Using insights from water isotopes to improve simulation of surface water-groundwater interactions

Tina Jafari; Anthony S Kiem; Saman Javadi; Takashi Nakamura; Kei Nishida

doi:10.1016/j.scitotenv.2021.149253

Using insights from water isotopes to improve simulation of surface water-groundwater interactions

Sci Total Environ. 2021 Dec 1:798:149253. doi: 10.1016/j.scitotenv.2021.149253. Epub 2021 Jul 27.

Authors

Tina Jafari¹, Anthony S Kiem², Saman Javadi³, Takashi Nakamura⁴, Kei Nishida⁴

Affiliations

¹ Centre for Water, Climate and Land (CWCL), School of Environmental and Life Sciences, College of Engineering, Science and Environment (CESE), University of Newcastle, Callaghan, NSW 2308, Australia. Electronic address: Tina.Jafari@uon.edu.au.
² Centre for Water, Climate and Land (CWCL), School of Environmental and Life Sciences, College of Engineering, Science and Environment (CESE), University of Newcastle, Callaghan, NSW 2308, Australia.
³ Department of Water Engineering, College of Aburaihan, University of Tehran, Tehran, Iran. Electronic address: javadis@ut.ac.ir.
⁴ Interdisciplinary Centre for River Basin Environment, University of Yamanashi, Yamanashi 400-8511, Japan.

PMID: 34375237
DOI: 10.1016/j.scitotenv.2021.149253

Abstract

Understanding interactions between surface water (SW) and groundwater (GW) is challenging because of the lack of information available and the complexity of the processes involved. In this paper, SW-GW interactions are simulated using numerical modelling integrated with insights from water isotopes. Isotope analysis can be used to (i) determine the relative contribution from different sources of water into aquifer recharge and (ii) identify areas with high SW-GW interactions. The results, for the Shiraz catchment in Iran, show that (i) SWAT-MODFLOW has better performance than stand-alone SWAT (R² improvement from 0.50 to 0.54) and (ii) SWAT-MODFLOW calibrated with insights from isotope data (SWAT-MODFLOW-ISO) has significantly better performance than SWAT-MODFLOW (R² improvement from 0.54 to 0.68 and RMSE reduction from 1.67 to 1.33). This demonstrates that insights into SW-GW interactions that are revealed by isotopes can be used to improve hydrological modelling performance.

Keywords: Integrated modelling; SWAT; SWAT-MODFLOW; Water isotope.

MeSH terms

Groundwater*
Hydrology
Isotopes
Water Supply
Water*

Substances

Isotopes
Water