70 research outputs found

    Tools for Semi-automated Landform Classification: A Comparison in the Basilicata Region (Southern Italy)

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    Recent advances in spatial methods of digital elevation model (DEMs) analysis have addressed many research topics on the assessment of morphometric parameters of the landscape. Development of computer algorithms for calculating the geomorphometric properties of the Earth’s surface has allowed for expanding of some methods in the semi-automatic recognition and classification of landscape features. In such a way, several papers have been produced, documenting the applicability of the landform classification based on map algebra. The Topographic Position Index (TPI) is one of the most widely used parameters for semi-automated landform classification using GIS software. The aim was to apply the TPI classes for landform classification in the Basilicata Region (Southern Italy). The Basilicata Region is characterized by an extremely heterogeneous landscape and geological features. The automated landform extraction, starting from two different resolution DEMs at 20 and 5 m-grids, has been carried out by using three different GIS software: Arcview, Arcmap, and SAGA. Comparison of the landform maps resulting from each software at a different scale has been realized, furnishing at the end the best landform map and consequently a discussion over which is the best software implementation of the TPI method

    Morphometry and debris-flow susceptibility map in mountain drainage basins of the Vallo di Diano, southern Italy

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    In watershed mountain basins, affected in the last decades by strong rainfall events, the role of debris-flow and debris flood processes was investigated. Morphometric parameters have proven to be useful first-approximation indicators in discriminating those processes, especially in large areas of investigation. Computation of morphometric parameters in 19 watershed mountain basins of the western side valley of the Vallo di Diano intermontane basin (southern Italy) was carried out. This procedure was integrated by a semi-automatic elaboration of the potential susceptibility to debris flows, using Flow-R modelling. This software, providing an empirical model of the preliminary susceptibility assessment at a regional scale, was applied in many countries of the world. The implementation of Flow-R modelling requires a GIS application and some thematic base maps extracted using DEMs analysis. A 5-meter-resolution DEM has been used in order to produce the susceptibility maps of the whole study area, and the results are compared and discussed with the real debris flow/flood events that occurred in 1993, 2005, 2010, and 2017 in the studied area. The results have provided a good reliability of Flow-R modelling within small catchment mountain basins

    Universal photonic processors fabricated by femtosecond laser writing

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    Universal photonic processors (UPPs) are reconfigurable photonic integrated circuits able to implement arbitrary unitary transformations on an input photonic state. Femtosecond laser writing (FLW) allows for rapid and cost-effective fabrication of circuits with low propagation losses. A FLW process featuring thermal isolation allows for a dramatic reduction in dissipated power and crosstalk in integrated thermally-reconfigurable Mach-Zehnder interferometers (MZIs), especially when operated in vacuum, with 0.9 mW dissipation for full reconfiguration and 0.5% crosstalk at 785 nm wavelength. To demonstrate the potential of this technology we fabricated and characterized a 6-mode FLW-UPP in a rectangular MZI mesh with 30 thermal shifters

    Comparison of Different Methods of Automated Landform Classification at the Drainage Basin Scale: Examples from the Southern Italy

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    In this work, we tested the reliability of two different methods of automated landform classification (ACL) in three geological domains of the southern Italian chain with contrasting morphological features. ACL maps deriving from the TPI-based (topographic position index) algorithm are strictly dependent to the search input parameters and they are not able to fully capture landforms of different size. Geomorphons-based classification has shown a higher potential and can represent a powerful method of ACL, although it should be improved with the introduction of additional DEM-based parameters for the extraction of landform classe

    Geomorphic analysis and semi-automated landforms extraction in different natural landscapes

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    Increasing knowledges in the computer algorithms for calculating morphometric properties of the Earth's surface has provided in the last decades many methods of semi-automated extraction and classification of landforms. The use of digital elevation models (DEMs) and specific algorithms in GIS applications has made easier and faster the semi-automated recognition of landform classes. In this paper, we propose a new toolbox, implemented from the original version of the Jenness's landform classification, which takes into account a revision of the standard landform classes extracted by GIS. The new toolbox allowed us to extract 48 landform classes, and refined the typology of landform features in different natural landscapes, from a geomorphological point of view. The landforms classification and the morphometry of six different selected sites pertained to volcanic areas, mountain ridges, karst endorheic basins, hilly areas, fluvial sectors, and coastal plain areas were analysed and discussed. The selected areas are located in Southern Italy, where many different geological and geomorphological landscapes exist

    Electrical imaging and self-potential survayes to study the geological setting of the Quaternary, slope depositsin the Agri high valley (Southern Italy)

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    We present the results of a geophysical survey carried out to outline the structural modelling of Quaternary slopedeposits in the northern part of the Agri high valley (Basilicata, Southern Italy). Quaternary folding and brittle deformations of the subaerial slope deposits have been studied combining electrical imaging and self-potential surveys with geological structural analysis. This integrated approach indicates that the area underwent both transpressional and transtensional tectonics during Pleistocene times as testified by the existence of a push up structure in the basement buried by deformed Quaternary breccias. On this basis, the valley appears to be a more complex structure than a simple extensional graben, as traditionally assumed in the literature
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