Modifying SWAT-CS for simulating chloride dynamics in a Boreal Shield headwater catchment in south-central Ontario, Canada

Dejian Zhang; Huaxia Yao; April James; Qiaoying Lin; Wenjie Fu

doi:10.1016/j.scitotenv.2020.137213

Modifying SWAT-CS for simulating chloride dynamics in a Boreal Shield headwater catchment in south-central Ontario, Canada

Sci Total Environ. 2020 May 15:717:137213. doi: 10.1016/j.scitotenv.2020.137213. Epub 2020 Feb 8.

Authors

Dejian Zhang¹, Huaxia Yao², April James³, Qiaoying Lin⁴, Wenjie Fu⁵

Affiliations

¹ College of Computer and Information Engineering, Xiamen University of Technology, Ligong Road 600, Xiamen 361024, Fujian, China; Key Laboratory of Ecological Environment and Information Atlas (Putian University), Fujian Provincial University, Xueyuan Road 1133, Chengxiang District, Putian 351100, Fujian, China.
² Dorset Environmental Science Centre, Ontario Ministry of Environment, Conservation and Parks, 1026 Bellwood Road, Dorset, Ontario, P0A 1E0, Canada.
³ Department of Geography, Nipissing University, 100 College Drive, Box 5002, North Bay, Ontario P1B 8L7, Canada.
⁴ Department of Resources and Environmental Sciences, Quanzhou Normal University, Donghai Street 398, Quanzhou 362000, Fujian, China. Electronic address: qylin@qztc.edu.cn.
⁵ Key Laboratory of Ecological Environment and Information Atlas (Putian University), Fujian Provincial University, Xueyuan Road 1133, Chengxiang District, Putian 351100, Fujian, China; College of Civil Engineering, Putian University, Xueyuan Road 1133, Chengxiang District, Putian 351100, Fujian, China.

PMID: 32062236
DOI: 10.1016/j.scitotenv.2020.137213

Abstract

Rising chloride concentrations in surface water due to applications of deicing practices is proving detrimental to aquatic systems. In this study, a new chloride module is developed for a version of the Soil and Water Assessment Tool specially designed for Canadian Shield catchments (SWAT-CS) to model long-term chloride dynamics in a headwater catchment in south-central Ontario, Canada. In this modified model (SWAT-CS-CL; extended SWAT-CS model for chloride), chloride sources, sinks, internal storages or pools, and movement between these components are depicted. Performance of SWAT-CS-CL is assessed using a two-stage evaluation process based on the generalized likelihood uncertainty analysis (GLUE) framework. SWAT-CS-CL was found to perform moderately well, with simulated monthly chloride in streams and lake outflow following overall chloride trends and capturing regular chloride dynamics. However, simulations fail to consistently reproduce some instances of large or low chloride fluxes. Limitations in simulating large chloride fluxes may be attributed to the inadequate ability for SWAT-CS-CL to closely simulate snowpack and snowmelt processes. Parameter transferability among sub-catchments does suggest that there is a potential to extend SWAT-CS-CL to other Canadian Shield catchments for chloride modelling. Further improvements are needed through more trials to other catchments in a same or different landscape, and by modifying the simulation structure, especially representation of snow hydrology and chloride inputs.

Keywords: Atmospheric chloride deposition; De-icing application; GLUE; SWAT-CS-CL; Water quality modelling.