Tangjiashan Barrier Lake Research Articles

Flood inundation evolution of barrier lake and evaluation of regional ecological spatiotemporal response-a case study of Sichuan-Tibet region.

The Himalayan volcanic earthquake zone has significantly impacted China's Sichuan-Tibet region. Many barriers have formed as a result of the earthquake and secondary disasters, such as landslides, which have blocked the river. The breach of the barrier lake seriously threatens the lives and property safety of downstream personnel. There has been little research on the surrounding ecology for the later treatment of the barrier lake. This paper aims to scientifically predict the risk of dam break in a barrier lake as well as to explore its impact on the ecological environment and put forward controllable measures. Based on four major barrier lake events in the Sichuan-Tibet area, Diexihaizi, Tangjiashan barrier lake, and so on, we extract water bodies from remote sensing images and use the HEC-RAS (Hydrologic Engineering Center of River Analysis System) model to investigate whether there is a dam break risk and the route of the dam break is predictable. Simultaneously, from 1990 to 2020, the smallest administrative region is located. The InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) model is utilized to evaluate and analyze its habitat and create an evaluation based on flood inundation data. The results suggest that a stable barrier lake (such as Diexihaizi) has a sound effect on the habitat quality index following engineering treatment. The development of the barrier lake has altered the types of neighboring lands used and the natural patterns of the region's landscape. The habitat quality index will marginally deteriorate within a 1-km radius of the barrier lake. However, the quality of habitats in the area ranging within 3km and 5km has improved. It is necessary to discharge and strengthen the barrier lake artificially. Human-controlled regions, according to studies, will recover higher habitat quality index values than other locations. Whether the barrier lake has a positive impact on the surrounding area, on the other hand, is primarily dependent on the original ecology. The development of barrier lakes is damaging and unprofitable in Tibet, where the actual ecology is better in the short term. Still, in Sichuan Province, where the habitat quality is relatively low, the appearance of dammed lakes has played a role in correcting the ecology.

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.

Research on the hydrological emergency monitoring system of high-risk Barrier Lake based on PDCA theory

In recent years, there have been some barrier lakes formed by earthquakes or landslides in China, such as the Tangjiashan barrier lake in 2008 and the Baige barrier lakes (twice) in 2018. The barrier lake often brings huge destructive risks to the upstream and downstream affected areas. In order to protect the lives and property of the people, it is necessary to carry out corresponding scientific disposal. The premise of disposal is to obtain detailed and reliable dynamic monitoring information. And hydrological monitoring information is the basis of various types of information. Therefore, hydrological emergency monitoring must be carried out to obtain the information. This paper summarizes and puts forward the design of the high-risk barrier lake hydrological emergency monitoring system based on PDCA theory, which can provide support and guidance for the implementation of hydrological emergency monitoring in the future, and it has a strong practical significance.

Cascading dam breach process simulation using a coupled modeling platform

This study evaluates the possibility of a cascade failure by developing a coupled breach-modeling platform based on one-dimensional flow modeling of the river channel, flood propagation, regulation process of reservoir fluctuation, overtopping with breaching, and wave damping downstream. A hyperbolic model of the DB-IWHR was embedded into the platform to simulate the dam breaching process. Five breach models and software were used to calculate the Tangjiashan barrier lake breaching. The results of a sensitivity study were then compared with the measured data. The peak flow and the time of occurrence were confirmed to be predictable with a reasonable accuracy if the input values were within ranges appropriate for the model. The approach was applied to a case involving two layout planning schemes for a cascade of rock-filled dams under extreme operating conditions. The probability of the failure of a key control cascade downstream caused by a continuous cascade breach upstream was simulated. Moreover, measures to prevent the transmission of risk by advance warnings were investigated. The proposed methodology and the discharge capacity measures provide guidelines to assess the risk to a cascade of dams under extreme operating conditions and offer support for the design criteria of unusual discharge structures for very large dams.

Breach mechanism and numerical modeling of barrier dam due to overtopping failure

As a production of natural process, the barrier dam has its own features, and is easily to fail due to overtopping. Based on the breach mechanism revealed by small-scale model tests and the draining case of Tangjiashan Barrier Lake, a numerical breach model for barrier dam due to overtopping failure is put forward. In terms of the geometrical characteristics, physical and mechanical properties of barrier dam, a unified approach is developed to model the evolution of breaches in the dam crest and downstream slope, as well as the morphological change of the barrier dam in streamwise. Furthermore, different failure modes, such as one- and two-sided erosion, incomplete and base erosion are taken into account. The draining of Tangjiashan Barrier Lake is adopted to testify the present model, and the comparison of measured and calculated results indicates the rationality of the present model with the relative errors are less than 10% for peak discharge, final breach widths, and time to peak; in addition, the calculated breach discharge hydrograph and the changing process of water level are in accord with the measured data. The sensitivity analysis shows that the residual dam height after breaching and soil erodibility affect the breach flow prediction of the barrier dam significantly, whereas the one- or two-sided breach mode is less sensitive.

Discussion of “Back Analysis of the Draining Process of the Tangjiashan Barrier Lake” by Zuyu Chen, Liqiu Ma, Shu Yu, Shujing Chen, Xingbo Zhou, Ping Sun, and Xu Li

Discussion of “Back Analysis of the Draining Process of the Tangjiashan Barrier Lake” by Zuyu Chen, Liqiu Ma, Shu Yu, Shujing Chen, Xingbo Zhou, Ping Sun, and Xu Li

Closure to “Back Analysis of the Draining Process of Tangjiashan Barrier Lake” by Zuyu Chen, Liqiu Ma, Shu Yu, Shujing Chen, Xingbo Zhou, Ping Sun, and Xu Li

Closure to “Back Analysis of the Draining Process of Tangjiashan Barrier Lake” by Zuyu Chen, Liqiu Ma, Shu Yu, Shujing Chen, Xingbo Zhou, Ping Sun, and Xu Li

Registration for Variform Object of Remote-Sensing Image Using Improved Robust Weighted Kernel Principal Component Analysis

For pre- and post-earthquake remote-sensing images, registration is a challenging task due to the possible deformations of the objects to be registered. To overcome this problem, in a previous paper, we proposed a registration method based on robust weighted kernel principal component analysis (RWKPCA) to precisely register the variform objects. Which was proved very effective in capturing the common robust kernel principal components (RKPCs) and generalized well for registration. Compared with previous paper, there are two improvements in this paper: Firstly, we developed the improved RWKPCA method from the robust loss function, and theoretically proved the robustness of the method; Secondly, a new construction of weight function by projection residual was given, which enables the great reduction of computing time. Finally, two experiments were conducted on the remote-sensing image registration in Wenchuan earthquake and change detection of Tangjiashan barrier lake, and the results showed that compared with the previous method, the registration accuracy was increased while the computational time was decreased a lot. Meanwhile, good performance on the change detection of barrier lake is obtained.

Back Analysis of the Draining Process of the Tangjiashan Barrier Lake

AbstractThis study attempts to use a dam breach model to reproduce the well-monitored outflow hydrograph obtained during the dam breaching process of the Tangjiashan barrier lake, which was formed by a landslide triggered by the Wenchuan earthquake on May 12, 2008 in China. The key parameters that affect the model results, such as soil erosion and breach lateral enlargement, are reviewed by using field measurements followed by extensive sensitivity studies. The present paper advocates a hyperbolic model for soil erosion rate and a circular slip surface approach for breach lateral enlargement, which contribute to more reliable model results. The governing equations are solved using a numerical method that allows straightforward calculations coded in an Excel 2007 spreadsheet. This provides an easy, transparent, and robust tool that could enable practicing engineers to perform dam breach analyses with a comprehensive understanding of the uncertainties involved. This back analysis confirms that the peak outf...

The Feature Information Rapid Extraction of Barrier Lake and Downstream Channel Based on Point Cloud Data

The goal of this paper is extracting the Barrier Lake characteristics information quickly using LiDAR point cloud data. This research includes two keys. One is extracting the boundary information of Barrier Lake and downstream channel based on the point cloud data and high-resolution image data. The other one is generating DEM with point cloud data, and then extracting slope, aspect, profile, ridge lines and valley lines from the DEM. As the Tangjiashan barrier lake as the study area induced by Wenchuan earthquake in 2008, the researching content of this paper is extracting Tangjiashan Barrier Lake and downstream channel characteristics information using the LiDAR point cloud data in this area. The characteristics information contains the water boundary information and terrain characteristics information. The extraction result of Tangjiashan barrier lake characteristics information is more accurate. Meanwhile, the extraction time is not too long to meet the needs of accessing characteristics information quickly. Therefore, this study provides a set of complete and workable methods about extracting barrier lake information accurately and quickly.

Dynamic analysis of the Wenchuan Earthquake disaster and reconstruction with 3-year remote sensing data

Earth observation is an effective technique that plays an important role in earthquake damage reduction and reconstruction. This paper introduces the results of dynamic analysis on monitoring and assessing heavily impacted areas affected by the Wenchuan Earthquake using remote sensing data acquired in the past 3 years from 2008 to 2010. Immediately after the disaster on 12 May 2008, the Chinese Academy of Sciences launched a project entitled ‘Wenchuan Earthquake Disasters Monitoring and Assessment Using Remote Sensing Technology.’ More than 400 images from 17 satellites and 20.2TB airborne remote sensing data were acquired to facilitate quick monitoring and evaluation of severely damaged areas in 14 counties. Results of the image analyses were forwarded on a timely basis to assist with consultative service and decision-making support. In subsequent years, in order to monitor the process of environmental restoration and reconstruction, airborne optical remote sensing images covering most of the severely damaged areas were again acquired in May 2009 and April 2010. These images were analyzed and compared along with images from 2008. Results were useful in support of further work on environmental protection and reconstruction in earthquake-damaged areas. Three typical areas were selected for illustrative purposes including Tangjiashan Barrier Lake, Beichuan County, and counties of Yingxiu and the new Beichuan. These results well demonstrate the importance and effectiveness of the utility of earth observation for disaster mitigation and reconstruction.

Draining the Tangjiashan Barrier Lake

This paper documents the emergency breaching of an approximately 110-m-high landslide dam that was created at Tangjiashan during the 2008 Wenchuan earthquake of China’s Southwest Sichuan Province. As an emergency measure, a 13-m-deep channel was excavated to reduce the volume and head of the released water during the dam breaching and to create a controlled flood that was intended to prevent catastrophic consequence for 1.2 million people downstream. From detailed monitoring and survey works carried out during and after the dam break it was found that (1) the breaching initiated at a pool water level of 742.1 m with an estimated flow velocity of 2.4 m/s, and virtually terminated at a pool water level of 720.3 m with an estimated velocity of 2.5 m/s, which can be regarded as the incipient velocity that initiated erosions for the soils at this particular site; (2) a controlled flood released 167× 106 -m3 reservoir water with a peak flow rate of 6,500 m3 /s , during which a maximum velocity of about 5.0 m/s...

Change detection of an earthquake-induced barrier lake based on remote sensing image classification

The earthquake-induced barrier lakes that are caused by landslides are at risk of bursting after excessive rainfall, and they are a serious threat to the surrounding residents. This paper proposes a change detection approach of the barrier lake using the method of post-classification comparison combined with background subtraction. The case studied in the paper is the detection of the Tangjiashan barrier lake, which is one of the largest lakes induced by the Wenchuan Earthquake on 12 May 2008. Both the pre- (31 March 2007) and post-earthquake (16 May 2008) images of the Advanced Land Observing Satellite (ALOS) Advanced Visible and Near Infrared Radiometer type 2 (AVINER-2) were collected in the paper. The results show that the river widened through the Zhangping area, increasing from 90 m pre-earthquake to 545 m post-earthquake, and the surface area of the barrier lake increased from 0.945 km2 to 1.471 km2.

THE APPLICATION OF CBERS-02B DATA TO THE DISASTER MONITORING OF THE “5, 12” WENCHUAN EARTHQUAKE: THE DYNAMIC MONITORING OF THE TANGJIASHAN BARRIER LAKE

In this paper,the authors used multi-temporal CCD data from the CBERS-02B satellite and adopted the human-computer interaction to extract water information from the Tangjiashan barrier lake. Statistic analysis was employed to detect the change of the lake area so as to understand its variation and trend. The result can provide some quantitative basis for the study of geological hazards situation and hazards prevention.

Monitoring and assessment of barrier lakes formed after the Wenchuan earthquake based on multitemporal remote sensing data

The Wenchuan earthquake on May 12, 2008, triggered many secondary disasters, among which the barrier lakes formed by landslides were extremely serious. We monitored the number and spatial distribution of the barrier lakes in the earthquake-hit area from ADS40 airborne images, which covered areas of about 23,700 km2. The results showed that there were 51 barrier lakes in the monitored area; among these, 10 were large-scale lakes and 14 were middle-sized lakes. The barrier lakes were distributed along the Longmen Mountain fault from the northeast to southwest direction. We used the dimensionless blockage index (DBI) to assess the potential risk of the barrier lakes. A small DBI value indicated a stable barrier lake, but the lake might have a higher risk with potential accumulative secondary disasters. Our study emphasized the monitoring and analysis of the high-risk Tangjiashan Barrier Lake from the multitemporal ADS40 airborne images acquired on May 16, 19, 23, and 27. We found that the water level at this barrier lake reached 66 m within 15 days after the barrier lake was formed, and the reservoir storage capacity reached 1.2 × 108 m3 with an increase of 8 × 106 m3 of water per day. Therefore, it faced a very real and urgent risk of dam break and overflow, considering the predicted storm rainfall and the continuous aftershocks. According to the analysis results, airborne remote sensing demonstrated the advantages of being intelligent, being able to maneuver, and providing high resolution. These advantages allowed us to quickly monitor and assess the distribution and dynamic changes of the barrier lakes in the earthquake-hit region using multitemporal airborne remote sensing images.

Draining Tangjiashan Barrier Lake after Wenchuan Earthquake and the flood propagation after the dam break

Tangjiashan Barrier Lake is one of the largest barrier lakes caused by the Wenchuan Earthquake. Its risk analysis, emergency plan and effect of the emergency plan are introduced in this paper. The dam height of Tangjiashan Barrier Dam is about 105 m, and the reservoir storage capacity is 3.2×108 m3. When the dam broke the flood peak were estimated to be larger than 48000 m3/s, which might cause a enormous disaster to the downstream cities and residents. A discharge channel with 13 m deep and 8 m wide was drug, so that the water may flow out of the lake before the dam breaks. As a result, the drainage and risk mitigation project are successful. During the drainage process, the flood peak was about 6500 m3/s, and about 1.6×108 m3 of water was drained off and the residual reservoir capacity was only 8.97×107 m3. A new channel with average width 100 m was formed, which can bear floods of 200 years frequency. The successful experience and the collected data can be used to deal with the similar natural disasters in future.

Impact of community healthcare service center in emergency response to natural disaster

The Medical Healthcare Service Center,located at the Youxian District,Mianyang City of Sichuan Province,successfully rescued the people affected by the Wenchuan earthquake and the Tangjiashan barrier lake with great help from the senior hospitals.We suggest that the community healthcare service center could play an important role in emergency response system. Key words: Community health centers; Emergency mdeical services

Outburst risk of barrier lakes in Sichuan, China

34 barrier lakes induced by earthquake have been formed by wedged debris on the river channels after a massive earthquake happening on May 12 in Sichuan, China. Among them, the Tangjiashan Barrier Lake is the largest one. It faces very urgent risk of dam breaking when water level reaches the top and begins overflow in case of storm rainfalls and continually aftershocks, threatening already devastated cities and villages with about 1.5 million people downstream. The outburst of a similar barrier lake occurred in the Minjiang River in 1933, causing a catastrophic flood. Risk analysis indicates that not all barrier lakes are highly dangerous. Only those lakes with very high dams and water to be filled up in short period need to be dealt with immediately.