Barrier Lake Research Articles

Integrating an interferometric synthetic aperture radar technique and numerical simulation to investigate the Tongmai old deposit along the Sichuan-Tibet Railway

Numerous old deposits occur in the Eastern Himalayan Syntaxis, especially on the banks of the Yarlung Tsangpo River and its tributaries, where strong tectonic movement and riverine erosion increase the potential for landslides. The possible future deformation and failure processes of these old deposits and their impacts on the surrounding environment are important research topics. Field investigations and temporarily coherent point interferometry synthetic aperture radar (TCP-InSAR) monitoring show that the Tongmai old deposit is prone to catastrophic failure and landsliding. A geomorphological analysis and the related dating results indicate that the Tongmai old deposit consists of residual colluvial or early moraine debris and was formed later than 11.06 ± 0.94 ka BP. The TCP-InSAR analysis indicates that creep deformation is present within the deposit and that this creep is closely related to the precipitation and activity of nearby faults, which may cause slope failure and lead to landslide dam formation. As a result, this study further predicts the likely scale of a landslide dam through numerical simulations. In the worst-case scenario, a landslide will seriously block the Parlung Tsangpo River and form a dam with a height of 100–152 m and a length of approximately 2.4 km. The Tongmai old deposit will likely form a geohazard chain including landslides, barrier lakes, and outburst flooding. Finally, this paper discusses the influence of the Tongmai old deposit on river and landscape evolution.

Determination of low environmental free cyanide concentrations in freshwaters

Cyanide compounds are naturally emitted into the environment in low levels by degradation processes or emitted from anthropogenic sources. In surface water, complex cyanide compounds as well as “free cyanide” are present. The latter term covers hydrogen cyanide and cyanide compounds which easily liberate hydrogen cyanide under slightly acidic conditions. Especially free cyanide may cause adverse effects in the environment. To exclude negative impacts on freshwater systems, in the context of the European Water Framework Directive (WFD), preventive regulatory activities for free cyanide are currently under discussion. However, established analytical methods for quantification of free cyanide only obtain limits of quantification (LOQs) in the range of 1 μg L−1. Thus, these methods are not sufficiently sensitive for a potential environmental quality standard (EQS) compliance monitoring at water concentrations below the current predicted no effect concentration (PNEC) level of free cyanide. In the present study, a standardized continuous flow analysis (CFA) method for quantification of low free cyanide concentrations was adapted by applying a special system which allows an ultra-sensitive photometric detection of a colored cyanide derivative. By this means, LOQs in a range of one magnitude below the PNEC are achievable. The method was validated according to ISO/IEC 17025 requirements. Free cyanide concentrations in tested surface water samples from a small river and a barrier lake with low anthropogenic influences were very low and clearly below the PNEC. The results prove that the adapted CFA method is suitable for the analysis of low concentration free cyanide in freshwaters and appropriate for a possible EQS compliance monitoring.

Research on the improvement of hydrologic emergency monitoring capacity of barrier lake

Based on the analysis of the current situation of hydrologic emergency monitoring capability of barrier lake, and consider the actual needs of portability, environmental adaptability, technological advancement, accuracy suitability, reliability, etc. The overall structure of the improvement of hydrologic emergency monitoring capability of the barrier lake was designed, and the detailed program were carried out on data collection, data transmission, data processing and monitoring and guarantee. Through the improvement of emergency monitoring capacity, can provide better basic support for emergency disposal of barrier lake.

Simulation of Flood Process Based on the Model of Improved Barrier Lake's Gradual Dam Break Model

Simulation of Flood Process Based on the Model of Improved Barrier Lake's Gradual Dam Break Model

A big landslide on the Jinsha River, Tibet, China: geometric characteristics, causes, and future stability

On October 10, 2018, a big landslide occurred on the right bank of the Jinsha River in Baige Village, Polo Township, Jiangda County, Tibet (hereafter called the Baige landslide), which blocked the Jinsha River, forming a barrier lake. Afterward, the landslide dam broke, producing a flood. On November 3, the rear wall of this landslide failed again, also blocking the Jinsha River and creating a bigger barrier lake. Then, by local people, a discharge channel was excavated on the top of the landslide dam, making lake water cross over the discharge channel. As the water flow gradually increased, the landslide dam broke again, producing a more severe flood, resulting in huge economic losses downstream. The purpose of this study is to understand the cause of this landslide and predict the future stability of its head scarp, providing some support for the control scheme in the later stage. A digital orthophoto map (DOM) and a digital elevation model (DEM) of the landslide were created using an unmanned aerial vehicle. Then based on the DOM and DEM, the geometric characteristics of the landslide were described. Multi-phase Planet 5 images were used to infer the development process of the landslide. Finally, the cause of the landslide was analyzed based on the rainfall data and the limit equilibrium calculation. The results show that the Baige landslide was a self-weight creeping event, and its development and trigger were independent of the rainfall. Before the landslide, the slope experienced five stages of evolution: steady deformation, slow deformation, rapid deformation, steady deformation, and rapid deformation. The limit equilibrium calculation indicates that the stability coefficient of the middle section of the head scarp is the lowest, thus which should be cut down as a priority. This study provides a typical example of a self-weight creep type landslide, and an important reference for prediction and prevention of similar large landslides in the Tibetan Plateau, southwestern China.

Combined numerical investigation of the Yigong rock slide-debris avalanche and subsequent dam-break flood propagation in Tibet, China

On April 9, 2000, a long run-out landslide occurred in Yigong, Bomi county, Yarlung Zangbo Grand Canyon, China. The displaced materials traveled approximately 10 km with an elevation difference of 3 km, and finally generated a barrier lake at the toe of the mountain. The landslide and the collapse of the associated landslide dam killed 30 people, left more than 100 people missing, and destroyed several bridges. A combined debris avalanche-dam break flood simulation was performed in this study to better understand the long run-out mechanism and behaviors of such an event. The dynamic model DAN3D was used to simulate the run-out process of the sliding mass, while the Computational Fluid Dynamics software FLOW-3D was used to simulate the duration of landslide dam break and subsequent outburst flood propagation. Output data from the DAN3D simulation were used as input parameters for landslide dam modeling in FLOW-3D. Simulated results indicated that the duration of the landslide movement was estimated at 300 s with a maximum velocity of 90 m/s. Also, the maximum flow of the outburst flood at the Tongmai bridge was approximately 130,000 m3/s. The observed phenomena and measured data in situ verified the validity of the numerical simulation. It is expected that the work conducted in this study could help improve the understanding of the chain disaster of the rock slide-debris avalanche and subsequent dam-break flood.

Numerical Simulation and Risk Assessment of Cascade Reservoir Dam-Break

Despite the fact that cascade reservoirs are built in a large number of river basins nowadays, there is still an absence of studies on sequential embankment dam-break in cascade reservoirs. Therefore, numerical simulations and risk analyses of cascade reservoir dam-break are of practical engineering significance. In this study, by means of contacting the hydraulic features of upstream and downstream reservoirs with flood routing simulation (FRS) and flood-regulating calculation (FRC), a numerical model for the whole process of cascade reservoir breaching simulation (CRBS) is established based on a single-embankment dam-break model (Dam Breach Analysis—China Institute of Water Resources and Hydropower Research (DB-IWHR)). In a case study of a fundamental cascade reservoir system, in the upstream Tangjiashan barrier lake and the downstream reservoir II, the whole process of cascade reservoir dam-break is simulated and predicted under working schemes of different discharge capacities, and the risk of cascading breaching was also evaluated through CRBS. The results show that, in the dam-break of Tangjiashan barrier lake, the calculated values of the peak outflow rate are about 10% more than the recorded data, which are in an acceptable range. In the simulation of flood routing, the dam-break flood arrived at the downstream reservoir after 3 h. According to the predicted results of flood-regulating calculations and the dam-break simulation in the downstream reservoir, the risk of sequential dam-break can be effectively reduced by setting early warnings to decrease reservoir storage in advance and adding a second discharge tunnel to increase the discharge capacity. Alongside the simulation of flood routing and flood regulation, the whole process of cascade dam-break was completely simulated and the results of CRBS tend to be more reasonable; CRBS shows the great value of engineering application in the risk assessment and flood control of cascade reservoirs as an universal numerical prediction model.

An extended hesitant group decision-making technique based on the prospect theory for emergency situations

Throughout the present manuscript, we are going to introduce a novel group emergency decision-making technique in which the application of prospect theory explains the psychological behaviour of the decision maker who is affected by the hesitancy and uncertainty of cognition in decision making problems.\Instead of usual aggregation procedure, we implement here a new fusion technique that is based on modified version of extended hesitant fuzzy set (EHFS), and it definitely keeps possible amount of expert's information more than the existing fusion technique of hesitant fuzzy set (HFS).The main motivation of re-visiting the concept of EHFS comes from its potential role in increasing the richness of numerical appearance in the form of value-groups, and of course its ability in identifying various decision makers in decision making situations. Such a definition further expands the practical applications of HFSs.\Finally, we employ the barrier lake problem to illustrate the feasibility and the validity of the presented technique.

Back analysis of the breach flood of the “11.03” Baige barrier lake at the Upper Jinsha River

<p indent="0mm">A second landslide took place in China on 3 November 2018 at the provincial boundary between Sichuan and Tibet. This landslide blocked the reach of the Jinsha River and created a barrier lake with a <sc>5.79×10⁸ m³</sc> storage reservoir and a <sc>31000 m³/s</sc> peak breach flood. To reveal the beach formation process of the barrier lake, this paper gathers the lake’s geography and hydrology information and conducts material property tests including gradation, soil erosion, and shear strength experiments. Back analyzes on the dam breach hydrograph were conducted in tandem with the parametric sensitivity studies based on the tested knowledge using the DB-IWHR and DB-NHRI respectively. The measured results show that the theory, methods, and tools currently available for dam beach analysis can accurately predict the flood of a dam breach. Among the feedback regarding the hydraulic and geotechnical parameters, only those related to the relationship between the rate of erosion and shear stress are more important to the measured peak flow. The results from this study may provide a reference in the event of an emergency to other barrier lakes.

Effects of Rapid Water-Level Fluctuations on the Stability of an Unsaturated Reservoir Bank Slope

The instability of reservoir slope is likely to cause some severe natural hazards such as surge and barrier lake. In this study, the changes in seepage field and the distribution of the unsaturated zone of a reservoir bank slope subjected to rapid water-level fluctuations are investigated using the finite element method. The stability analysis of a reservoir slope under water-level fluctuation with a rate of 2 m/day is performed. The stability analysis is based on the theory of unsaturated soil mechanics and saturated-unsaturated seepage and accounts for the hydromechanical coupling effect. The changes in shear stress and strain as well as pore water pressure due to rapid water-level fluctuations are explicitly examined. Furthermore, the stability factor of safety, the underlying failure mechanism, and relevant influence factors are discussed. Based on the finite element analysis, it is found that the rapid loss of matrix suction would give rise to the surface landslide near the slope toe.

Breaches of the Baige Barrier Lake: Emergency response and dam breach flood

This paper documents the emergency response to the breaches of the Baige Barrier Lake. The lake was successively formed by landslides that occurred on October 10th and November 3rd, 2018 at the provincial border between Sichuan and Tibet in China. The barrier lake created by the “10.10” landslide breached on October 12th and triggered a flood with a peak discharge around 10000 m3/s. The residual landslide barrier was enhanced by a second landslide on November 3rd, resulting in a higher barrier with larger flood potential. An overflow channel was excavated in the crest of the barrier to prompt the breach to be triggered at a lower water level. The second breach happened on November 12th with a measured peak discharge of 31000 m3/s. Nearly 75000 people were evacuated before the two breaches. In order to prevent the downstream dams from possible over-topping, nearly 3.27 × 108 m3 of the stored volume was released from the Liyuan reservoir 688 km downstream of Baige Barrier Lake. This paper presents the measured hydrographs and the back-analysis results for the “11.03” barrier lake. It is shown that the modern models of dam breach hydraulics can reasonably reproduce the barrier breach hydrographs; however, further studies are needed to define the key parameters which highly influence the calculated results. Knowledge acquired during the emergency response to the case can be shared with experts working on breaches of embankment dams and can be referenced to promote both the theory study and the engineering practice to mitigate the potential risks caused by this type of catastrophic events.

Impact of spring freshet flooding and summer rainfall flooding on the water quality of an alpine\xa0barrier lake

BackgroundBarrier lakes, formed by river interception, are particularly influenced by the upstream river. As such, spring freshet flooding and summer rainfall flooding due to wet precipitation (e.g. snow and rainfall) may sharply increase the concentrations of nitrogen, phosphorous, and carbon compounds in barrier lakes. Too much nutrients will lead to lake eutrophication. In this study, we used Lake Jingpo, the world’s second largest alpine barrier lake, to examine the impact of spring freshet flooding and summer rainfall flooding on its water quality by building a hydrodynamic water quality model with MIKE 21.ResultsThe MIKE 21 HD hydrodynamic model and MIKE 21 AD convection and diffusion module were calibrated using meteorological data, hydrological data, and water quality data collected in 2018. All errors were in the acceptable range. According to model simulation results, the flow velocity in Lake Jingpo is generally weak (mostly lower than 0.015 m/s), but it increases to 0.045 m/s and above during spring freshet flooding (April–May) and summer rainfall flooding (August–September), which is much higher than in other months. The flow volume of its largest inflowing river reaches 4.81 × 108 m3, 29.77 × 108 m3, and 58.4 × 108 m3 during spring freshet flooding, summer rainfall flooding, and 30-year frequency rainfall flooding period, respectively. The longest diffusion distances from the lake mouth to the downstream way are 16.3 km, 33.1 km, and 43.6 km during the spring freshet flooding, summer rainfall flooding, and 30-year frequency rainfall flooding period, respectively. A larger amount of precipitation leads to longer diffusion distances and increased concentrations of total nitrogen (TN), total phosphorous (TP), chemical oxygen demand (CODMn), and ammonia–nitrogen (NH4-N) in the lake.ConclusionsThe sudden increase in water volume during spring flooding and summer rainfall flooding led to the rapid spread of nutrients and pollutants carried by the water into the barrier lake, resulting in a deterioration of lake water quality. In addition to pollution source control measures, ecological restoration, and the construction of a buffer system in the catchment are very important measures to effectively improve the buffer capacity of barrier lakes in light of spring freshet flooding and summer rainfall flooding.

Dam breach analysis for the Hongshiyan barrier lake

This paper presents a hyperbolic erosion rate model and a calculating circular slip surface method of lateral enlargement, and obtain a numerical analysis method of the relative stability dam-breach flood analysis. This paper develops a DB-IWHR procedure based on this principle, preparing a dam breach flood procedure is simple, easy to understand and use program in Excel 2010 spreadsheet. This improves this program, and writes a flood regulation calculation program, forming a complete program of dam breach flood and flood regulation. This paper calculates Hongshiyan barrier lake breach flood flow and the reservoirs downstream impacts.

Cover Image, Volume 7, Issue 2

AbstractThe cover image is based on the Focus Article Evaluation of barrier lake breach floods: Insights from recent case studies in China, by Zuyu Chen, Qiang Zhang, Shujing Chen, Lin Wang, and Xingbo Zhou. https://doi.org/10.1002/wat2.1408 image

Magnetotactic bacteria diversity of and magnetism contribution to sediment in Wudalianchi volcanic barrier lakes, NE China

Magnetotactic bacteria (MTB), the members of sediment microorganisms, play an important role in geochemical iron-cycling and sediment magnetism. This study aimed to investigate the diversity and magnetism contribution of MTB in three volcanic barrier lakes with different waterbody types (open waterbody, YC; semi-enclosed waterbody, WB; and enclosed waterbody, YYP). High-throughput sequencing results showed that MTB affiliated to Alphaproteobacteria, Betaproteobacteria and Nitrospira distributed widely in these lakes. The genera of Magnetococcus (98.10%) and Candidatus Magnetoovum (1.47%) were endemic to YC and WB, respectively. The changes in frequency-dependent susceptibility (χfd) values before and after magnetic collection in YC, WB and YYP samples were − 0.28%, 0.05% and − 0.22%, respectively. The magnetic susceptibility was significantly associated with Chao1 (R2 = 0.637 to 0.763, p < .01) and Shannon index (R2 = 0.803 to 0.998, p < .01). The room- and low-temperature magnetic characteristics of sediment samples were analyzed by vibrating sample magnetometer (VSM) and radio-frequency superconducting quantum interference device (SQUID). Results indicated that the presence or absence of MTB could lead to the changes in the room- and low-temperature magnetism of volcanic lake sediments, which would extend our knowledge of MTB magnetism contribution to volcanic ecosystems.

Retrieval of historical surface displacements of the Baige landslide from time-series SAR observations for retrospective analysis of the collapse event

Landslides and resultant barrier lakes are significant threats to human lives and infrastructures. Three-dimensional (3D) surface displacements can give vital clues to the exploration of internal structure of landslides, but they are difficult to be retrieved from spaceborne Synthetic Aperture Radar (SAR) observations due to the intrinsic limitation of SAR imaging geometry. Meanwhile, studies on predicting slope failure based on SAR-measured displacements are rarely seen. Here, we used SAR pixel offset tracking to investigate the Baige landslide before the collapse on 10 October 2018. 3D surface displacements retrieved by combining satellite SAR and optical observations revealed heterogeneous spatial patterns within the landslide complex. We observed linear secondary creep and accelerating tertiary creep prior to the failure from multi-sensor SAR data. The possibility of forecasting the failure was demonstrated by applying an inverse velocity method to the time-series displacements measured by Sentinel-1 during the tertiary creep, which is valuable for risk evaluation and disaster early warning.

Barrier lake bursting and flood routing in the Yarlung Tsangpo Grand Canyon in October 2018

Ice-soil mixture landslide dams formed frequently in the Tibetan Plateau in response to global warming, which pose great threats to both upstream and downstream areas due to inundation and lake bursting. On 17 October 2018, a large landslide, induced by an ice-avalanche at the Sedongpu Basin of the Yarlung Tsangpo, blocked the main course of the river near Gyalha. The barrier lake level rose quickly and the dam was overtopped naturally at 13:30 on 19 October 2018, generating a dam-breaching flood with a peak flow rate of 32,000 m3/s. This paper presents a comprehensive study of the disaster chain of landslide-barrier lake-dam breaching-river flooding in the Yarlung Tsangpo Grand Canyon, detailed geological and hydrological characteristics of the study region, rapid prediction of the dam breaching hydrograph using an erosion-based numerical model, and analysis of the flood routing in a 460 km canyon reach along the Yarlung Tsangpo. The simulated peak discharge at the dam site is over 30,000 m3/s and the corresponding dam-breaching and flood routing hydrographs agree well with the observations. Two additional scenarios with larger inflow rates are also considered. Results show that with a larger inflow into the barrier lake, the erosion of the dam body becomes more rapid. When the inflow rate is increased by six times, the peak dam-breaching discharge can be doubled. The study serves as basis to manage the flood risks due to landslide dam bursting on the Yarlung Tsangpo or similar rivers.

New insights into the occurrence of the Baige landslide along the Jinsha River in Tibet

The catastrophic Baige landslide occurred on October 10, 2018 in the Tibet Autonomous Region, China, and formed a barrier lake with a direct economic loss of 6.8 billion RMB (~ 963.5 million USD). After the landslide, field investigations were conducted both to support emergency operations and to understand the failure mechanism immediately after the landslide. Detailed field surveys, borehole exploration, discharge measurements, laboratory experiments, and meteorological analyses were employed in this study to explore the mechanisms underlying the Baige landslide. A key influence from the water source in Bogong Gully on the Baige landslide formation was newly found. The results show that the underground of the slope comprises extremely weathered serpentinite, and fresh rock has not yet been revealed in boreholes. The seepage outlets are 450–550 m higher than the Jinsha River and ~ 118 m lower than the bed of Bogong Gully. Water flow in the channel of Bogong Gully is strongly infiltrated, with a flow loss of 62.6%. Seepage into the Bogong Gully, along with the landslide, caused by the local geological structure and lithology, accelerated the extreme weathering of rock masses and promoted landslide formation. Furthermore, extreme annual rainfall also contributed to the occurrence of the Baige landslide by increasing the discharge of the Bogong Gully. Further risk management measures in this area should include increasing the depth of geological explorations and the construction of drainage systems.

Evaluation of barrier lake breach floods: Insights from recent case studies in China

AbstractHistorically, China has experienced frequent barrier lake breach hazards, and several cases have been monitored during their occurrences using complete breach flood hydrographs. These have enabled the analysis of dam breaches to be improved by merging hydraulics and soil mechanics expertise. Some novel improvements to analytical methods have also been published. This study presents the authors' proposed hyperbolic soil erosion and lateral enlargement models, together with a numerical algorithm that enables easy calculation of the breach flood hydrograph. In general, the peak flows calculated using this improved method agree with field measurements and are less sensitive to input parameters. The research outcomes are presented on an Excel spreadsheet (DB‐IWHR, online download available), and these are self‐explanatory with minimal tutorials. This software will be of particular use in an emergency situation, when it is necessary to quickly evaluate the breach flood. This study reviews four large‐scale barrier lake breaches; the Yigong breach which documented a peak flow close to 100,000 m3/s and the recent Baige breaches featuring burst recurrences over a month‐long period.This article is categorized under: Science of Water&gt; Water Extremes Engineering Water &gt; Planning Water

Barrier lake formation due to landslide impacting a river: A numerical study using a double layer-averaged two-phase flow model

A granular landslide impacting a river may lead to the formation of a landslide dam blocking the streamflow, and subsequently create a barrier lake. Should a barrier lake outburst, the flood may be destructive and spell disastrous consequences downstream. The last decade or so has witnessed a number of experimental and numerical investigations on barrier lake outburst flooding, whilst studies on barrier lake formation remain rare – a physically enhanced and practically viable mathematical model is still missing. Generally, barrier lake formation is characterized by multi-physical, interactive processes between water flow, multi-sized sediment transport and morphological evolution. Here, a new double layer-averaged two-phase flow model is proposed, which is an advance on existing continuum models that involve a single-phase flow assumption and presume a single sediment size, and discrete models that preclude fine grains and assume narrow grain size distributions. The proposed model is first validated against data from previous laboratory experiments of waves due to landslides impacting reservoirs and landslide dam formation over dry valleys. Then it is applied to explore the complicated mechanism and threshold for barrier lake formation. The water and grain velocities are shown to be disparate, characterizing the primary role of grains in driving water movement during subaqueous landslide motion and also demonstrating the need for a two-phase flow approach. The grain size effects are revealed, i.e., coarse grains and grain-size uniformity favour barrier lake formation. A new threshold condition is proposed for barrier lake formation, integrating the landslide-to-river momentum ratio and grain size effects. The present work facilitates a promising modelling framework for solving barrier lake formation, thereby underpinning the assessment of flood hazards due to barrier lakes.