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Taking the Xinshan iron ore mine as an example, this paper, based on collecting and analyzing the actual production data and similar simulation test data of this iron ore mine, analyses various factors affecting ore depletion by bottomless column segmental chipping method by using hierarchical analysis method (AHP) and fuzzy comprehensive evaluation method (FCE), and establishes an evaluation system for comprehensively assessing the depletion of the ores. The results show that structural parameters, blasting parameters, loading parameters, and geological conditions are the main factors affecting ore depletion. The structural parameters are the most important factors, accounting for 35%. With the increase of the released amount, the released grade gradually decreases, the depletion rate gradually increases, and the comprehensive evaluation value gradually decreases. The released body is an approximate ellipsoidal block with a wide upper and narrower lower part. The end wall plays an obstructive role in the flow of the bulk body, which makes the end of the released grade higher and the middle of the released body higher. At the same time, due to the influence of blasting and shovel loading, the particles in the release body show some sorting phenomena. This paper provides a scientific basis and reference for predicting and controlling ore depletion in the bottomless column segmental chipping method. [ABSTRACT FROM AUTHOR]

This paper assessed soil degradation over different land uses in the Kebbi area, Northwestern Nigeria. The specific objectives entailed identifying major forms of soil loss in the study area, estimating soil loss and examining the responses of soil physico-chemical properties over dominant land use types. Slope angles were determined using a GPS, a handheld Abney level, ranging poles and a 30 m measuring tape while gully depths, widths and lengths were taken at 5 m-30 m intervals. Key soil physico-chemical parameters were determined using standard procedures. Descriptive statistics such as mean, standard deviation and coefficient of variation were used to summarize the data generated from the study. The analysis of variance and the student's t-test was used to test for significant association between and within pairs of land uses. The results show that slopes range from 4° - 16°, while the magnitude of soil loss ranged between 3580.32 m³ in K1 (Kalgo 1), 3550.89 m³ in G2 (Goru 2) and 161.01 m³ in A1 (Angwar Daji 1). Results show significance at p= 0.05 in bulk density values over the different land uses with the highest bulk density value of 1.78 g/cm³ in badland and lowest value of 1.35 g/cm³ in plantation land use. Total nitrogen range between 0.01 - 0.38% with the least values in badland and scrubland, while soil base saturation is highest over plantation (76.3%) and lowest in badland (50.4%). The study concludes that the dominant geomorphic responses identified in the study area are gully initiation and development and a varying magnitude of soil degradation over the different land uses. The findings should facilitate policy initiation to rehabilitate degraded lands, adopt sustainable soil management practices such as tree planting while linking geomorphological information to infrastructural planning and development. [ABSTRACT FROM AUTHOR]

One of the world's most pressing needs today is access to groundwater. Although hydrological parameters can generally be estimated using underground studies, these methods are time-consuming and expensive. By taking the direct relationship of these parameters with electrical resistivity and measuring it with a cheaper and faster geoelectric method, a qualitative estimate of these parameters will be obtained. The electrical resistivity method is one of the most widely used methods to probe aquifers. The main objective of this paper is to show how, by interpreting and modeling the data of this exploratory method along with other geological information, the hydrogeological modeling of groundwater reservoirs can be done, and then, with an informed vision, the wells can be drilled for exploitation. For this purpose, the electrical resistivity data at 189 points and 9 profiles in the Shahroud region with Schlumberger array, after reviewing and making some modifications, were subjected to one-dimensional inverse modeling. According to the peripheral vision, the electrode distance was considered to be 50 meters and the length of the profiles is different. The longest profile was 1000 meter and related to profile 3. Then, using the results of modeling along with other available information, the hydrogeological models of the area were prepared in the form of iso-resistivity contour map and interpreted in terms of resistivity and thickness of subsurface layer using computer software Geographic Information System (GIS). Similarly, the thickness map of the aquifer unit (s) was also prepared to classify the good and poor zones. Using the prepared models and also considering the direction and piezometric of the groundwater flow inside the aquifer, suitable places were identified and suggested for future exploitation. [ABSTRACT FROM AUTHOR]

The igneous rocks of Cerro Cacheuta are considered a typical expression of the Permian-Triassic magmatism within the Andes Precordillera of Mendoza, Argentina. In particular, the southwestern margin of this hilltop is characterised by intermediate volcanic and felsic intrusives from the Choiyoi Group, one of the most extensive volcano-sedimentary suites of southern South America. The Choiyoi magmatism is widely associated with dramatic tectonic and environmental changes in the Gondwana supercontinent. Therefore, a better characterisation of the igneous facies of Cerro Cacheuta is critical to understand the evolution of Gondwana and recognise the multiple events that occurred towards the end of the Permian. This paper presents new data about the mineralogy, petrography, and geochemistry of the plutonic and volcanic units of Cerro Cacheuta, which enables authors to draw additional conclusions about the genesis and evolution of the magmatism in the region. Microscope observations indicate that the volcanic rocks are largely consistent with intermediate facies dominated by a porphyry texture with plagioclase and sanidine phenocrystals within a trachytic groundmass. Coetaneous breccias of possible hydrothermal origin and geodes with cryptocrystalline silica, limonite, and quartz are also recognised in outcrops. Geochemical analysis suggests that the lavas would likely correspond to andesites from a calc-alkaline magmatic arc. Furthermore, trace elements show enrichment in LREE/HREE, a slight negative anomaly in Eu, and concentration ratios compatible with crustal extension during the initial stages of the Choiyoi Group. Based on their chemical similarities, the monzonites of the Boca del Río Pluton would correlate with the lower section of the Choiyoi Group, of Permian age. In contrast, granites of the Cacheuta Pluton show a signature typically recognised in units from the Triassic and, therefore, would be comparable to the upper member of the Choiyoi Group. [ABSTRACT FROM AUTHOR]

Mining activities are liable to injuries and different types of diseases. The occurrence of an accident threatens safety in dimension stone mines. Therefore, the safety risk assessment in such mines is an important issue that needs special consideration. In this paper, the safety risk of incidents in dimension stone mines in Iran is evaluated using the fuzzy inference system. The fuzzy analytical hierarchy process is used to identify the importance degree of each incidence and then, the overall risk priority number is calculated based on the fuzzy inference process. The results of this study show that vehicle traffic and wire rupture are the most hazardous incidents. [ABSTRACT FROM AUTHOR]

Accurate identification of oil and water layers is the basis of qualitative evaluation of reservoir fluid properties or industrial value and selection of testing layers of the well. The traditional oil and water layer identification is mainly based on the extensive use of the well's logging and logging data, which is inefficient and easy to leak interpretation or misinterpretation for those reservoirs with complex geological conditions. In this paper, the random forest method of machine learning is used to select the lithology, porosity, permeability, movable fluid, oil saturation, S0, S1, S2, Tmax of rock as characteristics; smote oversampling is used to expand the sample, and the packet estimation is used to establish the oil and water layer identification model. This method is simple and easy to use, not prone to severe overfitting, and can find the potential rules in the data. The classification performance is excellent, and the accuracy rate can reach more than 89.9%, which solves the problem of low accuracy in oil-water layer identification in the past. [ABSTRACT FROM AUTHOR]

Most of the coal mining in China is underground, which will inevitably cause surface deformation and trigger a series of geological disasters. Therefore, it is essential to find a suitable method to forecast the ground sinking caused by underground mining. The most commonly used prediction model in China is the probability integral model (PIM). But when this model is used in the geological condition of mining under thick loose layers, the predicted edge of the sinking basin will converge faster than the actual measured sinking situation. A geometric model (GM) with a similar model shape as the PIM but with a larger boundary value was established in this paper to solve this problem. Then an improved cuckoo search algorithm (ICSA) was proposed in this paper to calculate the GM parameters. The stability and reliability of the ICSA were verified through a simulated working face. At last, the ICSA, in combination with the GM and the PIM, was used to fit 6 working faces with the geological mining condition of thick loose layers in the Huainan mining area. The results prove that GM can solve the above-mentioned PIM problem when it is used in geological mining conditions of thick loose layers. And it was obtained through comparative analysis that the GM and the PIM parameters can take the same value except for the main influence radius. [ABSTRACT FROM AUTHOR]

The paper presents new data on mineral composition and geochemical peculiarities of ores from the Albazinskoe gold-bearing deposit (Khabarovsk region, Far East of Russia). Excepting earlier known ore minerals represented by sulfides of iron, arsenic, lead, zinc, and copper, authors have established about two tens of ore minerals, new for this deposit. Among them are sulfides of antimony, bismuth and molybdenum, native bismuth, copper, nickel, silver, tellurides of bismuth, cobalt sulphoarsenite, nickel sulphoantimonite, silver sulphobismuthites, lead-antimony-bismuth sulphosalts, oxides of tin, titanium, tungsten and some others. The revealed specificity of the ores' material composition indicates this deposit belongs to the gold-rare metallic ore-formational type. The sets of geological and structural data show that gold-bearing deposits of this ore-formational type are spatially and genetically associated with the granitoid magmatism, which is exhibited within transform continental margin and related to the geodynamic mode of sliding of the continental and oceanic lithospheric plates. [ABSTRACT FROM AUTHOR]

A quest for life on Mars (LoMars) started in the early 1960s when the most prestigious scientific journals published several research articles. According to Elsevier's Scopus database, the rise in annual literature production started in the late 1990s, most likely associated with the launch of the National Aeronautics and Space Administration's (NASA) first rover, Sojourner, in 1996. The number of articles on Mars will likely continue to rise sharply, given that the launch and landing of the Mars 2020 Perseverance Rover are critical to discovering and understanding the present or past life on the planet. Thus far, the USA has dominated in the number of citations and collaborations related to Mars research, given its facilities equipped with relevant infrastructure and researchers' capacity to explore the Solar System beyond Earth. Most of these frequently cited papers report observational and theoretical research results. However, a highly cited article is based on analytical studies of a unique Martian meteorite (i.e., Allan Hills 84001) found in Antarctica. It is expected that the future sample return mission associated with the Perseverance Rover caching system could increase the LoMars research exponentially in the coming decades if Martian samples are successfully brought to Earth. Based on the total number of publications on LoMars, the most influential institute, the author, and the journal are Caltech, C.P. McKay, and Icarus, respectively. Both the institute and the author are directly affiliated with NASA, indicating the leadership offered by the organization in LoMars research. [ABSTRACT FROM AUTHOR]

In recent decades, important steps have been taken to implement the physical concepts of Geodesy in practice, concerning height systems. Despite the difficulties involving gravity field modeling, with the establishment of conventions, standards, and computation strategies, the realization of the International Height Reference System (IHRS) is well underway. For a global system, there are constraints for some countries, especially for those with sparse gravity data, mountain regions, and vast areas. In terms of methodology, the computation can be performed directly using the Global Geopotential Models (GGM), recovering existing geoid models, or determining pointwise the gravity potential using integral formulas. In general, the regional gravity modeling is given by numerical integration or least-squares collocation and more recently adopting the spherical radial basis functions. The first approach allows determining the earth's gravity component at a specific point and adjusting the integral formula according to the gravity coverage. Since so far there is no common sense about the best methodology, computation strategies are been analyzed. In this context, the paper aims to contribute to IHRF, computing the geopotential number in the scope of IHRF, using numerical integration to solve the Geodetic Boundary Value Problem and an existing recent quasi-geoid model in four stations in São Paulo state, Brazil. The first approach was performed considering two cases: a radius of 210 km and 110 km of gravimetric data coverage and the Global Geopotential Model GOCO05S truncated at 100 and 200, respectively. The results between solutions have shown a maximum difference of 94 cm, and a minimum difference of 10 cm. [ABSTRACT FROM AUTHOR]

Under the influence of geological structure, the surrounding rock of semi-coal seam is easy to be loose and fractured, and the repairing rate is high. Therefore, it is of great theoretical and practical significance to study semi-coal seam mining's mechanism and control technology. In this paper, the geological evolution principle of the semi-coal seam is analyzed theoretically. The mechanic's relationship between the mining height of the semi-coal face and the lower coal seam's pressure relief is interpreted. The mechanism of eliminating bad blind areas in non-pillar mining of upper protective seam is analyzed. Through numerical simulation analysis, it is concluded that the expansion deformation rate of a protective layer increases linearly with the increase of mining thickness of the protective layer, and the width of undesirable blind zone of coal seam increases linearly with the rise of protective layer thickness. This paper puts forward the technology of non-pillar mining in the protective seam's semi-coal and rock face. Field industrial test results show that the technology achieves the overall pressure relief and reflection reduction of low permeability and high gas coal seams. The underlying 3 + 4 protective layer achieves the general pressure relief and reflection reduction of low permeability and high gas coal seams. Coalbed methane can be pre-drained up to 18 m³/min with a concentration of 90%. [ABSTRACT FROM AUTHOR]

The probability integral method is the most commonly used mining subsidence prediction model, but it is only applicable to ordinary geological mining conditions. When the loose layer in the geological mining conditions where the mining face is located is too thick, many inaccurate phenomena will occur when the movement deformation value is predicted by the probability integral method. The most obvious one is the problem that the predicted value converges too fast compared with the measured value in the edge of the sinking basin. In 2012, Wang and Deng proposed a modified model of probability integral method for the marginal errors in the model of probability integral method and verified the feasibility of the method through examples. In this paper, the method is applied to the prediction of surface movement under thick and loose layers after modified. Through practical application, it is found that due to the angle between the working face and the horizontal direction, the average mining depth in the strike direction is different from the average mining depth in the inclined direction, and the main influence radius of the two main sections are often. Therefore, based on this problem, this paper divides the main influence radius into trend and tendency and adjusts the parameters in the model to find the rules of the parameters. The original method uses a dynamic scale factor to adjust the predicted shape of the graph by adjusting the sinking coefficient. This study is aimed to set the scale factor to 0.5 and fix the value of the sinking factor, and propose to adjust the integral range and then adjust the shape of the graph to make it more in line with the actual measurement situation. [ABSTRACT FROM AUTHOR]

The potential analysis of geothermal energy based on geothermal characteristics requires research of the regional shallow geothermal energy. Then, an evaluation model can be constructed. Taking Weinan City as an example, this paper studied the depth and temperature characteristics of the constant zone of subsurface temperature, the vertical variation characteristic of geotemperature, and the horizontal distribution characteristic of geotemperature in Weinan City. Based on the analysis of geotemperature characteristics, the analytic hierarchy process was used to construct the zoning evaluation system of the suitability of ground source, groundwater source, and surface water source. Then, the suitability of Weinan city was comprehensively zoned by the zoning evaluation system. The heat capacity and heat-exchange power of the heat pump system at the groundwater source were calculated based on the zoning results, and the heat-exchange power of the ground-coupled heat pump was obtained. According to the evaluation index, the development potential of shallow geothermal energy resources was evaluated. It can be seen that the heat pump system has great potential for heating in winter and cooling in summer through the experimental analysis model applied in this paper. The area is 50.79 km². The area of the potential middle region of the buried pipe heat pump is 135.74 km², and the potential of the pump system is low. The possible area of the ground source heat pump is 82.14 km². Upon comparing the model results with the current results, it was found that the consistency between the two is high. [ABSTRACT FROM AUTHOR]

Taking Jinghe River Basin in the Loess geomorphological area and Guangnan County in the karst geomorphological area as the study area, the spatial distribution characteristics of urban and rural areas of different geomorphological types are analyzed. By using GIS and related statistical analysis software, this paper summarizes three basic urban and rural types: river channel type, plateau surface type, and loess terrace horizon prototype in the Loess Landscape Jinghe River Basin. It is known that most towns in the loess plateau gully area are in the Jinghe River Basin. According to the spatial distribution characteristics of urban and rural areas, the optimal layout based on the main structure of five districts, nine River corridors, and four plates is proposed. Using the DEM module of ArcGIS to divide the elevation and gradient of Guangnan County, we know that the density of urban and rural settlements in Guangnan County is low and the spatial distribution is dispersed, and the distribution of urban and rural settlements shows a strong elevation orientation. The distribution of urban and rural settlements has a normal distribution relationship with the elevation. The largest number of urban and rural settlements is between 2.1° and 25°. According to the present situation of settlement distribution, this paper puts forward some optimization strategies, such as appropriate settlement scale, settlement space development monitoring, and so on. [ABSTRACT FROM AUTHOR]

The morphotectonic analysis is a useful time-saving and cost-effective method to assess tectonic activity, especially in large regions. In this paper, the morphotectonic study was carried out in Kerman city which is in the southeast of Iran and is a part of the Central Iran structural zone. Despite the occurrence of numerous historical and instrumental earthquakes around Kerman city, there is a gap in earthquake records of this city that has obscured its seismicity status. The aim of this study is to identify active faults and the associated seismic hazard to Kerman city. For this purpose, seven geomorphic indices namely stream length-gradient index (SL), drainage basin asymmetry (Af), hypsometric integral (Hi), ratio of valley-floor width to valley height (Vf), index of drainage basin shape (Bs), index of mountain front sinuosity (Smf) and Transverse Topographic Symmetry Factor (T) were examined for 51 basins of the study area, using digital elevation model (DEM) and geological maps in a GIS environment. Then, two kinds of relative tectonic activity indices were calculated for each basin, i.e., Iat and Iat_T, from the combination of these indices. The Iat_T was chosen because its results show better agreement with the structural geology and seismic records of this region. Finally, the study area was divided into three regions according to the Iat_T values. The morphotectonic analyses indicate that the Kuhbanan fault system, especially its southern splays, has the potential to produce serious seismic hazards to Kerman city in the future; the Mahan-Jupar fault-related folds, the southern tip of the Jorjafk fault, the probable fault of Zangi-Abad, the Rafsanjan-Zarand fault system, and Gowk fault are considered as other threats to Kerman city. Furthermore, this study reveals that morphotectonic analysis is a reliable tool to evaluate fault capability and to determine the fault types, and therefore to estimate seismotectonic hazard. [ABSTRACT FROM AUTHOR]

This paper presents detailed mineralogical results together with a geochemical characterization for a sequence of six natural soil profiles. Bedrock samples (R series) and overlying soil samples (S series) were characterized. The soil profiles are distributed in a series of Paleozoic lithological units from lower Ordovician to upper Carboniferous in age (Iberian Massif, NW Iberia). The lithological influence on mineral properties and geochemical composition and, how different weathering may be occurring under very similar temperate and acidic conditions, have been studied. Field observations together with laboratory analyses were indicative of differential weathering. So, a series of selected chemical indices and relations were applied to clarify this assumption. The mineralogy was analysed by Scanning electron microscopy (SEMEDS), X-ray diffraction (XRD) of rock powder and soil oriented aggregates. X-ray fluorescence spectrometry (XRF) and inductively coupled plasma mass spectroscopy (ICP-MS) were applied to analyse chemical composition. The first results showed how major elements, SiO2, Al2O3 and Fe2O3, slightly enriched in the soil profiles, are consistent with the dominant mineralogy: quartz, chlorite, muscovite and/or illite, together with kaolinite and albite. The bases K2O, Na2O, CaO and MgO are also coherent with mineral composition and experience little variation, but are gradually removed in the profiles. The mobility of major elements leads to a general loss of bases and, in general, a slight enrichment in silica and sesquioxides. SiO2 is enriched, firstly accumulated in soils and partially depleted by dissolution as colloidal form. Al2O3 in some soils is slightly less than in former rocks, so other physical processes are expected to take place, involving clay removal with consequent aluminium depletion too. A special emphasis has been given to albite coexisting with kaolinite, firstly supposed to be directly inherited from parent substrates when present, but finally the chemical index PIA shows it was mainly due to mineral alteration of plagioclases. The best correlations to explain the albite alteration and kaolinitization progress were obtained with chemical indices PIA, CIW, CIA and Al2O3/Na2O ratio. This together with mineralogical signatures, suggest that kaolinite is the result of gradual dissolution due to the acid hydrolysis of albite in such acidic environments, which may also be attributed to the organic matter influence. [ABSTRACT FROM AUTHOR]

This paper took the Fengmaoding slope, typically found in the mountainous areas of central Shanxi province, as its research area. The stratum structure of the Fengmaoding slope is a typical coal measures stratum covered by a layer of loess. There are communication towers on the slope mass and top of the slope; railways, roads, and rivers at the foot of the slope. There are many villages across from the slope, therefore, the buildings and structures nearby, even the lives of the villagers are threatened by the damages caused by the deformation of the slope. Tectonic development and mining activities have very profound effects on the stability of the slope. Considering the above, this paper analyzed the effects of the fault in controlling the deformation features of the destabilized slope during underground mining by adopting the method of numerical simulation from these perspectives including displacement, stress, strain, among others. under different circumstances (the faulted and unfaulted) so as to provide guidance for future studies about landslides of the same type and give preventive proposals for reference. [ABSTRACT FROM AUTHOR]

Supporting earthquake risk management with clear seismic communication may necessitate encounters with various popular misapprehensions regarding earthquake prediction. Drawing on technical data as well as insights from anthropology and economics, this paper addresses common and scientifically-unsupported ideas about earthquake prediction, as well as the state of science-based studies regarding statistical forecasting and physical precursors. The authors reflect on documented social and economic effects of unsubstantiated earthquake predictions, and argue that these may be dangerous but may also present certain opportunities for outreach and education in formal and informal settings. This paper is written in light of the importance that the United Nations Office for Disaster Risk Reduction has placed on coordination and communication within and among diverse organizations and agencies as well as by the recent popularity of so-called earthquake prediction in Mexico. [ABSTRACT FROM AUTHOR]

Predicting the outcomes of earthquakes before they occur is one of the fundamental components of modern disaster management. Loss estimation analyses have an important place at the assessment stage of earthquakes and in estimation of losses that earthquakes may lead to. With these analyses, it is possible to access information that is relevant to potential damages and losses. In this paper, loss estimation analyses were carried out by using the earthquake scenario which foresaw a previous earthquake that was experienced in an around Kırşehir which is seismically active and located in the Central Anatolia Region in Turkey. The 1938 Akpınar earthquake which occurred in and around the province of Kırşehir was taken into consideration as an earthquak escenario, and loss estimation analyses were conducted for this earthquake scenario. In this paper, significant contributions will be made for preparation of an earthquake master plan and risk management plan for Kırşehir. Besides, studies on reduction of earthquake losses in the region may utilise these results. [ABSTRACT FROM AUTHOR]

This paper designs a highly parallel Nested Factorization (NF) to solve large linear equations generated in reservoir numerical simulation problems. The NF method is a traditional linear solution preprocessing method for reservoir numerical simulation problems and has regained attention in recent years due to its potential to extend to parallel architectures such as GPUs (Graphics Processor Units). The parallel algorithm of this paper is based on the MPNF (Massively Parallel Nested Factorization) framework proposed by Appleya. The MPNF algorithm designed in this paper focuses on its efficient implementation on the GPU parallel architecture. Its features include: using a custom matrix structure to achieve merge access, improving access bottlenecks, and improving the efficiency of the SpMV algorithm. It is also applicable to the two-stage preprocessing method CPR (Constrain Pressure Residual). CPR pressures solution and global preprocessing stage; the MPNF method is extended to the solution of the 2.5-dimensional unstructured grid problem. The parallel algorithm in this paper has been integrated into the reservoir numerical simulator. For the SPE10 (million grid, highly heterogeneous) standard example, the GPU-based parallel NF algorithm is in the structured grid model and the equivalent 2.5-dimensional non-on the structured grid model. Compared with the serial version of the NF method, the acceleration ratios of 19.8 and 17.0 times were obtained, respectively; compared with the mainstream serial solution method; the efficiency was also improved by 2 to 3 times. [ABSTRACT FROM AUTHOR]

In this paper, the soil profile of the Costa Rican Strong-Motion Network (CRSMN) stations is classified based on actual measurements and seismic regulations. The soil classification of the Costa Rican Seismic Code based on the average shear-wave velocity of the top 30 m (VS30) is used as a reference. The site fundamental period (Tf) is included as a parameter to complement the existing characterization. For this, VS30 measurements from 52 accelerometric stations are related to the site fundamental period obtained through horizontal-to-vertical spectral ratios (HVSR) using ground motion records from the Costa Rican Strong-Motion Database. The H/V ratios are estimated with 5% damped acceleration response spectra and with traditional Fourier amplitude spectra from the S-wave window. From the relation between VS30 and Tf, different ranges of Tf are assigned to the existing soil profile classification and a graph with three-lines and four-areas is proposed to classify the stations of the CRSMN. These lines are plotted from the intersection between values assigned to each site class. The assigned classification at each station will be the one corresponding to the area where the pair of values (VS30 - Tf) falls. With this proposal, both parameters take relevance and are compensated, reducing the differences due to possible errors in measurements or interpretations. [ABSTRACT FROM AUTHOR]

Fast Marching Method (FMM) boasts high calculation efficiency and strong adaptability and stability while being applied to seismic traveltime. However, when it is applied to the largescale model, the calculation precision of FMM is insufficient. FMM has poor calculation precision near the source, which is an essential reason for the low accuracy of the whole algorithm. This paper puts forward a common traveltime calculation method to address the problem. Wavefront Construction (WFC) with a relatively high calculation accuracy rather than FMM is adopted for calculation of the grid nodes' traveltime near the source. After that, FMM is used to calculate the seismic traveltime in the remaining area. Joint traveltime calculation method greatly improves the calculation accuracy of the source's surrounding area and the calculation accuracy of FMM. According to the new method, FMM is still adopted for the calculation of most grid nodes in the model, so the high calculation efficiency of FMM is maintained. Multiple numerical models are utilized to verify the above conclusions in the paper. [ABSTRACT FROM AUTHOR]

In order to reduce the risk of slope stability evaluation due to the fuzziness of calculation parameters, a finite element analysis method of slope stability based on fuzzy statistics is proposed. Based on the principle of quasi-static method and with the help of the finite element software COMSOL multiphysics, this paper studies the stability of the gravel soil accumulation rock slope under the action of different seismic acceleration. By analyzing the displacement, plastic zone and safety factor of the rock soil slope, the stability of the rock soil slope is analyzed. The research results show that the fuzziness of mechanical parameters of rock and soil slope will lead to the fuzziness of position displacement and stress analysis results of rock and soil slope, and the analysis of rock and soil slope with the method of fuzzy finite element analysis can strengthen the comprehensive understanding of position displacement, stress and safety of rock and soil slope by engineers and technicians, and reduce the stability of rock and soil slope due to the fuzziness of calculation parameters to a certain extent Evaluate the risk qualitatively. [ABSTRACT FROM AUTHOR]

Peat is an organic material that has been widely used as an efficient and low-cost adsorbent. As many studies tend to focus on temperate peats, there is a lack of knowledge about the adsorption mechanism of tropical peats. This paper investigates the use of two Brazilian peats (Cravinhos - C and Luis Antônio - LA) from the Mogi-Guaçu river basin for the adsorption of lead (Pb), zinc (Zn), and cadmium (Cd), in order to contribute to the use of local and easy access materials to remediate contaminated sites. The peats adsorbed a high percentage of cations, especially Pb cations (100.0-46.3%), with commercial peat C showing higher adsorption than peat LA. The removal order was Pb2+ > Cd2+ = Zn2+ for C and Pb2+ > Zn2+ > Cd2+ for LA. The batch data for both peats and for all metals were better fit by the Langmuir isotherm, with adsorption capacities (qm) for Pb, Zn, and Cd of 37.3134, 29.0674 and 21.2890 mmol kg-1 in peat C and 21.7391, 14.2550 and 3.6460 mmol kg-1 in LA, respectively, values comparable to those of other peats and biosorbents. The studied peats are considered efficient, alternative and low-cost adsorptive materials for these metals. The proximity of peatlands to areas with high potential for contamination necessitates the use of local materials to reduce remediation costs. [ABSTRACT FROM AUTHOR]

In the last decade, the Persistent Scatterer Interferometry - PSI have been largely employed to predict instabilities and failure in open pit mines. The PSI is a powerful technique, which combines radar satellite data in order to detect and monitor tiny surface displacements over vast areas. In the last years, the Sentinel-1 radar mission have produced images of the globe acquired with different spatial and temporal resolutions that are now freely available. In recent years, the footwall slopes of the Riacho dos Machados Gold Mine - MRDM (Minas Gerais state, southeastern Brazil) have recorded large planar failures controlled by foliation planes. Therefore, the focus of this paper is to evaluate a stack of 39 Interferometric Wide Sentinel-1 scenes, spanning from January 2018 to April 2019, acquired in descending orbit geometry, for the detection and monitoring of surface displacements. The results have shown that descending IW Sentinel-1 scenes can be used to provide a broad picture of the Line-Of-Sight - LOS deformation phenomena. In order to monitor the evolution of the deformation phenomena induced by mining activities, LOS deformation maps with millimeter accuracy could be only delivered at least every 12 days. [ABSTRACT FROM AUTHOR]

In view of the inaccuracy of the traditional correlation analysis method, this paper proposes a correlation analysis method between the multifractal characteristics of regional landforms and the development of geological disasters. Firstly, the multifractal characteristics of regional landforms are described by using the basic fractal characteristics of self-similarity or scale invariance. Then the corresponding relation table is established according to the width of the fractal spectrum and the number of landslides and hidden dangers, and the spatial relationship of geological disaster development is analyzed. Combined with the above-mentioned spatial relationship of geological disaster development and the multifractal characteristic data of regional landforms, the correlation coefficient between the two is calculated to complete the correlation analysis between the multifractal characteristics of regional geomorphology and the development of geological disasters. The experimental results show that compared with the traditional correlation analysis method, the correlation analysis results of the multifractal characteristics of regional geomorphology and the development of geological disasters are more accurate. [ABSTRACT FROM AUTHOR]

In order to improve the flexibility of GPS measurement, a high-precision GPS measurement method that is not restricted by the geographical location under crowd-sensing technology was proposed. The performance of the crowdsensing network was improved through a regular hexagon-based crowd-smart big data sensing network deployment mechanism. The GPS /SINS/DR fast and high-precision combined measurement methods were used to achieve high-precision measurement without geographical restrictions. It has been verified that the proposed method in this paper has much better stability in the deployment strategy of a regular hexagon than that of the square. The proposed method can achieve fast acquisition of satellite signals and high-precision positioning, and its measurement accuracy in the low-latitude city and high-latitude city is higher than the online measurement method based on Google Earth, indicating that it has significant application value. [ABSTRACT FROM AUTHOR]

Desertification control is an important issue that must be considered in modern society. In order to effectively improve the accuracy and practicability of the evaluation algorithm of desertification control effect, the Alhagi sparsifolia index under different irrigation amount was taken as the research object, and the evaluation algorithm of desertification control effect was proposed. In the "vegetation-sandstorm-soil" index system, a number of indexes were selected according to the core environmental parameters of Alhagi sparsifolia and grassland desertification. And the analytic hierarchy process, remote sensing, geographic information system, and landscape technology were used to assign index weights of desertification control capacity, which were calculated by multiple discriminant matrices. Finally, the data regression analysis was performed based on remote sensing and computer image information screening and processing to determine the final evaluation results. The experimental data show that the true positive rate of the algorithm in this paper is between 160 and 200, which is within a large range of advantages, indicating that the overall evaluation accuracy of the algorithm is high and the evaluation effect is perfect. [ABSTRACT FROM AUTHOR]

Great progress has been made in middle Permian exploration in Northwest Sichuan in recent years, but there are still many questions in understanding the hydrocarbon accumulation conditions. Due to the abundance of source rocks and the multi-term tectonic movements in this area, the hydrocarbon accumulation model is relatively complex, which has become the main problem to be solved urgently in oil and gas exploration. Based on the different tectonic backgrounds of the middle Permian in northwest Sichuan Basin, the thrust nappe belt, the hidden front belt, and the depression belt are taken as the research units to comb and compare the geologic conditions of the middle Permian reservoir. The evaluation of source rocks and the comparison of hydrocarbon sources suggest that the middle Permian hydrocarbon mainly comes from the bottom of the lower Cambrian and middle Permian, and the foreland orogeny promoted the thermal evolution of Paleozoic source rocks in northwest Sichuan to high maturity and over maturity stage. Based on a large number of reservoir physical properties data, the middle Permian reservoir has the characteristics of low porosity and low permeability, among which the thrust nappe belt and the hidden front belt have relatively high porosity and relatively developed fractures. The thick mudstone of Longtan formation constitutes the regional caprock in the study area and the preservation condition is good as a whole. However, the thrusting faults destroyed the sealing ability of the caprock in the nappe thrust belt. Typical reservoir profiles revealed that the trap types were different in the study area. The thrust fault traps are mainly developed in the thrust nappe belt, while the fault anticline traps are developed in the hidden front belt, and the structural lithological traps are developed in the depression belt. The different structural belts in northwest Sichuan have different oil and gas accumulation models. This paper built three hydrocarbon accumulation models by the analysis of reservoir formation conditions. The comprehensive analysis supposed the hidden front belt is close to the lower Cambrian source rock, and the reservoir heterogeneity is weak, faults connected source rock is developed, so it is a favorable oil and gas accumulation area in the middle Permian. [ABSTRACT FROM AUTHOR]

In this study, we tried to estimate the optimum linear equations among the parameters associated with different earthquake fault mechanisms for Iranian earthquakes. For this purpose, we tested different curve fitting methods in order to present the most proper empirical relationships between several seismic parameters for different fault systems. In the present paper, 46 large and destructive Iranian earthquakes whose magnitudes change between 5.8 and 7.8 from 1900 to 2014 were used for the analyses. A comparison was made by using four types of curve fitting techniques. The estimation procedures are considered as (1) L2 or Least Squares Regression, (2) L1 or Least Sum of Absolute Deviations Regression, (3) Robust Regression and, (4) Orthogonal Regression. Confidence intervals were selected as 95% for all types of regression relationships. In the selection of the best probability distribution, we considered the correlation coefficients of the linear regressions as a powerful and conceptually simple method. Correlation coefficients of all relationships change between 0.299 and 0.986 with Orthogonal regression, between 0.168 and 0.792 with L1 regression, between 0.059 and 0.829 with Robust regression. For Iranian earthquakes, the most suitable and reliable empirical relationships between moment magnitude (Mw) and surface wave magnitude (Ms), Mw and surface rupture length (SRL), Mw and maximum displacement (MD), and SRL and MD were obtained by Orthogonal regression since it supplies stronger correlation coefficients than those of the other regression techniques in most estimates. The results show that estimated empirical relationships among the different fault parameters by using the Orthogonal regression method can be accepted as more up-to-date and more appropriate in comparison with the other regression norms. Consequently, these equations were suggested as more reliable in the estimation of the maximum surface displacement, maximum surface rupture length and associated with the maximum credible earthquakes for different areas of Iran. Furthermore, obtained relationships can be statistically significant for the assessment of seismic, tectonic and geologic activities, and they can be used to evaluate the rupture hazard of the Iranian Plateau. [ABSTRACT FROM AUTHOR]

The Zhangwu-Heishan area is located in the east of the Fuxin-Yixian basin. Besides the Quaternary soil, the study area is mostly covered with volcanic rock. The horizon and age of volcanic rock play an essential role in understanding fossil beds, structures, and sedimentary evolution of West Liaoning Province and coal seeking. During this work, 11 volcanic rock samples were measured by SHRIMP U-Pb isotope analysis. Based on the reported data on the age of the Mesozoic volcanic rock in West Liaoning Province, in combination with new measurement data, Cretaceous volcanic activities in West Liaoning Province can be divided into five stages, namely 132±1 Ma, 126±1 Ma, 122±2 Ma, 115±2 Ma, and 100±5 Ma. Based on statistical results, this paper concluded that the thinning time of the crust in Northeast China is from 132±1 Ma to 115±2 Ma. [ABSTRACT FROM AUTHOR]

Soil and water conservation is one of the key measures to improve the ecological environment of small watersheds and maintain the healthy life of the region. With the current method used to monitor the evolution of topographic and hydrological characteristics of a small watershed, the edge keeping index of the image and the signal-to-noise ratio of the image are low, the monitoring results are inaccurate, and there are some problems such as low edge keeping ability, poor denoising effect, and low monitoring accuracy. A monitoring method based on remote sensing and GIS for the evolution of topographic and hydrological characteristics of small watersheds is proposed. The hyperspectral data was transformed by the Principal Component Analysis (PCA). Group principal component images, use sparse representation method based on adaptive dictionary and dual-tree complex wavelet transform method to denoise principal component images with a small amount of information were the objectives of the paper; also the use the multi-scale wavelet transform to detect image edge; build a binary model of a pixel, extract vegetation index, and terrain factor based on a binary model of the pixel, and realize terrain and hydrological characteristics of the small watershed. The experimental results show that the proposed method has the high edge-preserving ability, good denoising effect, and high monitoring accuracy. [ABSTRACT FROM AUTHOR]

Monitoring of longitudinal land subsidence and deformation in seismic and geological hazards plays an important role in preventing and curing land collapse, land subsidence, and ground cracks. In this paper, a distributed monitoring model experiment on vertical land subsidence and deformation of seismic and geological hazards is carried out by Brillouin optical frequency-domain analysis technology (BOTDA). By using the self-made indoor longitudinal land subsidence and deformation simulation box, different intensity seismic ground is simulated by air bag. Distributed optical fibers are used to monitor the longitudinal land subsidence and deformation during different intensity seismic and geological disasters. According to different intensity seismic and geological disasters, distributed sensing optical fibers cooperate with the ground to compress or stretch longitudinally and obtain the data of longitudinal land subsidence and deformation. The correction coefficient is introduced to modify the monitoring data of confining pressure-sensing optical fiber and complete the precise monitoring of vertical land subsidence and deformation in seismic and geological hazards. The experimental results show that this method can monitor the vertical ground subsidence and deformation of seismic and geological hazards under different conditions, and the monitoring efficiency and cost are superior to GPS and inertial monitoring methods, and the practical application value is high. [ABSTRACT FROM AUTHOR]

Soil remote sensing image classification is the most difficult in the National Soil Census work. Current soil remote sensing image classification methods based on deep learning and maximum likelihood estimation are challenging to meet the actual needs. Therefore, this paper combines deep learning with maximum likelihood estimation and proposes a maximum likelihood classification method for soil remote sensing images based on deep learning. The method is divided into four parts. Firstly, the pretreatment of soil remote sensing image is carried out, including three processes: image gray, image denoising, and image correction; secondly, the target of soil remote sensing image is detected by deep learning algorithm; thirdly, the maximum likelihood algorithm is used to classify soil remote sensing image; finally, the classification performance is tested by an example. The results show that this method can effectively segment the remote sensing image of soil, and the segmentation accuracy is high, which proves the effectiveness and superiority of the method. [ABSTRACT FROM AUTHOR]

This paper presents the analysis of a regional groundwater model via Feflow in tropical regions using two techniques: pilot points (PP) and constant zones (CZ). These methodologies allow the proper identification of biased parameters and heterogeneities of hydraulic properties. For this purpose, we developed a numerical density-variable model that is limited to reinterpreted data from real measurements. For the CZ, the initial parameters are considered constant; in contrast, in the PP technique, the initial parameters are assigned according to interpolations using in-situ point measurements. The developed model was applied in an area under the influence of the Inter-tropical Convergence Zone, located in the middle valley of Magdalena (MMV). This area is important in the development of Colombia due to its contribution to Gross Domestic Product, and it has been subject to significant changes in land use, as a result of intense economic activities. The established model shows a link between the observed state variable (hydraulic head) and hydraulic conductivity (K) proving the importance of spatial heterogeneity in K. The model is calibrated in order to establish K, the porosity and the specific storage capacity, reducing the mean square error of the state variable dependable on the observation points. The results show that the PP system approach provides a better heterogeneity representation and shows that each parameter is sensitive, and does not depend on other parameters. This research compiles the first breakthrough toward a methodology to assertively restrict a highly parameterized inverse regional model in a tropical basin. [ABSTRACT FROM AUTHOR]

In order to analyze the tension stress of Geomembrane in the seepage control system of a landfill in a heavy metal contaminated area under the action of the overlying landfill weight, the internal force of Geomembrane in a landfill is studied in this paper. Firstly, according to the internal force analysis of Geomembrane model, the basic equation of Geomembrane is obtained, and the equation is analyzed by finite difference numerical solution, so as to analyze the internal force of Geomembrane in a landfill. The method can analyze three stress states of Geomembrane-clay interface at different positions: elastic state, softening state and residual state, which makes the stress analysis of Geomembrane on landfill slope more reasonable. Parametric analysis shows that when the strength loss and the difference between residual displacement and peak displacement are small in the softening stage, the peak strength of Geomembrane-clay interface has little influence on the maximum tensile stress of Geomembrane and its residual strength is the main controlling factor, and when the softening characteristics of Geomembrane-clay interface are obvious, the influence of peak strength and residual displacement is more obvious. [ABSTRACT FROM AUTHOR]

For the traditional GPS elevation fitting method, the accuracy has not been significantly improved in recent years, and the method has become increasingly complicated. This paper proposes to insert the geodetic height 'H' into the calculation system and use a ternary polynomial regression function to fit the GPS elevation anomaly. The feasibility of the ternary polynomial regression method in GPS elevation fitting was verified by an example, and compared with the results of the traditional plane fitting and quadric surface fitting method, it was proved that the proposed method is suitable for terrain with large terrain fluctuations. The fitting residual error and the standard deviation are smaller, and through example calculations, it is concluded that the ternary polynomial regression method under the seven parameters has the highest fitting accuracy. [ABSTRACT FROM AUTHOR]

This paper is focused on analyzing the engineering properties and geotechnical changes of the soil contaminated by petroleum hydrocarbons, compared to non-contaminated soil. Also, identifying the physical and chemical behaviors and the interaction mechanisms between soil and contaminants at the time of contamination is far-reaching. This study aims to investigate the effects of petroleum contaminants on Atterberg limits, cation-exchange capacity, electrical conductivity and acidity, maximum dry density, and optimum moisture content of clay soil compared to non-contaminated samples with similar geological conditions in Gachsaran petroleum refinery region. The significant effects of contaminants on clay soil include an increase in cation-exchange capacity and electrical conductivity, but a decrease in acidity compared to non-contaminated samples. The results of the Atterberg limit as a physical index of the soil showed an increase in the petroleum hydrocarbon concentration, which enhanced the plastic and liquid limits, but decreased the plasticity index. The results of compaction tests using water and oil fluids indicated that the concentration of petroleum hydrocarbons in sandy soil increased maximum dry density and decreased optimum moisture content. Moreover, in a soil sample with stable pollution levels, maximum dry density and optimum moisture content were higher and lower in the compaction test using water fluid compared to those in compaction tests using oil fluid, respectively. Finally, increasing the soil pollution level reduced the difference between maximum dry density and the optimum moisture content in the compaction test using water fluid compared to the same test using oil fluid. [ABSTRACT FROM AUTHOR]

The numerical simulation of sediment transport in the Yellow River estuary is an important method to quantitative analyze the problems by water and sediment movement, including sediment deposition and river bed evolution, beach deposition and development, the formation and development of the delta, and so on. Making an intensive study of the problems is useful to study the principles of sediment movement and the evolution law of the estuary bed, and it is also important significance to scientific demonstrate of the estuary sediment deposition, sea water intrusion prevention treatment scheme and solve the problems of engineering. Based on the mathematical modeling of sediment transport and our research work, this paper analyzes the research statement, the unsolved issues and the developed trend of this kind problem, to provide the theoretical reference on more accurate numerical simulation of sediment transport in the Yellow River estuary and the scientific reference on the demonstration and decision of estuarine regulation scheme. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to investigate the standard light source for grading and displaying the color of red jadeite and to classify the color. With Raman spectrometer, ultraviolet-visible spectrophotometer and X-ray fluorescence spectrometer, the results show that, the Fe 3+ is the main chromogenic mineral of red jadeite, which negatively correlates with the tonal angle, while the color of red jadeite has a positive correlation with the hematite content. The color of 120 red jadeite samples was examined by collecting the reflective signaled from the sample surface using an integrating sphere with the portable X-Rite SP62 spectrophotometer based on CIE 1976 L*a*b* uniform color space. The color parameters of jadeite samples under D65, A and CWF standard light sources were analyzed. The light spectrum of D65 light source is continuous, relatively smoothed with high color temperature, which makes the sample color close to that under the natural light and can be used as the best evaluation light source. A light source contributes to improve the red tone of jadeite, which is the best light source for commercial display of red jadeite. CWF light source can be used as the auxiliary lighting for color evaluation. The color of red jadeite is divided into five levels from best to worst using K-Means cluster analysis and Fisher discriminant analysis under D65 light source: Fancy Vivid, Fancy Deep, Fancy Intense, Fancy dark and Fancy. [ABSTRACT FROM AUTHOR]

Through the regularization downward continuation of gravity and magnetic anomalies, the depth of the field source can be solved. However, due to the Gibbs effect, the horizontal resolving power of the field source is poor. In view of this, based on the depth of field source established by regularization downward continuation, this paper proposes a physical property parameter inversion method based on iterative continuation and anomaly separation, which can effectively improve the inversion accuracy of superimposed anomaly physical parameters, and provide a new idea for solving the physical parameters of superposition gravity and magnetic anomalies. [ABSTRACT FROM AUTHOR]

In hard rock masses, discontinuities control the slope stability, rather than block matrix breakage. The relative position and orientation of joints and slope face define the most likely mechanisms of failure. Among these mechanisms, the wedge failure is one of the most common modes of failure in which joint sets dip and dip direction, slope geometry and direction, external forces (including water pressure and earthquake) and rock and joints mechanical properties control the stability. The determination of these input parameters is not straightforward, mainly due to their variability and the limited amount of information available. Besides, in most projects, input parameters come from different sources (e.g., expert opinion, back-calculation, laboratory tests, field test or different project stages). Therefore, this limited information from different sources should be appropriately incorporated into the stability analysis to assist the design and decision-making process. In this context, random sets arise as a powerful tool to combine different sources of information and to perform a reliability assessment under limited information. This feature makes it possible to update the probability of failure as new evidence is available. With this framework, this paper presents a reliability assessment of wedge stability in a rock slope of a sandstone quarry, located in Une Cundinamarca, where information on mechanical and geometrical parameters has been collected for 20 years. This approach allowed to update the probability of failure. As a result, an updated probability of failure raging between 0.04 and 0.25 was calculated. [ABSTRACT FROM AUTHOR]

Erzurum and its surroundings are one of the most seismically active areas in the Eastern part of Turkey, also known for its hydrothermal activity. This study is the first approach to characterize the crust using the local earthquake tomography. The earthquake source location and three-dimensional velocity structures were solved simultaneously by an iterative tomographic algorithm, LOTOS-12. Data from permanent networks consisting of 59 seismometers, which were installed by Ataturk University-Earthquake Research Center and Earthquake Department of the Disaster and Emergency Management Authority, are used to monitor the seismic activity in the Eastern Anatolia. In this paper, three-dimensional Vp and Vp/Vs characteristics of Erzurum geothermal area were investigated down to 30 km by using 1685 well-located earthquakes with 29,894 arrival times, consisting of 17,298 P wave and 12,596 S wave arrivals. We developed new high-resolution depth-cross sections through Erzurum and its surroundings to provide the subsurface geological structure of the seismogenic layers and geothermal areas. We applied various size horizontal and vertical checkerboard resolution tests to determine the quality of our inversion process. The basin models are traceable down to 3 km depth, in terms of P-wave velocity models. The higher P-wave velocity areas in surface layers are related to the metamorphic and magmatic compact materials. We reported that the low Vp and high Vp/Vs values were observed in Yedisu, Kaynarpinar, Askale, Cimenozu, Kaplica, Ovacik, Yigitler, E part of Icmeler, Koprukoy, Uzunahmet, Budakli, Soylemez, Koprukoy, Gunduzu, Karayazi, Icmesu, E part of Horasan and Kaynak regions. As an important result, these regions indicate geothermal reservoirs. [ABSTRACT FROM AUTHOR]

Lima City is situated on alluvial fan deposits of rivers flowing through geological formations that contain different levels of uranium. In this paper, a study is made on the average spatial and temporal behavior of radon gas in soils of Lima City. Radon concentration was determined using the LR-115 type 2 track detector during 36 periods, of 14 days each, in twenty holes distributed in the fifteen districts of Lima City. Radon concentration in soil pores ranged from 0.1 to 64.3 kBq/m3 with an average value of 5.6 kBq/m3. The average radon concentration in soil gas was about two times lower in winter than in the other seasons. High radon values during October/November 2017 were related to the earthquakes perceived in Lima City in that period. The highest radon concentrations were found in areas of alluvial deposits whose parental material has been removed from the Quilmaná and Huarangal volcanics by the Chillón and Huaycoloro Rivers. Soil gas radon concentrations were even higher in areas closer to volcanic and less distant from rivers. During the period of maximum flooding of the Chillón, Rímac and Lurín rivers, due to the natural phenomenon "El Niño Costero", anomalous high soil radon concentrations were observed in most of the measurement sites located near rivers. These high radon values were associated with ground vibrations caused by rock and debris avalanches in rivers and creeks. [ABSTRACT FROM AUTHOR]

To study the vertical distribution of oil, gas in the fracture zone of the oil and gas bearing basin, based on the mechanism and influence factors of vertical sealing oil and gas, this paper has studied the necessary conditions of unconsolidated fault vertical sealing oil, gas, determination method for compaction and diagenetic of the fault filling. Concluded that the static period of fault vertical sealing oil and gas required that fault should be cut by mudstone, through comparing the relative period of the fault rock starting consolidate and the fault stopping activity to determine whether the fracture fillings are compacted into rock. If the time fault rocks began compaction into rock is earlier than the time fault stopped activity, fault filling has been consolidated; otherwise not compaction. By determining the displacement pressure of the fracture filling material and the rock displacement pressure of the underlying reservoir, a method is established to evaluate static unconsolidated fault vertical sealing oil and gas ability by comparing the relative size of the two. Applied it in the evaluation of the vertical sealing capacity f1 in the one to three sections of the Dongying formation and 5 sections of the formation in the southern Bohai Bay Basin. The results show that the fault f1 in one to three of the Dongying formation have the greater filler displacement pressure than the displacement pressure of underlying reservoir rock, as the vertical sealed is favorable for oil and gas accumulation and preservation. It's accordant with oil and gas distribution has been found in Dongying formation at present in the formation of the South Fort 5 structure, which indicates that the method is feasible to evaluate the vertical sealing ability of the fault in the stationary phase. [ABSTRACT FROM AUTHOR]

Safety of the mine roadway constructions is controlled by geological disasters such as faults, goaves and so on. The advanced prediction has become an in-demand topic, and advanced detection method of the reflected wave is a crucial technology for advanced prediction of geological anomalies. However, due to the influence of the complex near-source seismic wavefield in the coal mine roadway, the result of wavefield separation and migration imaging is not accurate, which lead to the fact that the fine imaging of geological anomaly is difficult. A comparative analysis of wavefield separation method of kinematics and dynamics is carried out in this paper to solve this problem. A factor of principal polarization direction is introduced according to "the orthogonal difference between the propagation direction of P-wave and S-wave and the vibration direction of particle" starting from the real-time polarization analysis from three-component seismic signals. By the factor, a modified function is constructed and integrated into pre-stack diffraction migration, which put forward the polarization migration method that incorporates wavefield separation with migration imaging. The results of physical simulation and field survey in Xiangyuan coal mine in western China are as follows: The fine imaging by using advanced detection of the reflected waves in underground coal mine can be achieved by using polarization migration in linear observation system and the polarization migration has the effect of enhancing the spatial resolution. [ABSTRACT FROM AUTHOR]

Oil seepage is one of the most important characteristics of hydrocarbon formation, and understanding oil seepage is crucial for oil-gas exploration and the assessment of petroleum resources. Remote sensing and geochemical methods have the same material and theoretical bases for extracting oil and gas information from underlying strata and the identification of media features. As an emerging exploration method, hyperspectral remote sensing is efficient compared with traditional geochemistry because it is a finer, and sometimes more directly quantitative method for determining the specific mineral anomaly content. Hence, the use of both methods together is important. This paper describes the analysis of hyperspectral remote sensing data and the extraction of abnormal index information, including the level of carbonate alteration and the content of acidolytical hydrocarbons, pyrolysis hydrocarbons, headspace gas, and ferric and ferrous ions. The two methods have mutual authentication, and they are complementary and are useful in oil-bearing areas. When these methods are integrated, the acidolytical hydrocarbon index is the most effective geochemical index and is better at characterizing the oil field distribution than other indices. Also, hydrocarbon geochemical anomalies occurring in oil fields generally show continuous distribution points and are consistent with oil reservoirs. Consequently, a 3D model was established to comprehensively utilize hyperspectral remote sensing and geochemical data to determine the distribution of petroleum reservoirs efficiently as well as to delineate oil- and gas-bearing prospects. There is great potential for determining oil- and gas-bearing fields through the integration of hyperspectral and geochemical data. [ABSTRACT FROM AUTHOR]

A natural phenomenon (hazard) may be characterized in terms of temporal, spatial and magnitude probabilities. The effects of the interaction between the hazard and the exposed element depend on the intensity of the hazard and on the resistance, sometimes called susceptibility, of the element at risk, which describes the propensity of a building or other infrastructure to suffer damage from a specific hazard impact. Consequently, a modern concept of vulnerability must consider the intensity of the hazard as well as the structural resistance of the exposed infrastructure. This concept is referred to as physical vulnerability, and the most accepted definition is a representation of the expected degree of loss quantified on a scale of 0 (no damage) to 1 (total destruction). Thus, this work presents a mathematical model for landslide physical vulnerability assessment, here named the T-Model, based on the "Principle of Natural Proportionality" and calibrated with field observations of the massive rainfall-triggered landslide event that occurred in Nova Friburgo, Brazil in November of 2011. The model was also calibrated for a flow-type movement that is based on field observations of the failure of a tailing dam that affected the district of Bento Rodrigues, Brazil in November of 2015. The results showed a good agreement between predictions and the observed level of damages. Thus, it is possible to conclude that from a mathematical point of view, the model may be qualified as universal. It is recognized that a real universal objective model for vulnerability to landslides is not practical at present. More important than the model itself is the methodology that is presented here, which leads the user to take qualitative damage information from the field and develop it into a quantitative mathematical framework. Potential users of the T-Model must be cautious regarding the values of parameters that are presented in this paper. The T-Model is just a modest proposal that requires further calibration and deep expert criticisms. [ABSTRACT FROM AUTHOR]

The retardation factor (Rd) is one of the main important solute transport parameters. Its value can vary significantly depending on the method used for its determination. In this paper, the sodium Rd is experimentally determined using undisturbed sandy soil columns to compare four methods of Rd determination and assess the impact of the chosen method on the prediction of sodium movement. Column experiments in undisturbed soil samples and analytical analysis were performed. The results showed that the soil has dual-porosity and preferential pathways. The breakthrough curves were in accordance with the soil's physical characteristics. The Rd values ranged from 1.7 to 7.77 depending on the initial concentration and on the method used. These differences arise from the conceptual model of each Rd determination method. The experimental and analytical analysis indicated that the higher the Rd, the slower the movement. The methods that best reproduced the laboratory sodium movement were Ogata and Banks' (1961), Langmuir and Freundlich's isotherms. The prediction models presented smaller errors with the increase of the initial concentration. In these cases, the predicted concentrations can be overestimated up to 22.5% when using a not suitable method. These results suggest that the Rd determination method can strongly affect the prediction of the sodium movement. Because of that, it is of vital importance to evaluate each method and how they can be adequate for the soil under investigation when determining Rd. [ABSTRACT FROM AUTHOR]

This paper investigates the capability of acoustic Full Waveform Inversion (FWI) in building Marmousi velocity model, in time and frequency domain. FWI is an iterative minimization of misfit between observed and calculated data which is generally solved in three segments, i.e., forward modeling, which numerically solves the wave equation with an initial model, gradient computation of the objective function, and updating the model parameters, with a valid optimization method. FWI codes developed in MATLAB herein FWISIMAT (Full Waveform Inversion in Seismic Imaging using MATLAB) are successfully implemented using the Marmousi velocity model as the true model. An initial model is obtained by smoothing the true model to initiate FWI procedure. Smoothing ensures an adequate starting model for FWI, as the FWI procedure is known to be sensitive on the starting model. The final model is compared with the true model to review the amount of recovered velocities. [ABSTRACT FROM AUTHOR]