Abstract The Chang 8 reservoir of the Huanjiang Oilfield in the Ordos Basin is a tight sandstone reservoir with poor reservoir physical properties and uneven oil distribution. In this study, the effective reservoirs developed on a large scale under the condition of horizontal well volume fracturing technology of the Chang 8 Member was identified based on the data of core observation, experimental analysis, logging, oil test, and production dynamics, and the identification standard of effective reservoirs in terms of reservoir physical properties, oil content, and comprehensive logging characteristics of gas logging was established. This scheme allows for a thorough identification of the effective reservoirs for horizontal well development in tight sandstone reservoirs. The findings indicate that the study area’s tight oil resources can be successfully produced. The well logging results show that the oil-bearing property of sand bodies with oil stains is better than that of oil spots. The bottom limit of the acoustic wave time difference is 210 μs/m, the permeability is 0.03 mD, the porosity is 6.0%, the rock resistivity is 30 Ω m, and the total hydrocarbon gas measurement value exceeds five times the baseline. At the same time, the total oil thickness is greater than 6 m, and the thickness of a single sand body is above 4 m. We have defined the lower limit standard of high-efficiency reservoir of Chang 8 tight oil in L289 block of Huanjiang oilfield. According to the analysis of oil-bearing property, comprehensive logging display, and reservoir thickness, the geological “sweet spots” is optimized to provide reference for subsequent mining. Through comparative analysis, the rules and trends are found to provide a basis for selecting mining strategies. With the help of technical means such as numerical simulation and geological modeling, the prediction accuracy and decision-making effect are improved. By clarifying the lower limit standard of reservoir, optimizing geological “sweet spots” and avoiding risk areas, the mining efficiency is improved and the cost is reduced, which provides reference for similar oilfield development.

Abstract The red clay of the Chinese Loess Plateau (CLP) is an important geological archive for understanding the variability in the late Neogene East Asian monsoon. The periodicity of the summer monsoon of the red clay on the eastern CLP is dominated by eccentricity cycles within the constraints of the palaeomagnetic chronological framework, whereas global climate change characteristics represented by the deep-sea oxygen isotope record at that time show a dominating obliquity cycle. Here, we analyzed the East Asian summer monsoon proxies from the Shilou red clay section with the cyclostratigraphy method. The results show that the summer monsoon variation was dominated by obliquity, the optimum deposition rate was 4.451 cm/kyr, and the floating age of the Shilou red clay section was ca. 1.7 Ma. The late Neogene East Asian summer monsoon inferred from the eastern CLP was thus paced by the obliquity cycle, which is consistent with global change.

Abstract The geological data of the mineral resource potential evaluation results (MRPERs) are diverse and extremely large; efficiently retrieving data remains a challenging problem. In this work, a new way of using the Hadoop platform is proposed. The Hadoop distributed file system is used to store the massive data and construct the data storage model of geological and mineral resources. Using a distributed Hadoop database (HBase) that supports the fast query of a single record, it manages its metadata and retrieves the data of MRPERs quickly. At the same time, a multi-level index directory is designed to support the non-main key query on the HBase. This overcomes the shortcoming that the HBase only supports the simple index based on the main key and realizes the intelligent, efficient retrieval of MRPERs. The validity and feasibility of the proposed method are further verified by experiments using the MRPER data in the Institute of Mineral Resources, Chinese Academy of Geological Sciences.

Abstract Toplica district represents an area in Southern Serbia with significant forms of geoheritage that have not been valorized yet. The aim of this pioneering study is to systematically analyze and evaluate all manifestations of the geodiversity in the Toplica district. Based on the geological importance, degree of attractiveness, and size, a total of six geosites were selected. The main goal of the study is to emphasize the insufficient utilization of huge geotourism potentials of the Toplica district and to determine the current geotourism development and geotourism potential of evaluated geosites. The geotourism suitability of each geosite is defined through comparative analysis. The Geosite Assessment Model (GAM) is used to assess the current state of the various elements of geodiversity in the study area. Positioning within the GAM matrix is defined by the values of the investigated parameters. Visualization of the distribution of the GAM indicators is an innovative approach for the interpretation of the obtained results. As a projection of the geotourism potential, the study presents the results of the traffic accessibility of geosites using the Geographic Information System (GIS)-based isochronous method. GIS and Digital Terrain Models are used in the visualization of the research area. The results of GAM apostrophize the current tourist value of Devil’s City, while the isochron analysis of GIS highlights the great geotourism potential of publicly little-known and touristically unaffirmed geosites. The results represent a basis that can support the affirmation of geotourism, the improvement of existing, and the development of new geotourism strategies in the Toplica district.

Abstract Underwater biological detection is of great significance to marine protection. However, the traditional target detection techniques have some challenges, such as insufficient feature extraction for small targets and low feature utilization rate. To address these challenges, an underwater biological detection model IG-YOLOv5 based on the idea of feature reuse is proposed. An Improved-Ghost module with feature reuse is designed. The module adds batch normalization operations to the identity mapping branch using the Add operation with feature fusion and the Sigmoid Linear Unit activation function with smoother zeros. The proposed model uses the Improved-Ghost module to reconstruct the CSPDarknet structure of YOLOv5, so as to realize the lightweight and accuracy improvement of the model. In addition, in order to solve the problem of target size and shape change in underwater environment, the optimized loss function is Wise-IoU v3, which is used to evaluate the accuracy and robustness of detection results. The results show that the IG-YOLOv5 model performs well in the 2021URPPC data set, with 0.5 mAP reaching 74.2, 4.3% higher than that of YOLOv5 model, and 2.7 less floating-point operations. In a word, IG-YOLOv5 model has high accuracy and robustness in underwater target detection, and Wise-IoU index can evaluate the quality of target detection results more accurately, which is suitable for underwater robots, underwater monitoring, and other fields and has a practical application value.

Abstract Extensively used Mechanically Stabilized Earth (MSE) walls in Rail Transportation System (RTS) are vulnerable to surface vibrations generated by moving vehicles. Hence, it is necessary to consider the effects of surface vibrations during the design of MSE walls for RTS. Steel-reinforced panel-type MSE walls are shown to perform well during vibration loading, but costly steel materials have led to greater reliance on affordable and readily available geosynthetics for reinforcement. Limited research exists on the behavior of panel-type MSE walls with geosynthetics considering RTS-induced vibrations frequencies. Thus, this study employs Finite Element software PLAXIS 3D to simulate the impact of surface vibration frequencies on panel-type MSE walls. The qualitative study encompasses two reinforcement cases (geogrids and steel strips) of 4 m MSE wall height and four harmonic loading frequencies representing RTS-induced surface vibrations for simulation. The dynamic responses of MSE wall are presented in terms of lateral wall displacements and lateral earth pressure distributions. Furthermore, the distributions of tensile strain and the identification of potential slip surface locations are presented. The findings indicated that MSE wall and reinforcement responses are governed by RTS-induced vibrations and fundamental frequency of backfill soil. This highlights the need for consideration of both the fundamental frequency of the backfill soil and RTS-induced vibrations in the design of MSE walls.

Abstract Walkaway vertical seismic profiling (WVSP) is known for its high level of credibility in obtaining the relationship between first-arrival traveltime and detector depth through first-arrival picking. This relationship can be utilized for seismic velocity model inversion to improve velocity model accuracy and rationality. Here, we present a WVSP first-arrival velocity model with velocity structure constraints, by utilizing layer and fault data interpreted by ground seismic structure technique. We constructed a geological structure and layer sequence models based on sedimentary patterns to obtain complex velocity structures. Furthermore, we introduced a smooth regularization term based on the velocity structure into the inversion model to enhance its consistency with geological laws and compensate for the reduced inversion accuracy owing to the regularization term based on flat structures. This approach addressed the limitations of the regularization term based on flat structures, resulting in more accurate and reliable inversion results. Through simulation analysis, the proposed method realized the WVSP first-arrival velocity inversion, with results being closer to those of the real velocity model.

Abstract Water pollution and protection of water resources have become an urgent task for humanity today and are also important components of environmental risk assessment. In response to the problems of high risk level and low risk credibility in the current environmental health risk assessment of urban water sources, this article aims to use fuzzy set theory to comprehensively evaluate the environmental quality and quickly monitor the safety of urban water sources. Therefore, this article analyzed the health factors of the urban water source environment and then studied the content and uncertainty analysis of health risk assessment. Finally, it constructed a health risk assessment system and proposed corresponding water environment protection strategies. In the experimental section, the risk level and risk credibility of the water environment were analyzed. Through comparison, it was found that the risk level in the new water environment health risk assessment was 0.16 lower than that in the traditional water environment health risk assessment, and the risk credibility was 0.11 higher than that in the traditional water environment health risk assessment. The water quality monitoring effect in the new water environment health risk assessment was 7.3% higher than that in the traditional water environment health risk assessment, The health hazard effect is 8.2% lower than traditional water environment health risk assessment. In summary, water environment health risk assessment plays an important role in protecting the water source environment. Health risk assessment of the water environment helps to reduce water pollution, improve water quality, and ultimately improve human health. Moreover, using fuzzy set theory makes it easier to comprehensively and efficiently evaluate the water environment. The innovation of this article lies in paying attention to the importance of fuzzy set theory in water pollution risk assessment and applying fuzzy technology to water pollution control strategies, to better improve water quality and optimize water source environmental health risk assessment methods.

Abstract Near-surface velocity variations are the main cause of seismic scattering in exploration seismology. Many studies create the near-surface heterogeneity as velocity models that have random velocity distribution, random objects, or irregular subsurface topography to study and mitigate the resultant scattering effects of the near-surface layer. Von Kármán (self-similar) method is a known method in the literatures for modeling heterogeneous earth in a statistical way. This research modifies the self-similar method, and throughout the work, it has proven that the self-similar provides a robust method for generating realistic near-surface velocity models with different spatial velocity distributions. This study creates four-velocity models with simple subsurface layering and structure, three of which include a near-surface layer in three different degrees of velocity heterogeneity. Synthetic acoustic seismic reflections are produced for the four-velocity models to investigate the resultant scattering effects of the near-surface velocity heterogeneity on the quality of seismic waveform coherency. Spectacular negative observations are witnessed of the near-surface layer involvement to the quality of seismic reflection coherency that increases as velocity dramatically varies. Subtracting the scattering noise, which is modeled using an exact heterogeneous model, enhances seismic reflection coherency for the subsurface layers, but waveforms that are affected by scattering must be reconstructed for true amplitude and seismic waveform analysis.

Abstract The petrogenesis of Sukadana Basalt remains an enigma till present. Major and trace element data are analyzed from Sukadana Basalt lava, located at East Lampung, Sumatra, to study the processes involved in the petrogenesis of the erupted magmas and the origin of mantle source compositions. The Sukadana Basalt display SiO2 (48.1–52.5 wt%), MgO (5.3–9.3 wt%), TiO2 (1.3–2.6 wt%), P2O5 (0.2–0.6 wt%), and Fe2O3T (8.9–11.3 wt%) contents. The Sukadana Basalt enriched in light rare earth elements with weak negative Eu anomalies (Eu/Eu* = 0.8–1) and show Ocean Island Basalt (OIB)-like characteristics. There are two different petrogenesis groups, namely group A and group B. Group A samples show enrichment of Hf, Pb, K, and Sr and depletion of Nb. Group B samples show enrichment of K, Sr, and depletion of Pb. These differences are closely related to the mechanism of slab roll-back and normal fault activity. This study shows that Sukadana Basalt has Nb = 7.4–29.8 ppm, Nb/U = 18–060.3, and Nb/La = 0.8–1.6. These characteristics were similar to those found in typical Nb-enriched basalts. Geochemical analyses suggest that the Sukadana Basalt have experienced minimal crustal contamination and Olivine plagioclase, clinopyroxene, and magnetite fractional crystallization. The chemical features, together with high incompatible-element ratios, are consistent with low degrees of partial melting of a dominantly a partial melting of garnet–peridotite mantle source. The trace-element patterns suggest a mantle source influenced by an enriched component. The occurrence of OIB-like basalt suggests significant upwelling of the asthenosphere in response to slab roll-back. These processes occured in the above of a Paleo Indo-Australia subducting N–S beneath the southern part of Sumatra.