| Summary: | In the Dolomites area (North-Eastern Italian Alps), debris flows can be regarded as one of the most hazardous geomorphological processes. In the last few years, these natural phenomena amplified their occurrence rate due to the rise of extreme rainfall events, and the increasing availability of debris material yielded by the retreat of the glaciers and the permafrost areas to higher elevations. In order to cope with debris flow hazard, it is common to couple structural and non-structural measurements, such as the zoning of risk prone areas by means of routing models. Since the motion of gravity-driven flows is extremely sensitive to surface morphology, topographic data in the form of Digital Elevation Models (DEMs) represent the most important input in debris flow routing models. As a matter of fact, a DEM can be regarded as a mathematical representation of the bare earth in digital form, and it is commonly used to represent the surface morphology in three dimensions. The “quality” of DEMs depends on the accuracy, density, and spatial distribution of the topographic data (i.e., on the employed survey technique); on the characteristics of the surveyed surface; and on the applied gridding methodology. Therefore, the choice of both the survey technique and the gridding methodology might represent a critical concern for the reliability of routing modeling outcomes. In order to advance in the knowledge regarding the influence of geomatic techniques on the numerical modeling of stony debris flows routing, in the present research we initially assessed the performances of common digital terrain modelling algorithms (i.e., linear triangulation, natural neighbor, nearest neighbor, inverse distance to a power, ANUDEM, completely regularize spline function, thin-plate spline function, thin-plate spline plus tension function, multi-quadratic function, inverse multi-quadratic function, point ordinary kriging, and block ordinary kriging) and survey techniques (i.e., full-waveform Light Detection And Ranging, LiDAR; and Global ...
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