Digitalni modeli reliefa in matematično modeliranje drobirskih tokov

Digital terrain models and mathematical modelling of debris flows

Author(s):

Jošt Sodnik, Anja Vrečko, Tomaž Podobnikar, Matjaž Mikoš

Abstract:

Mathematical modelling is a common approach when assessing debris-flow hazards. In this study on the mathematical modelling of debris flows, we applied the widely used Flo2D model. The high accuracy of the input parameters is essential for obtaining acceptable results. The numerical grid in the area of the debris-flow movement is generated from topographic data. The aim of our research was to assess the usefulness of public data for debris flow-modelling and to compare this data to the LiDAR-derived data. In Slovenia, DEM5 and DEM12.5 are publicly available data. However, the morphological accuracy of these datasets is questionable because of their development methods and their low morphologic resolution. A better solution is LiDAR-derived data with higher resolutions and a multiple options for further improvements with different methods and algorithms. The results with LiDAR data are more accurate; the torrential channel is better expressed. One downside of LiDAR data is its high price, which prevents wider usage of more precise data. Another downside is the much longer computational times of the model. More precise data means a more agitated surface of the computational grid, which results in shorter computational steps to ensure numerical stability. Methods for LiDAR-derived DEMs improvements are proposed in this study. With modified data, computational times are much shorter and results are even more precise than with non-modified DEMs.

Keywords:

digital elevation model, LiDAR, debris flow, mathematical modelling, natural hazard assessment

DOI: 10.15292/geodetski-vestnik.2012.04.826-837

Citation:

Jošt Sodnik, Anja Vrečko, Tomaž Podobnikar, Matjaž Mikoš (2012). Digitalni modeli reliefa in matematično modeliranje drobirskih tokov. | Digital terrain models and mathematical modelling of debris flows. Geodetski vestnik, 56 (4), 826-837. DOI: 10.15292/geodetski-vestnik.2012.04.826-837