Collaborative Research: A theoretical framework for the evolution of distributary networks on wave-influenced deltas

由于缺乏对三角洲河道(分流)网络演化的了解，我们预测和缓解三角洲对自然和人为干扰的响应的能力受到限制。该项目将通过理论、实验和实地相结合的方法，从根本上提高三角洲对自然和人类干扰的反应的预测和缓解的能力。卫星图像和实地数据将被用来得出各种三角洲的航道网络统计数据，形成建模工作的目标。密西西比三角洲地下沉积物的测绘将考察环境对分流形成和随时间演变的控制。实验室实验将以更小的规模重现分流网络，并探索基本的控制参数(例如，泥沙和供水、波浪能量、海平面上升)。实验结果将指导理论模型的发展，该模型将从数学上描述创建渠道网络的过程。该模型将用于在密西西比河三角洲下游的恢复计划中帮助预测新的河流三角洲的增长。广泛的影响。河流三角洲是相当大一部分人口的家园，是支持不同物种的生态热点。三角洲上的河道网络构成了三角洲的骨架：河道位置决定了沉积模式，并决定了沉积物、营养物质和淡水如何输送到海岸线。建模框架将为负责三角洲管理的个人和机构提供宝贵的预测能力。特别是，这项研究将通过与NSF科学和技术中心国家地球表面动力学中心的同事合作，帮助指导密西西比河三角洲土地建设的人工改道设计。该奖项还将支持研究生和家庭机构初级教员的早期职业生涯。该奖项由地球科学部地貌学和土地利用动力学项目支持。

Our ability to predict and mitigate the response of deltas to natural and human disturbances is limited by a lack of understanding of the evolution of delta channel (distributary) networks. This project will fundamentally advance the ability to predict and mitigate the response of deltas to natural and human disturbances through a combined theoretical, experimental, and field-based approach. Satellite imagery and field data will be used to derive the statistics of channel networks for a wide variety of deltas, forming a target for modeling efforts. Mapping of subsurface deposits on the Mississippi Delta will examine environmental controls on distributary formation and evolution through time. Laboratory experiments will reproduce distributary networks at a much-reduced scale, and explore the fundamental control parameters (e.g., sediment and water supply, wave energy, sea level rise). Experimental results will guide the development of a theoretical model, which will mathematically describe the processes that create channel networks. The model will be used to help predict the growth of new river deltas in restoration schemes for the lower Mississippi Delta.Broader Impacts.River deltas are home to a significant fraction of the human population, and are ecologic hotspots that support diverse species. The network of channels on a delta forms its skeleton: channel locations determine patterns of deposition and dictate how sediment, nutrients and freshwater are delivered to the shoreline. The modeling framework will provide valuable predictive capabilities for individuals and agencies tasked with delta management. In particular, this research will help to guide the design of artificial diversions for land building on the Mississippi Delta, through collaboration with colleagues at the National Center for Earth-surface Dynamics, an NSF Science and Technology Center. This award will also support graduate students and the early career of a junior faculty member at the home institution.The award is supported by the Division of Earth Sciences's program in Geomorphology and Land-Use Dynamics.