Modelling interactions between groundwater and surface water at catchment-scale influenced by groundwater abstractions and climate change
Nøgleord:Climate change, SWAT, SWAT-MODFLOW, Hydrology, Groundwater Abstraction, Flow Regime, Stream biota
With intensifying water crisis, environmental and ecological degradation, as well as ongoing climate change worldwide, integrated water resources management, which considers surface water (SW) and groundwater (GW), is becoming increasingly important. As integrated surface–subsurface hydrological models are capable of simulating water processes in an integrated and holistic fashion, provide spatially and temporally detailed description of the catchment-scale hydrological cycle, enable scenario analysis, and may be coupled with other models (e.g. solute transport model), they are essential and useful tools in integrated water resources management. The SWAT-MODFLOW is such a surface-subsurface model.
Excessive groundwater abstractions can decrease the groundwater table, and thereby affect the aquifer-connected surface water bodies, which may deteriorate the quality of aquatic ecosystems. At the same time, climate change affects inland water ecosystems not only by increasing the water temperatures but also by influencing hydrological processes (e.g. evapotranspiration) and thereby alter the flow regime. The overall objective of my Ph.D. project was to further develop and apply a newly integrated surface-subsurface model SWAT-MODFLOW in order to improve the understanding of SW-GW interactions, and to assess the impacts of groundwater abstractions and climate change on the hydrological regime and on stream biota.
In the first part of my study (presented in manuscript 1), we further developed the SWAT-MODFLOW complex based on the previous publically available version (v.2) to enable the application of a Drain Package and an auto-irrigation routine. To better understand how groundwater pumping wells may influence streamflow patterns, we applied both the semi-distributed SWAT model and the further developed the integrated surface–subsurface hydrological, SWAT-MODFLOW model to a Danish, lowland, groundwater-dominated catchment - the Uggerby River Catchment (357 km2). Both models were calibrated and validated, and an approach based on PEST (Model-Independent Parameter Estimation and Uncertainty Analysis) was developed and utilized to enable simultaneous calibration of SWAT and MODFLOW parameters. The performance of the models when simulating streamflow and the simulated streamflow signals when running four groundwater abstraction scenarios through the two models were analyzed and compared. Both models demonstrated generally good performance of the temporal pattern of streamflow, albeit SWAT-MODFLOW performed somewhat better. 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.
To quantitatively assess the effects of groundwater abstractions and climate change on the hydrological regime and on stream biota, we combined the SWAT-MODFLOW model with novel nationwide-scale flow-biota empirical models for three key biological taxonomic identities (fish, macroinvertebrates, and macrophytes). We applied the integrated approach to the Uggerby River Catchment and assessed to what extent the flow regime and key biota in stream segments of different sizes may be altered by groundwater abstractions and climate change. In the second part of my study (presented in manuscript 2), we therefore analyzed and assessed the impacts of the present level of groundwater abstractions and a scenario with extreme groundwater abstraction for three subbasin outlets representing stream segments of different sizes. The current groundwater abstraction level had only minor impacts on the flow regime and stream biotic indices at the three subbasin outlets. The simulated extreme abstractions, however, led to significant impacts on the smallest stream but had comparatively minor effects on the larger streams. The fish index responded most negatively to the groundwater abstractions, followed by the macrophyte index, decreasing, respectively, by 23.5% and 11.2% in the small stream in the extreme groundwater abstraction scenario. No apparent impact was found on the macroinvertebrate index s in any of the three subbasin outlets.
In the third part of my study (presented in manuscript 3), we analyzed and assessed the effects of predicted climate change towards the end of this century in two climate change scenarios of different greenhouse gas emission levels (RCP2.6 and RCP8.5) for all subbasin outlets classified into streams of three size classes, and we compared the results with the reference period (1996-2005). The overall streamflow and groundwater discharge in the catchment decreased slightly in the RCP2.6 scenario, while it increased in the RCP8.5 scenario. The differently sized streams underwent different alterations in flow regime and also demonstrated different biotic responses to climate change as represented by the fish and macrophyte indices. Large and some small streams suffered most from climate change, as the fish and macrophyte quality indices decreased up to 14.4% and 11.2%, respectively, whereas these indices increased by up to 14.4% and 6.0% respectively, in medium and some small streams. The climate change effects were larger in the RCP8.5 scenario than in the RCP2.6 scenario, as expected.
In conclusion, the further developed SWAT-MODFLOW model calibrated by PEST provided a better hydrological simulation performance 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 great potential to be a useful tool in water resources management in groundwater-dominated catchments. The novel approach of combining SWAT-MODFLOW and flow-regime biota models is a useful tool to quantitatively assess the effects of groundwater abstractions on stream biota and thereby support water planning and regulations related to groundwater abstractions. To the best of my knowledge, the third part of my study is the first to quantitatively assess the impacts of streamflow alterations induced by climate change on stream biota beyond specific species, which would assist in water planning and regulations in the response to the challenges posed by climate change.
Anand, J., Gosain, A. K., and Khosa, R.: Prediction of land use changes based on Land Change Modeler and attribution of changes in the water balance of Ganga basin to land use change using the SWAT model, Science of the total environment, 644, 503-519, 2018.
Arthington, A. H., Olden, J. D., Balcombe, S. R., and Thoms, M. C.: Multi-scale environmental factors explain fish losses and refuge quality in drying waterholes of Cooper Creek, an Australian arid-zone river, Marine and Freshwater Research, 61, 842-856, 2010.
Bailey, R., Rathjens, H., Bieger, K., Chaubey, I., and Arnold, J.: Swatmod-Prep: Graphical User Interface for Preparing Coupled Swat-Modflow Simulations, J Am Water Resour As, 53, 400-410, 10.1111/1752-1688.12502, 2017.
Bailey, R. T., Wible, T. C., Arabi, M., Records, R. M., and Ditty, J.: Assessing regional‐scale spatio‐temporal patterns of groundwater–surface water interactions using a coupled SWAT‐MODFLOW model, Hydrol Process, 30, 4420-4433, 2016.
Bixio, A., Gambolati, G., Paniconi, C., Putti, M., Shestopalov, V., Bublias, V., Bohuslavsky, A., Kasteltseva, N., and Rudenko, Y.: Modeling groundwater-surface water interactions including effects of morphogenetic depressions in the Chernobyl exclusion zone, Environmental Geology, 42, 162-177, 2002.
Blin, N., Hausner, M. B., and Suarez, F. I.: Evaluating groundwater recharge variations under climate change in an endorheic basin of the Andean plateau, AGU Fall Meeting Abstracts, 2017,
Brunner, P., and Simmons, C. T.: HydroGeoSphere: a fully integrated, physically based hydrological model, Groundwater, 50, 170-176, 2012.
Bunn, S. E., and Arthington, A. H.: Basic principles and ecological consequences of altered flow regimes for aquatic biodiversity, Environ Manage, 30, 492-507, 2002.
Camporese, M., Paniconi, C., Putti, M., and Orlandini, S.: Surface‐subsurface flow modeling with path‐based runoff routing, boundary condition‐based coupling, and assimilation of multisource observation data, Water Resources Research, 46, 2010.
Chunn, D., Faramarzi, M., Smerdon, B., and Alessi, D. S.: Application of an Integrated SWAT–MODFLOW Model to Evaluate Potential Impacts of Climate Change and Water Withdrawals on Groundwater–Surface Water Interactions in West-Central Alberta, Water, 11, 110, 2019.
Clement, T. P.: A modular computer code for simulating reactive multi-species transport in 3-dimensional groundwater systems, Pacific Northwest National Lab., Richland, WA (US), 1999.
Condon, L. E., and Maxwell, R. M.: Implementation of a linear optimization water allocation algorithm into a fully integrated physical hydrology model, Advances in Water Resources, 60, 135-147, https://doi.org/10.1016/j.advwatres.2013.07.012, 2013.
Cui, T., Yang, T., Xu, C. Y., Shao, Q. X., Wang, X. Y., and Li, Z. Y.: Assessment of the impact of climate change on flow regime at multiple temporal scales and potential ecological implications in an alpine river, Stoch Env Res Risk A, 32, 1849-1866, 10.1007/s00477-017-1475-z, 2018.
DEPA: The future water supply of Denmark. Recommendations from the Water Council. Report no. 1. (in Danish), Ministry of the Environment, Copenhagen, 1992.
Diaz, J. R., Weatherhead, E., Knox, J., and Camacho, E.: Climate change impacts on irrigation water requirements in the Guadalquivir river basin in Spain, Regional Environmental Change, 7, 149-159, 2007.
Döll, P.: Vulnerability to the impact of climate change on renewable groundwater resources: a global-scale assessment, Environmental Research Letters, 4, 035006, 10.1088/1748-9326/4/3/035006, 2009.
Donn, M. J., Barron, O. V., and Barr, A. D.: Identification of phosphorus export from low-runoff yielding areas using combined application of high frequency water quality data and MODHMS modelling, Science of The Total Environment, 426, 264-271, https://doi.org/10.1016/j.scitotenv.2012.03.021, 2012.
Eaton, J. G., and Scheller, R. M.: Effects of climate warming on fish thermal habitat in streams of the United States, Limnology and oceanography, 41, 1109-1115, 1996.
Fleckenstein, J. H., Krause, S., Hannah, D. M., and Boano, F.: Groundwater-surface water interactions: New methods and models to improve understanding of processes and dynamics, Advances in Water Resources, 33, 1291-1295, 2010.
Flindt Jørgensen, L., Villholth, K. G., and Refsgaard, J. C.: Groundwater management and protection in Denmark: a review of pre-conditions, advances and challenges, International journal of water resources development, 33, 868-889, 2017.
Freeze, R. A., and Harlan, R. L.: Blueprint for a physically-based, digitally-simulated hydrologic response model, Journal of Hydrology, 9, 237-258, https://doi.org/10.1016/0022-1694(69)90020-1, 1969.
Gao, F., Feng, G., Han, M., Dash, P., Jenkins, J., and Liu, C.: Assessment of Surface Water Resources in the Big Sunflower River Watershed Using Coupled SWAT–MODFLOW Model, Water, 11, 528, 2019.
Gassman, P. W., Reyes, M. R., Green, C. H., and Arnold, J. G.: The soil and water assessment tool: historical development, applications, and future research directions, Transactions of the ASABE, 50, 1211-1250, 2007.
Gassman, P. W., Sadeghi, A. M., and Srinivasan, R.: Applications of the SWAT model special section: overview and insights, Journal of Environmental Quality, 43, 1-8, 2014.
Gilfedder, M., Rassam, D. W., Stenson, M. P., Jolly, I. D., Walker, G. R., and Littleboy, M.: Incorporating land-use changes and surface–groundwater interactions in a simple catchment water yield model, Environmental Modelling & Software, 38, 62-73, https://doi.org/10.1016/j.envsoft.2012.05.005, 2012.
Goudie, A. S.: Global warming and fluvial geomorphology, Geomorphology, 79, 384-394, https://doi.org/10.1016/j.geomorph.2006.06.023, 2006.
Graham, D. N., and Butts, M. B.: Flexible, integrated watershed modelling with MIKE SHE, Watershed models, 849336090, 245-272, 2005.
Guzman, J. A., Moriasi, D. N., Gowda, P. H., Steiner, J. L., Starks, P. J., Arnold, J. G., and Srinivasan, R.: A model integration framework for linking SWAT and MODFLOW, Environmental Modelling & Software, 73, 103-116, 10.1016/j.envsoft.2015.08.011, 2015.
Hassan, S. M. T., Lubczynski, M. W., Niswonger, R. G., and Su, Z.: Surface–groundwater interactions in hard rocks in Sardon Catchment of western Spain: An integrated modeling approach, Journal of Hydrology, 517, 390-410, https://doi.org/10.1016/j.jhydrol.2014.05.026, 2014.
Henriksen, H. J., Troldborg, L., Højberg, A. L., and Refsgaard, J. C.: Assessment of exploitable groundwater resources of Denmark by use of ensemble resource indicators and a numerical groundwater–surface water model, Journal of Hydrology, 348, 224-240, 2008.
Henriksen, H. J.: Implementering af modeller til brug for vandforvaltning: delprojekt-effekt af vandindvinding: konceptuel tilgang og validering samt tilstandsvurdering af grundvandsforekomster, GEUS, Geological Survey of Denmark and Greenland, 2014.
Heppner, C. S., Ran, Q., VanderKwaak, J. E., and Loague, K.: Adding sediment transport to the integrated hydrology model (InHM): Development and testing, Advances in Water Resources, 29, 930-943, 2006.
Ivanov, V. Y., Bras, R. L., and Vivoni, E. R.: Vegetation‐hydrology dynamics in complex terrain of semiarid areas: 1. A mechanistic approach to modeling dynamic feedbacks, Water Resources Research, 44, 2008a.
Ivanov, V. Y., Bras, R. L., and Vivoni, E. R.: Vegetation‐hydrology dynamics in complex terrain of semiarid areas: 2. Energy‐water controls of vegetation spatiotemporal dynamics and topographic niches of favorability, Water Resources Research, 44, 2008b.
Jeppesen, E., Brucet, S., Naselli-Flores, L., Papastergiadou, E., Stefanidis, K., Nõges, T., Nõges, P., Attayde, J. L., Zohary, T., Coppens, J., Bucak, T., Menezes, R. F., Freitas, F. R. S., Kernan, M., Søndergaard, M., and Beklioğlu, M.: Ecological impacts of global warming and water abstraction on lakes and reservoirs due to changes in water level and related changes in salinity, Hydrobiologia, 750, 201-227, 10.1007/s10750-014-2169-x, 2015.
Jonubi, R., Rezaverdinejad, V., Behmanesh, J., and Abbaspour, K.: Investigation of quantitative changes in the groundwater table of Miandoab plain affected by surface and groundwater resources management using the MODFLOW-NWT mathematical model, IRANIAN JOURNAL OF SOIL AND WATER RESEARCH, 49, -, 2018.
Kim, B. S., Kim, B. K., and Kwon, H. H.: Assessment of the impact of climate change on the flow regime of the Han River basin using indicators of hydrologic alteration, Hydrological Processes, 25, 691-704, 2011.
Kim, N. W., Chung, I. M., Won, Y. S., and Arnold, J. G.: Development and application of the integrated SWAT–MODFLOW model, Journal of Hydrology, 356, 1-16, 10.1016/j.jhydrol.2008.02.024, 2008.
Kollet, S. J., and Maxwell, R. M.: Integrated surface–groundwater flow modeling: A free-surface overland flow boundary condition in a parallel groundwater flow model, Advances in Water Resources, 29, 945-958, https://doi.org/10.1016/j.advwatres.2005.08.006, 2006.
Kollet, S. J., and Maxwell, R. M.: Capturing the influence of groundwater dynamics on land surface processes using an integrated, distributed watershed model, Water Resources Research, 44, 2008.
Koohestani, N., Halaghi, M., and Dehghani, A.: Numerical simulation of groundwater level using MODFLOW software (a case study: Narmab watershed, Golestan province), International Journal of Advanced Biological and Biomedical Research, 1, 858-873, 2013.
Liu, W., An, W., Jeppesen, E., Ma, J., Yang, M., and Trolle, D.: Modelling the fate and transport of Cryptosporidium, a zoonotic and waterborne pathogen, in the Daning River watershed of the Three Gorges Reservoir Region, China, Journal of Environmental Management, 232, 462-474, https://doi.org/10.1016/j.jenvman.2018.10.064, 2019a.
Liu, W., Bailey, R. T., Andersen, H. E., Jeppesen, E., Nielsen, A., Kai, P., Molina-Navarro, E., Park, S., Thodsen, H., and Trolle, D.: Quantifying the effects of climate change on hydrological regime characteristics and stream biota in a lowland catchment: A modelling approach combining SWAT-MODFLOW with flow-biota empirical models, Journal of hydrology, 2019b.
Liu, W., Bailey, R. T., Andersen, H. E., Jeppesen, E., Park, S., Thodsen, H., Nielsen, A., Molina-Navarro, E., and Trolle, D.: Assessing the impacts of groundwater abstractions on flow regime and stream biota: combining SWAT-MODFLOW with flow-biota empirical models, Science of The Total Environment, 2019c.
Liu, W., Park, S., Bailey, R. T., Molina-Navarro, E., Andersen, H. E., Thodsen, H., Nielsen, A., Jeppesen, E., Jensen, J. S., Jensen, J. B., and Trolle, D.: Comparing SWAT with SWAT-MODFLOW hydrological simulations when assessing the impacts of groundwater abstractions for irrigation and drinking water, Hydrol. Earth Syst. Sci. Discuss., 2019, 1-51, 10.5194/hess-2019-232, 2019d.
Loague, K., Heppner, C. S., Abrams, R. H., Carr, A. E., VanderKwaak, J. E., and Ebel, B. A.: Further testing of the Integrated Hydrology Model (InHM): Event‐based simulations for a small rangeland catchment located near Chickasha, Oklahoma, Hydrological Processes: An International Journal, 19, 1373-1398, 2005.
Loukika, K., Reddy, K. V., Rao, K. D., and Singh, A.: Estimation of Groundwater Recharge Rate Using SWAT MODFLOW Model, in: Applications of Geomatics in Civil Engineering, Springer, 143-154, 2020.
Markstrom, S. L., Niswonger, R. G., Regan, R. S., Prudic, D. E., and Barlow, P. M.: GSFLOW-Coupled Ground-water and Surface-water FLOW model based on the integration of the Precipitation-Runoff Modeling System (PRMS) and the Modular Ground-Water Flow Model (MODFLOW-2005), US Geological Survey techniques and methods, 6, 240, 2008.
Markstrom, S. L., Hay, L. E., Ward‐Garrison, C. D., Risley, J. C., Battaglin, W. A., and Bjerklie, D. M.: Integrated watershed scale response to climate change for selected basins across the United States, Water Resour. Impact, 11, 8-10, 2009.
Maxwell, R. M., Chow, F. K., and Kollet, S. J.: The groundwater–land-surface–atmosphere connection: Soil moisture effects on the atmospheric boundary layer in fully-coupled simulations, Advances in Water Resources, 30, 2447-2466, 2007.
Maxwell, R. M., and Kollet, S. J.: Interdependence of groundwater dynamics and land-energy feedbacks under climate change, Nature Geoscience, 1, 665, 2008.
Maxwell, R. M., Lundquist, J. K., Mirocha, J. D., Smith, S. G., Woodward, C. S., and Tompson, A. F.: Development of a coupled groundwater–atmosphere model, Monthly Weather Review, 139, 96-116, 2011.
Merriman, K. R., Daggupati, P., Srinivasan, R., and Hayhurst, B.: Assessment of site-specific agricultural Best Management Practices in the Upper East River watershed, Wisconsin, using a field-scale SWAT model, Journal of Great Lakes Research, 45, 619-641, 2019.
Mittal, N., Bhave, A. G., Mishra, A., and Singh, R.: Impact of Human Intervention and Climate Change on Natural Flow Regime, Water Resources Management, 30, 685-699, 10.1007/s11269-015-1185-6, 2016.
Molina-Navarro, E., Andersen, H. E., Nielsen, A., Thodsen, H., and Trolle, D.: Quantifying the combined effects of land use and climate changes on stream flow and nutrient loads: A modelling approach in the Odense Fjord catchment (Denmark), Science of The Total Environment, 621, 253-264, 2018.
Molina-Navarro, E., Bailey, R. T., Andersen, H. E., Thodsen, H., Nielsen, A., Park, S., Jensen, J. S., Jensen, J. B., and Trolle, D.: Comparison of abstraction scenarios simulated by SWAT and SWAT-MODFLOW, Hydrological Sciences Journal, 2019.
Neitsch, S. L., Arnold, J. G., Kiniry, J. R., and Williams, J. R.: Soil and water assessment tool theoretical documentation version 2009, Texas Water Resources Institute, 2011.
Niu, G. Y., Paniconi, C., Troch, P. A., Scott, R. L., Durcik, M., Zeng, X., Huxman, T., and Goodrich, D. C.: An integrated modelling framework of catchment‐scale ecohydrological processes: 1. Model description and tests over an energy‐limited watershed, Ecohydrology, 7, 427-439, 2014.
Olesen, M., Madsen, K. S., Ludwigsen, C. A., Boberg, F., Christensen, T., Cappelen, J., Christensen, O. B., Andersen, K. K., and Christensen, J. H.: Fremtidige klimaforandringer i Danmark, DMI, 2014.
Pachauri, R. K., Allen, M. R., Barros, V. R., Broome, J., Cramer, W., Christ, R., Church, J. A., Clarke, L., Dahe, Q., and Dasgupta, P.: Climate change 2014: synthesis report. Contribution of Working Groups I, II and III to the fifth assessment report of the Intergovernmental Panel on Climate Change, Ipcc, 2014.
Park, S., Nielsen, A., Bailey, R. T., Trolle, D., and Bieger, K.: A QGIS-based graphical user interface for application and evaluation of SWAT-MODFLOW models, Environmental Modelling & Software, https://doi.org/10.1016/j.envsoft.2018.10.017, 2018.
Pradhanang, S. M., Mukundan, R., Schneiderman, E. M., Zion, M. S., Anandhi, A., Pierson, D. C., Frei, A., Easton, Z. M., Fuka, D., and Steenhuis, T. S.: Streamflow Responses to Climate Change: Analysis of Hydrologic Indicators in a New York City Water Supply Watershed, 49, 1308-1326, 10.1111/jawr.12086, 2013.
Qadir, A., Ahmad, Z., Khan, T., Zafar, M., Qadir, A., and Murata, M.: A spatio-temporal three-dimensional conceptualization and simulation of Dera Ismail Khan alluvial aquifer in visual MODFLOW: a case study from Pakistan, Arabian Journal of Geosciences, 9, 149, 2016.
Ricci, G. F., De Girolamo, A. M., Abdelwahab, O. M., and Gentile, F.: Identifying sediment source areas in a Mediterranean watershed using the SWAT model, Land degradation & development, 29, 1233-1248, 2018.
Richards, L. A.: Capillary conduction of liquids through porous mediums, Physics, 1, 318-333, 1931.
Semiromi, M. T., and Koch, M.: Analysis of spatio-temporal variability of surface–groundwater interactions in the Gharehsoo river basin, Iran, using a coupled SWAT-MODFLOW model, Environmental Earth Sciences, 78, 201, 2019.
Shen, C., and Phanikumar, M. S.: A process-based, distributed hydrologic model based on a large-scale method for surface–subsurface coupling, Advances in Water Resources, 33, 1524-1541, 2010.
Sith, R., Watanabe, A., Nakamura, T., Yamamoto, T., and Nadaoka, K.: Assessment of water quality and evaluation of best management practices in a small agricultural watershed adjacent to Coral Reef area in Japan, Agricultural Water Management, 213, 659-673, https://doi.org/10.1016/j.agwat.2018.11.014, 2019.
Somaye, I., Delavar, M., and Niksokhan, M. H.: Identification of Nutrients Critical Source Areas with SWAT Model under Limited Data Condition, Water Resources, 46, 128-137, 10.1134/S0097807819010147, 2019.
Sophocleous, M.: Interactions between groundwater and surface water: the state of the science, Hydrogeology Journal, 10, 52-67, 10.1007/s10040-001-0170-8, 2002.
Srivastava, V., Graham, W., Muñoz-Carpena, R., and Maxwell, R. M.: Insights on geologic and vegetative controls over hydrologic behavior of a large complex basin–global sensitivity analysis of an integrated parallel hydrologic model, Journal of hydrology, 519, 2238-2257, 2014.
Stefania, G. A., Rotiroti, M., Fumagalli, L., Simonetto, F., Capodaglio, P., Zanotti, C., and Bonomi, T.: Modeling groundwater/surface-water interactions in an Alpine valley (the Aosta Plain, NW Italy): the effect of groundwater abstraction on surface-water resources, Hydrogeology Journal, 26, 147-162, 10.1007/s10040-017-1633-x, 2018.
Tian, Y., Zheng, Y., Wu, B., Wu, X., Liu, J., and Zheng, C.: Modeling surface water-groundwater interaction in arid and semi-arid regions with intensive agriculture, Environmental Modelling & Software, 63, 170-184, 10.1016/j.envsoft.2014.10.011, 2015.
Tian, Y., Zheng, Y., and Zheng, C.: Development of a visualization tool for integrated surface water–groundwater modeling, Computers & Geosciences, 86, 1-14, https://doi.org/10.1016/j.cageo.2015.09.019, 2016.
Trolle, D., Nielsen, A., Rolighed, J., Thodsen, H., Andersen, H. E., Karlsson, I. B., Refsgaard, J. C., Olesen, J. E., Bolding, K., Kronvang, B., Søndergaard, M., and Jeppesen, E.: Projecting the future ecological state of lakes in Denmark in a 6 degree warming scenario, Climate Research, 64, 55-72, 10.3354/cr01278, 2015.
Trolle, D., Nielsen, A., Andersen, H. E., Thodsen, H., Olesen, J. E., Børgesen, C. D., Refsgaard, J. C., Sonnenborg, T. O., Karlsson, I. B., and Christensen, J. P.: Effects of changes in land use and climate on aquatic ecosystems: Coupling of models and decomposition of uncertainties, Science of the Total Environment, 657, 627-633, 2019.
VanderKwaak, J. E.: Numerical simulation of flow and chemical transport in integrated surface-subsurface hydrologic systems, 1999.
Wang, R., Yuan, Y., Yen, H., Grieneisen, M., Arnold, J., Wang, D., Wang, C., and Zhang, M.: A review of pesticide fate and transport simulation at watershed level using SWAT: Current status and research concerns, Science of the Total Environment, 2019.
Wang, W., Xie, Y., Bi, M., Wang, X., Lu, Y., and Fan, Z.: Effects of best management practices on nitrogen load reduction in tea fields with different slope gradients using the SWAT model, Applied Geography, 90, 200-213, https://doi.org/10.1016/j.apgeog.2017.08.020, 2018.
Wei, X., Bailey, R. T., Records, R. M., Wible, T. C., and Arabi, M.: Comprehensive simulation of nitrate transport in coupled surface-subsurface hydrologic systems using the linked SWAT-MODFLOW-RT3D model, Environmental Modelling & Software, https://doi.org/10.1016/j.envsoft.2018.06.012, 2018.
Wei, X., and Bailey, R. T.: Assessment of System Responses in Intensively Irrigated Stream–Aquifer Systems Using SWAT-MODFLOW, Water, 11, 1576, 2019.
Winter, T. C.: Ground water and surface water: a single resource, DIANE Publishing Inc., 1998.
Winter, T. C.: Relation of streams, lakes, and wetlands to groundwater flow systems, Hydrogeology Journal, 7, 28-45, 10.1007/s100400050178, 1999.
Wu, B., Zheng, Y., Wu, X., Tian, Y., Han, F., Liu, J., and Zheng, C.: Optimizing water resources management in large river basins with integrated surface water‐groundwater modeling: A surrogate‐based approach, Water Resources Research, 51, 2153-2173, 2015.
Yang, T., Cui, T., Xu, C.-Y., Ciais, P., and Shi, P.: Development of a new IHA method for impact assessment of climate change on flow regime, Global and planetary change, 156, 68-79, 2017.
Yano, T., Aydin, M., and Haraguchi, T.: Impact of climate change on irrigation demand and crop growth in a Mediterranean environment of Turkey, Sensors, 7, 2297-2315, 2007.
Yi, L., and Sophocleous, M.: Two-way coupling of unsaturated-saturated flow by integrating the SWAT and MODFLOW models with application in an irrigation district in arid region of West China, Journal of Arid Land, 3, 164-173, 2011.
Yu, X., Moraetis, D., Nikolaidis, N. P., Li, B., Duffy, C., and Liu, B.: A coupled surface-subsurface hydrologic model to assess groundwater flood risk spatially and temporally, Environmental modelling & software, 114, 129-139, 2019.
Zheng, C.: MT3D: A modular three-dimensional transport model for simulation of advection, dispersion and chemical reactions of contaminants in groundwater systems, SS Papadopulos & Associates, 1992.
Zhulu, L.: Getting Started with PEST, Athens, The University of Georgia, 2010.