Hydraulic Jump Mechanics and Channel Interactions in Mountain Rivers

0207713帕斯特纳克山区河流中的水跃是空气和水的湍流混合物，产生显著的动能耗散、空气娱乐、表面波和喷雾。 尽管他们的流行，自然水跃的作用，河流流动力学，泥沙输运，河道变化和流域演变是未知的，主要是因为不利的现场条件，以前有限的现场数据收集。 本项目的总体目标 是为了克服过去的限制，调查水跃流体力学在自然环境中，其相关性河流地貌的援助，使精确的原位测量的第一次新技术。 加州大学戴维斯分校开发和测试的新技术包括River Truss、空气含量传感器和大规模粒子图像测速仪。 新技术将被用来解决三个假设，预测系统的变化，在外部控制通道的几何形状和流量直接影响水面地形，速度，压力，空气含量，空气娱乐和能量耗散的响应变量。 响应变量在泥沙输运、河道变化和盆地演变中的作用将从响应变量本身的彻底调查中得出，特别是在处理河床附近的条件时。 观察13个自然水跃在美国河流域超过3年的时间将测试假设。 结果将进行比较跳跃和对工程水槽为基础的研究，使用理论和经验公式的结果。 更好地了解自然跳跃在河道变化中的作用对科学非常重要，因为它将改善景观演化模型的物理学，为河流恢复和重建中的河流特征提供必要的指导，并对生态学和水生地球化学做出跨学科的贡献。 在未来的研究中，其他科学家将能够应用新验证的现场技术和由此产生的模型，以更好地了解山区河流中发生的复杂流动力学和通道相互作用。

0207713PasternackHydraulic jumps in mountain rivers are turbulent mixtures of air and water that produce significant kinetic energy dissipation, air entertainment, surface waves, and spray. Despite their prevalence, the role of natural hydraulic jumps on river flow mechanics, sediment transport, channel change, and basin evolution is unknown primarily because of adverse site conditions that previously limited field data collection. The overall goal of this project is to overcome past constraints on investigating hydraulic jump fluid mechanics in the natural setting and its relevance to fluvial geomorphology with the aid of new technologies that enable precise in situ measurement for the first time. New technologies developed and tested at UC Davis include a River Truss, an air content sensor, and large-scale particle image velocimetry. The new technologies will be used to address three hypotheses that predict how systematic changes in the external controls of channel geometry and discharge directly affect the response variables of water surface topography, velocity, pressure, air content, air entertainment, and energy dissipation. The role of response variables in sediment transport, channel change, and basin evolution will follow from a thorough investigation of the response variables themselves, especially when addressing conditions near the bed. Observing 13 natural hydraulic jumps in the American River basin over a 3-year period will test hypotheses. Results will be compared between jumps and against results from engineering flume-based studies using theoretical and empirical equations. A better understanding of the role of natural jumps in channel change is very important to science because it would improve the physics of landscape evolution models,provide needed guidance for including in-stream features in river restoration and rehabilitation, and make interdisciplinary contributions to ecology and aquatic geochemistry. In future research, other scientists will be able to apply the newly proven field technologies and resulting models to better understand the complex flow mechanics and channels interactions occurring in mountain rivers.