A WebGIS decision-support system for slope stability based on limit-equilibrium modelling

• The study presents the integration of CHASM into a WebGIS.
• Open Geospatial standards ensure interoperability and transferability.
• The decision-support system allows for quick calculation of slope stability.
• Calculations are carried out by a web processing service.
• The system is adaptable and transferable to other study areas.

Physically-based models are frequently applied for local landslide analyses and predictions in order to prevent the potentially disastrous consequences of slope failures. Limit-equilibrium modelling approaches are very common. However, the application of such models can be very time-consuming, and due to its two-dimensional nature, it generally has to be repeated for each profile that is investigated. In this study, the physically-based two-dimensional landslide model CHASM (Combined Hydrology and Stability Model) was implemented within a web-based GIS (Geographical Information System) environment for a study area in the Swabian Alb, Germany. The required input data for CHASM modelling were derived from a variety of data sources including geological maps, drillings, geophysical investigations, hydrological monitoring, laboratory analyses and literature sources. The implemented CHASM decision-support system is based on open-source software and utilises the WPS (web processing service) standard to execute the model algorithms on a server. The presented system allows the user to select from a variety of input data and model parameters to quickly perform limit-equilibrium analyses of slope stability. Simulation results are automatically stored to a database and can be visualised for interpretation. The implemented CHASM decision-support system represents an innovative prototype which demonstrates a promising approach to engage landslide modelling.