China’s regional meteorological disaster loss analysis and evaluation based on grey cluster model

To evaluate the regional meteorological disaster loss of China, this paper analyzed the different types of meteorological disasters, including droughts, floods, tropical storms, snowstorms and hail disasters. Based on the analysis about Chinese geographical features, the historical characteristics of different meteorological disasters are analyzed. In particular, these meteorological disasters influence to agriculture production are discussed. According to the analysis of data from 2004 to 2010, we know that the distribution characteristics are very different about different disasters. Provinces like Heilongjiang, Liaoning, Jilin, Inner Mongolia, Gansu, Shanxi and Yunnan are serious affected areas of drought influence. And Anhui, Shandong, Jiangsu, Henan, Jiangxi, Hubei, Hunan, Guangxi, Sichuan and Heilongjiang are serious affected areas by floods and heavy rain. While Guangdong, Fujian, Zhejiang, Shanghai, Jiangsu and Shandong are mainly affected by tropical storms, Henan, Hebei, Hunan and Hubei are serious affected by snowstorms and hail disasters. Then, a novel method based on grey cluster model is constructed and combined with the regional meteorological disaster loss evaluation index system. A total of 31 provinces are considered to evaluate the integrated meteorological disaster losses. The results indicated that Beijing, Tianjin, Shanghai, Xizang, Qinghai and Ningxia belong to the lighter loss grey class. Jiangxi, Hubei, Hunan, Hainan, Sichuan and Gansu belong to the serious loss grey class. Other regions belong to the general loss grey class that the influence caused by meteorological disasters not better than the lighter loss grey class and not worst than the serious loss grey class.     

China’s regional rainstorm floods disaster evaluation based on grey incidence multiple-attribute decision model

This paper deals with the problem of the estimation of rainstorm floods disaster. Based on the relevant historical disaster data of Yearbook of Meteorological Disasters in China (2005–2010), the initial disaster data of 31 provinces, municipalities and autonomous regions in mainland China (Hong Kong, Macao and Taiwan excluded) are processed into evaluation indices values. And then, the incidence degrees of disaster data are calculated. The disaster situation of rainstorm floods disaster for each region in mainland China from 2004 to 2009 is estimated by applied the grey incidence decision model of the dynamic multiple attribute. Simultaneously, the comprehensive quantitative assessment of the rainstorm and flood disaster of each region in mainland China nearly 6 years is conducted. According to the assessment results of 2004–2009 torrential rain and flood disaster in Chinese mainland, the level division of disaster loss is investigated. And the disaster loss of mainland China’s 31 provinces, municipalities and autonomous regions is divided into five levels in which the national flood disaster situation zoning maps are constructed. The results demonstrate that the evaluation method of rainstorm floods disaster is practical and effective.     

Research on comprehensive carrying capacity of Beijing–Tianjin–Hebei region based on state-space method

Based on state-space method and component analysis, this paper builds a comprehensive evaluation system of carrying capacity for the Beijing–Tianjin–Hebei region from four aspects, namely economy, environment, ecology and energy. The results show that the comprehensive carrying capacity in this region gradually rises in recent years and the economic carrying capacity plays an important role in this situation. Ecological and environmental carrying capacity are gradually enhanced but still affected by water shortages. The energy carrying capacity of this region is low, which is the major factor restricting its sustainable development. Based on the empirical results, following policy suggestions should be adopted: Firstly, local government should accelerate technological progress, promoting the optimization and upgrading of industrial structure; Secondly, the contradiction between supply and demand of water resource should be solved gradually; thirdly, government should develop recycling economy, realizing the coordinated development of economy and environment; last but not least, saving energy and improving energy efficiency.     

Susceptibility evaluation and mapping of China’s landslides based on multi-source data

Landslides are occurring more frequently in China under the conditions of extreme rainfall and changing climate, according to News reports. Landslide hazard assessment remains an international focus on disaster prevention and mitigation, and it is an important step for compiling and quantitatively characterizing landslide damages. This paper collected and analyzed the historical landslide events data of the past 60 years in China. Validated by the frequencies and distributions of landslides, nine key factors (lithology, convexity, slope gradient, slope aspect, elevation, soil property, vegetation coverage, flow, and fracture) are selected to construct landslide susceptibility (LS) empirical models by back-propagation artificial neural network method. By integrating landslide empirical models with surface multi-source geospatial and remote sensing data, this paper further performs a large-scale LS assessment throughout China. The resulting landslide hazard assessment map of China clearly illustrates the hot spots of the high landslide potential areas, mostly concentrated in the southwest. The study implements a complete framework of multi-source data collecting, processing, modeling, and synthesizing that fulfills the assessment of LS and provides a theoretical basis and practical guide for predicting and mitigating landslide disasters potentially throughout China.

     

Ecological security comprehensive evaluation on mineral-resource enterprises

This article analyzed the meaning of mineral-resource security, set up the ecological security index system for mineral-resource enterprises, made a method of evaluating ecological security. After empirical analysis, it was pointed out that evaluating the…     

Research on analytical method of multi-slip surfaces of landslide based on softening characteristics of geomaterialEI北大核心CSCD

Landslide often exhibits characteristics of multi-stage destruction in practical engineering. However, the most dangerous slip surface and corresponding minimum safety factor are only concerned in general computing and design, this often leaves security risk. Considering the softening characteristics of geomaterial, a theoretical framework of effective simulation and evaluation of landslide multi-stage destruction is established with FLAC(3D) and Matlab software platform. Taken landslide in low-rent housing area of Dangjiaba in Xunyang county as an example, the process of forming multi-slip surfaces is revealed by progressive evolution of plastic shear strain, plastic tensile strain and shear strain increment and so on. It is shown that time and space sequences are not necessarily corresponding sequence. The temporal sequences of multi-slip surfaces are first-class main slip surface, second-class main slip surface and sub-slip surface; the spatial sequence is first-class master slip surface, sub-slip surface and second-class main slip surface. The number of slip surfaces is equal to the number of tension cracks in collecting on-site. The entry location of first-class main slip surface is in excellent agreement with the tension crack in the frontal part of landslide, but the positions of second-class master slip surface and sub-slip surface have little error with the tension crack on-site. The distribution and magnitude of strength parameters in the slip surfaces gradually change with the development of slip surface from peak strength to residual strength, this is the root reason why the multi-slip surfaces of landslide can be simulated effectively. The evolution of vector sum safety factors according the temporospatial distribution of material parameters in the multi-slip surfaces is obtained. It turns out that there are three different sequences of safety factors in the process of forming the multi-slip surfaces of landslide. It illustrates the active and passive relationships among all slip surfaces in the formation process.     

Risk evaluation of China’s natural disaster systems: an approach based on triangular fuzzy numbers and stochastic simulation

To deal effectively with the evaluation problem of natural disaster risk system affected by many uncertain factors, a multivariate connection number expression is presented. This expression is based on the index samples and evaluation grade criterions of natural disaster risk system and is capable of describing the hierarchy property and fuzziness of membership relationship between index samples and evaluation grade criterions. In this proposed method, the fuzzy evaluation grade criterion problem is resolved by combining triangular fuzzy numbers with multivariate connection number theory, and triangular fuzzy numbers are used to express the discrepancy degree coefficients of connection number and evaluation index weights. Accordingly, a connection number-based evaluation method for the natural disaster system of China (named CN-TFN for short) is established using triangular fuzzy numbers and stochastic simulation. The application results show that the spatial distribution of natural disaster risk grades of China has the trend of aggrandizement from west to east of China. The economically developed and densely populated coastal areas are very likely to have a high level of natural disaster risk grade or above; thus, these areas are the key regions of the natural disaster risk management of China. The results also show that the CN-TFN is able to reflect practical conditions of the evaluation problem of natural disaster system and to provide more reliability information as compared to the existing evaluation methods. This is as a result of its comprehensive usage of various information of subjective and objective uncertainties in the evaluation process of natural disaster risk system and its expression by confidence intervals. Due to the simplicity and generalization, the CN-TFM is applicable to comprehensive risk grade evaluation of various natural disaster systems.     

Source parameters estimation of 2003 Bam earthquake Mw 6.5 using empirical Green’s function method,based on an evolutionary approach

We determine the source parameters for 2003 (Mw 6.5) Bam, Iran, earthquake using an empirical Green’s function summation approach to model ground motions recorded by two strong motion stations at approximately 45 km epicentral distance. We introduce a genetic algorithm technique to optimize the fit to observed elastic response spectra. The proposed genetic algorithm technique allows us to explore the sensitivity of the results to multiple source parameters, including hypocenter location, focal mechanism (Strike and Dip), P-wave velocity in depth, fault dimension and rupture and healing velocities.     

Snow avalanche susceptibility evaluation in the central Shaluli Mountains of Tibetan Plateau based on machine learning method北大核心CSCD

Snow avalanches,which are widely and frequently developed at high elevations,seriously threatens the built traffic corridors in the Tibetan Plateau. Susceptibility evaluation of snow avalanche via machine learning model with a high forecast accuracy can be appled to quickly and effectively assess the regional avalanche risk. This paper took the central Shaluli Mountain region as the study area,in which the snow avalanche inventory was established through remote sensing interpretation and field investigation verification. We quantitatively extracted 17 evaluation factors via GIS-based analysis,and these factors were selected through the variance expansion factor（VIF）. Four machine learning models containing SVM,DT,MLP and KNN were used to compile the susceptibility index map of snow avalanches,and kappa coefficient and ROC curve were used to verify the accuracy. The results suggested that the susceptibility indexes obtained from SVM,DT,MLP and KNN were in the range of［0,0. 964］,［0,815］,［0,0. 995］and［0,1］,respectively. The accuracy test results show that these four models all have good prediction accuracy. Among them,the SVM model is the best. The results also indicated that the areas with the high snow avalanche susceptibility mainly distributed in Genie Mountain and Rigong Mountain,most of which were above the planation surface of the Tibetan Plateau. The average altitude of the extremely high snow-avalanche-prone areas is 4 939 m,while the average altitude of the high snow avalanche-prone areas is 4 859 m. The snow avalanche has low perniciousness on the Sichuan-Tibet Highway and the Sichuan-Tibet Railway in the study area. This study can provide theoretical basis and method reference for disaster prevention and mitigation of snow avalanche along Sichuan-Tibet Railway and other major projects across Shaluli Mountains region. © 2022 Science Press (China).     

Optimizing the routing of ship’s tropical cyclone avoidance based on the numerical forecasts

In this paper, an algorithm to design a shortest-time route for a ship to avoid a tropical cyclone (TC) is proposed. The proposed algorithm takes into account the influence of the changing winds and sea waves on ship’s speed and the corresponding risk using the forecasts from a numerical weather prediction model. Experimental results show that the new algorithm is able to save more time comparing with the traditional sector diagram typhoon avoidance method. In the application of the new algorithm to the navigation practice, the distance between adjacent alternative waypoints should be adjusted to meet the navigational needs, and the route should be updated simultaneously with TC forecasts from a numerical weather prediction model.     

Assessment of formaldehyde pollution based on Weber exponent and perception of people’s smell

Formaldehyde’s, as the irritant and active gas in atmosphere, pollution assessment by perception of people is significative. Although related study is seldom reported, it is necessary to improve the general contamination evaluation based on Weber–Fischna law and combine with human’s real feeling. Therefore, based on the law, Weber exponents were counted by a convenient optimal calculation, and the results could accurately embody the different standard range of formaldehyde concentration. In addition, by the human smell perception experiment, it was firstly found that the score assessment could also express the pollution condition more practically. According to the scores, expanding exponents could cause the assessment more clearly and closer to human real smell perception.     

China’s tropical cyclone disaster risk source analysis based on the gray density clustering

In recent years, tropical cyclones on the Pacific Northwest have decreased. We cannot infer that tropical cyclones impact China have reduced, because the Pacific Northwest is not homogeneous, and the variation characteristics of tropical cyclones in different sea areas are not clear. This paper uses gray relational density clustering algorithm to cluster tropical cyclone data sets between 1949 and 2008, according to the generated position of tropical cyclones, generated density and the possibility of landing. The Pacific Northwest is divided into different sea areas. Then, we analyze the risk of tropical cyclones generated in these sea areas. The results show that the probability of tropical cyclones landing generated in some sea areas is very high, reached 74 %, but the probability of tropical cyclones landing generated in other sea areas is only 2 %. Tropical cyclones generated in some sea areas are more likely to develop into typhoons, strong typhoons and so on, but the intensity of tropical cyclones generated in other sea areas is lower, there is little risk for China. Finally, according to the climate change stage trends, we divide the period 1949–2008 into three stages and analyze the tropical cyclone risk of each sea areas.     

New data about tsunami evidence on Russia’s Pacific coast based on instrumental measurements for 2009–2010

Doklady Earth Sciences -     

Safety factor calculation of soil slope reinforced with piles based on Hill’s model theory

How to evaluate reasonably the stability of a soil slope reinforced with piles (SSRP) still is an urgent problem. At present, the three-dimensional (3D) finite element strength reduction method has been used for the soil slope stability analysis. However, to accurately determine the global instability of soil slopes is the key to implementing the strength reduction finite element method. In this paper, the 3D finite element strength reduction algorithm (FESRA), based on Hill’s model theory, is proposed to assess the stability of SSRP and study on the relationship between the safety coefficients of SSRP and the displacements of slope mass. The results show that: (1) the relationship between the safety coefficients of SSRP and the displacements of slope mass agrees with the Hill’s model; (2) the proposed method (3D FESRA based on Hill’s model theory) in this study may take into account simultaneously the pile response and slope stability, and makes the results of SSRP stability analysis reasonable and reliable, which could be used as a reference for the evaluation of stability of the same type of slope; and (3) further study should be done to confirm whether the proposed method in this study is suitable for other types of slopes.     

The deep structure of the earth’s crust beneath the White Sea based on seismic data

New data on the deep structure of the White Sea have been obtained. An interpretation of traverses 510 km in total length is presented. It has been found that the area of the Black Sea that was surveyed with the traverses is characterized by a consolidated crust consisting of two layers. In the velocity sections, interleaving of horsts and grabens is sharply identified. In the central part of the sea, an isometric trough is found with sediments up to 7–8 km thick. The trough is surrounded by east- and northeast-striking ledges and faults. Rocks with anomalously increased velocities are found in the lower part of the sedimentary cover. The thickness of the upper crust is 5–7 km. The lower crust is of a complicated structure and is 30 km thick; it forms a large fold surrounded by rocks with decreased velocitys.     

Assessment of provincial waterlogging risk based on entropy weight TOPSIS–PCA method

Natural Hazards - Over the past few years, urban waterlogging disasters have caused serious losses to the national economy of China; therefore, creating technology for assessing waterlogging risk...     

Estimation of high-frequency seismic wave radiation on fault plane of 2008 Wenchuan earthquake based on improved empirical Green’s function

A new strategy for inversion of high-frequency wave radiation condition on the fault plan is exhibited. One-dimensional source model of large earthquake was divided into subfaults, each subfault contains a series of subsources to express high-frequency wave radiation. Envelope of large earthquakes can be expressed as a root-mean-squared with combination of envelope attenuation relationship from all subsources. The envelope attenuation relationship is considered as the empirical Green’s function. Distribution of subsources is estimated by envelope inversion. According to this method, the high-frequency (>?1 Hz) wave radiation areas of 2008 Wenchuan earthquake are generally inverted by the differential evolution using acceleration data from 27 near-field stations, while acceleration waveforms of the Lushan earthquake from 43 near-field stations were utilized to create attenuation envelope. High-frequency waves radiated in: (1) surface rupture areas, including Yingxiu and Beichuan areas; (2) close to the boundaries of asperities near Yingxiu, Yuejiashan, Beichuan and Nanba areas; (3) within 30 km length near the fault northeastern tip; (4) around Qingchuan area.

     

Some observations from radiometric ‘8 bit’ data of sediment thin sections based on alternative petrographic image analysis method

This paper deals with the experiment of sediment microstructure analysis especially microfabric mapping by digital imaging. For that purpose the greyscale images (Red band from RGB combination) of the thin sections have been prepared from the selected 12 samples. The basis of this mapping is the reflectance capacity of different sediments which is influenced by the physical parameters like grain size and colour. The reflectances of different sediments are represented in digital format by different DN values from 0–255 within the radiometric ranges of ‘8 bit’ data. Density slicing has been chosen as the method of microstructure mapping in this research. This study shows that lower DN values normally present dark coloured coarser sand and clay while higher DN values present light coloured finer sediment samples. In the selected samples for this study the maximum DN value has been found from micaceous materials. Another remarkable thing observed from the microfabric mapping is that the presence of coarser sediments forms complex microfabric pattern than the finer sediments in the study area. Though this method have some demerits, still its simple technique can be very useful for accurate microstructure analysis.