Resilience Glossary: P – T

Term

Definition

Source

Pan seal

A pan sea works in a similar manor to a toilet bung, by creating a watertight cap around the inside of the main toilet bowl.

Centre for Resilience

Parameters

The parameters in a model are the “constants”, chosen to represent the chosen context and scenario. In general the following types of parameters can be recognised:

·        Exact parameters – which are universal constants, such as the mathematical constant: Pi (3.14259…).

·        Fixed parameters – which are well determined by experiment and may be considered exact, such as the acceleration of gravity, g (approximately 9.81 m/s).

·        A-priori chosen parameters – which are parameters that may be difficult to identify by calibration and so are assigned certain values. However, the values of such parameters are associated with uncertainty that must be estimated on the basis of a-priori experience, for example detailed experimental or field measurements

·        Calibration parameters – which must be established to represent particular circumstances. They must be determined by calibration of model results for historical data on both input and outcome. The parameters are generally chosen to minimise the difference between model outcomes and measured data on the same outcomes. It is unlikely that the set of parameters required to achieve a “satisfactory” calibration is unique.

FLOODsite

Passive defence

The opposite of a manual defence, a passive defence will require no human interaction in order to successfully complete its functioning task. This is often a resistance approach (E.g. a passive flood door).

Centre for Resilience

Pathway

Route that a hazard takes to reach Receptors. A pathway must exist for a Hazard to be realised.

FLOODsite

Perception

The way in which something (FRe technology/systems), understood or interpreted. (OED)

SMARTeST

Performance

The degree to which a process or activity succeeds when evaluated against some stated aim or objective.

FLOODsite

Performance indicator

The well-articulated and measurable objectives of a particular project or policy. These may be detailed engineering performance indicators, such as acceptable wave overtopping rates, rock stability, or conveyance capacity or more generic indicators such as public satisfaction

FLOODsite

Permeable paving

Hard surfaces capable of allowing water to pass through and be retained beneath it.

FMMEP

Pervious surfaces

Surfaces that allow inflow of rainwater into the underlying construction or soil.

FMMEP

Pipes and Accessories

A series of conduits and their accessories normally laid underground that convey surface water to a suitable location for treatment and/or disposal. (Although sustainable, these techniques should be considered where other SUDS techniques are not practicable).

FMMEP

Planning instrument

Planning instruments are maps or plans for formulating future goals in a specific area. It can consist of one or more maps and text.

FMMEP

Pluvial flooding

Rainfall-generated overland flow ponding on the urban surface because it overwhelms urban underground sewerage/drainage systems and surface watercourses by its high intensity or is for some reasons unable to enter drainage system or water courses.(ten Veldhuis 2010)

SMARTeST

Poll

A series of questions asked of a group of people in order to find out what they think about particular subject or how they will vote in an election

FMMEP

Porosity

The state or quality of being porous, expressed as a percentage, of the volume of the pores or interstices of a substance, as a rock or rock stratum, to the total volume of the mass.

Dictionary.com

Post-Flood Mitigation:

Measures and instruments after flood events to remedy flood damages and to avoid further damages.

FLOODsite

Precautionary Principle

Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation

FLOODsite

Precision

Degree of exactness regardless of accuracy.

FLOODsite

Pre-Flood Mitigation:

Measures and instruments in advance to a flood event to provide prevention (reducing flood hazards and flood risks by e.g. planning) and preparedness (enhancing organizational coping capacities).

FLOODsite

Preparedness

The ability to ensure effective response to the impact of hazards, including the issuance of timely and effective early warnings and the temporary evacuation of people and property from threatened locations.

FLOODsite

Preparedness Strategy

Within the context of flood risk management a preparedness strategy aims at ensuring effective responses to the impact of hazards, including timely and effective early warnings and the evacuation of people and property from threatened locations

FLOODsite

Probabilistic method

Method in which the variability of input values and the sensitivity of the results are taken into account to give results in the form of a range of probabilities for different outcomes.

FLOODsite

Probabilistic reliability methods

These methods attempt to define the proximity of a structure to fail through assessment of a response function.

FLOODsite

Probability

A measure of our strength of belief that an event will occur. For events that occur repeatedly the probability of an event is estimated from the relative frequency of occurrence of that event, out of all possible events.

FLOODsite

Probability density function (distribution)

Function which describes the probability of different values across the whole range of a variable (for example flood damage, extreme loads, particular storm conditions etc.).

FLOODsite

Process model uncertainty:

All models are an abstraction of reality and can never be considered true. They are subject to process model uncertainty. Measured data versus modelled data comparisons give an insight into the extent of model uncertainty but do not produce a complete picture.

FLOODsite

Progressive failure

Failure where, once a threshold is exceeded, significant (residual) resistance remains enabling the defence to maintain restricted performance. The immediate consequences of failure are not necessarily dramatic but further, progressive, failures may result eventually leading to a complete loss of function.

FLOODsite

Project Appraisal

The comparison of the identified courses of action in terms of their performance against some desired ends.

FLOODsite

Property level protection (PLP)

Property Level Protection, or PLP as it is often called, refers to inter-dependent product-based measures that can be taken to mitigate flood risk to a residential property.

UK Flood Barriers

Proportionate methods

Provide a level of assessment and analysis appropriate to the importance of the decision being made.

FLOODsite

Proprietary uncertainty

Indicates contested rights to know, to warn or to secrete. In both risk assessment and management, there are often considerations about the rights of different people to know, to warn or to conceal

FLOODsite

Random events

Events which have no discernible pattern.

FLOODsite

Receptor

Receptor refers to the entity that may be harmed (a person, property, habitat etc.). For example, in the event of heavy rainfall (the source) floodwater may propagate across the flood plain (the pathway) and inundate housing (the receptor) that may suffer material damage (the harm or consequence). The vulnerability of a receptor can be modified by increasing its resilience to flooding.

FLOODsite

Record (in context)

Not distinguished from event (see Event)

FLOODsite

Recovery capacity

The ability, or power to return to the original state, e.g. the capacity to recover (NL + OED)

SMARTeST

Recovery time

The time taken for an element or system to return to its prior state after a perturbation or applied stress.

FLOODsite

Reliability

The ability to be reliable. Reliable: constantly good quality or performance, trustworthy. (NL + OED)

SMARTeST

Reliability index

A probabilistic measure of the structural reliability with regard to any limit state.

FLOODsite

Relocating the building

Moving a building out of the floor area, a kind of flood proofing measures.

FMMEP

Remote Sensing

The observation of the earth or atmosphere from space with satellites or from the air using aircrafts is called Remote Sensing.

FMMEP

Representation

The action of speaking or acting on behalf of someone (OED)

SMARTeST

Representative

Typical (OED)

SMARTeST

Residual flood probability

An estimate of the chance of flooding taking place, taking account of the protection afforded by defences

FLOODsite

Residual life

The residual life of a defence is the time to when the defence is no longer able to achieve minimum acceptable values of defined performance indicators (see below) in terms of its serviceability function or structural strength.

FLOODsite

Residual life

The residual life of a defence is the time to when the defence is no longer able to achieve minimum acceptable values of defined performance indicators (see below) in terms of its serviceability function or structural strength.

UFM

Residual risk

The risk that remains after risk management and mitigation measures have been implemented. May include, for example, damage predicted to continue to occur during flood events of greater severity that the 100 to 1 annual probability event.

FLOODsite

Resilience

Resilience is defined as the capacity for the built environment to recover quickly from difficulties. In the built environment, it is the ability for infrastructure and society to withstand and recover from extreme events.

Centre for Resilience

Resilience, social

The capacity of a community or society potentially exposed to hazard to adapt, by resisting or changing in order to reach and maintain an acceptable level of functioning and structure. This is determined by the degree to which the social system is capable of organising itself to increase its capacity for learning from past disasters for better future protection and to improve risk reduction measures.

UFM

Resistance

The ability of a system to remain unchanged by external events.

FLOODsite

Response (in context)

The reaction of a defence or system to environmental loading or changed policy.

FLOODsite

Response function

Equation linking the reaction of a defence or system to the environmental loading conditions (e.g. overtopping formula) or changed policy.

FLOODsite

Retrofitting

Retrofitting describes the upgrading of an existing building to increase safety by adding or replacing items. This could be done by any combination of changes or adjustments incorporated in the design, construction, or alteration of individual buildings or properties. The reinforcement of structures tends the only aim to become more resistant and resilient to the forces of natural hazards. Retrofitting techniques involves flood-proofing, elevation, construction of small levees, and other modifications made to an existing building or its yard to protect it from flood damage.

FMMEP

Return period

The expected (mean) time (usually in years) between the exceedance of a particular extreme threshold. Return period is traditionally used to express the Frequency of occurrence of an event, although it is often misunderstood as being a probability of occurrence.

FLOODsite

Rising damp

Capillary movement of moisture from the ground into the walls of buildings. It results in structural damage up to a level of three feet

The Free Dictionary

Risk

Risk is a function of probability, exposure and vulnerability. Often, in practice, exposure is incorporated in the assessment of consequences, therefore risk can be considered as having two components — the probability that an event will occur and the impact (or consequence) associated with that event. Often this is abbreviated as Risk = Probability multiplied by consequence

FLOODsite

Risk acceptance

Risk acceptance describes the willingness to tolerate a risk, whereby the acceptable risk refers to the level of loss a society or community considers acceptable given existing social, economic, political, cultural, technical and environmental conditions.

FMMEP

Risk analysis

A methodology to objectively determine risk by analysing and combining probabilities and consequences

FLOODsite:

Risk assessment

Comprises understanding, evaluating and interpreting the perceptions of risk and societal tolerances of risk to inform decisions and actions in the flood risk management process

FLOODsite

Risk communication (in context)

Any intentional exchange of information on environmental and/or health risks between interested parties.

FLOODsite

Risk management

The complete process of risk analysis, risk assessment, options appraisal and implementation of risk management measures

FLOODsite

Risk management measures

An action that is taken to reduce either the probability of flooding or the consequences of flooding or some combination of the two.

FLOODsite:

Risk mapping

The process of establishing the spatial extent of risk (combining information on probability and consequences). Risk mapping requires combining maps of hazards and vulnerabilities. The results of these analyses are usually presented in the form of maps that show the magnitude and nature of the risk.

FLOODsite

Risk perception

Risk perception is the view of risk held by a person or group and reflects cultural and personal values, as well as experience.

FLOODsite

Risk profile

The change in performance, and significance of the resulting consequences, under a range of loading conditions. In particular the sensitivity to extreme loads and degree of uncertainty about future performance.

FLOODsite

Risk reduction

The reduction of the likelihood of harm, by either reduction in the probability of a flood occurring or a reduction in the exposure or vulnerability of the receptors.

FLOODsite

Risk register

An auditable record of the project risks, their consequences and significance, and proposed mitigation and management measures.

FLOODsite

Risk significance (in context)

The separate consideration of the magnitude of consequences and the Frequency of occurrence.

FLOODsite

River catchment

The river catchment, or drainage basin, is all the land from the mountain to the seashore, drained by a single river and its tributaries (NL/www)

SMARTeST

Robustness

Capability to cope with external stress. A decision is robust if the choice between the alternatives is unaffected by a wide range of possible future states of nature. Robust statistics are those whose validity does not depend on close approximation to a particular distribution function and/or the level of measurement achieved.

FLOODsite

Scale

Difference in spatial extent or over time or in magnitude; critical determinant of vulnerability, resilience etc.

FLOODsite

Scenario

A plausible description of a situation, based on a coherent and internally consistent set of assumptions. Scenarios are neither predictions nor forecasts. The results of scenarios (unlike forecasts) depend on the boundary conditions of the scenario.

FLOODsite:

Sea level rise

An increase of the relative mean sea level (Esteban)

SMARTeST

Sea water floods/flooding

Inundation of land areas adjacent to the coast solely by sea waters over and above the level normally wetted by sea water (Toumazis/NL)

SMARTeST

Sealing

Sealing is a dry proofing technique where the floodwater does not reach the interior of the building as the external walls and openings are sealed and used to hold back the floodwater

FMMEP

Security resilience

In our increasingly digital world, the way we operate and secure our buildings, homes and infrastructure, is highly dependent on resilient technology. Security resilience explores a range of issues around making our technology robust, protecting data and ensuring quality building performance.

Centre for Resilience

Sensitivity

Refers to either: the resilience of a particular receptor to a given hazard. For example, frequent sea water flooding may have considerably greater impact on a fresh water habitat, than a brackish lagoon; or: the change in a result or conclusion arising from a specific perturbation in input values or assumptions.

FLOODsite

Sensitivity Analysis

The identification at the beginning of the appraisal of those parameters, which critically affect the choice between the identified alternative courses of action.

FLOODsite

Severe flood warning

A severe flood warning indicates that there is a severe risk of flooding with a possible danger to life.

Centre for Resilience

Severity

Refers to either: the resilience of a particular receptor to a given hazard. For example, frequent sea water flooding may have considerably greater impact on a fresh water habitat, than a brackish lagoon; or: the change in a result or conclusion arising from a specific perturbation in input values or assumptions.

FLOODsite

Shielding

Shielding is a dry proofing strategy where flood barriers are installed at some distance from the building or a group of properties. free standing barriers or anchored barriers (pillars temporarily fixed at a concrete plate) are usually used

FMMEP

Smart technologies

Technology that responds to and reacts to flood incidents with minimal human intervention.  Smart technology has defined uses and performance measures and should be assessed through recognised testing methods and quality assurance. (Garvin)

SMARTeST

Social

This can be defined as the characteristics of a person or group in terms of their capacity to anticipate, cope with, resist, and recover from the impact of a natural hazard.

FLOODsite

Social learning

Processes through which the stakeholders learn from each other and, as a result, how to better manage the system in question.

FLOODsite

Social resilience

The capacity of a community or society potentially exposed to hazards to adapt, by resisting or changing in order to reach and maintain an acceptable level of functioning and structure. This is determined by the degree to which the social system is capable of organising itself to increase its capacity for learning from past disasters for better future protection and to improve risk reduction measures.

FLOODsite

Source

The origin of a hazard (for example, heavy rainfall, strong winds, surge etc.).

FLOODsite

Spatial planning

Public policy and actions intended to influence the distribution of activities in space and the linkages between them. It will operate at EU, national and local levels and embraces land use planning and regional policy

FLOODsite

Stakeholder Engagement

Process through which the stakeholders have power to influence the outcome of the decision. Critically, the extent and nature of the power given to the stakeholders varies between different forms of stakeholder engagement.

FLOODsite

Stakeholders

Parties/persons with a direct interest (stake) in an issue.

FLOODsite

Standard of service

The measured performance of a defined performance indicator.

FLOODsite

Standards

Standards cover a wide range of subjects from construction to nanotechnology, from energy management to health and safety, from cricket balls to goalposts. They can be very specific, such as to a particular type of product, or general such as management practices. The point of a standard is to provide a reliable basis for people to share the same expectations about a product or service. This helps to facilitate trade; provide a framework for achieving economies, efficiencies and interoperability; and enhance consumer protection and confidence.

BSI

Statistic

A measurement of a variable of interest which is subject to random variation.

FLOODsite

Statistical inference uncertainty:

Formal quantification of the uncertainty of estimating the population from a sample. The uncertainty is related to the extent of data and variability of the data that make up the sample.

FLOODsite

Statistical model uncertainty:

Uncertainty associated with the fitting of a statistical model. The statistical model is usually assumed to be correct. However, if two different models fit a set of data equally well but have different extrapolations/ interpolations then this assumption is not valid and there is statistical model uncertainty.

FLOODsite

Storm surges

An elevation of sea level caused by a combination of change in atmospheric pressure, currents, waves and the topography of the coastal shelf. (NL from web and other descriptions + input from Esteban)

SMARTeST

Strategic spatial planning

Process for developing plans explicitly containing strategic intentions referring to spatial development. Strategic plans typically exist at different spatial levels (local, regional etc.).

FLOODsite

Strategy (flood risk management)

A strategy is a combination of long-term goals, aims, specific targets, technical measures, policy instruments, and process, which are continuously aligned with the societal context.

FLOODsite

Structural mitigation measures

Measure taken to protect people and property that counteracts the flood event in order to reduce the hazard or to influence the course or probability of occurrence of the event. Often used as synonym for active protection measures.

FMMEP

Sump and pump system

A sump pump is a small pump installed in the lowest part of a basement or crawlspace. Its job is to help keep the area under the building dry and to prevent it from flood­ing. Usually, sump pumps are installed in specially constructed sump pits. Water flows into the sump pit through drains or by natural water migration through the soil. The sump pump’s job is to pump the water out of the pit and away from the building so the basement or crawlspace stays dry.

How Stuff Works – Home and Garden

Susceptibility

The propensity of a particular receptor to experience harm.

FLOODsite

Sustainable development

Sustainable development meets the needs of the present without compromising the ability of future generations to meet their own needs

FLOODsite

Sustainable drainage

Sustainable Drainage Systems: an approach to surface water management that combines a sequence of management practices and control structures designed to drain surface water in a more sustainable fashion than some conventional techniques.

FMMEP

Sustainable flood risk management strategy

An approach which aims to be effective in the long term, and can be combined (`integrated’) with other international, national and regional activities (transport, environment, conservation etc.)

FLOODsite

Swales

Shallow vegetated channels that conduct and retain water, and may also permit infiltration; the vegetation filters particulate matter)

FMMEP

System

An assembly of elements, and the interconnections between them, constituting a whole and generally characterised by its behaviour. Applied also for social and human systems. (FLOODsite).                                                     In the context of SMARTeST, “system” is an all-embracing one covering urban flood under various flood type scenarios (riverine, pluvial, flash, coastal, groundwater, etc.)  and embracing all flood management systems (warning systems, emergency service systems, drainage systems,  flood  risk models, resilience and protection systems, societal and stakeholder issues, flood risk management and governance, etc.) and over various scales from house to street to neighbourhood to city to conurbation to region to country. (Garvin and Lawson)

FLOODsite

System state

The condition of a system at a point in time.

FLOODsite

Temporary defence

A temporary flood barrier is one that is only installed when the need arises (that is, when high flood levels are forecast).

Environment Agency

Test

A procedure intended to establish the quality, performance or reliability of something (NL + OED)

SMARTeST

Threshold capacity

The ability of a society to build up a threshold against variation in order to prevent damage (de Graaf, 2009- supplied by Spekkers).

SMARTeST

Tide

The rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun and the rotation of the Earth (NL/www).

SMARTeST

Tolerability

Refers to willingness to live with a risk to secure certain benefits and in the confidence that it is being properly controlled. To tolerate a risk means that we do not regard it as negligible, or something we might ignore, but rather as something we need to keep under review, and reduce still further if and as we can. Tolerability does not mean acceptability.

FLOODsite

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