15-Evapotranspiration in Hydrological Modeling.

Abstract

Potential evaporation is one of the important inputs to hydrological models and actual evapotranspiration is one of the important output components of hydrological models. In general evapotranspiration provides the second largest quantity in a hydrological water balance. Accurate spatial and temporal predictions of evapotranspiration are required for hydrologic models. Research on the development and application of evaporation calculation methods at different complexity and climates has been carried out since the 19th century. As a result, a great deal of experience on various models and methods has been gained. This paper reviews these methods and discusses flexibility with different data availabilities. The applicability and limitations of the methods are addressed. The main purpose of the paper is to provide the readers with more or less a complete list of operational methods that are widely used by hydrologists and water resources engineers for calculating free water evaporation, potential/reference evapotranspiration, and regional actual evapotranspiration.