Correction of River Bathymetry Parameters Using the Stage?Discharge Rating Curve
Correction of River Bathymetry Parameters Using the Stage?Discharge Rating Curve
复制标题
利用阶段流量额定曲线修正河流测深参数
DOI：
10.1029/2021wr031226
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发表时间：
2022
影响因子：
5.4
通讯作者：
Yamazaki Dai
中科院分区：
文献类型：
--
作者：
Zhou Xudong;Revel Menaka;Modi Prakat;Shiozawa Takuto;Yamazaki Dai
河流水深测量是水动力学建模的重要参数;然而，由于直接大规模测量不切实际，因此它与大偏差相关。最近的研究调整河流测深数据的基础上评估的差异建模和观察到的水面高程（WSE），然而，模型的不确定性，河流流量可能会导致意外的错误，在纠正河流测深。在这项研究中，我们提出了一个简单的，但强大的和合理的河流水深校正方法，使用水位流量率定曲线之间的偏差，而不是WSE时间序列数据。流量曲线反映了断面的内在特性，对瞬时流量误差不敏感。我们的研究结果表明，校正后的河流水深测量对径流偏差具有鲁棒性，因为它们在由噪声污染或多模型径流强迫驱动的实验中收敛。用校正后的河流水深数据对虚拟真值进行了评价，结果表明，新方法比传统方法的绝对偏差减小了0.85-1.12 m。特别是在无回水影响的河段，计算结果之间的偏差减少了70%以上。对校正后的河流模型输出的评估也显示了等级曲线偏差校正的优势，因为模拟的WSE只有在更好的径流情况下才合理更好，并且它不会隐藏径流输入中的错误。考虑到流量误差和径流偏差难以消除的问题，一种不受流量和径流误差影响的河流水深修正方法对于改进水动力学模拟具有重要意义。
River bathymetry is an important parameter for hydrodynamic modeling; however, it is associated with large bias because direct large‐scale measurements are impractical. Recent studies adjusted river bathymetry data based on assessment of the difference between modeled and observed water surface elevation (WSE); however, model uncertainties in river discharge can lead to unintended errors in correcting river bathymetry. In this study, we propose a simple but robust and rational correction method of river bathymetry using the bias between stage–discharge rating curves rather than WSE time series data. The rating curve represents the internal characteristics of the river section, and is not sensitive to the instantaneous simulated discharge errors. Our results showed that the corrected river bathymetry are robust to bias in runoff as they converged among experiments driven by noise‐corrupted or multimodel runoff forcing. Evaluation with the corrected river bathymetry against virtual truth demonstrated that the new method reduced 0.85–1.12 m of the absolute bias than the result from the conventional method. The deviation among the results reduced by more than 70% particularly in river sections with no backwater effects. Evaluation of the corrected river model output also showed the advantage of rating‐curve bias correction, as the simulated WSE is reasonably better only with better runoff and it does not conceal errors in runoff inputs. Given the difficulty of eliminating discharge errors and bias in runoff, a method for correcting river bathymetry that is free from discharge and runoff errors is important for improving hydrodynamic modeling.