Average monthly rainfall data (as shown in Tables 1e2) and
reference evapotranspiration data provided by meteorological
services were used, as well as typical irrigation data collected in the
study area. Crop coefficients (Kc) are required to assess actual
evapotranspiration and were drawn from FAO and from local references
by the RID. Kc are linked to four crop growth stages, which
are initial, development, mid-season and ripening stages. The
CropWat platform (FAO, 1992) was used to calculate actual
evapotranspiration.