Zhiwei Li

Wuhan University | WHU · School of Water Resources and Hydropower Engineering

The distal reach of the Lower Jingjiang River (LJR) in the middle of the Yangtze River consists of five adjacent bends, among which the Qigongling Bend is a U-shaped meander with a mean sinuosity of 2.2 and the narrowest neck 525 m in width. This bend is slowly approaching neck cutoff owing to progressive bank erosion. An abnormal phenomenon has oc...

The goal of this study is to quantify morphodynamic roles of riparian vegetation and variable discharges in the process of neck cutoff, which is difficult to determine in natural meandering rivers due to the prolonged process and unpredictable occurrence of neck cutoffs. We achieved the goal in a highly sinuous flume channel (25 m × 6 m × 0.4 m) th...

Neck cutoffs in meandering rivers have long been thought to occur when the neck width (b) approximates the mean width of the parent channel (W). Empirical evidence for this paradigm is scarce, however, because tracking late-stage evolution of meander bends prior to cutoff at sufficient temporal resolutions is difficult in natural rivers. In this st...

Cutoffs, which include neck and chute cutoffs, are the results of the fluvial processes that fundamentally influence evolution of meandering rivers. Neck cutoff happens when the two limbs of a highly sinuous bend touch, whereas chute cutoff refers to the formation of a shortcut channel passing through a meander bend. In this review, we begin by dis...

The understanding of fluvial processes controlling morphological adjustments and stability of anabranching rivers remains incomplete. Focusing on a complex anabranching system in the Upper Yellow River, this study quantifies the morphological characteristics and lateral dynamics of islands and channels in four reaches over a 56‐km river course from...

River cutoffs and oxbow lakes represent ubiquitous features in alluvial plains, shaped by unidirectional meandering flow. Extensive studies have been conducted on these features as their presence immediately decreases meander sinuosity and plays a significant role in the long‐term eco‐morphodynamic and sedimentary evolution of landscapes they carve...

Alluvial rivers that exhibit multi-thread patterns are common in nature and can be the dominant channel morphology in large rivers. However, their ecological properties in response to diverse and dynamic channel morphology has gained limited attention and remained poorly understood. In this study, we adopted an ecohydraulic model by integrating a h...

The Yarlung Tsangpo Grand Canyon in southern Tibetan Plateau typically features incised bedrock and wide braided rivers. Yet, a recent discovery of two unique meandering streams within a young floodplain Cuoka offers insights into the formation of meandering rivers. Within the Cuoka floodplain, stratified layers of silty clay and root soil composit...

Southeast Xizang is one of the areas with the highest precipitation, runoff production, sediment yield, and transport on the Qinghai-Xizang Plateau and is also one of the areas most sensitive to climate change. The hydrological processes of the rivers in this area are not only affected by regional climate change. However, they are also closely rela...

Channel retreat can be responsible for the significant loss of banks, farmland, and wetlands, leading to drastic changes in fluvial sediment and local river regimes. Although current studies focus on the erosion process of natural river channels, the mechanism by which revetments, such as the flexible mattress, influence bank evolution is still unc...

The use of water detection (WD) indices to infer daily discharge (Qd) has a great potential to enrich needed hydrological data for understanding fluvial processes driving the morphological changes of braided rivers. However, no consensus has been reached on which one stands out for use in mid-sized braided rivers. In this study, we compared the phy...

Lowland multi-channel alluvial river systems are highly variable in frequency and magnitude of floodplain inundation and are vulnerable to human activities such as damming. In the Yangtze River Basin, the Three Gorges Dam (TGD) has trapped >80% of upstream sediment supply, causing downstream scouring and rapid geomorphic changes in river and its fl...

With the rising air temperature and precipitation, water and sediment flux in the Source Region of the Yangtze River have increased significantly since 2000. Nonetheless, the response of braided river morphology to climate-driven water and sediment flux change is still unknown. Water bodies of nine large braided rivers from 1990 to 2020 were extrac...

Rivers play a vital role in the maintenance of the biosphere and human society, since they participate in the global water cycle and provide varied habitats to support biodiversity. Microhabitat heterogeneity is regarded as a key factor driving biodiversity and it plays an active ecological role in different types of mountain rivers. Whether river...

Mountain rivers provide habitat or refuges and create migration corridors for diverse aquatic and riparian organisms. River microhabitat heterogeneity (RMH), which plays a key role in ecological restoration, is sensitive to external disturbances in mountain rivers. However, the effects of RMH, induced by hydro-geomorphological processes, on local m...

The lifespan of oxbow lakes in a meandering system typically exhibits considerable disparity due to the diverse evolutionary processes that lead to their terrestrialization. Although oxbow lakes generally undergo a long-term gradual shrinking trend, their hydrologic connectivity and morphologic variations under variable hydrologic conditions of the...

The spatiotemporal variability of groundwater level (GWL) is an important property of peatland hydrology that directly affects fluctuations of water storage. Nonetheless, current understanding of the variations of GWL in different time scales still remains unclear. In this study, two peatland watersheds (0.151 km for W1 and 0.844 km for W2) in the...

Suspended sediment concentrations in the Middle Yangtze River (MYR) reduced greatly after the Three Gorges Project operation, causing the composition of bed material to coarsen continuously. However, little is known about the non-equilibrium transport of graded suspended sediment owing to different bed material compositions (BMCs) along the MYR, an...

Bank retreat involving combinations of fluvial erosion and bank collapse has been found to be a major contributor to sediment transport, lateral migration, and planform evolution of meandering rivers. Previous studies have largely examined the general mechanism of cantilever bank failure. However, the composite process of beam (toppling) failure ca...

The Three Outlets Channel (TOC) consisting of three anabranching rivers formed due to natural avulsion by extremely high floods, is the primary water–sediment channel connecting the Jingjiang in the middle Yangtze River and Dongting Lake (the second largest freshwater lake in China). Since the impoundment of the Three Gorges Reservoir (TGR) in 2003...

Many large rivers are experiencing a significant reduction in sediment flux owing to human activity. Sediment transport capacity directly affects the predictive accuracy of sediment concentration in morphodynamic modelling. A total of 1092 datasets with extremely low sediment concentrations in a quasi-equilibrium state were selected at five hydrome...

The interaction between groundwater flow and river flow plays an important role in the bank erosion process, but field measurements on riparian groundwater flows remain very limited, especially in large river systems. Three monitoring wells of groundwater flow were constructed at two typical sites of the Middle Yangtze River (MYR) in 2021, with the...

The operation of the Xiaolangdi Reservoir has exerted prominent effects on the processes of sediment transport and channel evolution in the Lower Yellow River (LYR) since 2000. The investigation into the spatio-temporal adjustment characteristics of channel evolution is of significance to the management of the LYR covering different channel-pattern...

Mountain rivers exert critical ecological effects downstream by retaining or transmitting sediment and nutrients, providing habitat and refuge for diverse aquatic and riparian organisms, and creating migration corridors. River microhabitat heterogeneity (RMH), which plays a key role in ecological restoration and improvement, is sensitive to externa...

A climate-induced vegetation gradient induces marked variability in the character and behavior of anabranching reaches of the Upper Yellow River. Analysis of satellite imagery and field appraisal of biogeomorphic attributes shows that these reaches retain a good condition in geo-eco-hydrological terms. Degradational trends experienced in the late 2...

Sharp bends in the Lower Yellow River (LYR) remain highly active under the intensive river regulation works, threatening the safety of levees and riparian villages. Based on remote sensing images and hydrological data, the evolution processes of sharp bends in the LYR were quantitatively investigated. A total of 16 sharp bends were identified durin...

In the middle and lower reaches of alluvial rivers, various kinds of river regulation projects affecting natural channel evolution often are distributed due to the requirements of flood control, navigation, and channel stability. However, the influence of large-scale river regulation works on fluvial processes is not fully known. Therefore, a two-d...

In recent decades, climate warming has accelerated the melting of glaciers on the Qinghai-Tibet Plateau (QTP) so as to cause significant changes in water and sediment flux in the Source Region of Yangtze River (SRYR). The braided channel in the glacier piedmont in the SRYR may be adjusted due to the change of glacier runoff, but there is still a la...

Functional characteristics of braided rivers with very high elevations (>3400 m) located in the Qinghai-Tibet Plateau, China provide unique insight into fully understanding global braided river functioning, but have not yet been explored because of their remote locations and harsh physiographic conditions. In this study, we unveiled these character...

Computing movable bed roughness plays an important role in the modeling of flood routing and bed deformation, and the magnitude of movable bed roughness is closely associated with complex bedform configurations that change with the sand wave motion. The motion of sand wave is dependent on the incoming flow and sediment conditions and channel bounda...

It is of necessity to investigate the adjustment of flood discharge capacity in the Lower Yellow River (LYR) because of its profound importance in sediment transport and flood control decision-making, and additionally its magnitude is influenced by the channel and upstream boundary conditions, which have significantly varied with the ongoing implem...

It remains an open question whether the state of knowledge on bend hydrodynamics applies to sharp bends in the largest river systems on Earth. This paper reports a field investigation into the hydrodynamics in two consecutive sharp bends of the Middle Yangtze River (MYR), and demonstrates that the reduced‐order model of Blanckaert and de Vriend is...

The flow and sediment regime entering downstream rivers can be altered remarkably owing to upstream damming, and adjustments in low-water channel will occur consequently. The Upper Jingjiang Reach (UJR) downstream of the Three Gorges Dam (TGD) is chosen as the study region. Firstly, the rating curve between water level and discharge at each cross-s...

Among braided rivers developed on the Qinghai-Tibet Plateau of China at very high elevations (>3500 m), the middle and lower reaches of the Lhasa River have been affected by comprehensive human activities mainly involving dam construction, urbanization, farming, afforestation, and mining. In the current study, the impacts of these human activities...

The Yellow River Estuary (YRE) alternatively experienced channel aggradation and degradation during the period 1990–2016. To study the variation in flood discharge capacity during the process of river bed evolution, bankfull characteristic parameters were investigated on the basis of measured hydrological data and surveyed cross-sectional profiles,...

Floodplains on both sides of the braided reach in Lower Yellow River (LYR) are extremely wide, accounting for 80% of the total channel area, and large channel deformation occurs during the flood season in this reach. Thus, bed evolution and riverbank deformation are typical characteristics of channel evolution in the braided reach of LYR. To calcul...

The Yellow River (YR) covers three climatic zones including arid region, semi-arid region and temperate monsoon region, with frequent appearance of flow intermittence in the Lower Yellow River (LYR) before 1999. Channel migration occurs frequently in braided rivers, which is a major focus of study in geomorphology and river dynamics. The braided re...

This study investigated the roles of variable daily discharges in controlling processes of composite bank erosion in alpine meandering rivers located in the Zoige basin on the Qinghai-Tibet Plateau of China using Bank Stability and Toe Erosion Model (BSTEM). BSTEM was calibrated from compiled daily discharges, field measurements, and predetermined...

This study investigated bend morphology and dynamic changes of two highly convoluted meandering rivers, the Black River and the White River, in the Upper Yellow River Watershed of the Qinghai-Tibet Plateau (QTP), China. Using remotely sensed data, we characterized channel morphology and lateral changes of 290 meander bends in the two rivers. These...

In the meandering riverbank of the Upper Yellow River (UYR), the native alpine swamp meadow (AS) has continuously degenerated into an alpine meadow (AM) due to climate change and intensified grazing. Its implication on river morphology is still not well known. This study examined this effect by in situ measurings of (1) physical properties of roots...

Hyperconcentrated flows often occur in the middle and lower Yellow River (MLYR) and its tributaries, within which the main sediment source originates from the Loess Plateau of China due to serious water erosion. Little is known about the properties of river sediment that is transported by hyperconcentrated flows, particularly with respect to the mi...

Oxbow lakes generated from meandering river cutoffs are an indispensable component of riparian ecosystem. This study aimed to examine whether predictable patterns in water properties arise relative to oxbow lake geometry and lake-channel connectivity. We selected 24 oxbow lakes along a meandering river belt in Zoige Basin, the Tibetan Plateau, to c...

The long-term effects of increased temperatures on sediment fluxes in cold regions remain poorly investigated. Here, we examined the multidecadal changes in runoff and sediment fluxes in the Tuotuohe River, a headwater river of the Yangtze River on the Tibetan Plateau (TP). The sediment fluxes and runoff increased at rates of 0.03 ± 0.01 Mt/yr (5.9...

Understanding spatial variability of water table depth (WTD) in larger peatland area is crucial for peat conservation. This study investigated spatial patterns of WTDs in a peatland watershed of about 0.151 km2, located in the Zoige basin of the Qinghai-Tibet Plateau, China. Using conventional dipwells, we measured WTDs on 5/17/2017, 5/20/2017, 5/2...

Rainfall events have been reported of great influence on concentration and flux of aquatic organic carbon, but little is known in ditch water of peatlands. In this work we chose a ditch located in a peatland of Zoige Basin in northeastern Qinghai-Tibet Plateau, and studied the response of organic carbon (in dissolved form (DOC) and in particulate f...

This study examined the temporal properties of precipitation and actual evapotranspiration (ETa) in the Zoige basin of the Yellow River source region, China during the 1967-2011 period, as well as their impact on the area reduction of peatland. We extracted areas of different land use and land cover (LULC) types (peatland, grassland and forest land...

Climate change and gullies (and ditches) on peatlands are well known factors altering peat hydrology. Yet, exactly how this alteration emerges from interaction of these factors with groundwater dynamics is still not fully understood. In this study, we tackled this issue by coupling field measurement with model simulation using Visual MODFLOW. Groun...

The presence of microplastics was detected in the rivers of the Tibet Plateau.

Study region: The study area was in the upland peatland within the Zoige basin with elevations ranging between 3400 and 3800 m. It is located in the source area of Upper Yellow River that is developed on the Qinghai-Tibet Plateau, China. Study focus: We examined possible influence of two different types of gullies on groundwater hydrology in this a...

Riverbed structure in mountainous rivers is the product of the interplay between flow-sediment and riverbed, which determines the magnitude of riverbed resistance and significantly affects the bedload transport. In order to characterize the details of riverbed structure, this study proposed four new dimensionless parameters (concavity-convexity num...

Neck cutoff is an essential process limiting evolution ofmeandering rivers, in particular, the highly sinuous ones. Yet this process is extremely difficult to replicate in laboratory flumes. Here we reproduced this process in a laboratory flume by reducing at the 1/2500 scale the current planformof the Qigongling Bend (centerline length 13 km, chan...

Aeolian sand transport into rivers is a crucial factor influencing channel sediment dynamics and fluvial processes in rivers that flow through desert areas. Few studies have examined the dynamic processes, controlling factors, and the amount of aeolian sand transported into river channels. Here, we report a case study of aeolian sand transport into...

Peats have the unique ability of effectively storing water and carbon. Unfortunately, this ability has been undermined by worldwide peatland degradation. In the Zoige Basin, located in the northeastern Qinghai-Tibet Plateau, China, peatland degradation is particularly severe. Although climate change and (natural and artificial) drainage systems hav...

Neck cutoff is an essential process that significantly changes the morphodynamic characteristics of a meandering bend. In reality, however, observing natural processes of a neck cutoff is very difficult. In this study, we artificially triggered neck cutoffs by excavating a 0.4 m (width) × 0.5 m (depth) ditch to connect the beginning and ending of t...

Lhasa River basin is situated in the southern part of the Qinghai-Tibet Plateau, which is the most important region of economic and social development in Tibet. In order to efficiently utilize water resources in the basin and ease the shortage of regional electric power supply, Zhikong Reservoir was built in the upstream reach of the Lhasa River in...

The outer banks of meadow-type meandering river bends in the source zone of the Yellow River are especially vulnerable to bank failure. This study aims to understand how vegetation affects bank stability and the mechanism of bank failure, especially via a prediction of the width of a collapsed block of small rivers through a proposed bank stability...

Meandering channel with distorted bends develops along the Tarim River, the longest dryland river in China. The river bank and bed is majorly composed of coarse silt and fine sand and almost none clay content, making the bank strength very low. The development of meander bend in such environment hence is somehow irrational. We preliminarily investi...

physical principles underlying HG behavior. One impediment is the complexity of the natural

The root of riparian Homonoia (RRH), a medical plant with high economic value, is mainly distributed at riparian area in Southeast Asia. Its population has declined significantly, and the species has become endangered in recent decades. Understanding the habitat requirement, evaluating the habitat quality, and predicting its potential habitat are s...

Despite a growing interest in the sediment dynamics of dryland rivers, most research has been based on ephemeral streams in endogenic hydrological systems (runoff and sediment transport determined by local precipitation). Less attention, however, has been paid to allogenic and perennial dryland rivers. Here, we report a case study on the suspended...

Controlling desertification is an important ecological target for the Qinghai-Tibet Plateau of China, where studies on impacts of vegetation restoration measures on sandy soil improvement are still lacking. The Mugetan Desert in Guinan County, Qinghai Province, northeastern Qinghai-Tibet Plateau is a representative ecological restoration area. The...

It is generally believed that the slope of beaches can lead to a net downslope (usually offshore) sediment transport rate under shoaling waves, but very few high-quality measurements have been reported for a quantitative understanding of this phenomenon. In this study, full-scale (1:1) experiments of bottom-slope-induced net sheet-flow sediment tra...

A meandering channel has developed in the middle Tarim River, the longest inland river flowing through a hyperarid environment in northwestern China. Although the drainage basin of the Tarim River extends over 1 million km2, flow in downstream reaches is largely restricted to summer months, and irrigation pressures have made the flood season increa...

The Tarim River, the longest dryland river in an extremely arid region of China, has undergone ever-increasing human impacts over recent centuries (particularly since the late 1950s during which time large-scale land reclamation in the basin has taken place). Historical literature/maps, gauged hydrological data and satellite images were analyzed to...

The Ruoergai (Zoige) Wetland, the largest plateau peatland in the world, is located in the Yellow River source region. The discharge of the Yellow River increases greatly after flowing through the Ruoergai Wetland. The aquatic ecosystem of the Ruoergai Wetland is crucial to the whole Yellow River basin. The Ruoergai wetland has three main kinds of...

The Dongting Lake, a river-connected lake, plays a vital role in people's living, agricultural production, and ecological security of the Yangtze River basin. A systematic investigation of macroinvertebrates was conducted in the Dongting Lake during May 2004 - January 2005. Altogether 65 taxa belonging to 27 families and 53 genera were identified....

Step-pool system is one of the most important and widespread bed structures in mountain rivers and its failure mechanism plays a significant role on the stability and fluvial process of mountain river bed. Combined with the effects of water discharge, downstream scour of the step, surrounding grains, and grain impact, the forces acting on the keyst...

Mugetan sandy land is an inland desertification area of about 2,065 km² in the northeastern Qinghai-Tibet Plateau. In the ecological restoration region of the Mugetan sandy land, different crusts have formed under the action of vegetation in three types of sandy soil (i.e. semi-fixed sand dune, fixed sand dune and ancient fixed aeolian sandy soil)....

The Qinghai-Tibet Plateau is the source zone of China and Asian's large rivers, where river network well developed within the plateau. Under the superimposed impacts of plateau uplift, climate change, and human activities, the rivers may be significantly changed in the future, resulting in a series of interdisciplinary issues which are becoming a h...

The influence of vegetation upon bedload transport and channel morphodynamics is examined along a channel stability gradient ranging from meandering to anabranching to anabranching–braided to fully braided planform conditions along trunk and tributary reaches of the Upper Yellow River in western China. Although the regional geology and climate are...

The Yellow River is the third longest river in Asia and the sixth longest river in the world. The Upper Yellow River lies at the margins of and atop the Qinghai–Tibet Plateau, the highest plateau in the world with an average elevation of 4000 m above sea level and an area of about 2.6 million km2. This area contributes about 56 % of the total run-o...

Diverse wetlands such as alpine meadows, lakes and peatlands are extremely important resources for water supply and ecological protection of aquatic ecosystems in the source zone of the Yellow River. Field surveys (2010–2014) and interpretations of remote sensing images are used to provide insights into the distribution of wetlands in this region a...

Based on a thorough understanding of changing facts on fluvial morphodynamics and ecology on the Qinghai-Tibet Plateau, the research projects in River Morphodynamics and Stream Ecology of the Qinghai-Tibet Plateau study the effect of the plateau uplift on river network morphology, fluvial processes, aquatic ecology (i.e. wetland, lake and benthic i...

Rivers play an important role in people׳s living and agricultural production, however, intense human activities have broken the original ecological balance, and affected structures and functions of the river ecosystem. To restore the damaged river ecosystem back to a healthy status, effective ecological restoration measures need to be implemented....

The influence of vegetation upon bedload transport and channel morphodynamics is examined along a channel stability gradient ranging from meandering through anabranching through anabranching-braided to fully braided planform conditions along trunk and tributary reaches of the Upper Yellow River in western China. Although the regional geology and cl...

The stability of mountain stream bed is directly related to the effects of artificial step-pool system on mitigation of riverbed incision and control of debris flow. In this paper four cases of artificial step-pool system constructed in 2006-2010 are analyzed to figure out the control effect and the causes of destruction of the system. The step-for...

Riparian meadow plays a key role on controlling bank failure and maintaining channel meandering of meadow meandering rivers in source region of the Yellow River. Field investigation in 2011-2014 was conducted on root system of riparian vegetation, geometric dimension of slump blocks, and physical characteristics of root-soil composite in the Lanmuc...

The Ruoergai Swamp (Zoige) at the eastern margin of the Qinghai-Tibet Plateau in western China is the world's largest plateau peat wetland. Rapid shrinkage of the swamp since the 1950s has endangered the local terrestrial and aquatic ecosystems and the water supply of the upper Yellow River. The causes of the swamp shrinkage were evaluated based up...

Mid-channel bars occur in anabranching rivers. Fluvial processes of a mid-channel bar following variation of flow and sediment transportation are studied experimentally, which influences the equilibrium of flow and sediment transport in anabranching channel. The processes of development and erosion of a mid-channel bar were observed and measured un...