Mud-rock Flow Research Articles

Orbital Maneuver Optimization of Earth Observation Satellites Using an Adaptive Differential Evolution Algorithm

Earth observation satellite (EOS) systems often encounter emergency observation tasks oriented to sudden disasters (e.g., earthquake, tsunami, and mud-rock flow). However, EOS systems may not be able to provide feasible coverage time windows for emergencies, which requires that an appropriately selected satellite transfers its orbit for better observation. In this context, we investigate the orbit maneuver optimization problem. First, by analyzing the orbit coverage and dynamics, we construct three models for describing the orbit maneuver optimization problem. These models, respectively, consider the response time, ground resolution, and fuel consumption as optimization objectives to satisfy diverse user requirements. Second, we employ an adaptive differential evolution (DE) integrating ant colony optimization (ACO) to solve the optimization models, which is named ACODE. In ACODE, key components (i.e., genetic operations and control parameters) of DE are formed into a directed acyclic graph and an ACO is appropriately embedded into an algorithm framework to find reasonable combinations of the components from the graph. Third, we conduct extensive experimental studies to show the superiority of ACODE. Compared with three existing algorithms (i.e., EPSDE, CSO, and SLPSO), ACODE can achieve the best performances in terms of response time, ground resolution, and fuel consumption, respectively.

The rescue and relief plan based on the risk assessment of debris flow in Yunnan Province, China

Nowadays, natural disasters occur frequently in the world, causing a large number of casualties and economic losses. As a typical natural disaster caused by non-human activities, debris flow can not be fully prevented in advance. Therefore, timely emergency rescue and relief work after the disaster is particularly important. This paper takes Yunnan Province, a province with severe debris flow disaster, as an example to discuss the formulation of a reasonable and effective debris flow rescue and relief program, so as to ensure that the rescue and relief work can be carried out in an orderly manner and avoid greater losses caused by disasters. This paper uses a combination of qualitative analysis and quantitative analysis to study the deployment of personnel and material resources in the debris flow rescue and relief plan. First, we select the five influencing factors of the 24 ​hours precipitation, the number of rainstorm days in the month, the precipitation and the altitude of the month, and the terrain slope when the debris flow disaster occurs. We obtain the weight of each influencing factor through the Analytic Hierarchy Process (AHP), and use Fuzzy Evaluation Method to evaluate the risk of debris flow disaster index. Then through qualitative analysis, we concluded that debris flow rescue and disaster relief requires 3 types of rescue team personnel and 6 types of emergency supplies. According to the three indicators of the debris flow risk evaluation index, the affected population, and the direct economic loss of the disaster, the rescue personnel are dealt with through the Radial Basis Function neural network (RBFNN), so as to construct a debris flow rescue and disaster relief plan. Finally, taking the mud-rock flow event in Gongshan County, Nujiang Prefecture, Yunnan Province on May 31, 2018, as an example, a relevant plan for the event was formulated according to the rescue and relief plan constructed in this paper, and the feasibility of the plan was evaluated by comparing with the actual disaster relief data of the event.

The classifications of water and mud/rock inrush hazard: a review and update

Water and mud/rock inrush has been recognized as one of the major geological hazards in underground engineering, which resulted in huge casualties, financial losses, or environmental disruption. Classification of hazard types plays an important role in understanding hazard behavior and guiding corresponding treatment measures. Various classifications of water and mud/rock inrush have been widely discussed. This paper reviewed the available classifications and considered the applicability of those classifications for numerous hazard cases since the 1950s. However, the current classifications were incompatible with occurred cases. The mainly used three classifications based on criteria of material type, hazard size, and geological feature, therefore, were updated to eliminate the incompatibility. A classification was first presented to distinguish between various materials of water and mud/rock inrush, utilizing five terms including water flow, diluent mud flow, viscous mud flow, water-rock flow, and mud-rock flow, followed by presenting the definition and description. Second, this paper differentiated between small, moderate, large, and extremely large water and mud/rock inrush concerning the gushing water flux and mud/rock volume. Subsequently, four terms, including karst terrain, geological structure, differential weathering zone, and unconsolidated sediments, were used to make up a classification system that distinguishes hazard types through geological features. Sixteen subclasses were also subsequently defined and described. Moreover, to describe the hazard class in a shorthand way, a classification code was developed for each class of three updated classifications. Finally, the treatment technology for each hazard type was included in this paper. The updated classifications eliminated their incompatibility with numerous hazard cases, and targeted approaches for dealing with the hazards can now be quickly located, thereby saving time.

Spatial and temporal distribution and trend in flood and drought disasters in East China

Frequent floods and droughts have brought serious impact on economy, society and living environment in East China. Based on the disaster census data of rainstorm-induced flood (including landslide and mud-rock flow) and drought disasters in 637 counties (districts) in East China, the distribution and change of flood and drought disasters were analyzed. The results indicate that the number of records of flood disaster increased at a rate of 77.4 times per decade from 1984 to 2010, while that of drought disaster had no significant trend in East China as a whole. Population affected by floods and droughts increased at rates of 8.7 million and 3.8 million persons per decade, respectively, and the direct economic losses increased at rates of 12.6 billion and 1.9 billion Chinese Yuan per decade respectively, whereas the affected area and the total failure area of crops caused by floods and droughts showed no clear trends. Spatially, the number of records of floods in the southern parts of East China was higher than that in the northern parts, and Anhui, Jiangxi, Zhejiang and Fujian had more records of affected population, deaths, affected crops, total crop failures and direct economic losses, as well as more affected population and deaths. The affected crop area and total crop failure area by floods were also larger in Anhui, Jiangxi and Jiangsu. Drought disaster had higher number of records of affected population, affected crops, total crop failures and direct economic losses in Anhui, Jiangxi, Zhejiang and Shandong, and also affected more people and larger area of crops, leading to larger area of total crop failures and higher direct economic losses in Anhui, Jiangxi and Shandong. The results can provide reference for disaster risk regionalization and environmental risk assessment in East China.

Interannual Variation and Hazard Analysis of Meteorological Disasters in East China

Based on the historical data of meteorological disasters in East China during 2004–2015, the overall characteristics, interannual variations and the hazards of meteorological disasters in different provinces of East China were analyzed. The results indicated that flood disaster (including landslide and mud-rock flow) induced by rainstorms had caused the largest affected area and total failure area of crops, and also caused the largest number of affected people and collapsed houses. Strong convection weather (including gale, hail, thunder and lightning) disaster resulted in the largest number of deaths and typhoon disaster caused the greatest direct economic losses. There were significant decreasing trends in the affected area and the total failure area of crops, and the number of affected people and deaths during 2004–2015, while the direct economic loss caused by meteorological disasters showed no significant trend in East China. The hazards of meteorological disasters had obvious regional differences. In the northern part of East China, the hazards of drought and strong convection weather disasters were higher, but in the southern part, there were higher hazards of flood disaster. In the eastern coastal areas of East China, the hazards of typhoon disaster were higher. Hazard analysis of meteorological disasters has important significances for disaster prevention and mitigation, risk management and crisis response.

Experimental and Numerical Study on the Strain Behavior of Buried Pipelines Subjected to an Impact Load

Long-distance oil and gas pipelines are inevitably impacted by rockfalls during geologic hazards such as mud-rock flow and landslides, which have a serious effect on the safe operation of pipelines. In view of this, an experimental and numerical study on the strain behavior of buried pipelines under the impact load of rockfall was developed. The impact load exerted on the soil, and the strains of buried pipeline caused by the impact load were theoretically derived. A scale model experiment was conducted using a self-designed soil-box to simulate the complex geological conditions of the buried pipeline. The simulation model of hammer–soil–pipeline was established to investigate the dynamic response of the buried pipeline. Based on the theoretical, experimental, and finite element analysis (FEA) results, the overall strain behavior of the buried pipeline was obtained and the effects of parameters on the strain developments of the pipelines were analyzed. Research results show that the theoretical calculation results of the impact load and the peak strain were in good agreement with the experimental and FEA results, which indicates that the mathematical formula and the finite element models are accurate for the prediction of pipeline response under the impact load. In addition, decreasing the diameter, as well as increasing the wall thickness of the pipeline and the buried depth above the pipeline, could improve the ability of the pipeline to resist the impact load. These results could provide a reference for seismic design of pipelines in engineering.

Discussion on the Methods to Make the Military Highway Unimpeded in Plateau

This paper analyzed the types and feature of disaster which threatened the safety of military highway in plateau, and discussed the engineering methods to keep the military highway unimpeded from the disaster of mud-rock flow, landslide, sand-sliding, and damaged by flood, and the management methods.

Impulsive forces distribution along the sediment storage dam upstream face for different mud–rock flow unit weight

Because of the huge damage caused by mud-rock flow for the downstream life and property, engineering prevention must be given. It is one of fast and effective measures to build sediment storage dams in the formation zone to the circulation area. Due to the undercutting, scour and impact effect of mud-rock flows to sediment storage dam foundation or the unreasonable reconnaissance design, sediment storage dams possibly cause damage in the design period. However, the impulsive forces of mud-rock flow are the main reason to lead the engineering control structures (sediment storage dams, drainage grooves and block structure of pipe group) to damage. It is very important to study the law of mud-rock flow impulsive forces, and it is of great significance to prevent the damage of sediment storage dam and provide data support and technical support for the construction of sediment storage dam. First, the distribution rules of the maximum and mean value of the impulsive forces of mud-rock flow for the sediment storage dam upstream surface were studied for four mud-rock flow slurry unit weight as the experiment variable. The mud-rock flow impulsive forces value was collected by a numerical collection device that connected eight pressure sensors positioned in various locations, which received the mud-rock flow impact signal. Then, the distribution roles of the maximum and mean impulsive forces value imparted by water or water-rock flows were compared. The results indicate that (1) due to the randomness of particle impacts, the distribution law of the maximum impulsive forces is not obvious, and the maximum mud-rock flow impulsive forces of 99.277 kPa occur in A(1)B(3)C(7) (for a range of particle sizes of 2-4.5 cm); (2) the mud-rock flow impulsive forces mean value first increases and then decreases as the unit weight of the mud-rock flow increases; and (3) the mud-rock flow impulsive forces mean value gradually decreases along the height direction of the sediment storage dams' upstream surface and gradually decreases as the direction changes to the overflow section toward the dam abutments.

Dark Channel Prior-Based Altitude Extraction Method for a Single Mountain Remote Sensing Image

The altitude information of single remote sensing image may aid in detecting natural disasters such as landslides or mud-rock flow. Accordingly, in this letter, an approach based on dark channel prior is proposed for the altitude extraction of single remote sensing image, and it also overcomes the effect of mountain shadow. We first detect the mountain shadows based on machine learning, and then adjust the brightness of each shadow with an adaptive adjustment parameter. Next, we estimate the altitude information based on dark channel prior, including atmospheric light calculation and soft matting. The experimental results with real mountain remote sensing images demonstrate that the proposed algorithm can obtain the accurate relative altitude information, which is effective for the extraction of the relative altitude of single mountain remote sensing image with shadows.

Analysis of Solid T-Pier Dynamic Response to Debris Flow

In recent years, traffic lines are rapidly thrusting into the hilly regions[1]. It’s not hard to list such cases that bridges have been damaged by mud-rock flow. In this paper, it is studied that the dynamic response of the solid T-pier to mud-rock flow. a finite element method is applied to analyse the effects of the stress and strain of an T-pier under the impact action of mud-rock flow with different velocity.

Study on Rainfall-Induced Loess Geological Hazards Characteristics and Preventive Measures in Shanxi Province

Shanxi is one of the typical loessial areas in China, accompanied by plenty of loess geological disasters induced by rainfall. Based on the survey and compartment of geological disasters in the area, the geological conditions of them have been obtained by anglicizing the landslide, the mud-rock flow and dilapidation that have occurred. What’s more, the geological conditions, growing characteristics, and distribution law of these geological disasters induced by rainfall were summarized. On that basis, targeted preventive measures were put forward. These will provide reliable support to loess geological disaster warning work and to confirm the mechanism of hazard forming study.

New Fuzzy Classified Model for Disaster Loss

The quantitative assessment and classification of the disaster loss is a complex and difficult work. It often encounters the problem that different people will arbitrarily create different membership functions for the same issue, so the results of different model can not be compared. The other problem for the current classified models of the loss of disaster is that the evaluation factors may have mutual relationships between each other, which will affect the results. In the aim of solving these problems, a new model for fuzzy classification for the loss of disaster is proposed. Firstly, the related indexes are decomposed based on orthogonalization theory in order to solve mutual relations between the factors of loss. And then, in term of fuzzy and probabilistic reasoning theory, the fuzzy membership interval function of loss of disaster is obtained through establishing optimization model. Through solving the optimization model by Genetic algorithms, the fuzzy classified model is established. Finally, the model proposed is utilized to evaluate the loss of mud-rock flow in Bijie area Guizhou province. The conclusion shows that model proposed has highly precision to evaluate the loss of disaster.

Shanxi Highway Earthquake Disaster Risk Division Based on GIS

The paper take Shanxi Province as the object of study, through the analysis of the type after shaking the Shanxi Province road secondary geology disaster, the distribution rule and send the disaster mechanism's investigation and the analysis, the Shanxi Province earthquake secondary disaster mainly have the pitch geology disaster, the mud-rock flow disaster as well as the roadbed cave in three broad headings. The paper selection earthquake intensity, the terrain slope, the ground type, the surface cutting density, the surface cutting depth, the vegetation, the drainage density, the rainfall amount and so on take the pitch geology disaster's risk evaluating indicator, established three has ordered by type lives the geological disaster risk evaluating indicator system and the rank division system, and determined each influencing factor the weight. Has completed each influencing factor topic chart level using the GIS technology, through the GIS spatial analysis function, the superimposition has completed each kind of disaster's risk factor index chart. Finally can obtained the figure of shaanxi roadbed disaster risk classification.

Comparative study of the modern flood slackwater deposits in the upper reaches of Hanjiang and Weihe River Valleys, China

Modern flood slackwater deposits (SWD) were investigated and sampled in the upper reaches of Hanjiang River and the Weihe River valleys, China. Magnetic susceptibility and grain-size distribution were analyzed in the laboratory. The results show that the magnetic susceptibility values of the modern flood SWD vary between 20 × 10 −8 m 3 kg −1 and 60 × 10 −8 m 3 kg −1 , very close to that of the Malan Loess over the Weihe River basin . These sediments were newly deposited and uninfluenced by weathering and pedogenesis . The grain-size distribution of the modern flood SWD is dominated by silt, with sand and clay, indicating that these sediments were sourced from the suspended sediment load of floodwater. However, the grain-size distribution of the modern flood SWD has more sand-sized sediments in the upper reaches of Hanjiang River valley than that in the Weihe River valley. The modern flood SWD are defined as sandy silt and silty sand in the upper reaches of Hanjiang River valley, whereas the modern flood SWD are defined as silt, sandy silt and clayey silt in the Weihe River valley. The modern flood SWD have different sediment sources and transporting forces. The modern flood SWD are sourced mainly from the Qinling and the Bashan bedrock mountains and the related residual deposits, slopewash and mud-rock flow deposits in the upper reaches of Hanjiang River valley. During rainstorms , torrential tributary rivers can bring much coarse deposits into the mainstream of the Hanjiang River. However, the sources of the modern flood SWD are the eolian loess and the related surface soil in the Weihe River valley. Comparative study shows different sedimentary features between the modern flood SWD in the upper reaches of Hanjiang River valley and that in the Weihe River valley. These results give insight into the different sediment sources and transporting force of the modern flood SWD, which provide a basic reference to mitigate flood disasters, and to soil and water conservation.

Analysis of Characteristics of Potential Mud-Rock Flow in Huyu Valley

Taking potential debris flow in Huyu Valley as research object, the investigation of geological condition in Huyu Valley and different accompanied geological processes has been investigated such as complex topography, natural weathering and source of loose debris produced by the accumulation of human engineering activities, the role of uneven rainfall. With the analysis of potential debris flow characteristics of the Huyu Valley comprehensively, the results showes that the potential debris flow of the Huyu Valley already has satisfied conditions.

Rainfall-Induce Seepage Field of a High Slope and its Effect Factors

To investigate the rainfall-induce the seepage field of a high slope and effect factors, the theory of saturated-unsaturated infiltration was employed, and the numerical model of slope infiltration subjected to the rainfall are developed and programmed. The numerical results shown that, (1) With the increasing of the rainfall duration, rainfall water infiltration formed a transient saturated zone at slope surface, when the moist frontal surface reached to the groundwater level, the rainfall water would supply the groundwater. (2) Each effect factors on the seepage field play a strongest roles on the slope toe, weaker role on the middle part slope and weakest role on the top slope. (3) The longer rainfall duration, the deeper of infiltration depth. It also be deeper with the larger rainfall intensity, coefficient of permeability, the initial moisture content of the surface and the surface waterlogging depth. (4) The effect on seepage field would be faintly and could be ignored when the rainfall intensity was greater than 65.9mm/h and the surface waterlogging depth is greater than 0.3m. All above could provide technical ideas for analyzing slope seepage field under rainfall and accumulate fundamental data for early warning and preventing mud-rock flow and landslide.

Research on the Shield Measures of Flood Wave and Mud-rock Flow

Research on the Shield Measures of Flood Wave and Mud-rock Flow

Biodiversity of arbuscular mycorrhizal fungi in the hot-dry valley of the Jinsha River, southwest China

The diversity and community structure of arbuscular mycorrhizal fungi (AMF) in two sites (Pudu and Xiao Rivers) with different vegetation in the hot-dry valley of Jinsha River, southwest China, were investigated. Forty-three morphospecies of AMF were identified. Among them, 28 were in the genus Glomus, 7 in Acaulospora, 4 in Scutellospora, 2 in Entrophospora and 2 in Gigaspora. The most common and frequent genus was Glomus, and several species of Glomus and Gigaspora were the most common and frequent among the 43 species present in this hot-dry ecosystem. Although Sorenson's coefficient ( C s = 0.83) revealed considerable overlap in AM fungal species composition, AMF community structure varied considerably between the two sites. Non-random associations between AMF and host plants were commonly observed in this study and suggest some degree of host preference at the species level. AMF spore density (SD) was positively correlated with species richness (SR), and both were differed significantly between the undisturbed Pudu River site and the disturbed Xiao River site. We suggest that the hot-dry valley of Jinsha River appeared to harbor a high diversity of AMF with an uneven distribution, and that natural disturbance (mud-rock flow and landslides) is important in determining the diversity, density, and distribution of AMF.

Sequential analysis of China's hazards in geoscience

At the request of the IGU Study Group on Rapid Geomorphologic Hazards, the author has dealt with a lot of information on China's hazards in the course of compiling geomorphic hazard inventories. While analyzing those hazards throughout history, especially in the past two decades, the author found that quite many hazards used to be either interrelated or associated with each other. On the basis of a large number of eventful catastrophic cases both in China and its adjacent areas, this paper analyzes and sums up the following seven major sequences with respect to the occurrences and transformations in geo-hazards: 1) Dry-cold wind-drift sand (dust) storm type, 2) Warm-wet water-soil hazards type, 3) Wet-hot typhoon hazards type, 4) Alpine freezing-gravity hazards type, 5) Earthquake-rainstorm and mud-rock flow type, 6) Earthquake-forest fire hazards type and 7) Earthquake-tsunami hazards type.

The effects of the three gorges project on ecology and environment

The impacts of the Three Gorges Project are summarized in this paper from the viewpoint of the whole Changjiang (Yangtze) River basin and system ecology. Among the impacts on aquatic ecosystem and fishery of the river basin, the emphasis is placed on the survival of certain precious and rare species, such as the indigenous River Dolphin,Lipotes vexillifer. The impacts on terrestrial ecosystem include the ecological changes of the inundated, agricultural land, and the carrying capacity of the land for the resettled population in the upper reaches of the river, and changes of the environment of lowland district and lowlying paddy fields in the middle and lower reaches. The impacts on the surrounding geology and safety of the reservoir area include mud-rock flow, land slide and earthquake. The impacts on estuarine ecology involves increasing salinization of water and soil, erosion of coastline, and the security of Shanghai City. The impacts on the cultural landscape of the Three Gorges area are also highlighted. Through the overall and systematic analysis, the conclusion is drawn that there are both advantageous and disadvantageous aspects in the effects of the Three Gorges Project on ecology and environment, but the disadvantageous effects are the greater.