Application of RiskMaster to the Crayford ICM Model

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Poppy Martin
6 years ago
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1 Application of RiskMaster to the Crayford ICM Model Innovyze Conference June 2014 Francesca Hurt 1

2 CRAYFORD MODEL OVERVIEW 2

Crayford Model InfoWorks ICM 1D-2D Model Variable Mesh Integrate Sewer, River and Rainfall Models Utilized existing EA ISIS-TUFLOW model of Cray, combining it with Thames Water and Bexley data on the

3 Crayford Model InfoWorks ICM 1D-2D Model Variable Mesh Integrate Sewer, River and Rainfall Models Utilized existing EA ISIS-TUFLOW model of Cray, combining it with Thames Water and Bexley data on the surface water sewer system. Modelled a range of design scenarios. Rainfall events (5, 20, 75, 100, 100CC) Fluvial events (5, 20, 75, 100, 100CC) Combined rainfall and fluvial events (20, 100, 100CC) 3

4 Model Overview Vitbe Sluice & Mill Gauging Station Hall Place Weir River Cray Wansunt Culvert Stanham River Hall Place Siphon Hall Place Outlet to R.Wansunt R Wansunt Surface Water Sewer Network Hall Place Reservoir 4

5 RISKMASTER 5

development compared to simple property count without needing

6 Application of RiskMaster Why? Offer a more substantial basis on which to base future option development compared to simple property count without needing to complete a full cost-benefit analysis

7 Application of RiskMaster Data Existing Crayford ICM model EA National Receptors Database to determine damage receptors OS MasterMap to determine polygons The Multi-Coloured CD to determine damage functions 7

8 Damage receptors - Importing NRD Data Use toid as damage receptor ID. mcmcode = Code 1 Note NRD floor area is in m 2, ICM floor area is in ha. If import directly manually update column in ICM. Alternatively use SQL to set floor area based on associated polygon. Manually input Component data (Basement or No Basement) No floor level data held in NRD 8

9 Damage receptors Assigning Polygons Use SQL to link damage receptor with polygon data set. (eg: imported OS MasterMap polygons) NRD contains multiple points with the same co-ordinates. Flats Offices Flats above shops Can result in multiple damage receptors attached to the same polygon (when using OS MasterMap). Cause overestimation of damages if: Floor area of each damage receptor based on the polygon area. Damage receptors for upper floors have no floor level assigned. 9

Damage receptors Assigning Polygons Solutions: delete the duplicated points leaving one damage receptor per polygon (floor area set to polygon area).

10 Damage receptors Assigning Polygons Solutions: delete the duplicated points leaving one damage receptor per polygon (floor area set to polygon area). Where multiple uses are present for the same polygon use Google streetview to main use. Import floor area from NRD, and set floor levels for upper floors. If floor level not available remove points relating to upper floors. 10

Accuracy of data Check the date associated with the NRD data and OS MasterMap data. New buildings or changes of use may not be picked up by the existing datasets.

11 Accuracy of data Check the date associated with the NRD data and OS MasterMap data. New buildings or changes of use may not be picked up by the existing datasets. Sensibility checks against site visits and aerial photography recommended to ensure an accurate estimate of damages. Building Polygon, but no NRD point No building polygon or NRD point 11

Accuracy of data If updating floor area based on associated polygon area sensibility check the area to ensure the NRD points are not mismatched to unusually large

12 Accuracy of data If updating floor area based on associated polygon area sensibility check the area to ensure the NRD points are not mismatched to unusually large polygons. Alternatively, rather than using a polygon file which contains all MasterMap polygons (roughness polygons). Just extract those attributed as buildings. 12

13 Damage Functions Import depth-damage data from MCH CD. For Crayford residential sector averages used. NRD dataset did not provide additional level detail needed on property age and social class. Note you seem to have to import the short-duration and long duration separately. When you do it will overwrite duplicate data. I assumed overwriting does not cause a problem? Non-residential damage functions do not exist for all land uses/mcmcodes. Pre process the NRD remove those points which do not have a damage function or reassign them to another similar land type. Generally those land uses without a damage function would not be appropriate for inclusion in the damage calculations anyway (recreation grounds, car parks etc). 13

Fluvial only models need to include dummy rainfall events with the rainfall event name set to the fluvial return period being modelled.

14 Running RiskMaster Analysis Need a RiskMaster License If using an existing model, previous runs will need to be rerun in a licensed version, with damage receptors included and linked to mesh. Fluvial only models need to include dummy rainfall events with the rainfall event name set to the fluvial return period being modelled. When running multiple rainfall events using one run file all events must successfully complete for the run to be used in a Risk Analysis.» If one fails you have to rerun it or delete it from the run using the results manager. 14

15 RiskMaster Results Check the EAD produced, spuriously high value may highlight a problem with a damage receptor. RiskMaster does not appear to contain a function to automatically cap damages for individual receptors. This would have to be done through post processing the results. For large models, such as Crayford, it would be useful if the damages could be aggregated for key areas (such as the town centre). 15

16 Conclusions Useful tool, which can be easily used with existing models. Care should be taken when importing necessary data. Careful pre-processing of input data is recommended, to avoid need for multiple runs and ensure accuracy of damage calculations. 16

17 QUESTIONS 17

What's New in this Version

What's New in this Version This topic lists all the additions and improvements incorporated in InfoWorks ICM v4.5 which were not available in previous versions. Flood risk analysis New functionality has