Glossary

Abstraction
Removal of water from the river for urban, agricultural or industrial use, or for a transfer.

Actual evapotranspiration (ET or AET)
The amount of water actually evaporated or transpired by vegetation according to climate and water availability.

Directed graph
A structure consisting of nodes and connections with a specific direction, in this case the direction of river flow.

Environmental flow
The minimum flow established to maintain the ecological functioning of the river.

Local contribution
Flow generated within a drainage area from the balance between precipitation, evapotranspiration and snow.

Node
A point in the network where flow is generated, modified, stored or assessed.

Overflow
Volume that exceeds the maximum storage capacity and leaves the system.

Potential evapotranspiration (PET)
The evaporative demand of the atmosphere if the available water were not limiting.

Reservoir storage
Volume of water held in the reservoirs.

Return
Water that returns to the river after use, such as effluent from a wastewater treatment plant.

River reach
A connection between two nodes through which flow is routed.

Scenario
A set of modifications applied to the reference conditions.

Unmet demand
The difference between the water requested and the water actually available at a node.