In this study we present an approach to calibrate a three-dimensional hydrodynamic model of a salt-wedge estuary, the Araranguá Estuary, southern Brazil, based on the Delft3D-FLOW model. The calibration was carried out in four steps to predict the vertical salinity structure along the estuary in an efficient and effective way. Skill assessment was used to evaluate the calibration quality. The model is forced by water-level elevation along the offshore open boundary and river-discharge inflows from the two major tributaries. The hydrodynamic model was calibrated using field observation of water level, currents and longitudinal salinity structure. Calibration was performed adjusting vertical grid resolution, bottom-friction coefficient and background eddy viscosity. The model achieves high skill values at water level and currents variations during a 113-day period (in 2008) covering a wide range of river discharge and tidal forcing. Water surface fluctuations obtained from the model are in good agreement with the field data. Modeled depth-averaged currents reproduce the temporal pattern of observed data. Longitudinal salinity structure is also well reproduced, although the vertical structure is more diffusive than the observations. Results also demonstrate that the model predicts the overall measured phenomena and the effects of the flash-flood event, with the discharge affecting water level, currents and salinity.

在这项研究中，我们提出了一种基于 Delft3D-FLOW 模型校准巴西南部阿拉兰瓜河口盐楔河口三维流体动力学模型的方法。校准分四个步骤进行，以高效有效的方式预测沿河口的垂直盐度结构。技能评估用于评估校准质量。该模型是由沿近海开放边界的水位高程和来自两个主要支流的河流入流迫使的。水动力模型通过水位、洋流和纵向盐度结构的现场观测进行校准。通过调整垂直网格分辨率、底部摩擦系数和背景涡流粘度进行校准。该模型在 113 天（2008 年）的水位和水流变化方面实现了高技能值，涵盖了广泛的河流流量和潮汐强迫。模型得到的水面波动与现场数据吻合较好。建模的深度平均电流再现了观测数据的时间模式。纵向盐度结构也得到了很好的再现，尽管垂直结构比观测值更具扩散性。结果还表明，该模型预测了整体测量现象和山洪事件的影响，排放会影响水位、水流和盐度。建模的深度平均电流再现了观测数据的时间模式。纵向盐度结构也得到了很好的再现，尽管垂直结构比观测值更具扩散性。结果还表明，该模型预测了整体测量现象和山洪事件的影响，排放会影响水位、水流和盐度。建模的深度平均电流再现了观测数据的时间模式。纵向盐度结构也得到了很好的再现，尽管垂直结构比观测值更具扩散性。结果还表明，该模型预测了整体测量现象和山洪事件的影响，排放会影响水位、水流和盐度。