattern, which incise and extend headwards. Calanchi exhibit, in smaller temporal and spatial scales, many of the geomorphic processes and landforms that may by observed in a fluvial landscape, hence, this type of badland may be considered as micro-watersheds where geomorphic dynamics can be related to their geometric features. The aim of this investigation was to evaluate the morphometric characteristics of calanchi landforms in S…

Un nuovo modello per la stima dell'erosione in aree calanchive

Analisi morfometrica di due aree calanchive in Sicilia (Italia)

Modeling landslide susceptibility by using GIS-analysis and multivariate adaptive regression splines

Landslide susceptibility may be evaluated by defining statistical relationships between the spatial distribution of past slope failures and the variability of landslide triggering factors. In this research, susceptibility to landsliding was assessed by employing multivariate adaptive regression splines (MARS), a statistical model that has been rarely used to this aim. The experiment was carried out in an area of central Sicily (Italy), which is severely affected by shallow landslides mainly occurring during the wet autumn- winter semester. Bedrock lithology and a set of primary and secondary topographic attributes were exploited as proxies of main landslide driving factors. The robustness o…

Morphometric analysis of two calanchi areas in Sicily (Italy) by exploiting high resolution Digital Elevation Models

In the Mediterranean areas, specifically in Sicily (Italy), irregular rainfalls, strong seasonal changes, scarce vegetation cover and, frequently, outcropping of clayey deposits favor water erosion phenomena. Badland landscapes are the result of severe erosion processes, characterized by steep slopes, sparse vegetation, high drainage density, rapid erosion rates and a shallow or non existing regolith profile. In this investigation we focused on the calanchi badland type, consisting of heavily dissected terrain with steep, unvegetated slopes and channels that rapidly incise and extend headwards. This research was carried out in two calanchi sites located in Sicily. The geometry of 25 badland…

Elaboración de modelos 3D de diferentes morfologías y escalas utilizando técnicas Structure-from-Motion y fotografías terrestres

En este trabajo se evalúan los métodos de foto-reconstrucción automatizada basados en el uso conjunto de las técnicas Structure from Motion (SfM) y Multi-View Stereo (MVS) para medir, monitorizar y cuantificar la dinámica de tres formas geomorfológicas: i) el glaciar rocoso del Corral del Veleta (Granada, España), ii) un paisaje de cárcavas de tipo calanchi (Sicilia, Italia) y ii) cinco pequeñas cabeceras de cárcava (Cáceres, España). Se incluyen en este trabajo los resultados sobre la precisión, utilidad y aplicabilidad de estas técnicas. Para la cuantificación de la precisión se utilizan el error cuadrático medio (RMSE) de los puntos de control que se emplean en la georreferenciación y la…

Morphometric analysis of calanchi areas by low-altitude flight