Short-term Unsteadiness in Aeolian Sediment Transport Across Beaches

Bernard O. Bauer，主要研究者（PI）道格拉斯J.谢尔曼，合作PI南加州大学，洛杉矶 风成沙在海滩上输移的短期不稳定性 沉积物输运是地貌系统变化的一个基本因素。 我们对泥沙输运过程的概念性理解是强大的，但我们无法将理论转化为普遍适用的预测模型，这一知识的实际应用受到限制。 由于技术和后勤方面的障碍，出现了一些问题。 这项研究将提高我们的理解的潜在作用的不稳定性在泥沙输运过程和适当的手段参数化模型，重点是风成海滩环境。 其结果应能表明其他地貌环境中的迁移过程。 将系统地研究从几秒到几十分钟的时间尺度上的不稳定性，以确定风速波动对模拟海滩上短期沉积物通量是否至关重要-现有的模型参数化的运输是基于稳定状态假设。 将在实地部署采用电子测力计的连续测量、快速反应的集沙器，以提供风速和沉积物通量的同期时间序列。 现场数据将提供深入了解跨海滩的输送率变化的特点，并作为探索预测方程的改进的基础。

SBR-9511529 Bernard O. Bauer, Principal Investigator (PI) Douglas J. Sherman, Co-PI University of Southern California, Los Angeles Short-Term Unsteadiness in Aeolian Sediment Transport Across Beaches Sediment transport is a fundamental agent of change in geomorphological systems. Our conceptual understanding of sediment transport processes is robust, but practical implementation of this knowledge is constrained by our inability to translate theory into generally-applicable predictive models. Problems occur as a result of technical and logistical hurdles. This research will enhance our understanding of the potential role of unsteadiness in sediment transport processes and the appropriate means of parameterizing models by focusing on an aeolian beach environment. The results should be indicative of transport processes in other geomorphic environments. Unsteadiness at temporal scales of seconds to tens of minutes will be investigated systematically to determine whether wind speed fluctuations are critical to modeling short-term sediment flux across beaches--existing model parameterizations of transport are based on steady-state assumptions. Continuously-measuring, fast-response sand traps employing electronic load cells will be deployed in the field to provide contemporaneous time series of both wind speed and sediment flux. The field data will provide insight into the character of transport rate variability across beaches and serve as a foundation for exploring improvements in predictive equations.