Modelling rapid mass movements using the shallow water equations in Cartesian coordinates
We propose a new method to model rapid mass movements on complex topography using the shallow water equations in Cartesian coordinates. These equations are the widely used standard approximation for the flow of water in rivers and shallow lakes, but the main prerequisite for their application – an a...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-03-01
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| Series: | Natural Hazards and Earth System Sciences |
| Online Access: | http://www.nat-hazards-earth-syst-sci.net/15/671/2015/nhess-15-671-2015.pdf |
| Summary: | We propose a new method to model rapid mass movements on complex topography
using the shallow water equations in Cartesian coordinates. These equations
are the widely used standard approximation for the flow of water in rivers
and shallow lakes, but the main prerequisite for their application – an
almost horizontal fluid table – is in general not satisfied for avalanches
and debris flows in steep terrain. Therefore, we have developed appropriate
correction terms for large topographic gradients. In this study we present
the mathematical formulation of these correction terms and their
implementation in the open-source flow solver GERRIS. This novel approach is
evaluated by simulating avalanches on synthetic and finally natural
topographies and the widely used Voellmy flow resistance law. Testing the
results against analytical solutions and the proprietary avalanche model
RAMMS, we found a very good agreement. As the GERRIS flow solver is freely
available and open source, it can be easily extended by additional fluid
models or source areas, making this model suitable for simulating several
types of rapid mass movements. It therefore provides a valuable tool for
assisting regional-scale natural hazard studies. |
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| ISSN: | 1561-8633 1684-9981 |