Limites na utilização de um modelo de balanço hídrico decendial em função da capacidade de água disponível no solo

Abstract

The objective of this work was to evaluate the limitations of a ten-day climatic water balance model to simulate irrigation in four different Paraná State regions. Sixty-eight water balance scenarios were tested to allow the relationship among crop evapotranspiration (ETc), probable precipitation at 75% level (P75%), soil available water capacity (AWC) and annual water deficiency (DEF). The results showed that: the model estimates its components better for greater values of available water (AW) in the soil; the ideal AWC value to process the irrigation analyses based on variations of ETo, Kc and ETc should be established in the model itself. However, if the condition "larger ten-day ETo ≤ AW" of the period is valid, the water balance produces consistent results for 10 days periodicity.