Oasis Models¶
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Oasis Models¶
Oasis makes available a number of example models to demonstrate how different functionality options are implemented in Oasis. The available models are:
Deterministic Model¶
This is a single event model which allows users to apply deterministic losses to a portfolio, defining the damage factors
in the OED location file. It is similar to the exposure feature in the oasislmf package, but can be deployed as a model in
it’s own right to model deterministic losses which can then be passed through the Oasis financial module.
This model is availible to use here.
Paris Windstorm¶
This is very small, single peril model used for demonstration of how to build a simple model in Oasis.
This model is availible to use here.
PiWind¶
This is the original test model in Oasis and is an example of a multi-peril model implementation representing ficticious events with wind and flood affecting the Town of Melton Mowbray in England.
This model is availible to use here.
More information on this model can be found here: PiWind - toy model
PiWind Absolute Damage¶
This model expands upon the PiWind model with the absolute damage option. This option allows model providers to include absolute damage amounts rather than damage factors in the damage bin dictionary. If the damage factors are less than or equal to 1 in the damage bin dictionary, the factor will be applied as normal during the loss calculation, by applying the sampled damage factor to the TIV to give a simulated loss; but with absolute damage factors, where the factor is greater than 1, the TIV is not used in the calculation at all, but rather the absolute damage is applied as the loss.
This model is availible to use from here.
PiWind Complex Model¶
This is a version of the PiWind model which uses the complex model integreation approach to generate ground up losses in a custoim module, which then sits in the workflow and replaces the standard ground up loss calculation from Oasis.
This model is availible to use from here.
PiWind Postcode¶
This is a variant of the original PiWind model designed for running exposures whose locations are known at postcode level rather than by latitude and longitude. This model demonstrates the disaggregation features of Oasis.
This model is availible to use here.
PiWind Post Loss Amplification¶
This is a version of the PiWind model with post loss amplification factors applied. Major catastrophic events can give rise to inflated and/or deflated costs depending on that specific situation. To account for this, the ground up losses produced by the GUL calculation component are multiplied by post loss amplification factors, by the component plapy.
This model is availible to use here.
PiWind Post Pre Analysis¶
This model builds upon the original PiWind model with a pre-analysis adjustment hook. This step allows the user to modify input files before they are processed in the analysis. This functionality is utilised by this model by implementing an external geocoder: this checks the location data before it is analysed for any addresses that are missing OED location data. If an address is found t o be incomplete, it is geocoded to fill these gaps.
This model is availible to use here.
PiWind Single Peril¶
This is a simplified variant of the original PiWind model which has single peril (wind only) and would be a good basis for a single peril model in Oasis.
This model is availible to use here.
Note
More information about these models can be found here.
PiWind - toy model¶
Oasis has developed a toy model, PiWind, available here. PiWind is a wind storm model for a small area of the UK. The data is mocked up to illustrate the Oasis data formats and functionality, and is not meant to be a usable risk model. The PiWind toy model is availible to use from here.
There are three main components to a catastrophe risk model deployed in Oasis. A fuller discussion of the components of a hazard model can be found in Modelling methodology.
- Hazard footprint data:
This holds the hazard intensity data for each event in the stochastic event set. The hazard intensity footprint is defined on a model specific geospatial grid, and each grid cell is assigned a unique identifier.Note that a model may cover multiple perils, each with a different overlaid area peril grid. For example, a hurricane model will usually cover both wind and storm surge perils. Each peril has a defined hazard intensity measure, such as wind speed in metres per second.The Oasis Platform allows uncertainty to be specified in the hazard intensity measure in a particular grid cell for each event.
- Vulnerability data:
This holds curves that define the distribution of damage as a proportion of replacement value given the level of hazard intensity.Different curves as specified for structures with different building characteristics.For example, a wood-framed building will have a different vulnerability to wind damage as compared to a building of concrete construction.The curves also define the uncertainty in damage at different hazard levels.The Oasis Platform does not make any assumptions about the form of the damage distributions and represents them all as discrete distributions.
- Keys lookup logic:
This is model specific logic that maps a set of exposure attributes into the model specific grid and vulnerability type. A unique mapping is made for each location, coverage and peril combination. The lookup also provides informative messages about any exposures that will not be modelled.For example, an exposure may not be modelled if there is insufficiently detailed address information or if the exposure is not within the geographic scope of the model.
The PiWind model is a very small example model, so it’s files can be saved to a GitHub repository and easily queried.For real models the data sets can get much larger, in some cases more than 1 TB for a single model.The following link is to a Jupyter notebook that illustrates the setup of the PiWind model and how it can be ran using the Oasis MDK: Running PiWind.