Modelling crop-growing stages in CLEWs v2

In a CLEWs model for each land-use, the amount of water that goes in (precipitation and irrigation if needed) is equal to the output (evapotranspiration, runoff, and groundwater recharge). Previous CLEWs studies modelled land water requirements using yearly averages. However, despite this simplification is true for land covers where the vegetations regenerates naturally (such as forest, grassland and water bodies), water needs, and therefore outputs, can change greatly for cropland. Land used for growing crops has an intra-annual variability since crops are planted and harvested regularly within the year. Depending on the season, crops’ water requirements can be three times more if we are in the growing stage than the harvested phase. Rainfall precipitation patterns are forecasted to increase their variability due to climate change impact. The increased variability might lead to a mismatch in water availability and supply if water scarcity occurs when there is a higher water requirement from the crops. Because of that, we modelled seasonal crop-growth stages in order to represent variable water demand.