Preprints
https://doi.org/10.5194/hess-2019-232
https://doi.org/10.5194/hess-2019-232
25 Jun 2019
 | 25 Jun 2019
Status: this discussion paper is a preprint. It has been under review for the journal Hydrology and Earth System Sciences (HESS). The manuscript was not accepted for further review after discussion.

Comparing SWAT with SWAT-MODFLOW hydrological simulations when assessing the impacts of groundwater abstractions for irrigation and drinking water

Wei Liu, Seonggyu Park, Ryan T. Bailey, Eugenio Molina-Navarro, Hans Estrup Andersen, Hans Thodsen, Anders Nielsen, Erik Jeppesen, Jacob Skødt Jensen, Jacob Birk Jensen, and Dennis Trolle

Abstract. Being able to account for temporal patterns of streamflow, the distribution of groundwater resources, as well as the interactions between surface water and groundwater is imperative for informed water resources management. We hypothesize that, when assessing the impacts of water abstractions on streamflow patterns, the benefits of applying a coupled catchment model relative to a lumped semi-distributed catchment model outweigh the costs of additional data requirement and computational resources. We applied the widely used semi-distributed SWAT model and the recently developed SWAT-MODFLOW model, which allows full distribution of the groundwater domain, to a Danish, lowland, groundwater-dominated catchment, the Uggerby River Catchment. We compared the performance of the two models based on the observed streamflow and assessed the simulated streamflow signals of each model when running four groundwater abstraction scenarios with real wells and abstraction rates. The SWAT-MODFLOW model complex was further developed to enable the application of the Drain Package of MODFLOW and to allow auto-irrigation on agricultural fields and pastures. Both models were calibrated and validated, and an approach based on PEST was developed and utilized to enable simultaneous calibration of SWAT and MODFLOW parameters. Both models demonstrated generally good performance for the temporal pattern of streamflow, albeit SWAT-MODFLOW performed somewhat better. In addition, SWAT-MODFLOW generates spatially explicit groundwater-related outputs, such as spatial-temporal patterns of water table elevation. In the abstraction scenarios analysis, both models indicated that abstraction for drinking water caused some degree of streamflow depletion, while abstraction for auto-irrigation led to a slight total flow increase (but a decrease of soil or aquifer water storages, which may influence the hydrology outside the catchment). In general, the simulated signals of SWAT-MODFLOW appeared more plausible than those of SWAT, and the SWAT-MODFLOW decrease in streamflow was much closer to the actual volume abstracted. The impact of drinking water abstraction on streamflow depletion simulated by SWAT was unrealistically low, and the streamflow increase caused by irrigation abstraction was exaggerated compared with SWAT-MODFLOW. We conclude that the further developed SWAT-MODFLOW model calibrated by PEST had a better hydrological simulation performance, wider possibilities for groundwater analysis, and much more realistic signals relative to the semi-distributed SWAT model when assessing the impacts of groundwater abstractions for either irrigation or drinking water on streamflow; hence, it has the potential to be a useful tool in the management of water resources in groundwater-affected catchments. However, this comes at the expense of higher computational demand and more time consumption.

Wei Liu, Seonggyu Park, Ryan T. Bailey, Eugenio Molina-Navarro, Hans Estrup Andersen, Hans Thodsen, Anders Nielsen, Erik Jeppesen, Jacob Skødt Jensen, Jacob Birk Jensen, and Dennis Trolle
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
Wei Liu, Seonggyu Park, Ryan T. Bailey, Eugenio Molina-Navarro, Hans Estrup Andersen, Hans Thodsen, Anders Nielsen, Erik Jeppesen, Jacob Skødt Jensen, Jacob Birk Jensen, and Dennis Trolle
Wei Liu, Seonggyu Park, Ryan T. Bailey, Eugenio Molina-Navarro, Hans Estrup Andersen, Hans Thodsen, Anders Nielsen, Erik Jeppesen, Jacob Skødt Jensen, Jacob Birk Jensen, and Dennis Trolle

Viewed

Total article views: 3,019 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
1,932 1,032 55 3,019 50 50
  • HTML: 1,932
  • PDF: 1,032
  • XML: 55
  • Total: 3,019
  • BibTeX: 50
  • EndNote: 50
Views and downloads (calculated since 25 Jun 2019)
Cumulative views and downloads (calculated since 25 Jun 2019)

Viewed (geographical distribution)

Total article views: 2,569 (including HTML, PDF, and XML) Thereof 2,552 with geography defined and 17 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Latest update: 27 Feb 2024
Download
Short summary
We compared the performance of SWAT and SWAT-MODFLOW and assessed the simulated streamflow signals in response to a range of groundwater abstraction scenarios for irrigation and drinking water. The SWAT-MODFLOW complex was further developed to enable the application of the Drain Package and an auto-irrigation routine. A PEST-based approach was developed to calibrate the coupled SWAT-MODFLOW. The SWAT-MODFLOW model produced more realistic results on groundwater abstraction effects on streamflow.