Barrier Lake Research Articles

Palaeoclimate and palaeoseismic events discovered in Diexi barrier lake on the Minjiang River, China

Abstract. Studies on the formation of the ancient Diexi barrier lake on the Mingjiang River, southwestern China, have long been carried out. However, investigations into the correlation between the palaeoclimate and palaeoenvironment and the palaeoseismic events in this area are rarely found in literature. The present study took sediments from the ancient Diexi barrier lake to investigate the palaeoclimate, palaeoenvironment and palaeoseismic events. A drilling at the centre of the barrier lake was conducted and the core of about 260 m long was examined. The palaeoclimate and palaeoenvironment indicators (sporopollen, carbon and oxygen isotopes, organic matter, calcium carbonate, granularity) from the sediments have been tested and analysed, and indicate that there were 10 climatic and environmental periods between 30 000 and 15 000 a BP (before present). The discovered disturbance segments in the core indicate there were at least 10 seismic events during that period. The consistency between climate change and seismic events indicates that a strong seismicity is normally accompanied by a climatic variation. This may be a useful supplement for climate and geohazard predictions in the future.

Monitoring Geologic Hazards and Vegetation Recovery in the Wenchuan Earthquake Region Using Aerial Photography

On 12 May 2008, the 8.0-magnitude Wenchuan earthquake occurred in Sichuan Province, China, triggering thousands of landslides, debris flows, and barrier lakes, leading to a substantial loss of life and damage to the local environment and infrastructure. This study aimed to monitor the status of geologic hazards and vegetation recovery in a post-earthquake disaster area using high-resolution aerial photography from 2008 to 2011, acquired from the Center for Earth Observation and Digital Earth (CEODE), Chinese Academy of Sciences. The distribution and range of hazards were identified in 15 large, representative geologic hazard areas triggered by the Wenchuan earthquake. After conducting an overlay analysis, the variations of these hazards between successive years were analyzed to reflect the geologic hazard development and vegetation recovery. The results showed that in the first year after the Wenchuan earthquake, debris flows occurred frequently with high intensity. Resultantly, with the source material becoming less available and the slope structure stabilizing, the intensity and frequency of debris flows gradually decreased with time. The development rate of debris flows between 2008 and 2011 was 3% per year. The lithology played a dominant role in the formation of debris flows, and the topography and hazard size in the earthquake affected area also had an influence on the debris flow development process. Meanwhile, the overall geologic hazard area decreased at 12% per year, and the vegetation recovery on the landslide mass was 15% to 20% per year between 2008 and 2011. The outcomes of this study provide supporting data for ecological recovery as well as debris flow control and prevention projects in hazard-prone areas.

Study of disaster characteristics and emergency rescue engineering for June 5, 2009 Jiweishan rockslide in Wulong of Chongqing using remote sensing technology

Rockslide is one of the main geological disasters in China. Each rockslide disaster has different characteristics,so its emergency and rescue plans are not identical. The digital elevation model before and after rockslide and the aerial image with 0. 35 m resolution were used as the data source. The digital landslide technologies were also adopted to quantitatively interpret such information of the Jiweishan rockslide as scale, topographical change,direction of movement,disaster features and affected limits. The Jiweishan rockslide is a typical multiple huge disaster that experienced a chain reaction consisting of "creep sliding along week layer-burnish surrounding rock- fragment flow- barrier lake". According to the disaster characteristics,the best location of engineering work for buried miners underground was explored by combining the collected layout of the Gonghe iron ore deposit with the results of the remote sensing interpretation for the Jiweishan rockslide. The results obtained by the authors could provide valuable references for the study of rockslide disaster characteristics and emergency rescue engineering using remote sensing technology in the future.

Reliability Optimization of Barrier Lake Disposal Based on Engineering and Cost

Reliability Optimization of Barrier Lake Disposal Based on Engineering and Cost

Spatiotemporal simulation and risk analysis of dam-break flooding based on cellular automata

Chapinghe Barrier Lake was the largest among the barrier lakes formed in the aftermath of the magnitude 5.12 Wenchuan Earthquake. A rapid quantitative method for the evaluation of potential risk to lives and properties downstream was of the utmost importance for disaster management. The proposed method is based on spatiotemporal simulation using different dam-break scenarios and downstream hazard distribution analyses. This article adopts a cellular automata (CA) model to synthetically integrate multiple sets of geographic layers, including those containing the models needed for routine computation of flood hazards and those needed for vulnerability analysis of the people living downstream. A CA-based simulation and analysis method integrating hydrologic/hydraulic mechanisms is herein introduced, and relevant techniques are investigated. Our prototype experiment demonstrates that the proposed CA-based flood-hazard model can be conveniently integrated into a digital earth system and can further provide real-time simulation analyses of dam-break flood risks.

Recurrence of strong earthquakes in the active Hovd Fault Zone, Mongolian Altay

A geological, geomorphic, and paleoseismological study of paleoseismodislocation systems has been carried out. Numerous indications of prehistoric strong earthquakes expressed in sediments deposited in the fault-line region due to the formation of transient barrier lakes were revealed in the active Hovd Fault Zone on the eastern slope of the Mongolian Altay during a paleoseismological study of young near-surface sediments in trenches and dug pits. The paleosoils buried by these sediments were radiocarbon-dated. It has been established that the strongest earthquakes with magnitudes of ∼8, which took place here 7200, 6600, 1500, and later than 700 years ago, substantially changed the topography in the epicentral zone. By analogy with the results of paleoseismological investigations performed in the Gorny Altay and the western Mongolian Altay, the data obtained shed light on the recurrence of the strongest seismic events in the Great Altay.

Interactive Virtual Globe Service System Based on OsgEarth

These online tools, led by the Google Earth virtual globe, are changing the way we interact with spatial data. This paper focused on how to develop a virtual globe-based interactive service system for risk assessment of dam-break in Barrier Lake. Unlike existing work, virtual globe technology was used as a medium for geographic visualization and analysis. Moreover, GIS spatial analysis and real-time interactive operation with the service system will also be implemented to support the simulation analysis of dab-break flood routing. The experimental results show that the scheme developed in this paper is efficient and feasible.

Improved Robust Kernel Subspace for Object-Based Registration and Change Detection

Postclassification comparison is an approach to detect changes in remote sensing images that have strongly inhomogeneous scenes. It is a challenging task to register pre- and postevent scenarios, because variform classifications may induce an inadequate number of homologous points to be used as tie points. In this letter, we show how the variform objects can be precisely registered using their robust kernel subspace. There are two primary contributions in our work. First, a robust kernel subspace analysis method is proposed to capture the common patterns of the variform objects. Second, a registration method based on the common patterns and their preimage are derived. The power of the proposed approach is demonstrated by two real applications: one for lake monitoring in the Jiayu region and the other for damage mapping of earthquake-induced barrier lake at Tangjiashan. The results show that the proposed method is effective in structural pattern analysis and object registration.

Biodiversity in saline coastal lagoons: patterns of distribution and human impacts on sponge and ascidian assemblages

AbstractAimEstuaries are common focal points for industry and development, but often little is known of their biology or ecology, particularly for sessile taxa. We sought to examine how size and opening regime of shallow saline coastal lakes altered patterns of diversity and abundance for a suite of epifaunal invertebrates. We also sought to determine how these patterns were affected by the degree of lake modification by humans.LocationWe sampled 10 coastal barrier lakes of a range of sizes, opening regimes and degrees of modification in south‐eastern Australia.MethodsWe quantified the diversity and abundance of sponges and ascidians in transects and undertook timed searches for these fauna at multiple locations within each coastal lake; placing the data in a hypothesis testing framework.ResultsEighteen species of sponge, most of which appear to be new to science, and six species of ascidian were found among the 10 lakes we examined. All sponges and most ascidians were extremely patchily distributed among the lakes. Few species were widespread, with most restricted to one or two lakes. Diversity was largest in lakes mostly open to the sea and large in size. Diversity and abundance were smaller in highly modified lakes.Main ConclusionsWe suggest that sponge assemblages in these lakes consist of a combination of species largely restricted in distribution to lakes, and marine species that are at their limits of distribution. In contrast, ascidian assemblages were dominated by species that were more widespread. Conservation of biodiversity in these systems will rely heavily on effective management, which will in turn rely on a sound scientific understanding of natural processes; this will require the management of water quality through protection of catchments. The control of opening regimes should consider the ecological consequences rather than being purely based on ad hoc and reactive management.

Deriving landslide dam geometry from remote sensing images for the rapid assessment of critical parameters related to dam-breach hazards

Dam-breaches that cause outburst floods may induce downstream hazards. Because landslide dams can breach soon after they are formed, it is critical to assess the stability quickly to enable prompt action. However, dam geometry, an essential component of hazard evaluation, is not available in most cases. Our research proposes a procedure that utilizes post-landslide orthorectified remote sensing images and the pre-landslide Digital Terrain Model in the Geographic Information System to estimate the geometry of a particular dam. The procedure includes the following three modules: (1) the selection of the reference points on the dam and lake boundaries, (2) the interpolation of the dam-crest elevation, and (3) the estimation of dam-geometry parameters (i.e., the height, length, and width), the catchment area, the volumes of barrier lake and landslides dam. This procedure is demonstrated through a case study of the Namasha Landslide Dam in Taiwan. It was shown the dam-surface elevation estimated from the proposed procedure can approximate the elevation derived from profile leveling after the formation of the landslide dam. Thus, it is feasible to assess the critical parameters required for the landslide dam hazard assessment rapidly once the ortho-photo data are available. The proposed procedure is useful for quick and efficient decision making regarding hazard mitigation.

Landslide dam and subsequent dam-break flood estimation using HEC-RAS model in Northern Pakistan

On the morning of January 4, 2010, a massive landslide swept the Attabad and Sarat villages into the Hunza River. The debris from the landslide blocked the low-lying river, creating a barrier lake in the area and poses a major threat to the villages located downstream. The aim of the current study was to evaluate the environmental advantages and disadvantages created by the formation of the artificial lake. For this purpose, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data were used to create the contours and triangulated irregular network (TIN) of the region. Data from ‘Google Earth’ image on March 19, 2010 were used as the reference and to determine the river bed elevation of the study area. Landsat satellite data of Enhanced Thematic Mapper Plus (ETM+) sensor on January 10, March 15, April 24 and May 2, 2010, were used for constructing the Geographic Information System (GIS) layers of the river banks, land use area, overbank flow area and water area estimation. Our results show that the area covered by the water in the lake has increased from 1.28 km2 on January 10, 2010 to 6.25 km2 on May 2, 2010. The total upstream urban area affected by the river blockage is 13.99 km2. We also applied the Hydrologic Engineering Center River Analysis System (HEC-RAS) model to estimate the potential catastrophes due to dam burst for different peak outflow scenarios with conclusions and recommendations.

Mechanisms and runout characteristics of the rainfall-triggered debris flow in Xiaojiagou in Sichuan Province, China

The 2008 Wenchuan earthquake induced a large number of landslides, and a vast amount of loose landslide materials deposited on steep hill slopes or in channels. Such loose materials can become sources of deadly debris flows once triggered by storms. On 13 August 2010, a storm swept Yingxiu and its vicinity, triggering a catastrophic debris flow with a volume of 1.17 million m3 in Xiaojiagou Ravine. The debris flow buried 1,100 m of road, blocked a river and formed a debris flow barrier lake. A detailed field study was conducted to understand the initiation mechanisms and runout characteristics of this debris flow. Two types of debris flows are identified, namely hill-slope debris flow and channelized debris flow. The hill-slope debris flow was triggered in the forms of firehose effect, rilling and landsliding, whereas the channelized debris flow was triggered in the form of channel-bed failure. This debris flow was a water–rock flow since most particles were gravel, cobble or larger rocks and the fraction of silt and clay was less than 2%. Grain contact friction, pore-pressure effects and inertial grain collision were the three most important physical interactions within the debris flow. Such interactions yielded a smaller runout distance (593 m) compared with those of mud–rock flows of similar size.

Object registration for remote sensing images using robust kernel pattern vectors

The registration of multitemperal remote sensing images before and after a disaster is a challenging problem. The main reason is that there is a dearth of homologous features that can be used as tie points for registration of variform objects. This paper proposes a new registration method based on robust kernel pattern vector (KPV) for water objects in the remote sensing images, which have complex deformation before and after a disaster. We show how the variform objects can be precisely registered using their robust kernel pattern vectors (RKPVs). The contribution can be divided into three parts. First, a novel shape descriptor, named as kernel pattern vector (KPV), is defined. Second, a robust kernel principal component analysis (RKPCA) method is proposed, which can not only capture the common pattern of the variform objects but can also act as the Criterion for outlier detection. Finally, a registration approach is derived based on the implicit RKPVs. We demonstrate the power of the proposed approach by comparing it with other existing methods using two real cases: one for lake monitoring in the Jiayu region, and the other for damage mapping of earthquake-induced barrier lake at Tangjiashan (2008 Wenchuan Earthquake). The results show that the method is effective in capturing the common structural pattern of the variform objects before and after a disaster.

Efficient dam break flood simulation methods for developing a preliminary evacuation plan after the Wenchuan Earthquake

Abstract. The Xiaojiaqiao barrier lake, which was the second largest barrier lake formed by the Wenchuan Earthquake had seriously threatened the lives and property of the population downstream. The lake was finally dredged successfully on 7 June 2008. Because of the limited time available to conduct an inundation potential analysis and make an evacuation plan, barrier lake information extraction and real-time dam break flood simulation should be carried out quickly, integrating remote sensing and geographic information system (GIS) techniques with hydrologic/hydraulic analysis. In this paper, a technical framework and several key techniques for this real-time preliminary evacuation planning are introduced. An object-oriented method was used to extract hydrological information on the barrier lake from unmanned aerial vehicle (UAV) remote sensing images. The real-time flood routine was calculated by using shallow-water equations, which were solved by means of a finite volume scheme on multiblock structured grids. The results of the hydraulic computations are visualized and analyzed in a 3-D geographic information system for inundation potential analysis, and an emergency response plan is made. The results show that if either a full-break or a half-break situation had occurred for the Chapinghe barrier lake on 19 May 2008, then the Xiaoba Town region and the Sangzao Town region would have been affected, but the downstream towns would have been less influenced. Preliminary evacuation plans under different dam break situations can be effectively made using these methods.

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.

THE PERFORMANCE OF DAMS DURING THE WENCHUAN 5-12 EARTHQUAKE AND LESSONS LEARNED FROM THE EVENT

The performance of dams and hydropower structures during the Wenchuan 5-12 Earthquake is reviewed. Experiences and lessons learned from the seismic catastrophe of the earthquake are summarized and comments and discussions are forwarded, on the following subjects: (1) current seismic design specifications for hydraulic structures; (2) reservoir triggered earthquakes; (3) effects of secondary earthquake disasters, especially landslides and barrier lakes; and (4) mitigation measures and facilities especially for rescue activities.

Empirical-statistical models based on remote sensing for estimating the volume of landslides induced by the Wenchuan earthquake

The Wenchuan Ms 8.0 earthquake on May 12, 2008 induced a huge number of landslides. The distribution and volume of the landslides are very important for assessing risks and understanding the landslide — debris flow — barrier lake — bursts flood disaster chain. The number and the area of landslides in a wide region can be easily obtained by remote sensing technique, while the volume is relatively difficult to obtain because it requires some detailed geometric information of slope failure surface and sub-surface. Different empirical models for estimating landslide volume were discussed based on the data of 107 landslides in the earthquake-stricken area. The volume data of these landslides were collected by field survey. Their areas were obtained by interpreting remote sensing images while their apparent friction coefficients and height were extracted from the images unifying DEM (digital elevation model). By analyzing the relationships between the volume and the area, apparent friction coefficients, and the height, two models were established, one for the adaptation of a magnitude scale landslide events in a wide range of region, another for the adaptation in a small scope. The correlation coefficients (R2) are 0.7977 and 0.8913, respectively. The results estimated by the two models agree well with the measurement data.

THE APPLICATION OF SATELLITE REMOTE SENSING TO ANSWERING THE RIDDLE OF LOULAN'S DISAPPEARANCE

The disappearance of the ancient Loulan city in Xinjiang has been regarded as a riddle. Through the application of satellite remote sensing technology and the interpretation of the distribution characteristics of the old river in Loulan area from TM image, the authors have found that there are two landslide sites and barrier lakes located in the upper reaches of the river. Based on this discovery, it is thought that the abandoning and final disappearance of Loulan might be attributed to landslides which cut off its water source and broke off its water supply.

The freshwater crabs of Lake Kivu (Crustacea: Decapoda: Brachyura: Potamonautidae)

Lake Kivu is a volcanic barrier lake in the East African rift valley whose freshwater crab fauna (Potamonautidae) is largely undocumented. The present taxonomic revision revealed four species of freshwater crabs from Lake Kivu: Potamonautes idjwiensis (Chace, 1942), Potamonautes mutandensis (Chace, 1942), Potamonautes lirrangensis (Rathbun, 1904) and Potamonautes bourgaultae, sp. nov. Potamonautes idjwiensis and P. mutandensis are redescribed and distributional maps of all four species are provided. The four species are compared with each other, each species is illustrated, and a key to the species is included. The freshwater crab diversities of the African Great Lakes are also briefly compared.

A novel adaptive weights proximity matrix for image registration based on R-SIFT

We present an efficient and robust algorithm for image registration, which can be used to cope with large geometric and intensity variations between pair of images. There are two main contributions in this paper. First, a new robust scale invariant feature transform descriptor (R-SIFT) is presented, which is invariant under affine transformation. The second contribution is the development of a novel proximity matrix with adaptive weights based on the R-SIFT descriptor, in which the elements of the matrix combine the geometric information of feature points with the gradient information of feature points’ neighborhood. Quantitative comparisons of our algorithm with the related methods show a significant improvement in the presence of large viewpoint changes, scale changes, and illumination contrast. Experimental results for remote sensing image registration show our method outperforms the related methods. Finally, the experimental results of the proposed method applied to the problem of change detection of earthquake induced barrier lake are presented, validating the proposed algorithm.