Department of Civil and Environmental Engineering (Dept 2470), North Dakota State University, PO Box 6050, Fargo, ND 58108-6050, USA.
Department of Earth System Science & Policy, University of North Dakota, 4149 University Ave Stop 9011, Grand Forks, ND 58202-6089, USA.
Int J Environ Res Public Health. 2018 Nov 8;15(11):2492. doi: 10.3390/ijerph15112492.
Non-point source (NPS) pollution from agricultural lands is the leading cause of various water quality problems across the United States. Particularly, surface depressions often alter the releasing patterns of NPS pollutants into the environment. However, most commonly-used hydrologic models may not be applicable to such depression-dominated regions. The objective of this study is to improve water quantity/quality modeling and its calibration for depression-dominated basins under wet and dry hydroclimatic conditions. Specifically, the Soil and Water Assessment Tool (SWAT) was applied for hydrologic and water quality modeling in the Red River of the North Basin (RRB). Surface depressions across the RRB were incorporated into the model by employing a surface delineation method and the impacts of depressions were evaluated for two modeling scenarios, MS1 (basic scenario) and MS2 (depression-oriented scenario). Moreover, a traditional calibration scheme (CS1) was compared to a wet-dry calibration scheme (CS2) that accounted for the effects of hydroclimatic variations on hydrologic and water quality modeling. Results indicated that the surface runoff simulation and the associated water quality modeling were improved when topographic characteristics of depressions were incorporated into the model (MS2). The Nash⁻Sutcliffe efficiency (NSE) coefficient indicated an average increase of 30.4% and 19.6% from CS1 to CS2 for the calibration and validation periods, respectively. Additionally, the CS2 provided acceptable simulations of water quality, with the NSE values of 0.50 and 0.74 for calibration and validation periods, respectively. These results highlight the enhanced capability of the proposed approach for simulating water quantity and quality for depression-dominated basins under the influence of varying hydroclimatic conditions.
非点源（NPS）污染来自农业土地，是美国各种水质问题的主要原因。特别是，地表洼地经常改变 NPS 污染物向环境释放的模式。然而，大多数常用的水文模型可能不适用于这种以洼地为主的地区。本研究的目的是改善干湿气候条件下以洼地为主的流域的水量/水质模型及其校准。具体来说，应用土壤和水评估工具（SWAT）对北红河流域（RRB）进行水文和水质建模。通过采用地表划分方法，将 RRB 中的地表洼地纳入模型，并评估了两种建模情景（MS1（基本情景）和 MS2（洼地导向情景））对洼地的影响。此外，将传统的校准方案（CS1）与考虑干湿变化对水文和水质建模影响的干湿校准方案（CS2）进行了比较。结果表明，当将洼地的地形特征纳入模型时（MS2），地表径流模拟和相关水质建模得到了改善。纳什-苏特克利夫效率（NSE）系数表明，校准期和验证期分别从 CS1 到 CS2 的平均增加了 30.4%和 19.6%。此外，CS2 对水质提供了可接受的模拟，校准期和验证期的 NSE 值分别为 0.50 和 0.74。这些结果突出了所提出的方法在模拟干湿气候条件下以洼地为主的流域的水量和水质方面的增强能力。
