Geological Survey Data Research Articles

Numerical Runout Modeling Analysis of the Loess Landslide at Yining, Xinjiang, China

The Panjinbulake loess landslide is located in the western part of the Loess Plateau, in Yining County, Xinjiang, China. It is characterized by its long runout and rapid speed. Based on a field geological survey and laboratory test data, we used the DAN-W dynamic numerical simulation software (Dynamic Analysis Of Landslides, Release 10, O. Hungr Geotechnical Research Inc., West Vancouver, BC, Canada) and multiple sets of rheological models to simulate the whole process of landslide movement. The best rheological groups of the features of the loess landslide process were obtained by applying the Voellmy rheological model in the debris flow area and applying the Frictional rheological model in the sliding source area and accumulation area. We calculated motion features indicating that the landslide movement duration was 22 s, the maximum movement speed was 20.5 m/s, and the average thickness of the accumulation body reached 5.5 m. The total accumulation volume, the initial slide volume and the long runout distance were consistent with the actual situation. In addition, the potential secondary disaster was evaluated. The results show that the DAN-W software and related model parameters can accurately simulate and predict the dynamic hazardous effects of high-speed and long runout landslides. Together, these predictions could help local authorities make the best hazard reduction measures and to promote local development.

KUPRAVA CLAY DEPOSIT RESEARCH COMPARISON

Clay minerals and their structures are extensively studied in the world, both from the point of view of geological research and material science. The aim of the research is to identify and summarize the resources of the Kuprava clay deposit, their placement in the field and selective extraction possibilities. Total clay resources in the Kuprava area are significantly more than 16 million m³. The clays are located in several uneven layers with relatively different characteristics. Until now, clay has been studied in separate layers for the production of bricks and high quality lightweight expanded clay aggregate (LECA). The work is based on using and comparing the geological survey data of 1951 to 1992, the latest laboratory test data, as well as the technical documentation of the former Kuprava factory. The study also includes a review of two recent studies of the composition of Kuprava Member clay. New eco-innovative composite materials require clay with a fully defined composition and properties. Clay extraction must be selective - on separate layers, so that the use can be accurately determined by the research. Cartographic material has also been added to accurately locate each of the four fields studied.

Barium-isotopic constraints on the origin of post-Marinoan barites

Measurements of triple oxygen isotope ratios in barite horizons within post-Marinoan cap carbonates have provided some of the most compelling evidence that the Marinoan glaciation was a Snowball Earth event. However, the origin of these barite horizons remains unresolved. To constrain the Ba sources, and thus formation mechanisms of these horizons, we analyzed the Ba isotope composition of post-Marinoan barite deposits from Northwest Canada, Northern Norway, Brazil and South China. We augment these analyses with a Ba isotope survey of almost 100 modern and ancient additional barite measurements, including samples from pelagic (or ‘marine’), hydrothermal, terrestrial, Proterozoic stratiform and cold seep environments. Unlike modern cold seep or terrestrial barites, we find that globally-distributed post-Marinoan barites exhibit a relatively narrow isotopic range, suggesting a well-mixed, effectively limitless Ba source. Moreover, post-Marinoan deposits exhibit a similar mean Ba isotope composition to modern marine barites, which we interpret as evidence of a marine Ba source. Considered alongside existing geochemical, geological, and new Ba isotope survey data, we conclude that Ba in barite horizons was sourced from a well-mixed, Ba-replete but SO4-poor reservoir that accumulated during the Marinoan Snowball Earth interval. This deep Ba reservoir was then transported upward—either by ocean circulation or dolomitization of underlying cap carbonates—and was brought into contact with continental weathering-derived sulfate in a post-glacial meltwater surface layer. Thus, in addition to providing a plausible mechanism for generating globally-synchronous deposition of post-Marinoan barite horizons that reconciles all existing geochemical and geological data, our results demonstrate the utility of Ba isotopes to interrogate the origin of enigmatic barite deposits throughout the sedimentary record.

Correcting airborne gravity data for overburden thickness: a case study from the Nechako interior plateau, British Columbia

Large areas of bedrock in Canada, such as in the interior plateau of British Columbia, are covered by a thick glacial overburden. Lateral variations in overburden thickness can create spurious anomalies in gravity data. These anomalies can be of a size and amplitude similar to those associated with mineral bodies and can be mistaken for them. A methodology is introduced that corrects gravity data for changes in overburden thickness through the use of a bedrock topography map created by integrating information from a helicopter transient electromagnetic survey with geological survey data, well water data, and gravel pit locations. The approach is tested for a 68 km × 38 km area in the prospective Nechako interior plateau of British Columbia, Canada. The methodology extends the traditional Bouguer corrections by taking into account the gravitational contribution of the overburden. Results show that the capability of an airborne survey to detect a change in overburden thickness depends primarily on survey line spacing and to a lesser extent on the level of random noise in the gravity data. The bedrock topography correction has the capability of removing the gravitational attraction of overburden for the purpose of revealing, through interpretation, geological structures in the gravity data that originate from the bedrock and are otherwise concealed.

Peak phosphorus, demand trends and implications for the sustainable management of phosphorus in China

An increasing number of studies have suggested that global phosphate rock (PR) extraction will reach a peak in the coming decades, with subsequent implications for food security. This paper focuses on peak phosphorus in China, which serves as an "early warning indicator" for phosphorus security. The results indicate that China`s production of PR is likely to peak sometime between 2035 and 2045. This result was derived using Chinese data, which differs from the U.S. Geological Survey (USGS) data, upon which estimates are more commonly based. Drivers of Chinese phosphorus consumption were also identified, and trends in phosphate use from six developed countries were analysed to form an overall assessment of the current demand for phosphorus in China. This analysis indicates that the demand for Chinese PR has reached a plateau. Combining the forecasts of both extraction and demand, the study explores potential challenges for sustainable phosphorus management. The study concludes with a range of policies that may help ensure a sustainable supply of Chinese PR.

Evaluation of landslide susceptibility in a hill city of Sikkim Himalaya with the perspective of hybrid modelling techniques

ABSTRACTLandslides are common and frequent occurring phenomenon in hilly terrain during monsoon season. The primary objectives of the research work are to carry out a comprehensive analysis by quantifying the landslide susceptibility using an integrated approach of random forest (RF) with the probabilistic likelihood ratio (RF-PLR), fuzzy logic (FL) and index of entropy (IOE) in Gangtok city of Sikkim state, India. Landslide inventories are prepared based on LISS-IV (MX) satellite imagery, Google Earth and reported data of Geological Survey of India. Altogether 12 landslide conditioning factors viz. slope, elevation, curvature, aspect, land use/land cover, geology, lineament, rainfall, soil type, soil thickness, water regime and distance from road are considered as input data for geospatial modelling of landslide susceptibility. Finally, model-derived landslide susceptibility maps are classified into four hazard zones, i.e. low, medium, high and very high. To measure model compatibility model comparison is performed in ArcGIS environment and models performance is assessed by confusion matrix where RF-FL gives more accuracy of 69.36% than other two models with 9.68% and 19.35% of Type I and type II error, respectively. The outputs are validated using success and prediction rate method where, RF-PLR, RF-FL and RF-IOE show area under curve (AUC) of success and prediction rate as 76%, 67%, 83%, 78% and 85%, 80%, respectively. Additionally, the differences in model performances were analyzed by means of Wilcoxon signed rank test, where it was found that statistically differences in the performance was significant in case of RF-PLR vs. RF-FL and RF-PLR vs. RF-IOE.

ВРАХУВАННЯ ЗАКОНОМІРНОСТЕЙ ФОРМУВАННЯ, РОЗПОДІЛУ ТА ВПЛИВУ ПІДЗЕМНИХ ВОД З МЕТОЮ ОБҐРУНТУВАННЯ ПРОГНОЗНОЇ ГІДРОГЕОЛОГІЧНОЇ МОДЕЛІ НА ДІЛЯНКАХ УЩІЛЬНЕНОЇ МІСЬКОЇ ЗАБУДОВИ

The conducted researches have the purpose to develop the optimum approach which allows us to correctly estimate the hydrogeological conditions of buiding sites. The general patterns of formation, distribution and movement of groundwater within the sections of the planned and existing buildings and adjacent territories for Kyiv as an example were studied. For the study area and similar sites with complex hydrogeological conditions, which are caused by the alternation in section and in terms of layers of unsteady thickness with different filtration coefficients, it is more appropriate to use the method of mathematical modeling of geofiltration for predictive calculations. Since there is no detailed hydrogeological map of the site, it is advisable to build a natural hydrogeological model on the basis of engineering and geological survey data (groundwater levels data) for different periods reproducted by GIS. The obtained results make it possible to justify the mathematical model and to perform predictive modeling with sufficient accuracy for technogenically disturbed territories. The application of mathematical modeling allows avoiding unnecessary rough schematization of natural hydrogeological conditions, taking into account the complexity and diversity of boundary groundflow conditions, and thus give more realistic assessment of engineering measures impact on hydrogeological conditions of the territory. In order to take into account the patterns of formation, distribution and movement of groundwater for territories with dense urban development it is advisable, according to the authors, to simulate processes geofiltration according to the scheme given in this article. At the same time, the creation of scientifically sound mathematical and cartographic space-time natural hydrogeological model of the territory is the defining moment for further modeling. Application of Darcy Flow module of ArcGIS software enables to detect and specificate groundwater flow recharge and discharge conditions. This makes it possible, on the one hand, to avoid unnecessary schematization of natural hydrogeological conditions, and on the other hand, to take into account the complexity and diversity of groundflow boundary conditions, to give a more realistic assessment of possible engineering measures impact on the hydrogeological conditions of the territory during the construction.

On ore-bearing capacity of Chuya anticlinorium granitoids (Baikal fold mountain area)

The article presents the results of a petrochemical recalculation study of ore-bearing capacity of the Chuya anticlinorium granitoids in Baikal fold mountain area (BFMT). It is shown that the early Proterozoic granitoids of Kuanda and Chuya-Kodar complexes composing the anticlinorium core are not sufficiently studied in mineralogical terms and, according to the geological survey data (GSD), are identified as barren formations, while the geological maps of the research area mark the presence of different ore mineral resources, the contiguous zones being Bodaibo province (gold-bearing) and Mama province (muscovite-bearing). Based on the available chemical tests data, petrochemical ore-bearing capacity modules have been defined using the known techniques and original charts by Z.G. Karajeva and B.N. Permyakov. In the chart by Z.G. Karajeva, most of the test samples fall into the field of the modified leukocratonic granitoids being mother rocks for the molybdenum, wolfram and tin deposits of the silicate and polymetallic formations as well as for the mica-bearing and partially, rare metal pegmatites. In the classification by B.N. Permyakov, the favorable combination of the petrochemical modules observed for most of the test samples allows referring them to various types of the granitoid fields with tin-wolfram-molybdenum mineralization. The conclusion is that further study of the granitoids is necessary to evaluate the geological position of the potentially ore-bearing facies and their fraction in the examined complexes.

Adjustment of Thermophysical Rock Mass Properties in Modeling Frozen Wall Formation in Mine Shafts under Construction

Modeling of heat exchange processes in water-saturated rock mass during shafting with artificial freezing is performed. The problem of adjusting thermophysical properties of rock layers by the experimental measurements of temperature in the check thermal wells spaced from the freezing perimeter is analyzed. In terms of the abuilding shafts at Nezhinsky Mining and Processing Plant, significance of adjusting the the thermophysial parameters borrowed from the geological engineering survey data is illustrated. The number of independent adjustment parameters is determined from the analysis of the system of equations in two-dimensional two-phase Stefan problem in the dimensionless form. An inverse Stefan problem is formulated for a horizontal layer of rocks. The numerical algorithm is proposed for the inverse Stefan problem solution based on the gradient descent method. The algorithm minimizes functional of discrepancies between the model and measurement temperatures at the locations of the check wells. The functional of discrepancies in the phase space of the thermophysical properties and the algorithm convergence are analyzed.

Research on Stability of an Open-Pit Mine Dump with Fiber Optic Monitoring

China has over 1500 open-pit mines and 5000 dumps consisting of waste rock from the mining process. Due to dump instability in an open-pit mine and its diverse foundations, landslides and mudslides frequently occur. Heaped loose waste rock and concentrated heavy rainfalls are the two important factors affecting slope stability of a dump. Using the high Dump II within the Nanfen Open-Pit Iron Mine with a slope height of 300 m as a case study, this paper first proposes a physical model similarity ratio according to the on-site engineering geological survey data. The governing principles of deformation in the shallow dump layers in terms of different heaped loads and rainfall were then determined using fiber optic sensing to conduct an experimental study on the monitoring of the dump stability with an indoor physical model. Experimental results confirm that the amount of rainfall and heaped load has a great impact on the landslide in a dump. With an increase in the amount of material heaped onto the pile, the place between two heaped load points is squeezed and slowly deformed. As rainfall begins, the deformation of the rock-soil mass is significant, and constantly increasing rainfall intensity is accompanied by a dangerous sliding surface. Finally, the FLAC3D method was used to simulate the deformation features in the shallow part of Dump II under different heaped load conditions and verify the experimental results of the indoor physical model. By comparing the physical model experiments and numerical simulation results, we propose monitoring the stability of Dump II using this fiber optic sensing technology and provide the scientific basis for stability monitoring of similar dumps to detect the early warning signs of mudslides or landslides.

Topological and dynamic complexity of rock masses based on GIS and complex networks

Lithosphere is composed of a great number of rock masses. Crustal movement may cause the fracture of rock masses and stimulate tremendous energy. The interaction between rock masses may affect deep geological processes, especially earthquakes. This paper studies the spatial distribution of rock masses and proposes a network analysis method for mining the topological and functional characteristics of rock masses from complex networks and geographical information science (GIS) perspectives. Geological survey data covering Sichuan Province and Chongqing Municipality is used for experiments. Results show that if we do not consider the rock type or strength, the degree distribution of rock mass network satisfies power-law distribution; for nine types of rock masses and five levels of strengths, their topological relationships all follow power-law distributions. Moreover, the power-law exponents are greatly different for different rock types and strengths that may affect the interactions between rock masses.

A methodology for 3D geological mapping and implementation

Using 3D visualization models to exhibit geological structure has become a trend in geological studies. Compared to 2D geological mapping, 3D geological mapping is dependent on more geological sampling information. Geophysical methods (e.g., gravity, seismic, and electric) thus become the major tools in 3D geological mapping. In traditional works, people must extract the geological information from various data grids acquired through different geophysical methods and subsequently integrate the information to manually construct a 3D geological model. This approach usually causes inconvenience and inefficiencies in practice. Therefore, we propose a methodology of 3D geological mapping. It first constructs visualization models from different geophysical data grids and subsequently integrates these models for interpretation and finally converts to a 3D geological model. Based on this methodology, we implement the corresponding system which can accomplish the above process automatically. As an example, we gave a detail description for constructing the 3D lithological model by the methodology mentioned above with the geological survey data acquired in the western Jungger, Xinjiang of China. The demonstration show us that the methodology can effectively solve the matter of 3D geological modeling in case of enriched in geophysical data but in lack of sufficient geological sampling information.

ANALYZING SEISMIC ACTIVITIES DURING 1900 TO 2015 TO ASSESS URBAN RISK IN NEPAL HIMALAYAS USING GEOINFORMATICS

A high magnitude (Mw =7.8) earthquake caused a geological disaster recently on April-May 2015 in Nepal Himalayas and resulted in severe devastation in Nepal as well as neighboring states in India. Looking into its recurrent occurrence with varied intensity, in the present study, the earthquake pattern in Nepal Himalayas was analyzed during the period 1900 to 2015 using United States Geological Survey (USGS) data sources in GIS environment. The result exhibits that the intensity of earthquake events are increased in recent decade in Nepal Himalayas as compared to previous century (1900-2014). The information pertaining to earthquake epicenter, magnitude, depth to hypocenter, demography etc. was also analyzed in geospatial environment to deduce its relation with geotectonic settings and possible risk in the vicinity. The earthquake events were also observed at deeper location (more than 40 kms) during 1900-2014(414 events; 53.9%) as compared to the recent events (2015), where majority of eathquake events (146 events; 85.3%) recorded at below 10 km depth (Janakpur and Bagmati provinces in Nepal). The result exhibits high number of recent events with greater magnitudes in central Nepal during April-May 2015 affecting a very large population above and around their vicinity with varied intensity. The cities located in central Nepal are highly prone to frequent earthquake hazard and induced risk on population of 2,923,621 persons followed by north-western Nepal.

ANALYZING SEISMIC ACTIVITIES DURING 1900 TO 2015 TO ASSESS URBAN RISK IN NEPAL HIMALAYAS USING GEOINFORMATICS

A high magnitude (Mw =7.8) earthquake caused a geological disaster recently on April-May 2015 in Nepal Himalayas and resulted in severe devastation in Nepal as well as neighboring states in India. Looking into its recurrent occurrence with varied intensity, in the present study, the earthquake pattern in Nepal Himalayas was analyzed during the period 1900 to 2015 using United States Geological Survey (USGS) data sources in GIS environment. The result exhibits that the intensity of earthquake events are increased in recent decade in Nepal Himalayas as compared to previous century (1900-2014). The information pertaining to earthquake epicenter, magnitude, depth to hypocenter, demography etc. was also analyzed in geospatial environment to deduce its relation with geotectonic settings and possible risk in the vicinity. The earthquake events were also observed at deeper location (more than 40 kms) during 1900-2014(414 events; 53.9%) as compared to the recent events (2015), where majority of eathquake events (146 events; 85.3%) recorded at below 10 km depth (Janakpur and Bagmati provinces in Nepal). The result exhibits high number of recent events with greater magnitudes in central Nepal during April-May 2015 affecting a very large population above and around their vicinity with varied intensity. The cities located in central Nepal are highly prone to frequent earthquake hazard and induced risk on population of 2,923,621 persons followed by north-western Nepal.

ТЕОРЕТИЧЕСКАЯ МЕТОДИКА ОПРЕДЕЛЕНИЯ МУЛЬДЫ СДВИЖЕНИЙ ДНЕВНОЙ ПОВЕРХНОСТИ ДЛЯ ГОРИЗОНТАЛЬНЫХ И НАКЛОННЫХ ВЫРАБОТОК ПО РЕЗУЛЬТАТАМ ГЕОЛОГИЧЕСКИХ ИЗЫСКАНИЙ

ТЕОРЕТИЧЕСКАЯ МЕТОДИКА ОПРЕДЕЛЕНИЯ МУЛЬДЫ СДВИЖЕНИЙ ДНЕВНОЙ ПОВЕРХНОСТИ ДЛЯ ГОРИЗОНТАЛЬНЫХ И НАКЛОННЫХ ВЫРАБОТОК ПО РЕЗУЛЬТАТАМ ГЕОЛОГИЧЕСКИХ ИЗЫСКАНИЙ

Analysis on Geo-stress and casing damage based on fluid-solid coupling for Q9G3 block in Jibei oil field

Aimed at serious casing damage problem during the process of oilfield development by injecting water, based on seepage mechanics, fluid mechanics and the theory of rock mechanics, the multi-physics coupling theory was also taken into account, the mathematical model for production of petroleum with water flooding was established, and the method to solve the coupling model was presented by combination of Abaqus and Eclipse software. The Q9G3 block in Jibei oilfield was taken for instance, the well log data and geological survey data were employed to build the numerical model of Q9G3 block, the method established above was applied to simulate the evolution of seepage and stress. The production data was imported into the model to conduct the history match work of the model, and the fitting accuracy of the model was quite good. The main mechanism of casing damage of the block was analyzed, and some wells with probable casing damage problem were pointed out, the displacement of the well wall matched very well with testing data of the filed. Finally, according to the simulation results, some useful measures for preventing casing damage in Jibei oilfield was proposed.

Matching Descriptions to Spatial Entities Using a Siamese Hierarchical Attention Network

Spatial entity descriptions are written in natural language based on the observations and understanding of spatial entities and often contain rich semantic information beyond GIS systems. Therefore, entity descriptions must be related to spatial entities in GIS systems. However, most previous studies of this issue were confined to place-type spatial entities, and other types of instance-level spatial entity matching have rarely been studied. In addition, existing matching methods require complex semantic analysis and manual feature engineering for the description text. In this paper, we focus on the matching of semantic similarity between spatial entities with rich text attributes and descriptions. We propose a semantic textual similarity matching model that incorporates a hierarchical recurrent structure with a focus on learning low-dimensional semantic vector representations of spatial entities and the corresponding descriptions. The model minimizes the distance between the vectors of matched pairs and maximizes the distance between the mismatched pairs of samples. The proposed siamese hierarchical attention network is trained and evaluated using a geological survey data set. The results show that the proposed model effectively captures the salient semantic information of spatial entities and the associated descriptions in the matching task and significantly outperforms previous state-of-the-art matching models.

Features of western disturbances simulated over north India using different land‐use data sets

Three strong western disturbances (WDs) that occurred over north India in 2008 and 2009 are simulated with two different types of land‐use data using a Weather Research and Forecasting (WRF) model. The two different land‐use land covers (LULCs) used are Advanced Wide Field Sensor (AWiFS) data and United States Geological Survey (USGS) data. The distribution pattern of rainfall produced by the WRF is compared with a corresponding Tropical Rainfall Measuring Mission (TRMM) pattern. Rainfall at specific locations is compared with India Meteorological Department (IMD) station data at different locations over north India. Root mean square errors (RMSEs) in rainfall from model simulations using two sets of land‐use data are compared with the TRMM and it is found that the simulations with AWiFS data show lower RMSEs. The wind, mean sea‐level pressure and relative humidity simulated by the model are compared with the patterns from National Center for Environmental Prediction (NCEP) Final Analysis (FNL) data. From the study, it is observed that precipitation is affected by land‐cover changes. The precipitation and circulation patterns are better simulated using AWiFS land‐use data compared with USGS data.

Construction and simulation of reservoir scale layered model for production and utilization of methane hydrate: The case of Nankai Trough Japan

This study is focused on the utilization of oceanic methane hydrate as an energy resource under the real production situations of Nankai Trough, Japan. Due to the complex geological conditions and the sensitive thermal-mechanical properties of methane hydrate bearing layers, it is very difficult to extract and utilize the methane hydrate stably and economically. The current status of development in Japan and major challenges from real reservoir-scale analysis are discussed. Low-carbon emission process is discussed and shown into detail with careful numerical modeling procedures. The numerical model is constructed based on the geological conditions of Nankai Trough of Japan. Numerical model is also scaled-up from single thin-layer to thick multi-layer model for real reservoir conditions, based on the recent geological survey data. In the current study, the production behaviors, boundary conditions and reservoir parameter effects are discussed into detail. The predicted production rate level in this simulation agrees with recent real tests. It is found that proper selection of layer models and production strategy is very important for large-scale simulation and prediction. Combined methods and strategic production design are recommended in future real tests.

Characteristics and Numerical Runout Modeling Analysis of the Jiweishan Landslide at Chongqing, China

In this paper, we conduct a numerical simulation analysis of the catastrophic 2009 Jiweishan landslide in Wulong, Chongqing, China, which was characterized by its rapid velocity and long runout. The study is based on detailed field geological survey data, and employs DANW runout analysis software to simulate the debris flow motion process, and accumulation characteristics of the landslide. The best match to the actual characteristics of the debris flow process was obtained by applying the friction rheological model in the source and accumulation areas, and the Voellmy model in the scraping area. The simulation results estimated the duration of the landslide to be approximately 101s with a maximum velocity of 39.2 m/s. The initial source volume, total accumulation volume, and runout distance obtained from an analysis of the DANW numerical simulation results were in good agreement with the corresponding characteristics of the actual event. The modeling scheme and parameters employed here are expected to help clarify the motion process of the Jiweishan landslide and improve the accuracy of future hazard assessments in areas with similar geological, topographical, and climatic features.