Staff Research Highlight - Evaluating the significance of wetland representation in isotope-enabled distributed hydrologic modeling in mesoscale Precambrian shield watersheds
Tafvizi, A., James, A. L., Holmes, T., Stadnyk, T., Yao, H., & Ramcharan, C. (2024). Evaluating the significance of wetland representation in isotope-enabled distributed hydrologic modeling in mesoscale Precambrian shield watersheds. In Journal of Hydrology (Vol. 637, p. 131377). Elsevier BV. https://doi.org/10.1016/j.jhydrol.2024.131377
Aquanty’s very own Arghavan Tafvizi had her PhD research paper “Evaluating the Significance of Wetland Representation in Isotope-Enabled Distributed Hydrologic Modeling in Mesoscale Precambrian Shield Watershed” published in the Journal of Hydrology.
This new study published by Tafvizi, A., Holmes, T., Delavau, C., Carey, S.K., Stadnyk, T.A., and Spence, C., researchers have evaluated the significance of wetland representation in isotope-enabled distributed hydrologic modeling within mesoscale Precambrian shield watersheds.
This research sheds light on the impact of wetland connectivity on streamflow generation and isotope simulation in the Sturgeon River-Lake Nipissing (SN) watershed. Central to the investigation is the application of isoWATFLOOD, an advanced isotope-enabled distributed hydrological model. By leveraging the capabilities of isoWATFLOOD, the researchers were able to explore the effects of varying the percentage of connected wetlands (%CW) on the simulation of hydrological processes and isotope signatures across the watershed.
A key advantage of isoWATFLOOD is its ability to incorporate both streamflow and isotopic data, providing a comprehensive toolkit for analyzing hydrological processes. From simulating streamflow patterns to evaluating the impacts of different wetland connectivity scenarios, isoWATFLOOD allowed researchers to delve into the complexities of hydrological interactions in a heterogeneous watershed.
Abstract:
Evaluation of regional-scale models against both streamflow and stable isotopes of water is a relatively new and evolving area of distributed hydrological modeling. While applications of isoWATFLOOD, an isotope-enabled distributed hydrological model are increasing, evaluation of the impacts of model structural features, such as wetland connectivity, on simulation of runoff components is still limited. Wetlands are important water bodies that impact streamflow generation and its spatial variation in Precambrian shield watersheds in parts of Canada and elsewhere. This study investigates the efficiency of isoWATFLOOD in simulating streamflow and instream δ18O and the effects of model percent connected wetlands (%CW) in a mesoscale (∼12,000 km2) Precambrian Shield watershed in Northeastern Ontario, Canada. Model calibration and validation are performed using daily streamflow for five hydrometric gauging stations and biweekly to monthly instream δ18O from 11 river sampling locations from across the watershed. Five model versions with different %CW are generated, calibrated, and validated separately. Results show all models can simulate the timing and pattern of streamflow and δ18O. %CW impacts simulated streamflow during both calibration and validation periods, calibrated parameter sets and simulated internal hydrological processes. Model performance varies spatially with no single value of %CW providing best performance across sub-catchments with 40 % CW providing best mean streamflow simulations in calibration. Increasing %CW (10 % to 40 %) results in higher contribution of lower soil zone water to streamflow that markedly improves baseflow simulation. This study builds on recent isotope-enabled hydrologic simulation capacity of isoWATFLOOD, contributing new examination of model representation of wetland connectivity, a critical component of Precambrian Shield watersheds and evidence of how stable isotopes can contribute to addressing the challenge of equifinality. Results suggest the need to develop model capability for representation of spatial variation in wetland connectivity to recognize this important aspect of heterogeneity in watersheds influencing hydrologic function.