UseCase » Models as a service
The landslide pilot MaaS and their main input and output data are summarized in following table. In addition to these data, user input parameters are needed to execute the MaaS.
Ms2 Hydrological modelling
The hydrological modelling simulates the main mechanisms of the water cycle in a catchment basin (precipitation, evapotranspiration, infiltration, underground flow) by a system of reservoirs.
The main input data are precipitation time series (In5).
The output is a groundwater level. The result can be put in the form of a groundwater levels at a given time (Out2). This level can then be used as input (In7) for the computation of safety factors or probabilities of landsliding (Ms3).
Ms3 Computation of a map of safety factors or probabilities of landsliding
The computation is based on 2D static mechanical analysis using methods of slices, carried out on every topographical profile (cross section of a hillslope) over the study area. The safety factor (SF) is equal to the ratio of shear stress to the shear strength required for equilibrium. The SF is an overall measure of stability: SF smaller than 1 is equivalent to instability. The probability of landsliding is the probability of SF being smaller than 1.
The input data are the geotechnical model (In6) (For complexity reason, the geotechnical model is not delivered as a service), the groundwater level map (In7) and the Digital Elevation Model (ln1) (This DEM can be included in the geotechnical model).
The output is a map of safety factors or a map of probabilities of landsliding (Out3). The map of probabilities of landsliding can be used as input (In9) for runout modelling (Ms4).
Ms4 Landslide runout modelling
The runout model aims at assessing the probability of a given point being reached by propagated landslides. The map of probabilities of landsliding provides the zones where the propagations of landslides start. From these starting zones, the travel paths of the sliding masses are calculated over the study area.
The input data are the DEM (In1) (which can also be contained in a geotechnical model (In6)) and the map of probabilities of landsliding (In8).
The output is a landslide hazard map (Out4) showing the probabilities of being affected by landslides (due to instability or runout). This landslide hazard map can then be used as input (In9) for damage calculation (Ms5).
Ms5 Damage calculation for linear elements
The damage calculation consists in computing the probability of a linear element (road, railway, network…) or its sections being damaged by landslides.
The input data for this function are a landslide hazard map (In9) and a map of exposed elements (In10) with a vulnerability function for every type of element.
The output is a damage map (or risk map) (Out5) where a probability of a certain level of damage is associated with every element at risk.
| Input data | Model as a service | Output data | |||||
|---|---|---|---|---|---|---|---|
| Designation | Format | Designation | Format | ||||
| ln5 | Precipitation data series | Series | Ms2 | Hydrological modelling | Out2 | Groundwater level | Value |
| ln1 | DEM (Can be included into the Geotechnical model.) | Grid | Ms3 | Computation of maps of safety factors (SF) or probabilities of landsliding | Out3 | Map of safety factors (SF) or probabilities of landsliding | Grid |
| ln7 | Groundwater level | Value | |||||
| ln6 | Geotechnical model (Cannot be a web service, available as file on the processing server.) | Heterogeneous | |||||
| ln1 | DEM | Grid | Ms4 | Runout modelling | Out4 | Lanslide hazard map | Grid |
| ln8 | Map of probabilities of landsliding | Grid | |||||
| ln9 | Landslide hazard map | Grid | Ms5 | Damage calculation for linear elements | Out5 | Risk map | Vector |
| ln10 | Map of elements at risk (This map can be "built area", "roads", "railways", "electric network".) | Vector | |||||
The landslide pilot models as a service
Revision october 2011