3.2 Climate
The climate data needed as input to CROPWAT model has been taken from Thai Meteorological Department [14]. The climate data for each province contains temperature ( ), humidity (%), wind (km/day) and sunshine (hours).
3.3 Crop parame
The crop parameters is required for input to CROPWAT model are the crop coefficients (Kc) different crop development stage, the length of growth stage, the root depth, the planting date. The Kc was evaluated by the Penman-Monteith equation used data from Royal Irrigation Department [8] (Table 2).
Table 1 Area, production and yield by province of sugarcane and cassava. Period: 2008 – 2010