Short term evaporation estimation in a natural semiarid environment: New perspective of the Craig – Gordon isotopic model

• Published in: Journal of hydrology (Amsterdam) 2020-08, Vol.587, p.124926, Article 124926
• Main Authors: Hernández-Pérez, Eliseo, Levresse, Gilles, Carrera-Hernández, Jaime, García-Martínez, Rocio
• Format: Article
• Language: English
• Subjects: Craig-gordon model; Evaporation; Penman-monteith equation; Semi-arid areas; δ2H-δ18O stable isotopes
• ISSN: 0022-1694; 1879-2707
• DOI: 10.1016/j.jhydrol.2020.124926

•We present a physic and isotopic characterization of bi annual atmospheric vapor evolution.•We present an isotopic characterization of annual water pool evaporation in semi arid environment.•We compare physic and isotopic determination of evaporation equations in semi arid environment.•We illustrate the time function isotopic evaporation estimation and it seasonal significances.•We propose an adequate mathematical function to fit the isotopic evaporation seasonal variation. Evaporation is one of the most important processes in the hydrologic cycle and is considered as one of the lead factors governing climate in terrestrial environments, particularly in arid areas. In natural open systems, evaporation should be considered as a time dependent function and a cumulative process. We applied and compared Craig-Gordon isotopic model with the Penman-Monteith physical evaporation model, after a biannual hydrologic cycle characterization in a natural semi-arid environment to determine annually reliable balance budgets and estimations. Our results show that isotopic evaporation rates reflect a sinusoidal behavior during isotopic fractioning rather than a lineal and constant evaporation rate. This sinusoidal behavior exhibits the influence of solar radiation and other meteorological variables that have not yet been considered in the C-G isotopic mass balance model. The estimation of isotopic evaporation in natural environments are reliable during the dry season while estimations of isotopic loss fraction (f) in the wet season behave as an isotopic mixing model of evaporated water-precipitation-runoff. Physical and isotopic methodologies are difficult to relate due to basic fundamentals and development conceptualizations: accordingly, further work is required to enhance the Craig-Gordon and Gonfiantini evaporation model and its relationship with physical methodologies in order to improve the estimation of evaporation in natural semiarid environments.