Assessment of Climate-Based Agricultural Water Balance in East Kalimantan Province

The objectives of this study were to develop a soil water balance model for calculating the amount of water held in field storage. In dry land crop cultivation, water is the main source for plant grow and most determining limiting factor. This study conducted a Thornthwaite-Mather water balance analysis in the watershed in order to understand its hydrology capability. Components of the water balance are the existing amount of stored water, rainfall, and evapotranspiration. The result of the study show that fluctuation water balanced at East Kalimantan have 9 months water surplus with total 223 mm year-1, and the dry months begins in 3 months, August tends to be the driest month in the year with total deficit value reaches 72 mm year-1. Still, the annual rainfall is higher than the annual evapotranspiration.