A comparison of past small dam removals in highly sediment-impacted systems in the U.S.
A comparison of past small dam removals in highly sediment-impacted systems in the U.S.
复制标题
美国过去在受沉积物影响严重的系统中拆除小型水坝的比较
DOI：
10.1016/j.geomorph.2012.01.013
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发表时间：
2012
期刊：
影响因子：
3.9
通讯作者：
S. R. Sawaske
中科院分区：
文献类型：
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作者：
S. R. Sawaske
随着高度淤积系统中大坝拆除案例的数量不断增加，预测大坝拆除影响的能力变得越来越重要。拆除大坝的成本和潜在影响因地点而异，可能因当地条件而有很大差异。在受沉积物影响的清除中，特别值得关注的是水库沉积物侵蚀的数量和速度。用于预测此类大坝拆除影响的建模方法的复杂性和潜在准确性差别很大。目前的方法范围从基于大坝前河道几何形状的简单分析的预测到复杂的数据密集型三维数值模型。在这里介绍的工作中，我们利用从过去的大坝拆除中收集的数据来开发一个额外的工具来预测沉积物侵蚀的速度和体积。通过对泥沙、流量、淤积、移坝时间线、河道、流域等数据的分析，结合大量移坝工程的移坝后监测数据，可以看出移坝后水库沉积物演化的一些重要趋势。结果表明，中位粒径、黏聚力水平、沉积物空间变异性和迁移时间等参数是决定泥沙侵蚀速率和体积的最重要因素。通过将预定拆除的水坝和水库的当地条件与过去的拆除情况进行比较，我们希望能够有效地限制对沉积物侵蚀速率和体积的预测。
The ability to predict the effects of dam removal in highly sediment-filled systems is increasingly important as the number of such dam removal cases continues to grow. The cost and potential impacts of dam removal are site-specific and can vary substantially depending on local conditions. Of specific concern in sediment-impacted removals is the volume and rate of reservoir deposit erosion. The complexity and potential accuracy of modeling methods used to forecast the effects of such dam removals vary substantially. Current methods range from predictions based on simple analysis of pre-dam channel geometry to sophisticated data-intensive, three-dimensional numerical models. In the work presented here, we utilize data collected from past dam removals to develop an additional tool for predicting the rate and volume of sediment deposit erosion. Through the analysis of sediment, discharge, deposit, removal timeline, channel, and watershed data, in conjunction with post-removal monitoring data from a wide range of dam removal projects, some significant trends in the evolution of reservoir deposits following dam removal can be seen. Results indicate that parameters such as median grain size, level of cohesion, spatial variability of the deposit, and removal timeline are among the most influential factors in determining the rate and volume of sediment erosion. By comparing local conditions of dams and reservoirs slated for removal with those of past removals, we hope that predictions of the rate and volume of sediment deposit erosion can be usefully constrained.