ABSTRACT By the late nineteenth century, the scientific study of bedload transport had emerged as an offshoot of hydraulics and geomorphology. Since then, computing bedload transport rates has attracted considerable attention, but whereas other environmental sciences have seen their predictive capacities grow over time, particularly thanks to increased computing power, engineers and scientists are unable to predict bedload transport rates to within better than one order of magnitude. Why have we failed to improve our predictive capacity to any significant degree? A commonly shared view is that the study of bedload transport has more in common with the earth sciences than hydraulics: bedload transport rates depend on many processes that vary nonlinearly, involve various time and space scales, and are interrelated to each other. All this makes it difficult to view bedload as merely particle transport in a turbulent flow – something which can be studied in the laboratory in isolation from the natural environment. Over the last two decades, more emphasis has been put on the noisy dynamics characterizing bedload transport. This Vision Paper makes a strong case for recognizing noise (e.g. bedload transport rate fluctuations) as an intrinsic feature of bedload transport. Improving our predictive capacities requires a better understanding of the origins and nature of noise in bedload transport. This paper also reviews some of the challenges that need to be addressed in current research and teaching.

中文翻译：

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Bedload 运输：随机性和确定性之间的行走。第二部分 挑战与前景

摘要 到 19 世纪后期，对底物运输的科学研究已经成为水力学和地貌学的一个分支。从那时起，计算底物传输率引起了相当大的关注，但其他环境科学的预测能力随着时间的推移而增长，特别是由于计算能力的提高，工程师和科学家无法预测底物传输率的数量级以内震级。为什么我们未能在任何显着程度上提高我们的预测能力？一个普遍的观点是，与地球科学相比，底泥输送研究与水力学的研究有更多的共同点：底泥输送速率取决于许多非线性变化的过程，涉及各种时间和空间尺度，并且相互关联。所有这一切都使得人们很难将床负荷仅仅视为湍流中的粒子传输——这可以在实验室中独立于自然环境进行研究。在过去的二十年里，更多的重点放在了表征床载运输的嘈杂动态上。这份愿景文件有力地证明了噪声（例如，床载运输率波动）是床载运输的固有特征。提高我们的预测能力需要更好地了解底物运输中噪音的起源和性质。本文还回顾了当前研究和教学中需要解决的一些挑战。在过去的二十年里，更多的重点放在了表征床载运输的嘈杂动态上。这份愿景文件有力地证明了噪声（例如，床载运输率波动）是床载运输的固有特征。提高我们的预测能力需要更好地了解底物运输中噪音的起源和性质。本文还回顾了当前研究和教学中需要解决的一些挑战。在过去的二十年里，更多的重点放在了表征床载运输的嘈杂动态上。这份愿景文件有力地证明了噪声（例如，床载运输率波动）是床载运输的固有特征。提高我们的预测能力需要更好地了解底物运输中噪音的起源和性质。本文还回顾了当前研究和教学中需要解决的一些挑战。