Long-Term Water Balance for Sugarcane Joining Remote Sensing and Weather Data

Remote sensing parameters were used along with weather data to assess the large-scale sugarcane water balance in Northeast Brazil, using a dataset from 2007 to 2024. Rainfall (P) was spatially quantified from interpolated pluviometer data and actual evapotranspiration (ET) was estimated using the SAFER algorithm. Considering the sugarcane crop areas for each year, the mean annual P varied from 8555 million cubic meters in 2009 to 3172 million cubic meters in 2021. Regarding ET, it varied from 5869 million cubic meters in 2007 to 3375 million cubic meters in 2017. The assessments showed time lags of around two months between rainfall water supplies and root zone moisture levels and highlighted the use of evaporative fraction (Ef). Anomalies in P and ET were detected through their standardized indices by comparing the results for the years 2021 to 2024 with the long-term values from 2007 to each of these years, showing that the rainfall water supplies and water fluxes may vary along sugarcane phases and years. It can be concluded that large-scale water balance assessments can potentially serve as the basis for public policies aimed at sustainable crop management and rational expansion in areas with environmental suitability.