Evaluating erosion risk mitigation due to forest restoration treatments using alluvial chronology and hydraulic modeling
Evaluating erosion risk mitigation due to forest restoration treatments using alluvial chronology and hydraulic modeling
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使用冲积年代学和水力模型评估森林恢复处理带来的侵蚀风险缓解
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
V. Stempniewicz
中科院分区：
文献类型：
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作者：
V. Stempniewicz
离子比率)在用于确定所有现有手册CN表的方程中包含了更大范围的数字，使得所有手册CN值与最近公布的基于数据的CN值相比都是可疑的值。由于有限的参数化，CN方法也受到审查。众所周知，对降雨-径流关系有复杂的自然控制，117个CN号只有这些参数中的少数几个输入信息。神经网络几乎完全是经验的，而不是基于事实的，这限制了该方法的应用和有效使用。数据不足阻碍了模型校准和随后的泥沙建模。粗糙度系数的选择是具有挑战性的，并且在没有观测到的降雨/径流数据进行校准的情况下需要进行严格的审查。Schultz Creek没有可用的仪表数据，因此所选粗糙度系数的准确性是未知的。计算粗糙度系数需要流量数据，包括总流量或观察到的水面流速。有几个横截面的水面默认为临界深度。这很可能是由于在如此陡峭的斜坡上，截面密度相对较低（~2-5%）。建议至少每隔50英尺测量一次横截面几何形状（Willie Odem，个人通讯）。为本研究建立的模型旨在对可能的流量情景进行比较分析，而不是对特定条件的精确模拟，因为Schultz Creek没有水流流量校准数据。结果是沿舒尔茨河水力学的一个有用的初步分析，并没有开发用于详细的设计工具。未来的研究可以通过更详细的实地工作和监测来显著改善模拟。通过将流域的可用激光雷达数据转换为HEC-RAS友好格式，提取HEC-RAS中的截面数据，可以提高几何分辨率。对观测到的径流事件的详细监测可用于校准模型以进行流量测量。
ion ratio) in the equation used to determine all existing handbook CN tables has been found to include a much larger range of numbers, making all handbook CN values of dubious value compared to more recently published, data-based CN values.CN methods are also subject to scrutiny due to the limited parameterization. It is well understood that there are complex natural controls on rainfall-runoff relationships, and 117 CN numbers only have input information for a select few of these parameters. CNs are almost completely empirical and not based in fact, limiting the application and effective use of this method. There were data deficiencies preventing model calibration and subsequent sediment modeling. Roughness coefficient selection is challenging and subject to significant scrutiny without observed rainfall/runoff data for calibration. No gauge data are available for Schultz Creek, therefore accuracy of selected roughness coefficients is unknown. Flow data including either total discharge or velocity with observed water surfaces would be required to calculate roughness coefficients. There were several cross sections where the water surface defaulted to the critical depth. This is most likely due to the relative low density of cross sections on such steep slopes (~2-5%). It is recommended, at a minimum, cross section geometry should be measured every 50 ft (Willie Odem, personal communication). The model built for this study was intended to be a comparative analysis of possible flow scenarios and not an accurate simulation of a specific condition because no stream discharge calibration data exist for Schultz Creek. The results are a useful preliminary analysis of the hydraulics along Schultz Creek and were not developed for use as a detailed design tool. Future studies could significantly improve simulation with more detailed field work and monitoring. Geometry resolution could be improved by converting available LiDAR data for the watershed into a HEC-RAS friendly format to extract cross section data within HEC-RAS. Detailed monitoring of observed runoff events could be used to calibrate a model to discharge measurements.