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Flood-induced disaster caused by rainfall in loess area often occurs, causing serious engineering disasters and casualties. The investigation and cause analysis of existing flood-induced disaster can provide experience for disaster prevention and control areas. From mid-August to early October, 2021, more than 50 days of rainfall triggered a large number of Flood-induced disaster in the loess area of east Gansu Province. The damages made G211 national highway close for two weeks. This paper introduces the on-the-spot investigation of the flood disaster caused by this rainfall in villages and towns along route 211 and its vicinity, it happened in the villages and towns are mainly the collapse of loess living caves, collapse of earth-houses and fall of earth-walls. Geo-disasters on the road are subsidence and cracking of the soil filling subgrade, collapse of the cutting slope at inner side of the road, shallow flow-slide of the main slope. These disasters are small in scale and weak in influence, but it is large in number and serious in disastrous. We also investigated the positive and passive effects of vegetation on the loess slope. Based on investigation of the flood-induced disaster, this paper analyzes its causes, and puts forward some preventive measures in the construction of villages, towns and roads.

Israel is located in the Middle East. Due to it’s geographical position and low-amount and uneven-distributed precipitation, Israel is short of natural fresh water resources. National government has developed innovative technologies in producing, transporting and recycling water resources to solve its water shortage crisis. After several-year efforts, Israel has changed from a country with water scarcity to an agricultural country with highly-effective use of water resources. Israel is even called as the ‘Vegetable Basket for European countries’. This paper firstly introduces Israel’s geography and climate condition, as well as it’s water type, then introduces the utilization structure of water resources, and finally introduces six scientific and technological innovations used to prevent water crisis. This paper aims to share experience of effective use and management of water resources and to provide references for international cooperation and academic study.

Several local landslides occurred in the Quwajiasa giant landslide in the upper reaches of the Yellow River from 1985 to 2020, which seriously threatened the safety of G227 national highway and the housing security of the villagers below. Taking the H1 landslides at the middle front of the northeast section of Quwajiasa landslide on September 20, 2019 as an example, based on the field investigation, deformation data and stability analysis, this paper intends to research the deformation and failure characteristics of the landslide, further analyze the sliding range as it moves through dynamic simulation, and the back analysis validated that after the movement of the No.1 shallow landslide following the Frictional model, it accumulated in the highway G227 and residential area from the retaining wall to Jungong Road, however, the No.2 shallow landslide in unstable state was predicted to accumulat in the residential area from Jungong road to the Yellow River after its movement, which will not block the frontal. The research content of this paper can provide some reference for the evaluation method for dynamic prediction super large landslides in the upper reaches of the Yellow River.

Because of rainfall is one of the main inducing factors of sudden geological disasters, by analyzing the temporal and spatial distribution characteristics of typical rainfall and the induced geological disasters, this paper studies the characteristics and laws of different types of rainfall and its induced sudden geological disasters, so as to provide technical support for disaster prevention and reduction under extreme meteorological conditions. Using the method of typical case analysis, this paper systematically analyzes the "7·21" rainstorm with the greatest intensity since the meteorological records in Beijing and its geological disaster data, and studies the response relationship between the number, scale and disaster situation of different types of sudden geological disasters and rainfall and rainfall intensity, This paper focuses on the threshold of short-term heavy rainfall debris flow in the mountainous area of western Beijing.The results show that with the increase of the distance from the rainfall center, the number, type and scale of sudden geological disasters gradually decrease, and the rainfall intensity is the key factor inducing the occurrence of sudden geological disasters. The triggered rainfall and rainfall intensity of different types of sudden geological disasters are obviously different. The triggered rainfall intensity and rainfall of debris flow and landslide are higher than that of collapse. The cumulative rainfall threshold of debris flow induced in Beijing mountainous area is 187.4−257.2 mm, and the hourly rainfall intensity threshold is 51.2−62 mm. Based on the research results, the real-time data of debris flow triggered by “7·21” are compared with the previous critical rainfall of debris flow based on average rainfall intensity, and the critical rainfall prediction model based on average rainfall intensity in Beijing is modified, so as to provide technical guarantee for improving the accuracy of early warning and prediction of geological disasters.

It is still a difficult problem to determine the sliding surface of a rock slope quickly and accurately because the efficiency and accuracy cannot be met at the same time in traditional searching methods. The limit equilibrium method is widely accepted in the stability analysis of rock slopes. The planar shear sliding model of a rock slope is adopted to characterize the position of the potential sliding surface by the inclination of the sliding surface; the analytical solution of the potential sliding surface of a multistage rock slope under the condition of limit equilibrium is derived based on the extreme value method, and its accuracy is verified combined with the Sau Mau Ping slope in Hong Kong. Furthermore, the system stability of the Dayingpanshan slope in Yibi, Sichuan Province with multiple steps in a highway is analysed. The results show that the slope potential sliding surface inclination determined by this method is in agreement with the practical sliding inclination of the Sau Mau Ping slope. In practical engineering applications, the dip angles of the sliding surface obtained by using the Cuckoo search method and simulated annealing method in Slide software are 38.0° and 37.0°, respectively, and the dip angle obtained by the analytical method in this paper is 34.8°.The Janbu method, Morgenstern-Price method and Sarma method are selected to calculate the corresponding stability coefficients, the results are approximately 1.04. The stability coefficient obtained in this paper is 1.15. The results obtained by this method are basically accurate. Through parameter sensitivity analysis, it is found that with the increase in cohesion, the inclination angle of the slope slip surface decreases, and the stability coefficient also increases. When the internal friction angle increases, the slope slip surface inclination and stability coefficient also increase.

Aiming at the scientific problem of transmission line foundation freeze-thaw failure in frozen subsoil, this paper takes an assembled foundation with cone tubes and slabs as the research object. The research method of the indoor model test and analysis is adopted, and a series of freezing tests and uplift loading tests of the model foundation are carried out under different ambient temperatures. The distribution characteristics of the temperature field and displacement field of the foundation and the relationship between the ultimate uplift capacity and temperature are analysed. Simultaneously, the failure mode of the frozen soil foundation under uplift load is also revealed. The research results show that in the freezing test, the displacement of the model foundation is less than the frost heave displacement of the surrounding foundation soil; the closer the distance from the foundation is, the stronger the frost heaving anti-restraint effect of the foundation is.In the uplift loading test of the foundation under different freezing ambient temperatures, the ultimate uplift capacity increases approximately linearly with the decrease in the ambient temperature, and the increase rate is close to 1.8 kN/℃. Under the double action of freezing and uplift, the foundation soil first exhibits local tensile failure, and with the increasing uplift load, the foundation soil gradually transitions from local tensile failure to overall shear failure. The results of this paper can provide a theoretical basis and practical experience for the application of this type of foundation in frozen subsoil.

With the development of computer vision technology, studies on landslide identification have gradually been carried out by means of deep learning. By introducing the dual attention model, an optimization algorithm for landslide image recognition based on a convolutional neural network is proposed in this paper. Based on 2 200 landslide image datasets, this paper discusses the effects of 10 network structures and 4 attention models on landslide recognition results. The effectiveness of this method is verified by using a 4∶1 training set and test set for landslide recognition. The results show that the ResNet structure performs better than other network structures. For this example, the ResNet-101 structure has the highest recall rate, precision rate and F1-measure. Compared with a single neural network, the convolutional neural network with a dual attention model has a higher accuracy of landslide identification, and the segmentation result of the landslide boundary is closer to the real landslide boundary. Among them, the ResNet-101+DAN model is the optimal model. In contrast, a single neural network cannot overcome the influence of the image noise, and the result of the image segmentation is poor.

Translational rockslides are an important disaster that endangers the safety of mountain towns. The dip slopes with weak interlayers are the areas prone to translational rockslides. The regional translational rockslide susceptibility assessment should consider the sliding mechanism and spatial distribution uncertainty analysis of the weak interlayer. Taking Tiefeng Town of Wanzhou District as the study area, based on the detailed investigation of the material, structure and spatial distribution of weak interlayers, this paper analysed the evolution mechanism of shale and mudstone developing into sliding surfaces under the action of primary deposition, tectonic deformation and supergene transformation and summarized the deformation and failure mechanism of translational rockslides. Considering the spatial distribution uncertainty of the weak interlayer, a calculation model of the vertical distribution of the weak interlayer and the contribution of the weak interlayer to slip control in the effective control depth are proposed. The key factors that characterize the sliding structure, including the type of weak interlayer and the contribution degree of the weak interlayer, are selected as susceptibility assessment factors. In addition, four elements, topography, slope structure, hydrogeology and human activities, are considered. The susceptibility of translational rockslides in the study area was assessed with slope units adopting the analytic hierarchy process. The investigation and assessment results show that the mud interlayers of the Jurassic Zhenzhuchong Formation and the shale layer of the Ziliujing Formation are the main potential slip surfaces of the translational rockslide in the study area. The extremely high susceptibility area and high susceptibility area accounted for 9.7% and 25.8%, respectively. The distribution of the underlying weak interlayer and the excavation of the slope units are the main factors affecting the susceptibility to landslide disasters. Human activities such as house building and road excavation are the main triggering factors of translational rockslides.Compared with the susceptibility assessment results without considering the factors of the weak interlayer, the results of the method proposed in this paper are more consistent with the facts.

Most of the proven undeveloped reserves are presently low-grade ones. Overall effective utilization is difficult with current economic and technical conditions. Most of the existing methods evaluate overall utilization potential, which is no longer suitable for evaluating the utilization potential of currently-proven undeveloped reserves. In this paper, a case study has been carried out in Y reservoir. According to the heterogeneity of the spatial distribution of reservoir parameters, the selectivity of development technology and the uncertainty of economic parameters, a prediction model of single-well-controlled recoverable reserves under different development technologies is built. Combined with the economic limits of single-well-controlled recoverable reserves under different technical and economic conditions, movable probability can be obtained, and the movable potential of geological reserves can be further calculated. Field application shows that the coincidence rate of the movable potential reserves calculated by the method in this paper and the actual produced reserves reaches 97.2%, which has high accuracy and can meet the needs of field. The research in this paper provides an effective method for the evaluation of the potential of undeveloped reserves.

Since 2002, the China Geological Survey has successively organized and implemented hydrogeological survey and groundwater exploration in water deficient areas, such as severe water shortage areas in west China, Wumeng Mountain area, Yimeng mountain area and red bed area in southern Jiangxi, obtained a large number of exploration data conducive to promoting discipline development, and summarized the law of water abundance. In recent decades, water prospecting and well drilling in bedrock mountainous areas serving poverty alleviation have not been systematically summarized based on water storage structures and their attributes. This paper takes the water storage structure as the theoretical guidance, considers geomorphic catchment, lithological water accumulation, structural water control and other control factors, and takes structure as the main control factor. The factors such as topography, formation lithology, vegetation development and actual value of development and utilization are systematically summarized and water storage structures are divided into 8 types, further divided into 20 types, and more into 35 types, such as the horizontal rock stratum, monocline formation, fold, fault, contact zone, weathered crust, composite and cave reservoir. The common characteristics of different scales and types of water storage structures are analyzed and summarized with reference to and in combination with the neotectonic water control theory and groundwater system theory. From the aspects of spatial combination characteristics of water storage structure, boundary hydrogeological properties, hydrodynamic conditions, scale effect, symbiotic characteristics of water control and practical value of development and utilization, this paper puts forward the correlation between the lithology and geological structure, the relativity of permeability and water separation, the balance between catchment and water storage, the unity of scale and system, the inheritance of formation and transformation and the matching of scale and purpose. The research results refine and improve the classification of groundwater storage structure types in bedrock mountain areas with water shortage, summarize the attribute characteristics of water storage structure, deepen the understanding of the concept and connotation of water storage structure, not only further promote the research of hydrogeology in bedrock mountain areas, but also provide references for water prospecting and well locating in water shortage areas, and guide the sustainable utilization of water resources in water shortage areas.

SAR offset and optical offset are important techniques for glacier movement monitoring, but there are few researches on 3D deformation by integrating images from different platforms. In this paper, large glaciers in The Shisha Pangma area of Nyalam County, Tibet from November 2019 to January 2021 were selected as the research area. Based on variance component estimation, Sentinel-1 and Landsat8 data of the study area were combined for three-dimensional glacier calculation. Optical images of the same period were selected for comparative analysis of the offset estimation results. At the same time, the accuracy of the method was evaluated by selecting the stable area, and the applicability and accuracy of the method in glacier movement monitoring were analyzed. The results show that the maximum velocity of the glacier is 21 cm/day in the east-west direction, 68 cm/day in the north-south direction, and 17 cm/day in the vertical direction. Compared with the glacier displacement results obtained from a single image, the multi-image joint algorithm can compensate for the incoherence of SAR data and the low quality pixel values of optical data, and obtain more complete and detailed glacier information and higher accuracy of monitoring results. This paper can provide reference and technical support for using data from different platforms to jointly monitor multi-dimensional and high-precision changes of mountain glaciers.

Southeast Tibet, located in the southeast part of Qinghai-Tibet Plateau, is characterized by steep terrain, frequent occurrence and large scale of geological disasters due to multiple plate tectonic movements and compression movements between rock masses. It’s of great significance to investigate and monitor geological disasters in this region. In this paper, Ranwu area in southeast Tibet is taken as the study area, and the potential disaster points in this area are identified by using sentinel-1A satellite data, and the influence of geometric distortion of SAR image on geological disaster identification is analyzed. Through the analysis of InSAR monitoring results, 67 hidden danger points of landslides and glaciers in the region were delineated. At the same time, in order to better analyze the deformation characteristics and laws of the disaster bodies, three typical glacial disaster bodies in the north bank of Anmuco in Ranwu region were selected, and the two-dimensional (horizontal EAST-west and vertical) deformation rates and time series of the slope bodies were obtained by using multidimensional small baseline subset (MSBAS) technology.Based on the analysis of the deformation time series results of Jiqilong Glacier, Polong Glacier and Waba Village Glacier, it’s found that the maximum cumulative displacement in the horizontal east-west direction from January 2018 to October 2020 is 202 mm, 283 mm and 194 mm respectively. The maximum cumulative displacement in vertical direction is 97 mm, −155 mm and −163 mm respectively. In the horizontal direction, the three typical glaciers show an accelerated deformation trend and slow creep deformation trend in vertical direction. At the same time, the correlation between the two-dimensional deformation time series of Wabacun glacier and precipitation and temperature is analyzed. The results show that the variation of precipitation and temperature has certain influence on the deformation of slope glacier. The research results of this paper have a good reference value for the identification of geological hazards in alpine and canyon areas.

The theory of regional groundwater flow proposed by Tóth provides a quantitative analysis approach for the study of basin-scale groundwater circulation. This paper summarizes the development of the theory of regional groundwater flow from four aspects, compares the description of the theory of regional groundwater flow in foreign hydrogeology textbooks, and systematically summarizes the evolution of descriptions in the theory of regional groundwater flow in the four editions of the textbook "Fundamentals of hydrogeology" in Chinese published from 1986 to 2018. It is concluded that the textbook "Fundamentals of hydrogeology" plays an important role in promoting the study of regional groundwater flow in China. This paper also puts forward some scientific problems to be solved in the theory of regional groundwater flow and some suggestions to guide more young students to conduct research in this field.

The traditional field contact measurement for obtaining parameters of the rock mass discontinuity is of low efficiency and big workload, and the accuracy of the results are affected by human factors. In this paper a method is presented to automatically recognize the discontinuity based on the three dimensional (3D) digital surface model (DSM) of rock mass obtained with the digital photogrammetry and structure from motion (SFM) algorithm. The steps of rock mass DSM reconstruction include collecting rock mass images, matching image features based on the Scale-Invariant Feature Transform (SIFT) algorithm, reconstructing sparse point cloud, encrypting point cloud, and reconstructing the rock mass surface model. The main flow of the discontinuity recognition method include smoothing the DSM of rock mass, changing the searching radius and the angle threshold to split model plane, searching the discontinuity based on the regional growth principle, and fitting the discontinuity based on random sampling consistency to get the orientation. The method is applied to the underground experimental roadway in the Beishan area of Gansu, and the reconstruction of 3D digital surface model of roadway and the orientation acquisition of discontinuities are realized. The discontinuities are also mapped on the roadway model by groups. A comparison the results with those of the manual field measurement method and the existing discontinuity recognition software shows that the method proposed in this paper is of good accuracy and can provide a certain reference for engineering applications.

Identifying the permeability structure of the dam foundation rock mass is important for the formulation of seepage control schemes. For the horizontally-stratified red-bed rock mass of the Yellow River Guxian Dam foundation, this paper adopted a "continuous, high-resolution" water pressure test data processing method to analyze the relationships between rock mass permeability and elevation, lithology and shear zones, clarifiy the permeability structure of the dam foundation rock mass, and propose seepage control advice. The results indicate that the Guxian Dam foundation rock mass is characterized by a structural and random permeability behavior. The structure shows that the permeability decreases with elevation. The randomness shows that the permeability randomly fluctuates due to lithology and shear zones. For the river-bed dam foundation rock mass, the bottom elevation of the weathering and unloading zone is 450 m or so, and the 1Lu bottom boundary is at the elevation of approximately 340 m. For the rock mass of the dam abutment, the 3Lu bottom boundary is located at the elevation of 560～580 m. The section of 350～360 m elevation has a certain thickness of soft rock, a poor development of shear structure, and a low permeability. It can be regarded as a confining layer and a potential target for the optimization of seepage control schemes. In view of the universal applicability, the method proposed in this paper can be used for reference in similar projects.

The abandoned mines along the Yangtze River in Jiangsu Province is the key area along the Yangtze River Economic Belt, which need to be restored and governed. Among the ecological restoration projects, it has been one of the difficulties that how to quickly and intuitively track the progress of the distribution and restoration of a great many abandoned mines in the region. In this paper, the author takes the 10 km area on both sides of the Belt as study object. And selects high-resolution remote sensing images in each year from 2017 to 2020 as the data source. By human-computer interactive interpretation on the ArcGIS platform and field verification, the author obtains the information such as the distribution of open-pit abandoned mines, geological environment problems and ecological restoration in the study area. This paper mainly focus on the geological environment problems existing in abandoned mines and summarizes the ecological restoration measures. It is shown that it ’s a wide area need to be restored in Zhenjiang and Nanjing. The area of open-pit abandoned mines mainly focus on the quarries and transit sites of the mines, with construction limestone and construction sand mines as the main types of mines involved. The environmental problems mainly include topography and geomorphological destruction, geological disasters, ecological environment damage and soil and water pollution, etc. And the part rehabilitated and being rehabilitated of the study area show an increasing trend from 2018 to 2020. As of October 2020, the restoration area of abandoned mines has been effective, with 67.08% of the area restored. The main ecological restoration measures include natural restoration, soil backfilling, land leveling, slope cutting and integrated land management. It is recommended that the original landform of the mining area should be protected to the maximum extent and the land resources fully utilized when carrying out restoration and treatment. The results and suggestions provide technical reference for the ecological restoration and treatment of open-pit abandoned mines in the same type of area.

Biological reinforcement is a new branch that has developed in the field of engineering geology in recent years, among which, the microbially induced calcium carbonate precipitation (MICP) reinforcement technology is an effective method. MICP reinforcement technology utilizes the metabolic activity of widely existing microorganisms in nature to induce the precipitation of calcium carbonate with cementing and filling effects, thereby improving the strength of soil, reducing its permeability, and enhancing its engineering performance. Over the past two decades, significant progress has been made in theoretical research, model experiments, and field trials of MICP reinforcement technology. To promote a deeper understanding of MICP reinforcement technology, this paper systematically introduced the reinforcement mechanism and influencing factors of microbial-induced calcium carbonate reinforcement technology based on the current research on MICP reinforcement technology. In addition, the application of MICP reinforcement technology was discussed thoroughly. The current problems and challenges of MICP technology were analyzed in depth. The results show that the strengthening mechanism of MICP is formed based on microbial-induced mineralization, which includes the filling and cementation of soil pores by calcium carbonate precipitation. The influencing factors of the solidification effect of MICP mainly are the properties of bacterial solution and cementing solution, pH , temperature, soil type, and reinforcement method, by influencing the formation of calcium carbonate and cementing effect. The MICP reinforcement technology has shown great potential in soil reinforcement, crack resistance, impermeability, wind erosion resistance, and remediation of contaminated water/soil. At present, the MICP reinforcement technology still has some problems, including solidification uniformity, soil durability, economic benefits, environmental safety, and sustainability. To solve these problems, it is necessary to further integrate microbiology, soil mechanics, materials science, environmental science, and other disciplines to conduct in-depth research, which will help deepen the understanding of MICP reinforcement technology, promote MICP technology to achieve more comprehensive development in the engineering geological field, and further promote application of this technology.

The accurate determination of coal temperature in the hidden spaces such as goaf has always been a worldwide problem that needs to be solved urgently. The study of acoustic temperature measurement technology is of great practical significance for a fast and accurate detection of loose coal temperature, and the scientific and accurate construction of the mapping relationship between sound velocity and coal temperature is the key to acoustic coal temperature measurement. In this paper, considering the influence of the characteristic parameters of spontaneous combustion process of loose coal on sound wave propagation, a mapping model of sound velocity and coal temperature in the quasi-porous media of loose coal was established. An acoustic temperature measurement experimental system for loose coal was designed and built. By conducting the acoustic temperature measurement tests for the loose coal with various particle sizes (0.6～1.5, 1～3, 3～5 cm), the effect of gas composition and concentration on sound propagation during the low-temperature oxidation stage (30～50 ℃) of coal samples with different particle sizes was studied, and the equivalent path conversion factor λ was determined. Based on the relationship between the measured sound velocity and the equivalent path conversion factor, the medium correction coefficient φ of the gas component was proposed and determined, and the feasibility of the sound-temperature mapping relationship model was verified. The results show that the acoustic wave propagation path of loose coal is affected by the characteristic parameters of coal particle size, temperature and the change of gas component medium, etc. A mapping model of sound velocity and coal temperature was established. At normal temperature, the propagation path of sound waves in the quasi-porous medium of loose coal is mainly affected by the pores between the coal particles. The equivalent path conversion factor λ of sound waves is 1.426 1, 1.371 1 and 1.315 2, respectively, when the coal particle size is 0.6～1.5, 1～3, 3～5 cm, which is negatively correlated with the particle size. The influence of coal temperature on acoustic wave propagation is manifested by the change of gas component medium in the process of spontaneous combustion of coal, which verifies the feasibility of the mapping relationship between sound velocity and coal temperature. The error rate between the inversion model and the experimental coal temperature is 0～6.46%, and the average coal temperature error is 2.52 ℃, which can reflect the coal body temperature well.

The site selection optimization of coal mine safety emergency reserve center is an important foundation for promoting the construction of coal mine safety emergency response system. In order to improve the accuracy and reasonableness of coal mine safety emergency reserve center site selection, it is proposed to establish a machine learning combination model for coal mine safety emergency reserve center site selection, integrating multi-source spatial data by using demographic, transportation, economic and natural factors to improve the accuracy and scientificity of coal mine safety emergency reserve center site selection. The accuracy and scientificity of coal mine safety emergency reserve center site selection are improved. Firstly, the ArcGIS is used to process multi-source spatial data through tasks such as fishing net division, spatial linking and projection respectively, and the SMOTEENN algorithm is utilized to avoid the negative impact of data imbalance, so as to construct the dataset applicable to the analysis of machine learning model. Secondly, by comparing and analyzing different machine learning algorithms, different feature selection methods and different parameter optimization methods, it is concluded that the XGBoost machine learning algorithm, the Boruta algorithm and genetic algorithm have better performance than other machine learning algorithms, feature selection methods and parameter optimization methods in the site selection analysis of coal mine safety and emergency reserve center. Therefore, based on the advantages of each algorithm, this paper obtains a combined machine learning model for coal mine safety emergency reserve center site selection. Finally, the SHAP analysis is introduced to analyze the influence degree and direction of different features to quantitatively assess the contribution of input data in decision-making and enhance the interpretability of the model. The results show that the combined model of coal mine safety emergency reserve center siting has an excellent performance, with 0.976, 0.966, 0.989, 0.977, 0.996 in accuracy, precision, recall, F1 value and AUC, respectively, which can provide a powerful support for siting decision-making, and the model interpretable analysis can also provide a scientific reference for coal mine safety emergency reserve center siting.

Hydraulic fracturing is a widely used technique for increasing the permeability of coal seams. Its impact on the production capacity of coalbed methane(CBM) wells is significant. This paper makes detailed observations on the exposed coal seams and fracture distribution of 5 CBM wells in Tunlan block of Xishan coalfield, and studies the distribution characteristics of coal structure, microfractures, quartz sand and coal fine by using stereoscopic microscope, scanning electron microscope, and micro CT. The fracturing effect and influencing factors of CBM wells are analysed by combining regional geostress and hydraulic fracturing construction parameters. The research results indicate that the macroscopic fractures morphology produced by hydraulic fracturing are complex and diverse, including horizontal, vertical, X and T-shaped fractures. The degree of coal body fragmentation increases with distance from the CBM well. The coal body closer to the CBM well is mainly composed of fragmented and granular coal, while the coal body further away is mainly composed of undeformed coal with primary fractures. The quartz sands are mainly deposited in horizontal fractures, with only a small amount in T-shaped fractures. Quartz sand rubs, collides, and embeds strongly with the coal fracture surface. The fracturing fluid is then superimposed to fracture the coal body, resulting in a large amount of coal fines. This causes the coal fines to wrap around the quartz sand and block the fractures. The coal fines within the macroscopic fracture are primarily a result of the fracturing of the coal body, the flushing of the coal body by fracturing fluid, and the friction between the quartz sand and the fracture surface during hydraulic fracturing. Coal fine generation in micro-fractures during coal body fracturing. Coal fines and quartz sand accumulate in the fractures, creating enormous resistance to the carrying fluid and preventing the quartz sand from migrating to the far end of the CBM well. The magnitude and direction of the geostress, as well as the strength of the coal seam roof and floor, are important factors that influence the opening and direction of the hydraulic fracturing fractures. The low viscosity of the carrying fluid cannot suspend quartz sand, and the accumulation of quartz sand and coal fine can block the fractures, easy to cause quartz sand and coal fine to aggregate and block fractures.

The fracture (pore) development of coal specimen under axial stress loading and hydraulic permeability affects directly the mechanical indexes and the permeability characteristics. In this paper, using theoretical analysis and mechanical test methods, the relationships between permeability and fractal dimension, ringing count response under coal specimen fracture (pore) were analyzed, and the acoustic emission fractal-permeability model of coal specimens under hydraulic-loading coupling were established. The permeability experiments of coal specimens with hydraulic-loading coupling in different confining pressures (2−5 MPa，Δpw/p'c=0.75) were carried out, and the mechanical behavior, permeability characteristics and acoustic emission rules of coal specimens in different confining pressures (water pressure) were analyzed, and the relationship between the failure morphology of coal samples under different confining pressures and the acoustic emission positioning was discussed. The strength enhancement characteristics and the relationships between failure pattern and acoustic emission location of coal specimens under confining pressures were discussed. The rationality of the fractal-permeability model of coal specimens under hydraulic-loading coupling was verified. The results showed that the fracture (pore) change of coal specimen was consistent with acoustic emission ringing, the fracture (pore) development was closely related to the fractal dimension and the permeability, and the acoustic emission fractal and permeability could be characterized by the volume strain in the permeability experiments. The acoustic emission fractal-permeability model of coal specimen under hydraulic-loading coupling could be analyzed by a two-stage mathematical model. The permeability of the coal specimen showed the process of short-term decrease, long-term slow increase, rapid increase and slight decline, and the ringing count showed the wave-like development of rapid increase - decrease - increase - decrease during the total stress-strain process of coal specimen, the minimum permeability lagged behind the critical point of volume strain compression and expansion, and the minimum permeability varied from 0.124×10−17 m2 to 1.250×10−17 m2. With the increase of confining pressure (2−5 MPa), the peak deviating stress, peak axial strain and peak volume strain of coal specimen all showed an increasing trend, the linear characteristics were significant, the lag of peak permeability behind peak strength showed a decreasing trend, the reduction reached 93.34%, and the loudest ringing count (corresponding to the peak strength) showed an increasing trend. The effective cohesion and the effective internal friction angle of the coal specimen increased to 6.511 6 MPa and 36.56º under hydraulic coupling, respectively. With confining pressure (2−5 MPa) increase, the acoustic emission information of coal specimen changed from single inclined plane to irregular inclined plane, the angle of the main fracture plane from small angle to high angle, and the instability mode from single block shear to multi-block compression, and the specimen fracture could be expressed by acoustic emission positioning ringing count. Three experiment curves of acoustic emission fractal-volume strain, permeability and volume strain, and fractal and permeability of the coal specimens were consistent with the theoretical curves, the correlation during compression stage with confining pressure 2−5 MPa was 0.882−0.999, 0.950−0.998 and 0.849−0.997, respectively. The correlation during the expansion stage was 0.937−0.996, 0.891−0.998 and 0.873−0.966, respectively.

A M3.1 earthquake occurred in Qingpu District of Shanghai at 1:39 on June 15，2023. The Shanghai Earthquake Early Warning Network successfully received the earthquake early warning information released by the China Earthquake Early Warning Network，and the locally deployed Fujian Early Warning System EEW also successfully processed and produced the earthquake early warning results. In this paper，the results of 7 earthquake early warnings produced by Shanghai Earthquake Early Warning System and the earthquake early warning information released by China Earthquake Early Warning Network are compared and analyzed. The epicenter of the earthquake is located in the Shanghai Earthquake Early Warning Network. The first early warning information was released at 6.8 s after the earthquake. All 7 early warning processing results were produced within 15 s after the earthquake. Compared with the official earthquake catalogue，the first early warning processing result has an epicentral position deviation of 5 km and a magnitude deviation of −0.1. With the increase of the number of early warning stations involved in the calculation，the epicenter position is finally consistent with the official catalogue，and the magnitude deviation is also maintained at 0.5. The results of this earthquake early warning show that although Shanghai and its surrounding areas belong to the general early warning area with small and micro earthquakes as the main seismic activities，due to the large density of early warning stations，more accurate early warning processing results can also be produced in a short time after the earthquake，which is of great reference significance for the ongoing integration of monitoring and early warning business in the Yangtze River Delta.

Two typical analysis models for high rise building structures (the shear wall structure and the frame shear wall structure) were established in this paper. On the premise that the story drift meets the limit values specified in the specifications, the changes in the usage of concrete and steel bars with the characteristic periods of the design ground motions were studied. In addition, keeping the two structural models unchanged，the maximum story drift of the two structural models under different characteristic periods were analyzed, and then the failure states of the two structural models were given. Results show that when the story drift meets the requirements of the specification, the usage of concrete and steel bars in the shear wall structure and the frame shear wall structure increases with the characteristic period increasing. The larger the characteristic period, the greater the increment of concrete and steel bars usage. The increment of concrete and steel bars usage in the frame shear wall structure is smaller than that in the shear wall structure under the same characteristic period appreciation. Increasing the characteristic period will affect the failure states of the structures when the structural models remain unchanged, but mostly in a minor damage state, except for the shear wall structure that reaches to moderate damage state at Tg=0.9 s.

The destruction of cratons is one of the key research objects of geophysicists. According to China Earthquake Networks Center, small and medium-sized earthquakes have occurred more frequently in southern Hebei in recent years than before. In order to explore the reasons for the instability of the crustal structure in southern Hebei, in this paper the earthquakes are precisely located based on the P-wave arrival time data recorded by China Earthquake Networks Center, and the double difference tomography of the crustal velocity structure is performed by using the P-wave seismic phase data. It is found that the sources after fine location are mainly distributed in the crust depth of 5～15 km, mainly near the faults. In terms of velocity structure, the mean RMS value of seismic travel time residuals decreases from 0.81 s to 0.36 s, and the earthquakes are more likely to occur in the transition zone at the edge of the high-speed region. There is a low-speed anomaly zone at the junction of the crust and mantle in Handan and Xingtai. The Moho surface and upper mantle may be upwelling by hot flow materials such as magma, intruding into the crust and undergoing chemical reactions, leading to the thinning and damage of the lithosphere, resulting in an unstable crustal structure and creating favorable conditions for shallow earthquakes.

This paper mainly introduces a program written in Matlab for determining ground motion parameters. From the three framework modules of input, processing and output, the author combines his understanding and experience to analyze the process of determining design seismic parameters in detail. It uses an Excel file to control the input parameters as a whole, taking into account factors such as peak ground acceleration, site classification, design earthquake grouping, and zoning map adjustment factors. It simplifies the complex process of processing response spectrum data, and achieves automatic calibration of borehole response spectra under different standard spectra recommended by different codes, automatic saving of maps, and exporting of ground motion parameter tables. The program can comprehensively analyze multiple boreholes and multiple response spectrum data for different design reference periods and different probability levels of exceedance at one time, which is very efficient in handling regional seismic safety evaluation and other multi-site engineering projects. The application analysis of examples in seismic safety evaluation work is also presented in the article. The program can not only process bedrock response spectrum, but also analyze the overall or individual response spectrum of boreholes to obtain more reasonable ground motion parameters, which is helpful for the seismic safety evaluation work.

This paper utilizes data on the records of damage to expressways and main roads caused by precipitation in Liaoning Province from 2017 to 2021. It analyzes the temporal and spatial characteristics of damage accidents, calculates the effective rainfall before the occurrence of accidents, and establishes a probability fitting model for road water damage. The results show that precipitation-induced road damage events in Liaoning Province generally occur from May to October, with a peak in July and August. The occurrence of road water damage follows a pattern of gradually delaying from northwest to southeast, and the number of accidents is highly correlated with precipitation. The eastern and western parts of Liaoning are high-incidence areas, with Dandong, Chaoyang, Huludao, and Benxi being the high-incidence areas within the province. Among various methods compared, the fitting effect of the road water damage probability conforms to the Gaussian distribution probability density function. The critical rainfall threshold for disaster in the eastern and southern parts of Liaoning is higher than that in the central and northern parts. Under the same effective rainfall conditions, the risk of road water damage in plain areas is higher than in mountainous and hilly areas. The road water damage situation during a flooding process in Liaoning in 2022 is used for verification, indicating a strong role in flood control guidance.

Taking the landslide control project of landslide No.13 at Panzhihua airport as an example, this paper briefly describes the basic situation of the landslide and focuses on the hydrogeological conditions of the study area. The rainy season rainfall accounts for 95% of the annual rainfall in the study area, and the occurrence times of moderate to heavy rain and rainfall days of 3 days or more are concentrated in the rainy season from July to September, accounting for more than 95% of the total. The rainfall in the study area is characterized by high intensity and concentration during the rainy season. Geophysical exploration and drilling revealed that the ground water in the field filling area at the rear edge of the landslide was abundant, with a "nest" -shaped discontinuous distribution and obvious stratification. Aquifers are characterized by high clay content, good water-bearing properties, poor pore connectivity, and poor drainage, making it difficult to dissipate quickly. Based on the prominent feature of abundant groundwater in the landslide area, a remediation scheme combining anti-slide piles and joint drainage by well and inclined drainage holes is proposed. After the completion of the treatment project, the drainage effect of the joint drainage measures by well and drainage hole was evaluated, and the practical results demonstrated excellent drainage effectiveness.

The detailed seepage process and rainfall infiltration temporal variation cannot be observed visually due to the complexity and non-visibility of the internal structure of landslide body, thus making it difficult to identify the specific process of rainfall in the whole process of landslide catastrophic evolution, which leads to the incomplete understanding of the formation mechanism of rainfall-induced landslide. Therefore, the new technological methods for directly observing and monitoring the infiltration and seepage process of rainfall-induced landslide is of great significance for deep understanding the formation mechanism of landslide induced by raining. Transparent soil test technology enables non-invasive, continuous, non-destructive and visual measurement or monitoring inside soil or rock mass bodies. In this paper, the current status of the development of transparent soil testing technology and its application in different fields especially in the application of slope engineering and practice in the visual simulation of seepage processes are summarized from the aspects of transparent soil material properties, geotechnical engineering properties, experimental equipment and image processing analysis technology, and the feasibility of applying it to the visual observation of seepage in landslide is discussed. On this basis, the transparent soil material is screened and the preparation method is optimized. The transparent soil is used to replace the traditional geotechnical model material to establish a landslide transparent soil physical model suitable for seepage process observation. The physical simulation test of landslide seepage under rainfall conditions is carried out to obtain information on the whole process of rainfall infiltration-induced landslide disaster, and to determine the process and characteristics of the seepage process of the groundwater. The model test is an effective application of transparent soil test technology in the field of landslide seepage visual observation, expanding a new way of landslide disaster visual simulation, and further determining the complex impact of groundwater seepage on landslide. It is conducive to reveal the evolution law of rainfall-induced landslide, explore the sliding mechanism of landslide, and provide a scientific and technological support for rainfall landslide disaster prevention and disaster planning.

Coal energy has made a significant contribution to the development of human industrialization, but coal energy is faced with the major problem of high carbon emissions. Modern coal-based energy is a new path to crack the contradiction between coal energy and carbon. It can realize independent and controllable energy based on China’s resource endowment, enhance the autonomy of China’s oil and gas, support the clean transformation of electricity and the development of the renewable energy industry, and is an important innovative direction for guaranteeing energy security and realizing the dual-carbon goal. Based on the concept and technical system of modern coal-based energy, this paper systematically introduces the connotation and product lineage of modern coal-based energy. By analyzing and discussing the five core technology modules, 19 technical units and 61 key technologies of modern coal-based energy, including the new technologies such as coal-based gas, coal-based oil, coal-based hydrogen, coal-based electricity production, and dynamic carbon neutrality in mining area, ten revolutionary technologies for the development of low carbonization coal-based energy are proposed: ① Intelligent underground coal gasification technology based on self-moving plasma gasification machine which has the functions of automatic combustion, propulsion, sealing, monitoring and controlling; ② The coupling of underground coal gasification and indirect liquefaction can form a low-cost, low-emission, short-process coal-to-oil route (UCG-ICL); ③ In situ retorting chemical mining technology of oil-rich coal using solar heating or hot dry rock heating;④ In the deep coal underground gasification hydrogen production path (UCG-H2) based on in-situ carbon capture, utilization and storage (CCUS), recycled CO2 is used as a gasification agent to improve the production of effective components of coal gas, and captured CO2 is stored in the underground gasification cavity to form a zero-emission UCG-H2 technical route. ⑤ nanometer hydrogen-rich coal water slurry hydrogen-mixed power generation technology to achieve low-carbon coal-based power production at low temperature and low pressure, and significantly reduce carbon dioxide emissions of coal power; ⑥ The Low carbon power generation system concept of underground coal gasification coupled with IGCC (UCG+IGCC) reduces the coal-to-gas process of IGCC and significantly reduces CO2 emissions. ⑦ Pulverized coal deflagration linear drive power generation technology structure, the theoretical work energy is more than 15 times of coal combustion; ⑧ Based on the CO2 hydrogenation synthesis “green methanol” route of modern coal-based energy recycling, methanol is synthesized from coal-based “blue hydrogen” produced by low-carbon UCG and captured CO2; ⑨ The CO2 in situ storage technology system generated by modern coal-based energy can help achieve zero-carbon coal-based energy production; ⑩ Dynamic carbon neutral coal-based energy system architecture in mining area, coupling intelligent supply protection, green development, clean transformation, low-carbon utilization and clean emission in a closed-loop system in mining area to achieve dynamic carbon neutrality in mining area.

Sequestration of CO2 in the unmineable coal seams is not only one of the most ideal options for reducing greenhouse gas effects, but also the only way for the coal industry to reduce CO2 emissions and achieve low carbonization sustainable development. However, the key unresolved issues regarding the CO2 geo-sequestration in coal seams is: “how long does CO2 injected into a coal seam remain in the seam?”. In this regard, on the basis of clarifying the hysteresis law of CO2 desorption in coals, this paper reveals the mechanism of supercritical CO2 desorption hysteresis, establishes a quantitative model for the geological storage of CO2, and explores the use of desorption hysteresis to achieve a long-term safe storage of CO2 in coal seams. The study results shows that the degree of desorption hysteresis of supercritical CO2 in coal is greater than that of subcritical CO2, and a stable hysteresis characteristic similar to a “parallel line” in the supercritical phase is formed between the adsorption and desorption isotherm. The fundamental reason for the desorption hysteresis is that the micro and nano sized pores in coal form curved surfaces due to their hydrophilicity, which generate strong capillary pressure following the Laplace’s equation, absorb liquid water, truncate and fix the supercritical CO2 fluid, and ultimately form CO2 residual trapping. For example, the cylindrical inorganic pores with a diameter of 40–10 nm in coal can generate a capillary pressure of 7.30–29.12 MPa, which is sufficient to block supercritical CO2. Taking the desorption isotherm of Jiulishan coal as an example, using the quantitative model for the geological storage of CO2 established in this study, it has been estimated that the total trapping capacity of the No.21 coal seam at depths of 900–1 500 m is stable at 35–37 m3/t. Among them, the adsorption trapping capacity accounts for about 80%, residual trapping capacity accounts for about 15%, and structural trapping capacity only accounts for 5%. Desorption hysteresis suggests that some measures should be taken to increase the proportion of CO2 residual trapping in coal seams as much as possible, the reason is that the residual CO2 sealed by capillary blockage is safer and has no risk of leakage compared to the free and adsorbed CO2 sealed by surrounding rock. The physical parameters such as ash content, moisture content, pore size, and morphology of coal seams are the main factors affecting the residual trapping efficiency.

Objective Many important discoveries have been made in shale gas exploration in the Lower Carboniferous Luzhai Formation in the central and northern Guizhong Depression, southern margin of the Xuefengshan Uplift, and commercial test production has achieved successful gas ignition. However, the structure and evolution of the depression in this area have not been clearly defined, which restricts an accurate understanding of the formation conditions for organic-rich mud shale, the distribution of favourable sedimentary facies zones, and shale gas enrichment law. Methods Taking the Rongshui area as an example, this paper studies the main structures and their relationships with shale gas preservation through geological investigation and analysis, 2D-3D seismic section structural interpretation, evolutionary equilibrium section interpretation and other technologies. Results It is believed that there are three main faults and four main NE-NNE synclines in the study area. The preexisting NNE-trending Sanjiang-Rong'an fault is the main factor involved in extensional fault depression and compression-strike-slip transformation. In the study area, the extensional fault depression developed in the Late Devonian, strengthened in the Early Carboniferous and stopped in the late Early Carboniferous. The compression-strike-slip effect of the depression reconstruction developed in the Indochinese and Yanshanian stages, and the local tensioning effect developed in the Alpine stage. The main part of the present fold system was formed in the Indosinian period. Influenced by the increasing thrust of the Sanjiang-Rong'an fault from west to east, the structure pattern of broad and slow synclinal-compound synclinal-faulted folds is distributed. Complex synclines are favourable structural units for shale gas preservation, and the favourable structural styles for shale gas preservation are synclines and anticlines. Conclusion This understanding clearly defines the direction of shale gas exploration and deployment in the next step, and provides a beneficial idea for the structure and evolution of the Liucheng slope in the north-central part of the Guizhong Depression.

Objective The aperture of fractures (hydraulic equivalent aperture of fractures) of rock fractures is one of the key mechanical parameters of rocks.It has significant indicative significance in water conservancy projects, geological surveys and so on.At present, large-scale test methods such as cross-hole tests are often used to obtain the fracture apertures of deep rock masses in the field, but this method is rarely used many times in projects, and it is difficult to analyse the spatial variation in the aperture of fractures. This spatial variation is precisely what we need to focus on and discuss because it affects the accurate definition and application of the hydraulic equivalent fracture aperture in engineering applications. Methods In this paper, taking the surrounding rock of an underground power station cavern on the right bank of the Three Gorges Dam as an example, a new inversion method for determining the hydraulic equivalent aperture of fractures is proposed by using conventional single-hole water injection test data and three-dimensional fracture network simulation. The statistical data obtained from the measured fracture cataloguing data are used to carry out random simulation of fracture characteristics, and a three-dimensional discrete fracture network seepage model connected with water injection test boreholes is constructed to fit the relationship between the single-hole steady-state flow rate and injection. The hydraulic equivalent apertures of fractures at different depths of rocks are inverted. Results The results show that the hydraulic equivalent aperture of fractures in the research area is generally 0.07-0.30 mm, which confirms to the statistical characteristics of the log-normal distribution. Most of the inverted hydraulic equivalent apertures of fractures in boreholes decrease exponentially with burial depth, while a few boreholes show strong randomness of the hydraulic equivalent aperture of fractures and no obvious change with burial depth. Conclusion Compared to those of traditional methods, the inversion results of this approach are significantly different and require further verification.

Objective Knowledge of the regional groundwater level is an important foundation for groundwater resource evaluation and protection. Due to the limited amount of groundwater level data available at the regional scale, Kriging interpolation and deep learning methods are gradually being used for regional groundwater level prediction, but their applicability and robustness lack comparative analysis. Methods In this paper, spatial interpolation of groundwater levels in the Shenzhen-Shanwei Special Cooperation Zone was carried out using ordinary Kriging, coKriging and deep learning methods to explore the potential of these three methods for practical application to regional groundwater level prediction. To investigate the effect of the training set sample size on the prediction effect of the three methods, 239 monitoring wells were divided into two groups of 76 and 163 wells for the training of the three models. Results The results showed that the RMSEs were 6.09, 4.04, and 7.11 when the training data of 76 wells were used to fit the validation set, and the Kriging method, which accounts for surface elevation information, was significantly better than the ordinary Kriging method and the deep learning method. In addition, the predicted water level distribution improved when a larger number of samples was used to predict the water level in the region. However, the spatial distribution characteristics still differed significantly. Conclusion The results show that when the observation data are sparse, the prediction effect of coKriging with elevation information is significantly greater than that of ordinary Kriging and deep learning methods, while the RMSEs obtained by the three methods are similar when the amount of observation data increases to a certain amount.

Bedding-parallel lamellated fractures are widely developed in shale in the 7th member of Triassic Yanchang Formation (hereinafter referred to as Chang 7) in the southwestern Ordos Basin, which holds significant importance for sweet spot selection, fracturing operations, and development planning. In this paper, based on the surface outcrop and core observations in the Qingcheng to Huachi region of the southwestern basin, combined with analysis and testing of organic matter content, mineral composition and fabric characteristics, the developmental characteristics of bedding-parallel lamellated fractures in different lithologies in the Chang 7 shale were identified, and the main controlling factors of fracture development were analyzed. Results show that the morphology and distribution of the bedding-parallel lamellated fractures are mainly controlled by the laminates, exhibiting characteristics such as continuous flatness, wavy bending and branching due to the different characteristics of the laminae. Sandstone bedding-parallel lamellated fractures are mostly distributed along the biotite laminae, with good continuity and large aperture, and are generally unfilled. Shale bedding-parallel lamellated fractures are most developed in black shale, mostly distributed along the bedding laminates composed of organic matter layers, with a few partially or completely filled by calcite and organic matter. The aperture is smaller than that of sandstone, but the density is higher. Bedding-parallel lamellated fractures are also controlled by organic matter content, lithology, mineral composition, and laminate structure. The sandstone bedding-parallel lamellated fractures are mainly controlled by the content of biotite and the laminates formed by it. When sandstone sorting is good and biotite content is high with a layered distribution, the degree of fracture development is high. As the density of the laminates increases, the degree of development of bedding-parallel lamellated fractures also increases. Shale bedding-parallel lamellated fractures mainly develop in organic matter laminates and tuffaceous laminates, and are controlled by organic matter content and mineral components. Fracture density increases first and then decreases with the density of the layers. Fracture density in thin laminates is higher than that in thick laminates.

This paper collects relevant information on the newly added Yuping potential seismic source in western Huaihua, and analyzed the seismic hazard of the study area based on 1′×1′ grid points. We mainly discussed the changes in PGA before and after the new potential seismic source in the Hunan-Guizhou border region, and drawing isolines and zoning based on the PGA of site Ⅱ. The results of seismic hazard analysis show that the PGA has been greatly improved inside and 20 km away around the new potential seismic source. When the focal depth is 10 km, the PGA of exceeding probability of 10 in 50 years within the Yuping potential source range increases from 35～40 cm/s2 to 80～95 cm/s2, increase of about 2.3 to 2.4 times. In local areas such as Xinhuang and Zhijiang within the potential source, the basic intensity can reach Ⅶ degrees. And outside the potential source, PGA gradually increases from 35～80 cm/s2. When the focal depth is 15 km, the basic intensity in regions such as Xinhuang and Zhijiang remains at Ⅵ degrees. The article also conducted a preliminary analysis of the seismic capacity of different types of houses in Xinhuang and Zhijiang county in western Huaihua. Additional attention should be paid to the follow-up work of earthquake prevention and disaster reduction.

In this paper，the regional full waveform inversion using the broadband waveforms recorded by China Seismic Network were conducted，and the focal mechanism solutions of the 59 earthquakes with M≥4.0 occurred in the mainland of China during March to June 2024 were obtained. The types of these focal mechanism solutions show 18 reverse faulting，33 strike-slip faulting，7 normal faulting and 1 odd earthquakes.

X gas field is located in the central inversion structural belt of Xihu Sag, East China Sea Basin.The main target layer H4 is in shallow water delta sedimentary environment.The dominant frequency of seismic data of the gas field is low (25 Hz), while the buried depth of H4 layer is large (3 300-3 400 m).The reservoir has low porosity and low permeability, and the consistency of sand body thickness predicted by conventional seismic inversion is low.Aiming at the characteristics of full coverage of 3D seismic data and less drilling in X gas field, this paper makes up for the lack of sample points in SVR algorithm through forward and inverse modeling under the guidance of geological model and setting up virtual wells.Then, by extracting seismic attributes and optimizing sensitive attributes characterizing sand body thickness, SVR algorithm is used for multi-attribute fusion to complete the quantitative prediction of H4 sand body.Based on the reservoir prediction results, it is proposed that H4 layer is a distributary channel deposit of shallow water delta meandering flow type, and further completed the dissection of sand body deposition model.After the development adjustment wells drilled, the coincidence between the actual drilled sand body thickness and the predicted sand body thickness is more than 84%.This paper explores and obtains the quantitative reservoir prediction scheme of SVR algorithm constrained by geological model under the condition of few wells on the sea, which completes the accurate prediction of the middle and deep distributary channel reservoir in X gas field, and also has certain guiding significance for the reservoir description of the same type of oil and gas fields.

Due to the high concealment, short-lived time and low predictability of the rock avalanche, it is difficult to visually observe the process of it. In order to study the dynamic characteristics and the catastrophicto houses of rock avalanche, this paper analyzes the rock avalanche congeries and its particle size distribution.Taking the rock avalanche in Pusa Village as an example, this paper uses the PCAS system to identify congeries particles by image.And through the dimensional analysis method, the quantitative relationship between the congeries of particles and the damage of the building is analyzed.The author found that: compared with on-site screening statistics, the data obtained by the method of image recognition of congeries particles is more comprehensive and detailed, and can save a lot of manpower and material resources.In addition, the interaction between the house and the rock avalanche is explored, and it is found that the house has the effect of "blocking coarse and fine discharge" on the rock avalanche particles. At the same time, using the particle size data obtained by image recognition to derive the discrimination formula for building damage, the discriminating effect is good, laying the foundation for follow-up research.

The earth medium can be regarded as a porous medium. Because the attenuation of the wave is very significant, it can effectively reduce the energy of the shock wave. The porous medium can be used as a protective material for the shock wave, which is of special significance for large underground structures. In this paper, the measurement results of the artificial joint porous medium filled with water or ice with large amplitude and rapidly rising stress pulse are given. The influence of water as solid or liquid phase in the joint on the explosion effect is discussed. In this paper, two physical models of wave attenuation in porous media, namely double pore model and partial saturation model, are used. The calculation results show that the predicted P-wave velocity, as well as the degree of rock attenuation and dispersion, are consistent with the measured data. Water or ice in the joint has a great attenuation of shock wave. However, water filled joints are more obvious. Due to filling different materials, they show different properties. Therefore, pores and joints can be filled with different attenuation protective materials to meet the needs of different situations.

The recharge and discharge of groundwater are mainly vertical surface infiltration recharge, evaporation discharge (evaporation can be shown as negative value of infiltration) and lateral surface water recharge and discharge. One of the most basic problems in hydrogeology is the evaluation criteria of sustainable exploitation of groundwater, which involves the increment of recharge and the decrease of discharge. Therefore, the prediction model of groundwater exploitation must include the above two kinds of recharge and discharge factors, otherwise the evaluation of groundwater cannot meet the requirements. However, the classic Theis unsteady well flow model (1935) only involves the recharge and discharge of the side boundary, and does not considers the surface infiltration recharge of the upper boundary, even when groundwater is pumped near the river. In this way, the analytical model cannot be basically used for prediction, and can only be used for well flow test to obtain the aquifer parameters in dry season. Therefore, the goal of this paper is to develop the Theis unsteady well flow model with surface infiltration recharge. For the problem of phreatic flow, the equation of groundwater flow cannot be established by using head as the dependent variable in a confined aquifer. We use the potential function of the second linearization method to establish groundwater flow equation in the phreatic aquifer. For the solution of the generalized mathematical model of the complex hydrogeological problem with rainfall infiltration and a pumping well, we adopt the method of decomposing it into several simple sub-models and synthesizing them into the solution of the original complex mathematical model. Based on the principle of mass conservation and assuming that the seepage obeys the Darcy’s law and satisfies the Dupuit's assumptions, the differential equation of groundwater flow is established. Then, for the well flow problem with uniform and stable infiltration recharge in two parallel rivers and two kinds of strip regions formed by a river parallel to an impermeable boundary, the general equation of groundwater flow and several kinds of water table equations under specific conditions and their flux equations are obtained. In addition, the “boundary to boundary reflection method” is proposed and applied to solve the same problem in a strip of region between a river boundary in parallel to an impermeable boundary, which reduces many derivation processes. Finally, as a preliminary application of the above theoretical results, it is also an important application, that is, there is a pumping well near the river whose water quality cannot meet the requirements, and the critical flux equation of the pumping well is calculated on the premise of not absorbing the river water. The important and concise relation equation is obtained. The equation can also be used to calculate the critical pumping rate of pumping wells in coastal areas without seawater intrusion. In this paper, the groundwater flow network diagram at a certain time in the process of unstable well flow under the above conditions is given. Compared with the flow network of well flow near the river, which is commonly seen in the literature, the flow network has obvious characteristics.

The rough back of a wall causes the deflection of the soil stress direction behind the wall. At present, there are few studies on the influence of the deflection of the soil stress direction on the earth pressure in cohesive soils. For this reason, this paper firstly discusses the deflection law of the principal stress of the soil behind the wall, and adopts a layered formation of curved thin-layer elements along the principal stress trace. By analyzing the force of the curved thin-layer element, the static balance equation of the curved thin-layer element is established, and the formula for the distribution of the earth pressure of the cohesive soil along the wall height in the translational mode is derived, and the new analysis method of the cohesive earth pressure is obtained. Finally, the method in this paper is compared with the actual measurement results and the existing theory and the parameters are analyzed to verify the reliability and rationality of the method in this paper. The research results show that the calculation results considering the effect of wall-soil friction can more accurately reflect the distribution law of cohesive soil along the wall height; the magnitude of earth pressure decreases with the increasing cohesion. With the increase of wall-soil friction angle soil, the pressure resultant force gradually decreases, and the height of the point of application increases slowly.

How to identify deformed landslides in advance and conduct early risk assessments on them has become a research hotspot in the field of geological disaster prevention and control. In response to the above problems, the Jiangdingya landslide in the Bailong River Basin in Zhouqu is taken as a back analysis case, and a comprehensive study of the early identification and risk assessment of the landslide is carried out. In this paper, a full-process analysis method is proposed, which combine the small baseline subset interferometric synthetic aperture radar (SBAS-InSAR) technology interpretation, geo-mechanical analysis and dynamic process simulation. The research results show that the SABS-InSAR technology interpretation can effectively identify the range of the Jiangdingya landslide and its early deformation. It may be preliminarily determined that the failure mode of the Jiangdingya landslide is trailed and the plane characteristics of the landslide body is generally about 680 m in length and 210 m in width. Based on the early identification information and through geo-mechanical analysis, it is finally identified that the instability problem of the Jiangdingya landslide is a typical deformation problem of the front edge of the old accumulation layer landslide. The failure mode is the traction slip failure, the average thickness of the landslide body is in about 35 m, the overall slope of the sliding bed is relatively slow, and the moving speed is not large after instability. On the basis of the above analyses, a Coulomb friction model that conformed to the sliding friction characteristics of the Jiangdingya landslide body is selected. Based on the depth integral continuum equation, the dynamic process of the Jiangdingya landslide body is calculated and the speed of the landslide body is monitored. In terms of velocity monitoring curves and accumulation pattern, the sliding velocity of the landslide body is not large, the maximum value is about 2.2 m/s, the overall performance is pushing the Bailong River channel, and the possibility of blocking the river is relatively small. In addition, when the displacement of the front edge of the Jiangdingya landslide body is completed, the speed of the landslide body from the front edge to the rear edge quickly drope to zero, and the movement process is characterized by the traction movement. The analysis results of the Jiangdingya landslide in this paper are consistent with the actual event of the Jiangdingya landslide. The comprehensive analysis method and research model can provide a good reference for the early identification and risk assessment of similar landslides in the Bailong River Basin in Zhouqu county.

Due to the development of geological structure, frequent seismic activity, strong valley cutting, high steep and narrow bank slope, extremely broken rock mass, there have been many large-scale landslides blocking the Jinshajiang River in history.Taking the two river blocking events of Baige landslide (October 11, 2018 and November 3, 2018) as an example, this paper uses the multi-phase and Multi-source Satellite remote sensing data sources from December 4, 2009 to October 16, 2020 to analyze the deformation characteristics of the slope before sliding, the accumulation characteristics of the slope after sliding and the residual deformation characteristics of the slope after sliding by means of remote sensing identification and comparative analysis The analysis of telemotional states. According to the multi-stage remote sensing images, the deformation characteristics of Baige landslide are divided into five areas: early sliding deformation stage (2009-2011), stable deformation stage (2011-2015), rapid deformation stage (2015-2017), severe deformation stage (2017-2018) and deformation failure stage (after 2018). According to the deformation and failure characteristics of the landslide, the landslide is divided into sliding source area, scraping area, accumulation area and tensile fracture deformation area. According to the deformation and failure characteristics of the landslide after the second sliding, the landslide is divided into the secondary landslide source area, the secondary landslide accumulation area (weir body), the secondary scraping (accumulation) area, the secondary scraping affected area and the tensile fracture deformation area. Based on the above research results, this paper summarizes and analyzes the chain characteristics of Baige landslide disaster, which provides a reference for the research on the chain characteristics of long range and high position landslide disasters in Jinsha River junction zone.

Petroleum and gas are important strategic resources, among which natural gas as a clean energy resource has always been and still will be the most important energy resource in the foreseeable future, even after cutting global carbon emissions and China peaking carbon emissions. Diversification of energy import channels has been one of the effective measures to alleviate the energy shortage in China. The Arctic region is rich in oil and gas resources and is dominated by natural gas. The vast majority of oil and gas resources found in the Arctic are in Russia, but now more than 80 percent of the Russian natural gas production is already in their oil and gas fields in north Arctic Circle. In 2012, China and Russia officially launched a joint project to develop liquefied natural gas, marking significant progress in China's participation in the development and utilzation of Arctic oil and gas resources, and in fact started the cooperative process to integrate the China-led "Construction of the Silk Road Economic Belt"and the later Russia-led "Construction of Eurasian Economic Union".The total amount of oil and gas resources discovered in the Arctic region is 328.94 billion barrels of oil equivalent, of which oil equivalent amounts to 60.54 billion barrels (8.41 billion tons), only accounting for 2.5% of the world's discovered oil resources; Natural gas amounts to 41.4 trillion cubic meters (268.3 billion barrels, 37.26 billion tons of oil equivalent), and accounts for 15.5 percent of the world's discovered natural gas resources. The vast majority of oil and gas resources discovered in the Arctic region are in Russia, which has a total of 290.5 billion barrels of oil equivalent (40.35 billion tons), accounting for 88.3%, of which natural gas amounts to about 39.47 trillion cubic meters, about 255.79 billion barrels (35.53 billion tons) of oil equivalent, constituting more than 95% of the total discovered natural gas resources in the Arctic. The Arctic also has considerable undiscovered oil and gas resources, accounting for about 15% of the world's total undiscovered amount; The undiscovered natural gas, which mainly distributes in Russia, accounts for 30% of the world's total undiscovered amount. In the context of global warming and crackdown by the US-led Western world, Russia is bound to increase extraction and development of Arctic oil and gas, especially natural gas, and transport them through the Arctic Shipping Lanes to China and other consumer countries, in order to secure its natural gas export revenue and fiscal revenue. This paper takes as the basis the summary of the distribution characteristics of oil and gas resources in the Arctic, oil and gas resources and the Arctic strategy of Russia, and the traffic capacity of the Northern Sea Route (NSR), and reviews the launch and development of the liquefied natural gas joint project as well as the international power politics environment. Moreover, this paper briefly introduces the process of China's successful intervention in the Arctic oil and gas resources project, and puts forward the strategic measures for China to utilize Arctic oil and gas resources.

The rich oil and gas resources in the Arctic have attracted worldwide attention in recent years. According to the academically accepted assessment by the United States Geological Survey, the Arctic oil and gas resources are unevenly distributed, mainly concentrated in Russia, Alaska (the USA), Norway, Canada and Greenland. The exploration and development of oil and gas resources show different characteristics in different countries and regions, which may change under new circumstances. China is a big consumer and importer of oil and gas resources, and the Russian Arctic Region is becoming one of the China's important oil and gas suppliers. This paper presents the current development and utilization status of Arctic oil and gas resources in major Arctic Nations and the future development prospects. Based on China's current participation in oil and gas development and utilization in the Arctic, this paper concludes by suggesting that China should take Russia as a long-term partner in the Arctic oil and gas resources development and the two sides should carry out cooperation in various fields, including project investment, technology investment and channel construction.

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Changde-Anren fault is a large NW-trending fault in eastern Hunan Province.Based on a large number of basic geological data, this paper summarized the segmental characteristics of the fault; according to the oringin and distribution of Indosinian granite in the fault zone, the paper suggests that the activity of the fault in the main episode of Indosinian movement in the Late Middle Triassic was segmented.According to the structural characteristics of the fault and its two sides, the exposed strata and magmatic rocks, the Changde-Anren fault can be divided into four segments such as Anren-Hengshan segment (Ⅰ), Xiangxiang segment (Ⅱ), Taojiang segment (Ⅲ) and Changde-Shimen segment (Ⅳ), between which are NE-trending deep faults that cut through the deep crust and even the mantle.The NE-trending deep faults were mainly formed in Caledonian movement with sinistral strike-slipping, and cut the Changde-Anren fault into several disconnected segments, which resulted in the segmentation of the movement in Mesozoic of the Changde-Anren fault.In the region, the Late Triassic granites are mainly S-type granites formed by deep crustal melting in a post-collisional environment.The distribution characteristics of Late Triassic granites in the Changde-Anren fault indicate that the activity of the fault in the main episode of Indosinian movement is obviously segmented: there occurred shearing of the Xiangxiang segment of Changde-Anren fault in the deep part in Middle Triassic Indosinian movement, when the movement amplitude, shear strength and corresponding warming effect decreased from the middle to the end of the segment for the end restriction, which caused that the decompression-melting of deep crustal in Late Triassic only occurred in the middle part of Xiangxiang segment, and the corresponding granites were exposed in the middle and northern sections of Xiangxiang segment.This structural-magmatic mechanism is also reflected in Anren-Hengshan segment and Taojiang segment.The segmental movement of the Changde-Anren fault in Indosinian is a "passive" segmental movement after the first penetrating fault was divided into several segments by the NE-trending deep fault, which is different from the general "active" fault segmental movement or segmental growth with many small faults occurring, expanding and finally being connected into a large fault.

With the deepening of global oil and gas exploration research, the North Atlantic polar region has gradually become the frontier of oil and gas exploration, but the exploration degree of Jan Mayan micro-continent is very low.The study on stratigraphy, structures and tectonic evolution modelling of the Jan Mayan microcontinent (JMMC)is presented in the paper based on seismic, gravity and magnetic data newly acquired by CNOOC in its contract area and other new published papers which show the most update progress of the JMMC. Located in the central part of the Norwegian-Greenland Sea of the North Atlantic, the JMMC is conjugate with the Jameson Land Basin on the Greenland continent margin and the Vøring Basin on the Norwegian shelf margin of the Beltic Continent in accordance with similar Paleozoic-Mesozoic stratigraphy. The JMMC extends southwards from the Jan Mayan fracture zone towards northern Iceland and its architecture shows the characteristics of detachment faults which is similar to the Mesozoic fault system of the Vøring Basin. The distribution of SDR, volcanic intrusion and explosion can be interpreted on the seismic data which indicates the JMMC is the distal domain of the volcanic passive margin in the North Atlantic mostly during the Cenozoic age. The tectonic evolution model is setup by analogic basin analysis and is supposed to start from the Paleozoic-Mesozoic orogeny to rifting, and then be influenced by the twice seafloor spreading of the age 55 Ma and 25 Ma. The first seafloor spreading of 55 Ma age caused the continental crust break-up and formed the volcanic passive margin between the Greenland and Beltic, especially the JMMC's separating from the conjugate Norwegian shelf margin. The second seafloor spreading of 25 Ma age caused the oceanic ridge jump due to the Iceland mantle plume drifting off the Greenland and also caused the JMMC's separation from the Greenland Continent as an 'abandoned orphan' floating on the oceanic crust. The meaning of this study is to discuss kinematic evolution of residual continental crust detached from the distal domain of the plate and to indicate lithospheric extension and break while the embryonic oceanic crust generating through the detachment movements and mantle upwelling.

The Baqu glacial lakes outburst debris flow is close to a station of the Sichuan-Tibet Railway, which may threaten the construction and running of the railway. In this paper, the methods of in-site investigation and remote sensing were used to identify the basic geological characteristics of the Baqu gully. The kinetics parameters of debris flow were calculated by using the code-design-formulae method. Meanwhile, the stability of barrier dams of 7 glacial lakes in Baqu was evaluated based on the dimensionless blockage index (DBI). The results show that the DBI value of the 1# barrier dam was in the unstable region, and the DBI value of the 3#, 4# and 6# barrier dams were between the unstable region and the stable region, and there was a possibility of outburst. In this paper, we used RAMMS, a single-phase flow numerical method, to simulate and analyse the evolution process of glacial lakes outburst in the Baqu gully under 4 scenarios. The simulation results show that the evolution process is divided into 4 stages: initiation, confluence, runout and deposition, which lasted for 4.5 hours. The results also show that the maximum velocity, depth and discharge of the debris flow at the mouth of the channel were 5.92 m/s, 4.35 m and 1 954.42 m3/s (5.1 times of that of the rainstorm debris flow), respectively, under the condition of glacial lake 1#—4# and 6# outburst. In addition, the influence area of outburst flood in 4 scenarios affected the proposed station, and the maximum depth was 1.91 m, 3.36 m, 1.53 m and 4.35 m, respectively. Therefore, in the design of the station, it is necessary to take engineering measures such as drainage canal or diversion dike for protection and treatment, so as to ensure the safe running of the station. The above results can provide reference for the line selection of the Sichuan-Tibet Railway and the prevention and control of glacial lakes outburst debris flow in the Eastern part of the Qinghai-Tibet Plateau.

Located in east-central Qinghai-Tibet Plateau, the Sichuan-Tibet traffic corridor is one of fastest uplifting and geomorphic evolution regions on the earth. Under the coupling of internal and external dynamics, the landslide in this region is extremely developed, which seriously restricts the planning and construction of highways, railways and hydropower projects. Based on the data collection and analysis of regional geological data, this paper selects lithology, slope gradient, aspect, slope shape, topographic relief, terrain roughness, fault density and distance to rivers as contributing factors. Combined the advantages of traditional information value method and logistic regression, this paper uses the logistic regression-information value method to evaluate the landslide susceptibility of the study area. Through the multi-collinearity test and significance test of the contributing factors, it is found that the selected contributing factors have no multi-collinearity and have a significant impact on the occurrence of landslides. ROC curve is used to test the results of landslide susceptibility, and the AUC value is 0.81, which shows that the model can well predict the occurrence of landslides. The results show that the high risk areas in the study area mainly occur in the regions of the Longmenshan fault zone, Jinshajiang fault zone, Lancangjiang fault zone, Nujiang fault zone and Bianba-Luolong fault zone, as well as on the sides of deep valleys of large rivers with steep slope and large topographic relief. The middle risk areas widely exist on both sides of the tributaries of large rivers. The results are helpful in understanding the development and distribution of landslides in the Sichuan-Tibet traffic corridor, and also provide a scientific basis for the project planning and construction, disaster prevention and mitigation in the study area.