Assessment of the reliability to use NASAPOWER gridded weather applied to irrigation planning and management in Brazil

Abstract

The sustainability of irrigated agricultural systems depends on the water use efficiency based on management. The efficiency is reach first by an adequate estimation of crop water demand. However, the lack of weather data is a limitation to plan and estimation irrigation demand in Brazil. This way, the aim of this study was to investigate NASAPOWER gridded system as alternative source of weather data in Brazil. First, we tested how reliable are the meteorological variables between NASAPOWER and ground weather stations. Further, we calculated the maximum number of consecutive dry days within the crop cycle, and the irrigation demand through the soil-crop water balance for nine crops. The performance was investigated through coefficients of determination (r²), agreement (d) and normalized root mean square error (nRMSE). In general, air temperature and incoming solar radiation presented the best statistical metrics (r² ~ 0.53–0.83; d ~ 0.84–0.94; and nRMSE ~ 8.61–23.5%), whereas the wind speed had the worst (r² ~ 0.09; d ~ 0.53; and nRMSE ~ 93%). NASAPOWER figured as a valuable tool for determine the number of dry days and number of irrigation events during the crop cycle. Irrigation demand showed a good relation between NASAPOWER and ground weather station (r² = 0.79 and d = 0.94), but with nRMSE of 53%, due to a higher deviation when irrigation demand is above 200 mm cycle^− 1. NASAPOWER showed potential as source of meteorological information for irrigation management for different cropping systems, where local adjustment could improve performances for crops with long cycle.