This section describes a basic risk assessment approach that can be applied to all three LA roles.

Risk is usually defined as the product of the likelihood (or probability) of the occurrence of a hazard and the magnitude of its consequence. It can be represented by the following diagram.

Source: Willows and Connell, 2003

Clearly the level of risk increases from the bottom left to the top right of the diagram. However, how you choose to respond may be affected by a range of factors, such as costs and attitudes to risk. In particular, very high consequence events may need a response even if they have very low probabilities.

For a basic qualitative risk assessment likelihood and consequence are usually assigned to one of an equal number of categories. The simplest practical approach uses three category values of low, medium or high for the likelihood and consequence of a hazard as illustrated in the following diagram:

This is likely to sufficient for all of your initial assessments.

When completing the matrix, consider the following factors:

• A hazard is not simply a weather event, but the combination of a weather event and other factors that determine its impact. For instance, surface water flooding may be due to the combination of intense rainfall, the permeability of surfaces and the capacity of the drainage systems to cope with run-off
• When considering the likelihood of a hazard you will need to consider both the likelihood of a weather event and vulnerability to that event.
• Similarly, the consequence of a hazard is the combination the hazard and what is exposed to the hazard. In risk terminology this is known as the exposure unit. For instance the consequences of flooding will be very different on agricultural land to a city centre.
• A hazard will typically have a range of different impacts on different things, for instance, people, property, or the economy. In risk terminology these are known as receptors. The six business areas categories suggested as a means of identifying potential threats and opportunities are effectively different types of receptors.
• When considering the consequences of a hazard you should consider impacts on an appropriate range of receptors, noting that different receptors may have very different vulnerabilities to the same hazard. For instance, young children and older people are likely to be much more vulnerable to the impacts of a heat wave than the population as a whole.
• Likelihood is also related to the period being considered. Clearly the likelihood of event with a given probability will be greater the longer the period under consideration. But climate change scenarios suggest that the probability of many weather events will change over time. You may want to consider risks over various periods in order to get a better understanding of when adaptation measures should be planned for.

A simple 3 by 3 matrix should be sufficient for an initial scoping of risks although you may wish to consider a slightly more detailed approach using a 5 by 5 matrix for compatibility with the methods used for Emergency Planning under the Civil Contingencies Act.

Although matrices provide a very useful graphic means of visualising risks, you will probably find it more practical to assign a number to each category and to present the results in a table, especially if you are assessing a large number of risks. This will make it easier to rank and prioritise risks at the next step. You can download a number of forms and templates that can be customised to your requirements.

Risk management In recent years, risk management has been increasingly recognised as a vital component of the effective delivery public services. Your authority will already have a risk management unit with expertise in risk assessment. This may be a useful resource to assist in the assessment of climate risks, although typically they will not have considered climate change as a risk to date. Ensuring that climate risks are embedded in the risk management processes of the authority could be one of the key objectives of your Action Plan

Resources

1. UKCIP Risk framework
2. UK-resilience website contains information on the Civil Contingencies Act and Emergency Preparedness including government advice on risk assessmen t.
3. HM Treasury: Risk Guidance. The so-called Orange Book provides useful guidance on Principles and concepts of the management of risk
4. HSE: Risk Management The Health and Safety Executive site provides practical guidance on risk management.
5. The Association of Local Authority Risk Managers (ALARM)
6. The Association of Insurance and Risk Managers
7. The Institute of Risk Management