Probability

Given the scenario, you can then specify the hazard probability based on the data for the indicators defined in the previous modules, for example, by analysing and aggregating corresponding historical data, employing climate projections or simulation methods, or using expert judgement. For the extreme precipitation scenario from above, the historical number of days in a year with a precipitation above a critical threshold of x l/m²/hour could be calculated and used to estimate the hazard probability.

Impact

The hazard intensity can be assessed in similar fashion: you might correlate historical precipitation data to historical data on flood depth and coverage area from the same time period, giving you an inkling of the hazard intensity following a specific amount of precipitation. Alternatively, the historical precipitation data might be fed into a flood simulation model of your city to calculate the relevant hazard indicators. As an example for heat waves, you could relate historical monthly or weekly temperature data to monthly or weekly mortality rates.

Next to assessing the hazard intensity, the scores for vulnerability should be determined. These scores can be acquired by aggregating the normalised and weighted output values for indicators addressing the risk components sensitivity and coping capacity.

Once vulnerability scores and hazard intensity have been assessed, the expected impact of a given hazard on an exposed object under a specific scenario can be determined. The process of estimating the expected consequences of a hazard scenario is called Consequence Analysis. In the context of IVAVIA, it is the process of relating hazard intensities to expected consequences. There is no hard and fast standard process, but rather a suite of tools, models, and approaches that may be employed, depending on the data and resources (in terms of personnel, time, and funds) available. Here are some of the most frequently:

• Damage functions correlate hazard intensity, often quantified using a single measure, with potential damage. For example, flood depth-damage functions relate flood depth to damages; these may be damages in terms of monetary values, reductions in travel speed, number of fatalities, or other damages. Sources for damage functions include, for example, the JRC Technical Report on global flood depth-damage functions ²⁾
  Jan Huizinga, Hans de Moel, Wojciech Szewczyk, Global flood depth-damage functions, Methodology and the database with guidelines, JRC, 2017: http://publications.jrc.ec.europa.eu/repository/bitstream/JRC105688/global_flood_depth-damage_functions__10042017.pdf or the standard method for damage and casualty estimation in the Netherlands ³⁾Kok, Huizinga, Vrouwenvelder, and Barendregt, Standaardmethode 2004: schade en slachtoffers als gevolg van overstromingen, Ministerie van verkeer en waterstaat, 2004
• Computable General Equilibrium models can be used to model links between economic sectors and subsequently cascading effects between different sectors resulting from a hazardous event. They use input-output tables, i.e. symmetrical matrices describing transactions between economic sectors, and combine them with standard assumptions about economic behaviour of households, firms, and governments to analyse the responses of the economy.
• Computer simulations are computer programs that use abstract digital representations to imitate (parts of) real or hypothetical processes, mechanisms, or systems. Depending on their level of detail they may require quite a lot of data and other resources, as well as expert knowledge to calibrate the underlying models and validate their results.
• Inter-/Extrapolation may be used if only historical data on past intensities and consequences is available, but no further sources on their correlation are on hand. In this case the historical data may be used to inter- or extrapolate the consequences resulting from given hazard intensities.
• Expert judgement may be employed if absolutely no other data is available. Here, local experts are employed to estimate the consequences resulting from the given hazard intensities.

Multi-risk analysis

The above addresses a single-risk analysis, estimating the risk of a singular hazard in isolation from other hazards or risk scenarios⁴⁾EC (2010). Risk Assessment and Mapping Guidelines for Disaster Management. COMMISSION STAFF WORKING PAPER. Brussels, 21.12.2010 SEC(2010) 1626 final.. The challenge of multi-risk assessments is to adequately take account of possible follow-on effects (also: knock-on effects, domino effects or cascading effects) among hazards, i.e. the situation where one hazard causes one or more sequential hazards. The following work steps are recommended:

1. Identification of possible multi hazard scenarios, starting by a given top event and evaluating the possible triggering of other hazards or events leading to hazards;
2. Exposure and Vulnerability analysis for each individual hazard and risk within the different branches of the scenarios;
3. Risk estimate for each hazard and adverse event and for the multi-risk scenarios.

Software tools such as decision support system for mapping multiple risk scenarios can be used and facilitate the visualisation and information and the running of scenarios.

The IVAVIA workflow Support tool supports the selection of an Impact Chain from the Impact Chain Editor ICE+ [hyperlink], fetching data from the IVAVIA database that match the indicators in the Impact Chain Diagram and invoking the RIVAS tool for computing risk component values based on the fetched data. As a first prerequisite, therefore, you need to create at least one Impact Chain for your assessment. As second prerequisite, you need to gather the required hazard indicator data, socio-economic data, and other data and import them into the IVAVIA database. Thereafter, the RESIN Workflow Tool can be used.

• Go to the website of the IVAVIA Workflow Support Tool (To get an account and access to the tool, write an e-mail to resin@iais.fraunhofer.de)
• Select an Impact Chain Diagram corresponding to a scenario (city, spatial resolution, timeframe) that you want to investigate. It will automatically be imported from the Impact Chain Editor ICE+. The scenario description and the Impact Chain Diagram will be displayed
•  Select the indicator data normalization method, the aggregation method, and the weighting method. If you are not an expert in statistics, you may rely on the offered default methods.
• After you have made all required selections, you may press the “Calculate” button
• The “Download results” button finalizes the IVAVIA part of the RESIN workflow support software. It will download three files:
  1) the selected Impact Chain Diagram as a native JSON file (can be reimported by ICE+);
  2) the table of values per zone as a CSV file (can be read with Excel);
  3) the color-coded zone maps as shape files (GeoJSON file).
• When using the DSC: Upload the CSV or JSON file to the respective form in the Decision Support Center [hyperlink when available]

Nb. You may proceed from the workflow support software with fetching suitable adaptation options from the RESIN Adaptation Options Library that match the Impact Chain Diagram. Again, you may download the AOL results and manually upload them to your project in the RESIN e-Guide.

Modules 3, 4, 5 and 6 of IVAVIA support the development and performance of a quantitative vulnerability assessment. The Impact Chains and other outputs as defined in Modules 0, 1 and 2 are used as a starting ground for the assessment. The quantitative assessment requires a considerable amount of time and effort of city administrators and experts. A good part of this effort is dedicated to acquiring the required socio-economic and infrastructure data.

Guidance

• Go to the description of Module 3 and follow the instructions to identify indicators and acquire data for the risk components: hazards, drivers, stressors, impacts, sensitivity, and coping capacity;
• Go to the description of Module 4 and follow the instructions to normalize, weight and aggregate the indicators;
• Go to the description of Module 5 and follow the instructions to aggregate components to vulnerability and risk scores;
• Go to the description of Module 6 and follow the instructions to present the outcomes of IVAVIA;
• When using the DSC: Document the outcomes of all modules in the respective form in the Decision Support Center [hyperlink when available]

3Di is a complex sophisticated tool to model hydrodynamic processes. It offers two modes of usage:

• Directly: the user (with a background in GIS and hydrology) can explore the model by him-/herself. In this case, the user will be provided with online guidance on how to use the tool and can participate in a training.
• Support by a local partner: the model building will be performed by a local expert of the 3Di team.

• Install the CLIMADA toolset by following these instructions.
• Using the methodology guide, determine the risk levels for your climate threats and record these in your workspace.

To use, contact Climate-KIC. Record the results (water management related risks) in your workspace.

Elements of an complete risk analysis (from:http://www.resin-cities.eu/resources/tools/ivavia/) and the place of vulnerability in determining risk

This tool may be used to determine the vulnerability to climate hazards. To use this tool:

• Download the the RAMSES handbook and training package.
• Follow the instructions in the workbook ‘Vulnerability assessment’, provided as an annex in the guidance document.
• Use the results as an input for a complete risk analysis (for overview, see scheme above).
• Record the results in your work space.

• Download the manual and Excel tool
• Follow the instructions
• Record the results in your workspace

• Download the manual and follow the steps described here
• Record the results in your workspace