Underground rock that can hold water, and can therefore be a source of water (definition to be refined)


Water in lakes, rivers and groundwater, as opposed to green water (definition to be refined)


Number of people that can be supported by the available resources

The area of land that drains to a particular location in the landscape (definition to be refined)


Producing freshwater by removing salt

Volume of water flowing in a river channel per unit of time (e.g. m3/s)


Difficulty in accessing water for economic reasons, e.g. cost, effort required (definition to be refined)

Benefits that humans gain from the natural environment (definition to be refined)

Flow needed in a river channel or floodplain to sustain a properly functioning ecosystem (definition to be refined)

Liquid water that becomes vapor, returning to the atmosphere (definition to be refined)


The ability to provide sufficient food to meet needs, either by production or trade. Food production is a major water user globally.  (definition to be refined)


Rain and soil water that evaporates rather than infiltrating into groundwater or flowing as runoff to lakes and rivers.


A household's personal experience of their water needs

Risk of political tensions associated with water issues


Water that enters the soil from the surface (definition to be refined)

Transfer of water between river basins, between which water would not usually flow.

The use of water withdrawn from lakes, rivers or aquifers to increase soil moisture for vegetation planted by humans, especially crops. (definition to be refined)


Changes to how land is used. In terms of water scarcity, we are particularly interested in how these changes affect runoff, infiltration and evaporation, as well as how the changes might have been influenced by water users. (definition to be refined)


Water levels that need to be maintained in lakes, rivers, or aquifers

Minimal levels of water quality that need to be maintained in a water body (e.g. lake, river or aquifer). Lowering water volumes tends to worsen water quality. (Definition to be refined)


Insufficient water to meet both human and ecosystem needs (definition to be refined)


Water that has been withdrawn from a water body that has not been consumed, and therefore returns to a water body (not necessarily the same one) (definition to be refined)

An area of land from which water drains to a common outlet (definition to be refined)

Water that does not infiltrate or evaporate (definition to be refined)


A method to produce freshwater by removing salt from seawater. Water is forced through a filter (a membrane), leaving salt behind.

Water in the soil (definition to be elaborated)

A number of definitions exist.

A collection of 17 global goals set by the United Nations Development Programme (definition to be refined)


Upstream water dependency occurs if water from upstream is needed to avoid scarcity.


The reliance on imported goods and services to meet local needs, without which water scarcity would occur (definition to be refined)


The division of available water between users (definition to be refined)

Water that can be used by humans in a given location and time period (definition to be refined)

Conflicts in which water plays a central role (definition to be refined)

Water that either evaporates or is incorporated into products (definition to be refined)

Cooperation between actors (e.g. countries) regarding use of water (definition to be refined)

Used to move or store water (definition to be refined)

A multi-faceted concept related to ensuring sufficient water supply

The ability to ensure water supply to meet needs in the future (definition to be refined)

Flow of water in the atmosphere, in the form of water vapor.

Water withdrawn from lakes, rivers or aquifers