FAO-56 Crop Water Requirement Mapper
Maps FAO-56 crop water requirement (ETo, ETc, effective rainfall, net irrigation) for fields and points using global climate data.
Computes the FAO-56 crop water requirement chain for each field (polygon) or point: daily Penman-Monteith reference evapotranspiration ETo from NASA POWER climate data (downloaded automatically, no API key), single crop coefficient ETc = Kc x ETo with FAO-56 Table 11 stage lengths and Table 12 Kc values (checked against the printed publication), effective rainfall and net irrigation requirement in mm and m3 per dekad (CROPWAT-like) or per day. Runs as a Processing algorithm (batch and Graphical Modeler), writes a styled result layer, optional daily/dekad CSV files and an HTML run report with method, data source and warnings. Unlike Hargreaves-based tools it uses the full Penman-Monteith method; the calculation core is pure Python with unit tests against the FAO-56 worked examples. Experimental: climate data is a coarse global grid and no soil water balance is modelled yet.