Guidance

National Risk Register of Civil Emergencies chapter 3: methodology

Published 27 March 2015

This guidance was withdrawn on

This page is superseded by the National Risk Register 2020.

© Crown copyright 2015

This publication is licensed under the terms of the Open Government Licence v3.0 except where otherwise stated. To view this licence, visit nationalarchives.gov.uk/doc/open-government-licence/version/3 or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email: psi@nationalarchives.gov.uk.

Where we have identified any third party copyright information you will need to obtain permission from the copyright holders concerned.

This publication is available at https://www.gov.uk/government/publications/national-risk-register-for-civil-emergencies-2015-edition/national-risk-register-of-civil-emergencies-chapter-3-methodology

Previous National Risk Register of Civil Emergencies chapter 2: risk summaries

The National Risk Register of Civil Emergencies risk matrices

Where possible, risks are shown individually on the matrices as they appear in the National Risk Assessment (NRA). Due to the sensitivity of some of the information included in the National Risk Register of Civil Emergencies (NRA), some risks, particularly those concerning terrorist or malicious attacks, are grouped into categories (such as ‘terrorist attacks on crowded places’) rather than indicating their exact position in the NRA. These categories are shown in bold text on the matrices.

When seeking to place categories of risks within the matrix efforts are made to ensure that a position is selected that best represents a category’s spread. Particular focus is applied to the impact scores of risks within these categories, to make sure that the most serious risks are not undervalued. The positioning of these categories is kept under review, and updated as necessary.

Risks not shown in bold text in the risk matrices mirror their positions within the NRA.

How are civil emergency risks within the NRA and NRR identified?

This is done by consulting experts in government departments, devolved administrations and beyond, who between them can identify instances of possible major accidents, natural events (hazards) and malicious attacks (threats) that are reasonably likely to happen, and could cause significant harm and disruption in the UK in the next 5 years. A ‘reasonable worst case’ is chosen which represents a challenging manifestation of the scenario after highly implausible scenarios are excluded.

In the NRA, this consultation has produced a list of some 80 types of event that would meet the definition of a civil emergency given in the Civil Contingencies Act 2004 (referred to hereafter as ‘the act’). A further 40 or so are placed on a reserve list because, although they have been judged not to meet the definition, experts consider that they may do so in the future and need therefore to be kept under review.

The NRA and the NRR therefore cover:

  • all kinds of emergency that meet the definition given in the act but not every conceivable instance of an emergency, and not everyday occurrences — such as street crime — that can cause extended misery and damage over a long period of time but are not ‘emergencies’ within the meaning of the act
  • risks that are likely to happen in the next 5 years
  • risks of emergencies that directly and significantly damage human welfare or the environment somewhere in the UK, but not events that happen overseas unless they directly affect the UK.

Risks that are considered but excluded are kept under review and are reconsidered for inclusion in the NRR (and NRA), on the basis of the best available evidence.

The NRR and NRA cover only emergency events and do not include longer- term trends such as technological advances, climate change, or antimicrobial resistance within their risk matrices.

How are the likelihoods of civil emergencies assessed?

The NRA and NRR estimate the likelihood of events happening within a broad range. The likelihood scale used increases exponentially by an order of magnitude per step of the scale (ie it is logarithmic). For some risk scenarios, data such as historical analysis and numeric modelling can be used to inform estimates of likelihood (especially for naturally and accidentally occurring hazards). Scientific expertise is also sought to inform the development and review of risks. Where this is possible, a combination of this analysis and expert judgement is used to estimate the approximate likelihood of the event or situation occurring.

The likelihood of terrorist or other malicious attacks is assessed more subjectively. The willingness of individuals or groups to carry out attacks is balanced against an objective assessment of their capability — now and, as far as possible, over the next 5 years — and the vulnerability of their potential targets.

To demonstrate the different approach to the assessment of likelihood for hazard and threat risks, hazards and threats are shown on 2 separate risk matrices. The 2 scales are not directly comparable with one another; however, for the purposes of planning, a hazard or threat in the top right quadrant of either matrix would be given the same priority.

How are the impacts of civil emergencies assessed?

The NRA and NRR take account of the definition of an emergency given in the act in assessing the expected consequences of an emergency as follows:

  • the number of fatalities that are directly attributable to the emergency
  • illness or injury over the period following the onset of the emergency
  • levels of social disruption to people’s daily lives, from an inability to gain access to healthcare or schools to interruptions in supplies of essential services such as food, water and fuel, and the need for evacuation of individuals from an area
  • economic harm – the effect on the economy overall, rather than the cost of repairs
  • the psychological impact that emergencies may have, including widespread anxiety, loss of confidence or outrage that communities may experience

Each of the dimensions listed above is scored on a scale of 0 to 5. The overall impact is the mean of these 5 scores.

Local preparations for emergencies

Most emergencies are best managed by local emergency responders and emergency planners. The act provides a common framework for their planning, putting a duty on emergency planners and responders to identify and assess the risks of emergencies affecting the area in which they operate. The work of identifying potential risks and preparing plans for either preventing or mitigating the impact of incidents locally is coordinated through local resilience forums (LRFs). LRFs are multi-agency partnerships made up of representatives from local public services, including the emergency services, local authorities, the NHS and the Environment Agency. LRFs are supported by other organisations such as the Highways Agency and public utility companies. In Scotland, the role of LRFs is fulfilled by regional resilience partnerships.

The UK government provides guidance on the planning and preparing work coordinated by LRFs based on the NRA, as does the Scottish government in respect of matters devolved to the Scottish Parliament. Many local communities also plan for emergencies and they will want to think about developing their own local risk register as part of their community emergency plan. Further information about LRFs can be found on GOV.UK.

National preparations for emergencies

For each of the types of risk in chapter 2, a lead government department is identified and is responsible for the day-to-day policy oversight and the coordination, support and overall management of the central government response to an emergency. In Northern Ireland, Scotland and Wales, if the matter is devolved, the devolved administration performs the lead government department function.

For emergencies on a larger scale, the UK government has developed:

Wales and Northern Ireland all have their own resilience arrangements but these are broadly consistent with those outlined above. Details on their civil protection arrangements can be found at:

Back to top