scholarly journals The use of FLO2D numerical code in lahar hazard evaluation at Popocatépetl volcano: a 2001 lahar scenario

2014 ◽  
Vol 14 (12) ◽  
pp. 3345-3355 ◽  
Author(s):  
L. Caballero ◽  
L. Capra
Keyword(s):  
Rheological Properties ◽  
Numerical Code ◽  
Hazard Evaluation ◽  
Digital Elevation ◽  
Popocatépetl Volcano ◽  
Elevation Model ◽  
Definition Of ◽  
Digital Elevation Model Resolution ◽  
Excellent Tool ◽  
Popocatepetl Volcano

Abstract. Lahar modeling represents an excellent tool for designing hazard maps. It allows the definition of potential inundation zones for different lahar magnitude scenarios and sediment concentrations. Here, we present the results obtained for the 2001 syneruptive lahar at Popocatépetl volcano, based on simulations performed with FLO2D software. An accurate delineation of this event is needed, since it is one of the possible scenarios considered if magmatic activity increases its magnitude. One of the main issues for lahar simulation using FLO2D is the calibration of the input hydrograph and rheological flow properties. Here, we verified that geophone data can be properly calibrated by means of peak discharge calculations obtained by the superelevation method. Digital elevation model resolution also resulted as an important factor in defining the reliability of the simulated flows. Simulation results clearly show the influence of sediment concentrations and rheological properties on lahar depth and distribution. Modifying rheological properties during lahar simulation strongly affects lahar distribution. More viscous lahars have a more restricted aerial distribution and thicker depths, and resulting velocities are noticeably smaller. FLO2D proved to be a very successful tool for delimitating lahar inundation zones as well as generating different lahar scenarios not only related to lahar volume or magnitude, but also taking into account different sediment concentrations and rheologies widely documented as influencing lahar-prone areas.

scholarly journals The use of FLO2D numerical code in lahar hazard evaluation at Popocatépetl volcano: a 2001-lahar scenario

2014 ◽  
Vol 2 (7) ◽  
pp. 4581-4608 ◽  
Author(s):  
L. Caballero ◽  
L. Capra
Keyword(s):  
Numerical Code ◽  
Hazard Evaluation ◽  
Hazard Maps ◽  
Flow Properties ◽  
Popocatépetl Volcano ◽  
Rheologic Properties ◽  
Simulation Results ◽  
Definition Of ◽  
Excellent Tool ◽  
Popocatepetl Volcano

Abstract. Lahar modelling represents an excellent tool to design hazard maps. It allows the definition of potential inundation zones for different lahar magnitude scenarios and sediment concentrations. Here we present the results obtained for the 2001 syneruptive lahar at Popocatépetl volcano, based on simulations performed with FLO2D software. An accurate delineation of this event is needed since it is one of the possible scenarios considered during a volcanic crisis. One of the main issues for lahar simulation using FLO2D is the calibration of the input hydrograph and rheologic flow properties. Here we verified that geophone data can be properly calibrated by means of peak discharge calculations obtained by superelevation method. Simulation results clearly show the influence of concentration and rheologic properties on lahar depth and distribution. Modifying rheologic properties during lahar simulation strongly affect lahar distribution. More viscous lahars have a more restricted aerial distribution, thicker depths, and resulting velocities are noticeable smaller. FLO2D proved to be a very successful tool to delimitate lahar inundation zones as well as to generate different lahar scenarios not only related to lahar volume or magnitude but also to take into account different sediment concentrations and rheologies widely documented to influence lahar prone areas.

scholarly journals An algorithm for delineating and extracting hillslopes and hillslope width functions from gridded elevation data

2011 ◽  
Vol 8 (5) ◽  
pp. 8865-8901
Author(s):  
P. Noel ◽  
A. N. Rousseau ◽  
C. Paniconi
Keyword(s):  
Three Dimensional ◽  
Rainfall Runoff ◽  
Dimensional Representation ◽  
New Approach ◽  
One Dimensional ◽  
Digital Elevation ◽  
Elevation Data ◽  
Average Profile ◽  
Elevation Model ◽  
Digital Elevation Model Resolution

Abstract. Subdivision of catchment into appropriate hydrological units is essential to represent rainfall-runoff processes in hydrological modelling. The commonest units used for this purpose are hillslopes (e.g. Fan and Bras, 1998; Troch et al., 2003). Hillslope width functions can therefore be utilised as one-dimensional representation of three-dimensional landscapes by introducing profile curvatures and plan shapes. An algorithm was developed to delineate and extract hillslopes and hillslope width functions by introducing a new approach to calculate an average profile curvature and plan shape. This allows the algorithm to be independent of digital elevation model resolution and to associate hillslopes to nine elementary landscapes according to Dikau (1989). This algortihm was tested on two flat and steep catchments of the province of Quebec, Canada. Results showed great area coverage for hillslope width function over individual hillslopes and entire watershed.

scholarly journals Evaluation of Reliable Digital Elevation Model Resolution for TOPMODEL in Two Mountainous Watersheds, South Korea

2019 ◽  
Vol 9 (18) ◽  
pp. 3690 ◽  
Author(s):  
Daeryong Park ◽  
Huan-Jung Fan ◽  
Jun-Jie Zhu ◽  
Sang-Eun Oh ◽  
Myoung-Jin Um ◽  
...  
Keyword(s):  
South Korea ◽  
Cell Size ◽  
Digital Elevation Model ◽  
River Basin ◽  
Grid Cell ◽  
Dem Resolution ◽  
Digital Elevation ◽  
Mountainous Watersheds ◽  
Elevation Model ◽  
Digital Elevation Model Resolution

This study analyzed the result of parameter optimization using the digital elevation model (DEM) resolution in the TOPography-based hydrological MODEL (TOPMODEL). Also, this study investigated the sensitivity of the TOPMODEL efficiency by applying the varying resolution of the DEM grid cell size. This work applied TOPMODEL to two mountainous watersheds in South Korea: the Dongkok watershed in the Wicheon river basin and the Ieemokjung watershed in the Pyeongchang river basin. The DEM grid cell sizes were 5, 10, 20, 40, 80, 160, and 300 m. The effect of DEM grid cell size on the runoff was investigated by using the DEM grid cell size resolution to optimize the parameter sets. As the DEM grid cell size increased, the estimated peak discharge was found to increase based on different parameter sets. In addition, this study investigated the DEM grid cell size that was most reliable for use in runoff simulations with various parameter sets in the experimental watersheds. The results demonstrated that the TOPMODEL efficiencies in both the Dongkok and Ieemokjung watersheds rarely changed up to a DEM grid-size resolution of about 40 m, but the TOPMODEL efficiencies changed with the coarse resolution as the parameter sets were changed. This study is important for understanding and quantifying the modeling behaviors of TOPMODEL under the influence of DEM resolution based on different parameter sets.

scholarly journals Nation-wide, general-purpose delineation of geomorphological slope units in Italy

2018 ◽  
Author(s):  
Massimiliano Alvioli ◽  
Ivan Marchesini ◽  
Fausto Guzzetti
Keyword(s):  
Adaptive Algorithm ◽  
Central Italy ◽  
Optimization Procedure ◽  
General Purpose ◽  
General Requirement ◽  
Italian Peninsula ◽  
Slope Unit ◽  
Digital Elevation ◽  
Elevation Model ◽  
Definition Of

Slope units are portions of terrain, defined by the general requirement of maximizing homogeneity within a single unit and heterogeneity between different ones. Slope units are being used to describe a variety of processes and to assess different natural hazards. An unambiguous and reproducible definition of slope units based on quantitative hydrologic and topographic criteria was previously provided by the r.slopeunits software to automatically draw slope unit polygons on a digital surface. The software contains an adaptive algorithm allowing for a flexible yet well-defined slope unit delineation, by means of an iterative procedure. It requires a digital elevation model and a few input parameters, whose values must be optimized in a sound way, by means of multiple software runs and a proper objective function. The code is designed to quickly produce results on large areas, and in this work we devised an optimization algorithm to delineate slope units over the whole Italian peninsula. We outline the rationale of the optimization procedure for a general purpose slope unit delineation within very large areas. We present preliminary results in Central Italy, specifically a slope unit mosaic in the whole area affected by the 2016 earthquake sequence. The procedure represents a well-defined framework for slope unit delineation over the whole of Italy.

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