Methodology manual for EO based crop water requirements forecast

The EO methodology for mapping crop water requirements in a pixel by pixel basis is mature and operational by using FAO56 and soil water balance model, in combination with biophysical crop parameters and meteorological data. Consolidation of this approach will be the first step to do, including the implementation of algorithms for separating soil evaporation and canopy transpiration. The improved spectral resolution of new generation of sensors will be exploited to enhance existing methodologies. The forward step is to produce crop water requirements predictions for the next week (maps), which is a very practical product for users in addition to the estimates for the past week. Numerical weather prediction model outputs can be efficiently applied for retrieving reliable forecasts of the reference evapotranspiration, needed for optimization of the irrigation scheduling at farm level. To this end, distributed short term forecasting of relevant meteorological data (from global or high-­‐resolution limited area numerical weather prediction models) can be used as input in the above mentioned crop evapotranspiration models. Having the knowledge of crop water requirements, irrigation can be supplied either to satisfy full requirements, or either to manage a deficit controlled irrigation. Soil moisture measurements will provide all the adequate data to verify, through the soil water balance, the quality of the products.