Atmospheric water vapor flux convergence and basin water balance

Case study in Chao Phraya river basin, Thailand

Abstract

Atmospheric vapor flux convergence is introduced for the estimation of the water balance in a river basin. Flux convergence is calculated using the ECMWF global analysis data, and compared with the observed data in Chao Phraya river basin, Thailand. Through the balance equation of hydrological cycle, discharge is estimated from vapor flux convergence and is compared with observations. It was found that the absolute value of flux convergence is not applicable, but inclusion of a factor provided better estimation for the case under study. Such information is expected to give basin scale evaporation or water storage in a basin.