COLLABORATIVE RESEARCH: Avulsion, Anastomosis, and Floodplain Sedimentation in Meandering Fluvial Systems

[0304104] Slingerland本研究将探讨崩裂过程，即水流从现有河道永久转移的过程，以及崩裂在河流洪泛平原和冲积沉积层演化中的作用。该方法将是协作的，重点是数学建模实验，以及现代和近现代的河流洪泛平原。该项目将试图解决诸如崩裂的原因、崩裂在洪水盆地中产生和传播的过程、洪泛平原随后对崩裂的反应方式以及崩裂对洪泛平原沉积物特征的影响等问题。由于崩解作用是洪泛平原淤积的必然结果，它可能在冲积沉积序列的演化中起着至关重要的作用，但迄今尚未得到充分认识，因为它很可能是沉积的一个主要过程，而不仅仅是旧河道被抛弃和新河道形成的一种机制。如果理解得当，我们可能需要改变我们对曲流带的起源和作用、对冲冲与岸上洪水的相对重要性以及洪泛平原沉积形成方式的看法。＊＊＊

9304104 Slingerland This study will investigate the processes of avulsion, i.e., the permanent diversion of flow away from an existing river channel, and the role of avulsion in the evolution of river floodplains and alluvial sedimentary deposits. The approach will be collaborative, focusing on mathematical modelling experiments, and modern and near-modern river floodplains. The project will attempt to address such questions as the causes of avulsion, the processes by which avulsions initiate and propagate through flood basins, the manner in which floodplains subsequently react to avulsion, and the effects of avulsion on the character of floodplain deposits. Because avulsion is an inevitable consequence of floodplain aggradation, it may play a vital, and heretofore underappreciated, role int he evolution of alluvial sedimentary sequences because it is likely to be a major process of deposition instead of merely a mechanism by which old channels are abandoned and new ones formed. When properly understood, avulsions may require modifications in the way we view the origin and role of meander belts, the relative importance of avulsive vs overbank flooding, and the manners in which floodplain deposits are generated. ***