Estimation of evaporative loss based on the stable isotope composition of water using Hydrocalculator

Date

2015

Authors

Skrzypek, Grzegorz
Mydłowski, Adam
Dogramaci, Shawan
Hedley, Paul
Gibson, John J.
Grierson, Pauline F.

Journal Title

Journal ISSN

Volume Title

Publisher

Journal of Hydrology

Abstract

Accurate quantification of evaporative losses to the atmosphere from surface water bodies is essential for calibration and validation of hydrological models, particularly in remote arid and semi-arid regions, where intermittent rivers are generally minimally gauged. Analyses of the stable hydrogen and oxygen isotope composition of water can be used to estimate evaporative losses from individual pools in such regions in the absence of instrumental data but calculations can be complex, especially in highly variable systems. In this study, we reviewed and combined the most recent equations required for estimation of evaporative losses based on the revised Craig–Gordon model. The updated procedure is presented step-by-step, increasing ease of replication of all calculations. The main constraints and sources of uncertainties in the model were also evaluated. Based on this procedure we have designed a new software, Hydrocalculator, that allows quick and robust estimation of evaporative losses based on isotopic composition of water. The software was validated against measures of field pan evaporation under arid conditions in northwest Australia as well as published data from other regions. We found that the major factor contributing to the overall uncertainty in evaporative loss calculations using this method is uncertainty in estimation of the isotope composition of ambient air moisture.

Description

Keywords

Evaporation, Stable isotope, Water, Craig-Gordon, Hydrocalculator

Citation

Skrzypek, G., Mydłowski, A., Dogramaci, S., Hedley, P., Gibson, J. J., & Grierson, P. F. (2015). Estimation of evaporative loss based on the stable isotope composition of water using Hydrocalculator. Journal of Hydrology, 523, 781-789. https://doi.org/10.1016/j.jhydrol.2015.02.010.