About
196
Publications
46,302
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
2,746
Citations
Publications
Publications (196)
Granular materials in nature are nearly always non-spherical, but particle shape effects in granular flow remain largely elusive. This study uses discrete element method simulations to investigate how elongated particle shapes affect the mobility of dense granular flows down a rough incline. For a range of systematically varied particle length-to-d...
Gravel bed rivers often display pool‐riffle morphology. Downstream changes in channel width are often correlated with pool‐riffle topography. Considering self‐formed, alluvial, straight and single‐thread gravel‐bed rivers, here we provide an analytical solution for their equilibrium pool‐riffle morphology in the presence of spatially varying widths...
Granular materials in nature are nearly always nonspherical, but particle shape effects in granular flow remain largely elusive. This study uses discrete element method simulations to investigate how elongated particle shapes affect the mobility of dense granular flows down a rough incline. For a range of systematically varied particle length-to-di...
As one of the world’s largest braided rivers, the Yarlung Tsangpo River is subject to the tectonic activities of the Tibetan Plateau, that leads to the formation of the alternating river patterns of wide-braided and incised gorges. A geometric based method is proposed herein to estimate the sedimentation volume in the braided reaches of the middle...
Research on active particles has primarily focused on transport in relatively weak flows, during which their active swimming plays a significant role. However, in natural or manmade waterways, the ambient flow velocity and water depth can be on the order of approximately 1 m/s and 1 m, respectively, generating turbulent diffusion that may be strong...
In rivers, the addition of finer sediment to a coarser riverbed is known to increase the mobility of the coarser fraction. Two mechanisms have been suggested for this: a geometric mechanism whereby smaller sizes smooth the bed, increasing near-bed velocity and thus mobility of the larger sizes, and a viscous mechanism whereby a transitionally smoot...
Plain Language Summary
The bed surface layer of many rivers is a mixture of sand and gravel. This mixture is described by the probability distribution of grain sizes, and in particular by the median size. Consider the long profile of such a river. Surface median size commonly becomes finer downstream, but often changes abruptly from a value above 5...
Turbidity currents, which are stratified, sediment-laden bottom flows in the ocean or lakes, can run out for 100's to 1000's of kilometers in submarine channels without losing their stratified structure. Here we derive a layer-averaged, two-layer model for turbidity currents, specifically designed to capture long-runout. Previous models have captur...
Developing a process-based soil erosion model that comprehensively considers the effects of vegetation is complex but crucial for evaluating sediment reduction during vegetation restoration. Current understanding of the effect of vegetation on sediment reduction along hillslopes across different land uses is limited. In this paper, we developed a d...
Drainage basins are fundamental units of Earth's surface, describing how flows accumulate across landscapes. They are direct expressions of how tectonics and climatic forces alter Earth's surface morphology. Here, we measure the width‐to‐length ratios (WLRs) of 386,931 drainage basins (average area ∼157 km²), covering all continents except Antarcti...
Downstream width variations can generate pool‐riffle morphology under experimental conditions, in numerical simulations and natural river channels. The present understanding of how pool‐riffle morphology varies with sediment supply and caliber, however, is insufficient due to the limited range of sediment supply rates explored in previous experimen...
Since the 2008 Wenchuan (Ms. 8.0) Earthquake, the foreland rivers of the Longmen Mountains have suffered from significant bed degradation, among which the Shi‐ting River has experienced the largest local degradation of more than 20 m in 7 years. Potential reasons of the dramatic degradation include: (1) sediment disconnectivity due to in‐channel we...
Extreme weather patterns and unsustainable development dynamics have substantially increased disaster risks compelling widespread demand for community resilience worldwide. This study aims to develop and measure Risk-integrated Resilience (RiR) index of flood-affected downstream communities in West Rapti Basin (WRB) of the Nepal Himalaya. The evide...
Check-dams are structures used extensively around the world for soil and water conservation. However, existing models for check-dams are unable to simulate the Sediment Trap Efficiency (STE) at the catchment scale. A numerical model was developed to simulate the SEdiment Deposition upstream of Check-Dams (SEDCD) and integrated into a distributed se...
A dynamic model of soil erosion along hillslopes considering soil detachment and sediment transport is still a major challenge in terms of its applicability to field conditions. Data availability for model calibration and validation is very limited for physically process models. An improved hillslope erosion dynamic model (HED) with a simple struct...
Manyriversaredevelopedinmountainousareas,buttheseriversaredifficulttomeasureonsitedueto
thecomplextopography,anditisimpossibletoobtainsufficientbasicriverinformation,whichmakesmountain
riversatypicalpoorlygaugedbasin.Thisstudycombines68rivercrosssectionsextractedfrommultisourceremote
sensingdataand34rivercrosssectionsmeasuredbyhydrologicalstationst...
Study region: Twenty-six glaciated basins on the Interior Plateau (56 • N, 125 • W) in British Columbia, Canada. Study focus: Landscape and streamflow characteristics in glaciated basins show high spatiotem-poral variability, while the linkages among runoff characteristics, landscapes, and glacial history remain unclear. We compiled a 10-year datas...
Inter-basin water diversion projects have led to accelerated colonization of aquatic organisms, including the freshwater golden mussel (Limnoperna fortunei), exacerbating global biofouling concerns. While the influence of environmental factors on the mussel's invasion and biofouling impact has been studied, quantitative correlations and underlying...
One of the most common and severe natural hazards, flood has been intensified by anthropogenic climate change in many mountain regions affecting socioeconomic conditions during the twenty-first century. The study synthesized the past 50 years (1971–2020) flood loss data; then generated district-wise flood loss spatial maps and explored flood loss m...
Downstream hydraulic geometry (DHG) for multiple discharge frequencies remains poorly investigated. This paper seeks to clarify the DHG relations of different discharge frequencies and proposes the definition, mathematical expression, and geomorphological interpretation of multifrequency DHG (MFDHG). It also verifies the existence of DHG and MFDHG...
We present a comprehensive Euler-Lagrange solver, CP3d, for the direct numerical simulation of particle-laden flows. The solver can handle one-way, two-way, interface-unresolved four-way and interface-resolved coupling regime. To make the solver versatile, different numerical approaches are available for fluid, particle as well as the coupling sub-...
Direct numerical simulations at two friction Reynolds numbers (550 and 1000) have been performed to explore the statistical behaviors of wall-attached motions (WAMs) in open- and closed-channel flows (OCFs and CCFs). To fully capture the largest energetic WAMs, super-large domain sizes are employed (24–48 πh along streamwise direction with h being...
The rich and complex phenomena of the transport of active particles like microorganisms in shear flows are of great significance to various biological and environmental applications. Recent studies have shown that the motility and gyrotaxis of algae could greatly influence their transport in waters. However, little attention has been paid to the in...
Understanding the statistics of bedload particle motions is of great importance. To model the hop events which are defined as trajectories of particles moving successively from the start to the end of their motions, recently, Wu et al. (Water Resour. Res., vol. 56, 2020, p. e2019WR025116) have successfully performed individual-based simulations acc...
Mussel colonization can affect the water quality through restructuring nearby bacterial communities. In this study, we conducted an experiment to detect the bacterial alteration associated with live and dead golden mussel colonies, and used a high-throughput sequencing method based on 16S rRNA genes to reveal the changes in bacterial communities. I...
Short instrumental streamflow records in the South and East Tibetan Plateau (SETP) limit understanding of the full range and long-term variability in streamflow, which could greatly impact freshwater resources for about one billion people downstream. Here we reconstruct eight centuries (1200−2012 C.E.) of annual streamflow from the Monsoon Asia Dro...
Surface reactions such as the adsorption and desorption at boundaries are very common for solute dispersion in many applications of chemistry, biology, hydraulics, etc. To study how reversible adsorption affects the transient dispersion, Zhang, Hesse & Wang (J. Fluid Mech., vol. 828, 2017, pp. 733–752) have investigated the temporal evolution of mo...
We present a high order finite difference solver, ParaTC, for the direct numerical simulations of turbidity currents with canonical turbulent channel configuration (periodic boundary conditions in the horizontal directions and non-periodic in vertical direction). Uniform meshes are adopted in streamwise and spanwise directions, while stretched grid...
Tectonically active mountain regions such as Southwestern China are frequently hit by catastrophic floods caused by the breach of landslide dams. However, how these extreme events influence the morphodynamics of bedrock‐alluvial rivers is not well understood. More specifically, during a landslide dam outburst flood, bedrock can be eroded by intensi...
During its 6,300-km course from the Tibetan Plateau to the ocean, the Yangtze River is joined by two large lakes: Dongting Lake and Poyang Lake. We explain why these lakes exist. Deglaciation forced the ocean adjacent to the Yangtze mouth to rise ∼120 m. This forced a wave of rising water surface elevation and concomitant bed aggradation upstream....
River dams provide many benefits, including flood control. However, due to constantly evolving channel morphology, downstream conveyance of floodwaters following dam closure is difficult to predict. Here, we test the hypothesis that the incised, enlarged channel downstream of dams provides enhanced water conveyance, using a case study from the lowe...
The Sichuan-Tibet traffic corridor is an important transportation strategy in China that plays a key role in the economic prosperity, long-term stability, and the "Belt and Road" strategy in western China. However, the complex terrain, climate environment and active geological tectonic movements along the Sichuan-Tibet traffic corridor lead to extr...
The extraction of high-resolution geomorphic information from remote sensing images is a key technology for supporting mountain river research. Extracting small rivers (width < 90 m) from complex backgrounds based on satellite images remains a challenging issue. In this research, we propose an improved random forest (RF) algorithm, RF-ANN (artifici...
Image-based grain sizing has been used to measure grain size more efficiently compared with traditional methods (e.g., sieving and Wolman pebble count). However, current methods to automatically detect individual grains are largely based on detecting grain interstices from image intensity which not only require a significant level of expertise for...
Outburst floods released by failing barrier dams are likely to be catastrophic, posing high risk to downstream areas. However, emergent forecasting of the breaching process is still challenging due to the complex mechanisms as well as the lack of adequate data. During October and November 2018, four tremendous barrier lakes formed and breached on t...
Study region
The Huangfuchuan Basin on the Loess Plateau, China.
Study focus
Runoff and the sediment load of the Yellow River in China have received substantial attention owing to their marked declines over recent decades. Climate change and intensive anthropogenic activities—soil and water conservation measures on the Loess Plateau—are regarded a...
Event-based suspended sediment dynamics (ESSD) provides insights into soil erosion and sediment transport and signals of changing environments within catchments, but it is still poorly understood in the middle Yellow River basin (MYRB). This study focuses on the hysteresis relationship between suspended sediment concentration (SSC) and flow dischar...
For upland ephemeral gullies, gully erosion is strongly related to the formation and migration of cyclic steps. It is necessary to provide insight into the process of cyclic step development to accurately predict the pace of landscape evolution and soil loss. Information on the geometry of cyclic steps in subaerial environments is limited, and, to...
We conducted flume experiments in a step‐pool channel with different sediment supply regimes to explore how the sequencing and the grain‐size of sediment pulses affect channel evolution. Our results show that the sequencing of events is not a primary control as the trends in flow characteristics, bedload transport, sediment storage, step evolution,...
We present an efficient second- or fourth-order finite difference direct numerical simulation (DNS) solver using pencil-like domain decomposition parallel strategy, with the ability to handle different boundary conditions. The viscous term is treated implicitly, partial implicitly, or explicitly. The runtimes for different viscous treatments and di...
Image-based grain sizing has been used to measure grain size more efficiently compared to traditional methods (e.g. sieving and Wolman pebble count). However, current methods (e.g. BASEGRAIN) are largely based on detecting grain interstices from image intensity which not only require a significant level of expertise for parameter tuning but also un...
We present results from flume experiments in which an 8% steep channel with longitudinal width variations and step‐pool morphology was subjected to sediment feed pulses of different magnitude and frequency under constant water discharge. The channel response to these pulses included (a) large bedload transport rates, (b) bed aggradation, (c) fining...
The delayed response of fluvial rivers to external disturbances has been described by many researchers. To simulate such behavior, the rate law model (or the delayed response model) was developed by previous researchers, and has been applied to a series of river morphological problems. However, to date, the applicability of the rate law model has n...
With the increasing attention on environmental flow management for the maintenance of habitat diversity and ecosystem health of mountain gravel-bed rivers, much interest has been paid to how inter-flood low flow can affect gravel-bed river morphodynamics during subsequent flood events. Previous research has found that antecedent conditioning flow c...
Bedload particle hops are defined as successive motions of a particle from start to stop, characterizing one of the most fundamental processes of bedload sediment transport in rivers. Although two transport regimes have been recently identified for short and long hops, respectively, there is still the lack of a theory explaining the mean hop distan...
Many sand‐bed rivers worldwide have been experiencing significant reductions in sediment load over the past several decades. This is one of the causes of river delta drowning worldwide. This problem, however, has not been studied in detail in the context of sediment grain sorting. Considering the good performance of the original Engelund‐Hansen rel...
Runoff decrease triggered or exacerbated by human activities over the past decades on the Loess Plateau has been drawing nationwide concerns; quantifying human-induced runoff-altering factors is of great significance for decision-making on maintaining regional water, ecological and economic security. Sediment-trapping dams (STDs) construction and r...
With the increasing attention on environmental flow management for the maintenance of habitat diversity and ecosystem health of mountain gravel-bed rivers, much interest has been paid to how inter-flood low flow can affect gravel-bed river morphodynamics during subsequent flood events. Previous research has found that antecedent conditioning flow c...
Bed roughness height (k) is a key parameter for velocity prediction in open‐channel flows. There is not yet a firm consensus about whether characteristic particle size D84 or std (standard deviation of the channel thalweg) better describes k in gravel bed streams. A data set of 1,788 flume and 713 field measurements with a wide range of channel mor...
Incising rivers may be confined by low-slope, erodible hillslopes or steep, resistant sidewalls. In the latter case, the system forms a canyon. We present a morphodynamic model that includes the essential elements of a canyon incising into a plateau, including 1) abrasion-driven channel incision, 2) migration of a canyon-head knickpoint, 3) sedimen...
本书是在我国城市化进程快速发展的背景下,针对城市水资源严重短缺、水污染情势严峻、水旱灾害频繁等问题,有针对性地选择、调研了20个城市(其中国内城市8个,国外城市12个),总结各国城市化过程中在水安全保障方面的经验与教训,梳理了世界各国、特别是发达国家的大城市在水安全保障方面的发展历程,重点介绍国内外大都市的基本概况、自然条件、供需保障、节水与生态环境治理、洪涝灾害防治、地下水保护与修复、水文化和城市水智慧管理等方面的经验,为我国未来城市水安全保障建设提供一些经验。
As the resolution of DEMs is becoming higher, both the efficiency and accuracy of channel head recognition are important for drainage network extraction. In this paper, a D8-compatible high-efficient channel head recognition method is proposed. For each potential channel, this method first calculates a geomorphologic parameter series along the flow...
Significance
Fine-grained sediment transport systems (grain size under 2,000 μm) are ubiquitous over time and space on Earth and extraplanetary surfaces, and include rivers, deltaic coastal settings, and submarine, lahar, and subglacial systems. Forecasting the evolution of Earth’s surface requires a predictive algorithm for sediment transport. Her...