All definitions are adapted from Disaster Resilient Infrastructure Lexicon and the Sendai Framework Terminology on Disaster Risk Reduction unless stated otherwise.

Average Annual Loss (AAL)

A measure of annualized future losses over the long term, derived from probabilistic risk models (UNISDR, 2013).

Basic infrastructure

Infrastructure that provides services considered fundamental for human development, growth, safety, and security.

Climate adaptation

Adjustments in ecological, social, or economic systems in response to actual or expected climatic stimuli and their effects. It refers to changes in processes, practices and structures to moderate potential damages or to benefit from opportunities associated with climate change (UNFCCC, n.d. a).

Climate change

A change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods (UNFCCC, 1992).

Climate finance

Local, national or transnational financing, drawn from public, private and alternative sources of financing, that seeks to support mitigation and adaptation actions that will address climate change (UNFCCC, n.d. b).

Contingent liability

Potential liability that may occur in the future depending on the disaster-related outcome of a hazard impact. In disaster risk evaluations, contingent liability refers to future projected damage and loss that must be paid for by the government, individuals, private sector, or others.

Critical infrastructure

The physical structures, facilities, networks, and other assets, which provide services that are indispensable to the social and economic functioning of society, and which are necessary for managing disaster risk.

Disaster risk management

The application of disaster risk reduction policies and strategies to prevent new disaster risk, reduce existing disaster risk and manage residual risk, contributing to the strengthening of resilience and reduction of disaster losses. Disaster risk management actions can be distinguished between prospective disaster risk management, corrective disaster risk management and compensatory disaster risk management, also called residual risk management.
right-arrowProspective disaster risk management activities address and seek to avoid the development of new or increased disaster risks. They focus on addressing disaster risks that may develop in future if disaster risk reduction policies are not put in place. Examples are better land use planning or disaster-resistant water supply systems.
right-arrowCorrective disaster risk management activities address and seek to remove or reduce disaster risks which are already present, and which need to be managed and reduced now. Examples are the retrofitting of critical infrastructure or the relocation of exposed populations or assets.
right-arrowCompensatory disaster risk management activities strengthen the social and economic resilience of individuals and societies in the face of residual risk that cannot be effectively reduced. They include preparedness, response, and recovery activities, but also a mix of different financing instruments, such as national contingency funds, contingent credit, insurance and reinsurance and social safety nets.

Disaster risk

The potential loss of life, injury, and/or destroyed and damaged assets, which could occur in a system, society, or community in a specific period, determined probabilistically as a function of hazard, exposure, vulnerability and capacity.
right-arrowExtensive risk, the risk of low-severity, high-frequency hazardous events and disasters, mainly but not exclusively associated with highly localized hazards.
right-arrowIntensive risk, the risk of high-severity, mid- to low-frequency disasters, mainly associated with major hazards.

Essential services

The services provided by infrastructure, such as water and wastewater, power and energy, transport, telecommunications, health, and education that are essential for social and economic development. (Definition adopted in this Report)

Grey infrastructure

Engineered physical structures that underpin energy, transport, communications (including wireless and digital), built form, water and sanitation, and solid-waste management systems and that protect human lives and livelihood.


Individual assets, networks and systems that provide specific services to support the functioning of a community or society.

Infrastructure lifecycle

The series of stages during the lifetime of an infrastructure asset, starting from planning, prioritization and funding to the design, procurement, construction, operation, maintenance, and decommissioning.

Infrastructure governance

The capacity to plan, finance, design, implement, manage, operate, and maintain infrastructure systems (Hertie School of Governance, 2016).

Infrastructure maintenance

Maintenance is a cycle of activities designed and undertaken to preserve the optimal functioning of infrastructure, including in adverse conditions. It is a necessary precondition for the preservation of its operational capability, and to guarantee service continuity.

Infrastructure systems

Arrangements of infrastructure components and linkages that provide a service or services.

Local infrastructure systems