Alumni

Asst. Professor, East China Normal University

State Key Laboratory of Estuarine and Coastal Research

yuanxu@sklec.ecnu.edu.cn

The evolution of vegetated landscape occurs through the interplay of flow, vegetation, and sediment transport. There is a lack of predictive models that accurately account for the impact of vegetation morphology on sediment transport. Most previous studies have only considered circular cylinders as a model for vegetation. My study focuses on the sediment transport in channels with realistic models of emergent cattail. First, flume experiments will be used to describe and predict the turbulence level and form drag within a canopy of cattails. Second, the incipient sediment motion will be investigated and compared with the bare channel. Finally, I will attempt to construct a theoretical model that predicts sediment transport rate in channels with different distributions of realistic cattail models.

Graduate Student

gltso (at) mit.edu

Georgette Tso is an MEng student studying green seawalls. Seawalls are a common infrastructure used to protect coastal regions from storm surge and waves. Historically, seawalls have been constructed from marine concrete blocks with smooth, vertical geometry. Because the seawalls eliminate intertidal zones, they diminish marine biodiversity. To make seawalls more hospitable to marine fauna, researchers have introduced texture and shapes to seawall surfaces, and introduced concrete mixes with enriched levels of CaCO3. This study will compare marine cement and enriched cement for the attributes of recruitment rate and durability (measured through changes in material strength). The study can inform installation choices for optimizing green seawall design. Knowledge of recruitment and durability under high wave exposure is particularly relevant to future Boston-area developments.

Graduate Student

rbs@mit.edu

I grew up on the East Coast and have spent many summers in the Great Lakes region. It’s easy to take for granted the roles that vegetation play in nature, and view plants as ugly weeds to clear instead of species to protect. Seagrasses provide important habitat, carbon sinks, and other ecological functions, but are threatened by overdevelopment, pollution, and climate change. Long meadows of seagrass have been shown to attenuate currents and attenuate wave energy, but the dynamics of wave damping in the presence of currents are not as well understood. In addition, the morphological characteristics of plants vary widely in scope and in their relative contributions to vegetation-induced drag in oscillatory flow. I plan to investigate these areas to improve our understanding of the complex but ubiquitous interactions between flow and vegetation. Improved models of flow interactions with vegetation can help predict how storms and currents will affect vulnerable meadows, and help design infrastructure and living shorelines to protect coastal areas.

Graduate Student

Current Position: PhD student, Wuhan University

jiaoz (at) mit.edu

My research examines turbulence and sediment transport in flows with submerged vegetation. Turbulence can be generated by the wakes of individual plants. In addition, the velocity is redistributed by submerged vegetation, and a shear layer is formed at the top of the canopy, which generates canopy-scale turbulence.

Assistant Professor

School of Water Resources and Hydropower Engineering
North China Electric Power University

tangcaihong@ncepu.edu.cn

My study focused on the effects of submerged vegetation on sediment resuspension under waves. The plant-generated turbulence was shown to promote sediment resuspension, changing the velocity threshold for resuspension.

Visiting Scholar

Professor, Federal University of Mato Grosso do Sul

janzen (at) mit.edu

My research is in the broad area of Environmental Fluid Mechanics. I am particularly interested in (1) the influence of floating treatment inlands (FTIs) on the mass retention and sedimentation, (2) the influence of vegetation on groyne fields, (3) the evolution of vegetation in channels, and (4) the hyporheic exchange in stream restoration.

Associate Professor

Now: Sichuan University, Institute for Disaster Management and Reconstruction

yuqi_shan (at) qq.com

In my first project, I characterized the drag forces on individual mangrove trees in random and in-line tree distributions. I also studied the effect of floating aquatic vegetation on the velocity field and mass removal from a channel. Finally, I created an experiment to measure sediment transport inside regions of clustered vegetation.

Graduate Student

Assistant Professor in University of Minnesota (Sept 2020)

qjyang (at) mit.edu

Personal Website

At MIT my researched focused on the sediment transport inside a vegetation patch. Vegetation is a basic component of most natural water environments and has been widely used in river restoration, yet few practical models exist to predict the incipient motion and rate of sediment transport in a canopy. Using a LDV, a high-speed camera and a sediment-recirculating flume, I quantitatively connect the sediment motion with the flow characteristics inside vegetation canopies.

Visiting Graduate Student Nanjing Inst. of Geography and Limnology

Now at Liaocheng University

chinayinghao (at) 126.com

At MIT I studied the effect of submerged vegetation on wave-induced sediment resuspension. Previous studies suggest that the near-bed turbulence level is correlated with sediment resuspension. My experiment measured velocity and sediment concentration simultaneously, to determine the threshold level of turbulence needed for resuspension. In addition, I developed models to predict the level of near-bed turbulence associated with stem-wake turbulence generation.

MEng 2016-2017

danpas (at) mit.edu

Mangrove forests are an integral part of coastal ecosystems — they store carbon, provide habitat, and serve as a natural barrier to wave forces. My research quantified the degree to which mangrove forests dissipate tidal energy at varying growth densities and arrangements.