Actual evapotranspiration

Evapotranspiration that actually occurs when the water available for this process is limited (see potential evapotranspiration).


The process of adjustment to actual or expected climate and its effects. In  human systems, adaptation seeks to moderate or avoid harm or exploit beneficial opportunities. In some natural systems, human intervention may facilitate adjustment to expected climate and its effects. Source:

Adaptation assessment

The practice of identifying options to adapt to climate change and evaluating them in terms of criteria such as availability, benefits, costs, effectiveness, efficiency, and feasibility. Source:

Blue water production

The part of the rainfall that becomes runoff that does not evaporate naturally nor is stored. This includes the water balance of lakes.


An area that collects and drains precipitation. Source:


A collection of model simulations characterizing a climate prediction or projection. Differences in initial conditions and model formulation result in different evolutions of the modeled system and may give information on uncertainty associated with model error and error in initial conditions in the case of climate forecasts and on uncertainty associated with model error and …

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The combined process of evaporation from the Earth’s surface and transpiration from vegetation. Source:

Grid cell

Smallest unit of the geographical domain covered by a numerical model, such as a climate or a hydrological model. Because of the complexity of the processes they represent and the limitations of computing power, these models divide up their modelling domain into a juxtaposition of “boxes” called grid cells. In the case of a climate …

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Groundwater recharge

Renewable groundwater resources, i.e. the maximum amount of groundwater that could be used without causing a continuing loss of groundwater storage and groundwater table decline.