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Copyright of Journal of Geodesy & Geodynamics (1671-5942) is the property of Editorial Board Journal of Geodesy & Geodynamics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Underground natural gas storage is an essential infrastructure for strategic reserves， emergency peak shaving， and national energy security. It is also one of the directions for optimizing the industrial layout of mature oilfields and promoting green and low-carbon transformation and development. The geological conditions of Shengli Oilfield are complex， with shallow gas reservoirs， small scale， scattered distribution， and abundant oil and water trap resources. However， it is difficult to evaluate the sealing property. In view of these characteristics， significant progress has been made in research related to gas storage since the “Thirteenth Five-Year Plan in 2016-2020” period. Different types of gas storage， such as loose sandstone gas reservoirs， gas cap oil reservoirs， and aquifers， have been studied and designed， and the first gas storage in abandoned water-flooded gas reservoirs in China， Y21 Gas Storage， has been built. Key technologies such as target screening and evaluation of gas storage in aquifers， injection and production operation optimization design of gas storage in aquifers， sealing evaluation of gas storage traps， and tracking evaluation of gas storage have been developed， which align with characteristics of Shengli Oilfield. At present， the construction of other types of gas storage still faces challenges such as limited data， small scale， poor efficiency， and difficulty in evaluating the dynamic sealing of traps. It is necessary to propose corresponding technical countermeasures and research directions in the site screening and evaluation of gas storage in oil reservoirs， the construction of gas storage in combination with scattered gas sand bodies， and the collaborative construction of gas storage in oil reservoirs with high water cut， to provide technical support for the large-scale construction and green development of gas storage in Shengli Oilfield.

Objective The analytical solution model is computationally efficient and widely used to estimate aquifer surges. Analytical solution models are computationally efficient but involving many assumptions, such as that the aquifer is homogeneous, the amount of water pumped is constant, while the head loss in the well is ignored; these models are often referred to as homogeneous models. In fact, these assumptions are often not met, resulting in nonnegligible errors in the results, especially for heterogeneous giant thick aquifers.Meanwhile, the homogeneous model cannot estimate the permeability coefficient and water inflow of the broken zone, which is not conducive to solve the water problem during tunnel construction. Methods In this study, two pumping tests were carried out on the Shengli Tunnel Project in Tianshan Mountain, Xinjiang. A geological model was established based on comprehensive logging data and borehole data; a heterogeneous numerical simulation method was used to quantitatively investigate the amount of groundwater inflow in bore holes. The parameters in the rate determination model of the observation data of the first pumping test were used, and the rationality of the model and the postrate parameters were verified by the observation data of the second pumping test. Results The permeability coefficients of the fracture zone, intact granite and relatively intact granite were inverted and were 0.000 93 m/d, 0.000 5 m/d and 0.000 3 m/d, respectively. The total water inflow and the water inflow of the fracture zone were predicted to be 14.80 m3/h and 10.46 m3/h, respectively, of which the water inflow of the broken zone accounted for 70.676% of the total water consumption. Conclusion Field observations revealed head loss in aan ultradeepbore hole during pumping test. The heterogeneous numerical simulation model can explain the ultradeep hole pumping test data better than the homogeneous model, and the total water inflow calculated by the homogeneous model is 18.67 m3/h, which overestimates the water inflow. During tunnel construction, the hydrodynamic parameters and water inflow obtained by the heterogeneous model are more reliable.

Copyright of Petroleum Geology & Recovery Efficiency is the property of Petroleum Geology & Recovery Efficiency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Inorganic Analytical Chemistry / Zhongguo Wuji Fenxi Huaxue is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The age of shallow groundwater in Shenyang-Fushun section of Hunhe River Basin is calculated with 3H isotopic method. Through the age zoning of groundwater and analysis of its circulation characteristics, the paper provides a scientific basis for the rational development and utilization of groundwater resources and study on carrying capacity of urban resources and environment. The results show that the groundwater in the Shenyang-Fushun section is mainly the modern water replenished in the past 60 years, and the age of groundwater flow increases gradually from the eastern mountainous area to the western plain. The distribution area of groundwater aged less than 30 a, 30-60 a and more than 60 a account for 34%, 31% and 35% of the total of the study area, respectively. The upper reaches of the basin are hilly and mountainous area, with single aquifer structure, coarse particles, groundwater age less than 30 a and strong groundwater circulation. The aquifer in the middle reaches thickens gradually, the alternation of groundwater circulation weakens gradually, and the groundwater age increases to 30-60 a. The aquifer in the lower reaches gradually changes from single layer to double layer and multilayer, with fine particles and slow water circulation, and the groundwater age increases to more than 60 a. [ABSTRACT FROM AUTHOR]

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Uranium Geology is the property of Uranium Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The microbial denitrification process is the most important form of nitrate-nitrogen removal in groundwater. The reclaimed water reuse and livestock breeding caused antibiotic pollution usually co-occurs with nitrate. Therefore, it is necessary to conduct in-depth research on the effects of denitrification and the generation, accumulation, and dissemination of antibiotic resistance genes (ARGs) by antibiotics and their forms to comprehensively analyze the reasons for the increased concentration of nitrate in groundwater. Many studies in recent years have identified the dissociation/complexation, adsorption forms (interlayer adsorption/surface adsorption), and the products of hydrolysis and microbial degradation of antibiotics in groundwater systems; and have elucidated the inhibitory mechanism of antibiotics on the denitrification process from the perspectives of denitrifying microbial communities, the types and activities of functional enzymes, abundance of functional genes, as well as the production and transmission pathways of ARGs. The main conclusions are as follows: (1) In groundwater systems, antibiotics exist in various forms, and different forms of antibiotics exhibit significant differences in toxicity to microorganisms. (2) In the presence of antibiotics at levels ranging from nanograms to micrograms per liter, the denitrification process in groundwater is inhibited. Antibiotics alter the microbial community structure, suppress enzymatic activity, and increase the abundance of ARGs. Under the synergistic effects of these actions, the kinetics of nitrate degradation shift from zero-order to first-order. (3) During the antibiotic-induced inhibition of denitrification, there is also an increase in the emission of the greenhouse gas N2O. Antibiotics primarily affect the expression of the functional gene nosZ, and the concentration of N2O shows a negative exponential relationship with nosZ abundance. Based on the review of relevant literature, the prospects for future research are put forward: (1) quantitatively identifying the existence forms of typical antibiotics after entering groundwater systems; (2) elucidating the impact of antibiotics in different existence forms on denitrifying microbial communities, the types and activities of functional enzymes, and the abundance and diversity of functional genes; (3) exploring the dynamic process of denitrification functional genes under different existence forms and input modes of antibiotics, and establishing models for the production, enrichment, and transmission of ARGs; (4) combining field observations and laboratory experiments to study the denitrification process in groundwater systems under complex pollution from molecular biology, environmental chemistry, and hydrogeology perspectives. This research can provide a theoretical basis for addressing the increasingly complex groundwater pollution prevention and drinking water safety assurance.

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The mining of Huanglong Coalfield faces a serious threat from roof sandstone water disaster of the extremely thick Luohe Formation. A laboratory study on the microscopic pore characteristics of the sandstone of the Luohe Formation in the Gaojiapu Coal Mine, Binchang Mining Area were carried out using various methods. XRD diffraction, casting thin sections, and scanning electron microscopy were combined to study the pore types of the sandstone particles. Overburden porosimeter was used to illustrate the variation characteristics of porosity and permeability under different confining pressures. High-pressure mercury injection and nuclear magnetic resonance techniques were used to characterize the pore-throat radius of the sandstone core, and X-ray three-dimensional CT scanning was used to quantitatively characterize sandstone pores larger than 9 μm. The results show that, ①the sandstone particles of medium-grained sandstone are larger, and the pore types are mainly residual intergranular pores with a small amount of intergranular dissolved pores, while the particles of fine-grained sandstone are smaller, and the intergranular pores are mostly filled with clay minerals, secondary dissolution intergranular pores, and a smaller degree of pore development.; ②The pore throat radius of large pores in medium-grained sandstone ranges from 0.61 to 4.94 μm, with a cumulative distribution frequency of 48%, while in fine-grained sandstone, the pore-throat radius ranges from 0.188 to 0.683 um, with a cumulative distribution frequency of 47%, indicating that medium-grained sandstone has larger pore-throat radius, which are more conducive to groundwater storage and migration.; ③CT scanning shows that the average surface porosity of medium-grained sandstone is 7.081%, and that of fine grained sandstone is 2.032%. The highly developed macropores (equivalent pore diameter > 180 μm) and micropores contribute to a higher surface porosity. Combined with a larger pore throat radius, the medium-grained sandstone presents a higher permeability. The microscopic pore characteristics of the two types of sandstone are consistent with the on-site evaluation result of the water yield propertyof the corresponding aquifer. The research findings can provide a basic reference for the prevention and control of water disasters from the sandstone roof of the Luohe Formation.

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Based on the geological condition of Luohe Formation sandstone aquifer above the deep working face of 4# coal in Gaojiapu Mine, Binchang Mining area, the relationship between aquifer and dynamic disaster breeding is discussed. Firstly, the formation and its setting condition of the aquifer above 4# coal seam are introduced. Based on field water inflow monitoring data, we examined the relationship between the resistance of the support and the change of water inflow. The temporal and spatial correlation between micro seismicity and water movement is analyzed and identified, which will offer significant value for the early-warning of the dynamic hazards and water inrush. We expound the dynamic and static load of confined water movement on the working face after the increase of water inrush, and point out that it is important to pay more attention to the dynamic disaster risk of the working face after the water surge.

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Due to the unreasonable discharge of industrial waste, a large amount of heavy metal pollutant Cr(VI) enters the underground environment, which seriously threatens human health and ecological environment. The high mobility of Cr(VI) in groundwater environment makes it difficult to repair. A green, economic and effective interception method is urgently needed to improve the ability of groundwater Cr(VI) pollution control. In this paper, sodium metabisulfite is selected as a reducing agent, and Cr3+ generated from Cr(VI) in groundwater is used as an xanthan gum crosslinking agent to form a gel blocking barrier. The influences of various components on gel time and viscosity changes and the blocking effect of gel barrier on aquifer are studied. The results indicate that (1) in the system with Cr(VI) concentration up to 200 mg/L, xanthan gum solution with 0.4% mass concentration can form gel with certain mechanical strength within 1.5 h. (2) The gel has salt resistance and is suitable for common aquifers. Na+ and K+ of 2.5−5 g/L can promote the gel. (3) The injected gel blocking barrier can significantly reduce the coefficient of permeability of medium sand media to 1×10−7 cm/s, which can meet the demand of groundwater blocking. Injection-type gel barriers are formed without the introduction of harmful substances. After the interception, injection-type gel barriers can be naturally degraded by biological action without long-term changes under the aquifer hydraulic conditions. This study provides a theoretical basis for the construction of gel barrier in chromium contaminated groundwater.

The hydrogen and oxygen isotopes in precipitation have the altitude effect, and they participate in the groundwater circulation after the infiltration of precipitation. How does the altitude effect of hydrogen and oxygen isotopes in precipitation transform to the depth effect of hydrogen and oxygen isotopes in groundwater under the influence of groundwater flow systems? The existing research lacks quantification for this problem. In this study, the steady-state groundwater flow theoretical models represented by unidirectional inclined basin and bimodal wavy basin are constructed. The MODFLOW and MT3DMS programs are used to simulate the two-dimensional groundwater flow field in the profile and the convection-dispersion process of heavy isotope molecules to obtain the spatial distribution of D and 18O values in groundwater and discuss the mechanism of altitude effect of the hydrogen and oxygen isotopes transforming to depth effect in the groundwater flow systems. The results indicate that in the monoclinal basin, the altitude effect of D and 18O content in precipitation in the recharge area is transformed to the depth effect of δD and δ18O values in groundwater through the regional groundwater flow system which exponentially decreases with the increasing water table depth in the drainage area. In the bimodal wavy basin, when the permeability of the aquifer is relatively larger than the infiltration intensity (K0/w=1000), only one regional groundwater flow system develops, and the distribution of δD and δ18O presents a S-shaped curve with the increasing water table depth in the discharge area of regional groundwater. When the permeability of the aquifer is relatively smaller than the infiltration intensity (K0/w=250), multiple local groundwater flow systems develop in the bimodal wavy basin. The δD and δ18O indicate an S-shaped curve with the increasing water table depth in the discharge area of regional groundwater, while in the discharge area of local groundwater, they show a monotonic attenuation trend with the increasing water table depth. This study theoretically advances the understanding of the influence mechanism of groundwater flow systems on solute transport, and reveals the indicative role of hydrogen and oxygen isotopes in groundwater flow systems.

In view of the problem that the overlying goaf and the water-rich superimposed effect of the aquifer threaten the safe mining of the working face, taking Buertai Coal Mine of Shendong Coal Group as the research object, the techniques of surface geological drilling, drilling core fine cataloguing, surface-to-underground geophysical exploration, underground directional drilling, exploration-mining comparison are comprehensively adopted, theoretical analysis, numerical simulation and similar material simulation are used to reveal the mechanism of water-rich superimposed disaster in Buertai Coal Mine under 4-2 coal roof excavation disturbance. According to the comprehensive detection result of water-rich dangerous area and the precise regional treatment method of directional drilling, the accurate prevention and control mode of water disaster in advance of directional drilling of mining face was built, and the water-rich area was treated by engineering. The accumulated water quantity of 52 800 m3 was released, which realized the safe and efficient and smooth recovery of typical working face and effectively controlled the disaster caused by the disturbance and water-rich superposition of coal mining in 4-2 mine.

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The coexistence of ammonium, arsenic and dissolved iron in groundwater is a common phenomenon in aquifer systems. They have a strong interaction and affect the nitrogen cycling and the migration and transformation of arsenic in groundwater systems. Based on the systematic survey of international and national literature on the process and influencing factors of groundwater nitrogen cycling, the functional microorganisms and their characteristics related to groundwater nitrogen cycling, and the hydrogeochemical process of arsenic enrichment in groundwater, this paper deciphers effects of nitrogen cycling (including nitrification, denitrification, Feammox, Anammox, and dissimilatory nitrate reduction to ammonium) on the migration and transformation of arsenic in groundwater. We proposed that the dynamic transformation of iron oxides and dissolved Fe (II) in aquifers is an important bridge for nitrogen cycling and the migration and transformation of arsenic in groundwater. The processes of nitrogen cycling in aquifers with different redox environments, the coupling mechanism between nitrogen cycling and arsenic migration and transformation, the interactions among Fe(III) - Fe(II) cycling, nitrogen cycling, and arsenic migration and transformation, nitrogen-iron-arsenic cycling in the surface water-groundwater interaction zone and its response to human activities are important scientific issues and research trend that need to be paid attention to in this field in the future. The solution of these scientific problems is not only conducive to identifying the source, migration and transformation of nitrogen in groundwater, but also beneficial to improving the systematical understanding of enrichment mechanism of groundwater arsenic.

Objective The safe and efficient of hydrogen storage is of great significance to the development of clean energy industrialization. Aquifer, which is widely distributed and has huge storage potential, is a potential body for safe and efficient underground storage of hydrogen. The feasibility of hydrogen storage in underground aquifers is analyzed. Methods By investigating domestic and foreign literature on hydrogen storage of aquifer, on the basis of clarifying the influence of hydrogen physical and chemical properties on aquifers, the existing cases of underground hydrogen storage are analyzed, and the influences of various factors on hydrogen storage of aquifer are explored. Results The sandstone with low carbonate and sulfate cement content and the geological conditions with no calcite in the cap rock are more suitable for underground hydrogen storage, and it is advantageous to store hydrogen in the reservoir rich in clay minerals; The influence of microorganisms should be considered for underground hydrogen storage; Both carbon dioxide and nitrogen can be used as cushion gases. At the moment when China is making a major strategic decision on the "dual carbon" goal, the research on carbon dioxide as a cushion gas should be emphasized. Conclusions At present, there are no examples of pure hydrogen storage in underground aquifers, but the related numerical simulation researches and influence factors analysis demonstrate the feasibility of hydrogen storage in aquifers. [ABSTRACT FROM AUTHOR]

Based on the tested datum of total α, total β and 226Ra from over 80 drinking natural mineral water wells by had been explored and evaluated in Shanghai area, we obtained the distribution characteristics of mineral water radioactivity levels in different aquifers, and estimated the influence on residents' internal exposure while the mineral water used as the pure drinking water. The evaluation results show that the radioactive level is equal to the normal environmental background range, and all tested datum of radioactive indexes are inferior to the threshold value of the China's national Code of Drinking Natural Mineral Water, and drinking it will be beneficial and innocuous to human health. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Groundwater is an important source of recharge to the Yellow River in the area of the Maqu Plateau, but little is known about the groundwater hydrochemical characteristics and the formation mechanism. Phreatic water samples, surface water samples and sediment samples were collected from the study area to investigate their hydrochemical and isotopic characteristics and hydrogeochemical processes. The results show that river water and phreatic water samples have low salinity with Ca2+ and \begin{document}${\rm{HCO}}_3^- $\end{document} being the main constituents (TDS of 72−195 mg/L and 207−459 mg/L, respectively). Concentration of arsenic (As) in water samples range from 0.46 μg/L to 17.7 μg/L. The plot of hydrogen and oxygen isotopes shows that the phreatic water and surface water are mainly recharged from local meteoric water. The river water is relatively enriched in 18O and D relative to the phreatic water. The hydrochemistry of the river water are mainly influenced by evaporation, while the phreatic water is mainly influenced by rock weathering involving dissolution of carbonates. Saturation index of dolomite (SIdolomite) in 68% phreatic water samples is below zero, indicating that the phreatic water is unsaturated with respect to dolomite. As in the groundwater are possibly the result of reductive dissolution of iron-manganese oxide minerals in the unconfined aquifer sediments, which may be sourced from adsorbed As forms in the iron-manganese oxide minerals. This study is helpful in revealing the source of shallow groundwater and genesis mechanisms of groundwater chemicals in the upper stream of the Yellow River.

Stratified pumping can obtain accurately hydrogeological parameters, and the effect of stratified water stop determines the success of stratified water pumping. To summarize the research achievements of the stratified water stop, on the basis of literatures published in recent years, with the method of drawing, analysis, we summarize the layered water stop technology research status quo, and point out existing problems and developing trend. Research results show that: “variable diameter and different steps to stop water”, “one hole with the same diameter to stop water” can achieve stratified water stop, of which “variable diameter and different steps to stop water” outside the casing mainly fills with gravel and clay ball, often uses glue plug device to stop water inside the casing, Packer is mainly used in the stop water of “one hole with the same diameter to stop water”, which is the development trend of stratified water stopping technology. The research results provide a reference for project of the stratified water stop.

In view of the problem that water inrush is easy to occur in the mining of coal seam under aquifer, taking a mine in Shaanxi Province as an engineering background, this paper proposes a paste filling technology behind transitional support in fully mechanized top-coal caving mining, expounds its technical principle and technological process, and analyzes the development characteristics of water-conducting fracture zone in back-support filling mining and the variation laws of water inflow in working face by means of numerical simulation and field observation. The numerical simulation results show that the water-conducting fracture zone of the working face develops into a rectangle with a maximum height of 67.2 m after the backfilling technology is adopted. The field observation results show that the filling rate after support can reach 90%, the water inflow of working face decreases significantly from 220 m3/h to 90 m3/h, and the maximum development height of water-conducting fracture zone is 76.8 m after 200 m advance of working face. The research results show that the technology can effectively reduce the height of water-conducting fissures in overburden and realize safe mining of extra-thick coal seam under aquifer.

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ground fissures are of various types and cause serious disasters. According to the dominant factors and dynamic types, ground fissures are divided into two major categories (tectonic and non-tectonic) and 16 sub-categories. Based on the engineering geology, hydrogeology and activity characteristics of ground fissures, it is considered that the essential reason for the abnormal activity of tectonic ground fissures in land subsidence area is that ground fissures cut off the aquifer. Specifically, when excessive groundwater is extracted, obvious water head difference is formed on both sides of ground fissure and uneven compression is produced, which leads to large differential settlement on the surface. Therefore, the prevention and control method of CABHP for tectonic ground fissures in land subsidence area is put forward, which uses directional drilling to connect the miscut aquifer and balance the hydraulic pressure on both sides of ground fissure. The CABHP method can effectively control the activities of tectonic ground fissures in land subsidence area, and avoid a large amount of waste of land resources and disaster losses. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Water-conducting fissures formed in shallow seam mining in thin bedrock are easy to cause water resources damage. The determination of the height of water-conducting fissures is the key to avoid the damage of aquifers. Taking 5-20101 working face of Qinglongsi Coal Mine as the research object, the development height of water-conducting fracture zone in coal seam mining is analyzed by physical analogy simulation, theoretical calculation and water injection leak detection method. The research shows that the overburden rock above the goaf after mining forms an arch beam structure, the edge of the arch is a tension stress area, the vertical shear fracture is the main water conduction channel of the stratum, and the water conduction fracture is octagonal distribution; the height of water conduction fracture is 52.3 m to 62 m, with an average of 57.2 m, and the ratio of fracture to mining is 24.2; the development of water conduction fracture is not connected with the Sarawusu aquifer. The production process is not threatened by aquifer irrigation.

Copyright of Journal of Heilongjiang University of Science & Technology is the property of Journal of Heilongjiang University of Science & Technology Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Natural gas, as a clean energy, is one of the main energies fueling the green economic development of China. It is one of the main tasks to develop underground gas storage facilities so as to increase the natural gas storage capacity and to improve the quick access to large volume of natural gas during high demand periods. The state-of-the-art of the three principal types of underground gas storage, i.e., in depleted oil/gas fields, aquifers and salt caverns and the basic information on underground gas storage facilities used in USA and Europe were reviewed. The development of underground gas storage facilities in China was compared with that in other countries. Root causes for three typical accidents on three underground gas storage facilities were analyzed. The statistical results on the accidents on underground gas storage facilities documented in literature were summarized. "Ipc differences on the root causes of accidents on different types of underground gas storage facilities were analyzed. Some suggestions on the plan and construction of underground gas storage facilities in China were presented according to the experiences and lessons from the review on the development in other countries. [ABSTRACT FROM AUTHOR]

In order to evaluate thehydrochemical characteristics and evolution of groundwater in Yushen mining area and Shenfu mining area, 53 samples of groundwater of the researched area were collected and tested. It calculated the contribution rates of cations and anions, correlation coefficient matrix method, piper trilinear diagram, Gibbs distribution graph and milligram equivalent ration with Na+ and Cl- by mathematical statistics. It analyzed the characteristics of groundwater ion and hydrochemical characteristics and drew the isogram of groundwater hardness in the area and zoning map of hydrochemical type. The results show that the groundwater in the area is weak alkaline water. The less solubility of Ca2+ is precipitated out, which is affected by evaporation, is the highest contribution rate. The groundwater TDS content of Malan loess is the lowest and the groundwater TDS in the blunt pluvial aquifer is the highest. The total hardness increases gradually from the blown-sand region to the loess area. Ca2+ and SO2-4 are highly correlation with TDS. Groundwater hydrochemical characteristics are mainly controlled by water-rock interaction, the groundwater is dominated by HCO3 water in the blown-sand region and it is dominated by HCO3 • SO4 water in loess ridge-hilly area. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Heilongjiang University of Science & Technology is the property of Journal of Heilongjiang University of Science & Technology Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The drinking water source of Suzhou, Anhui province, is dependent on groundwater. At present, a large groundwater depression cone in Suzhou’s medium and deep groundwater has formed. Based on water level data and groundwater development and utilization information, in this study, the area of the groundwater depression cone was determines as 650km2and -8m in its center.Withdrawal of groundwater is the main factor affecting the groundwater depression cone in Suzhou; excessive exploitation leads to a continuous increase in groundwater depression cones. The unreasonable layout of production wells leads to an excessively deep water depth in the local area. The water level in the center of the groundwater depression cone continues to drop, and urban ground hardening makes it difficult for the aquifer to receive rainfall infiltration. [ABSTRACT FROM AUTHOR]

In order lo improve the experiment teaching effect of pollution control and remediation course and cultivate undergraduate innovation practice ability, design and optimization of heavy metal migration experiments in aquifer are carried out from two aspects of experimental equipment and experimental conditions. A small two-dimensional plexiglass simulation lank is used as experimental device. Cadmium nitrate is chosen as the target pollutant and quantitatively determined by atomic absorption spectrophotometer. The optimized experiment results are shown; (l)Cd2+ migration front is prolonged in the vertical and longitudinal in the groundwater with the extension of the leakage time; (2) Cd2+ concentration of sampling Port 7 decreases gradually after cutting off the pollution source, while increases gradually and then decreases gradually in sampling Port 11; (3) The groundwater flow rate is faster, the vertical migration velocity of Cd2+ is larger than the vertical direction, and the convection action is obvious. When the flow velocity is slower, the longitudinal migration velocity of Cd2+ is smaller than the vertical direction, and the dispersion effect is remarkable. [ABSTRACT FROM AUTHOR]

Groundwater heat pump system is an ideal approach to heat and cool the building due to its attractive advantages. When using groundwater as a primary energy source in combination with heat pump, the groundwater is pumped from the pumping area, heated/cooled in the heat exchanger of the heat pump, and then reinjected into the irrigation area. Single well groundwater heat pump (SWGWHP) is a new member of groundwater heat pump, which has become increasingly popular for using because of the economic advantages. In general, SWGWHP includes standing column well (SCW), pumping & recharging well (PRW), and forced external circulation standing column well (FECSCW). Their pumping and injection pipes are placed in a same well, the low part of which is pumping water and the top part recharging water. The SCW needs to drill hole in the bedrock directly, and then most of the water circulates in the well bore and the heat exchange takes place in the well wall, while small part of water goes out of the borehole and exchanges the heat with aquifer raw water. There are some clapboards in PRW that make the thermal well divided into 3 parts, i.e. injection zone (in the top part), seal zone (in the middle part), and production zone (in the low part). The FECSCW is similar to PRW. The difference between them is that the diameter of borehole in FECSCW is larger than the one in PRW. Moreover, the gap of borehole in FECSCW is filled with sorted gravel. Through previous research on the thermal features of three kinds of thermal wells, PRW has obvious advantages in 3 kinds of SWGWHP. Because its middle partition area exists, the backwater is reinjected into the aquifer completely, while thermal transfixion occurs rarely. In view of less experimental research on continuous operation, this paper selects the PRW as the research object. According to the heating/cooling period in Shenyang and Shanghai, 2 different modes of continuous operation in PRW have been carried out using a physical simulation experimental sandbox of SWGWHP, which can accurately reflect the actual physical phenomena. In this experimental research, time of operating condition has been distributed by heating season, air-conditioning season, and recovery season, while 2 test conditions are continuous heating mode and continuous cooling mode. In the heat/cold load dominant area, the results show that the aquifer can’t be restored to its original state during the natural recovery period. In continuous heating conditions of 6 cycles, the decreasing amplitude of accumulative heat absorption quantities of 6 cycles reaches 23.0%. Compared to the cooling condition, the decreasing amplitude of accumulative heat rejection quantities in 6 cycles is only 6.0%. These data show that the PRW is more sensitive in heating mode, while the heat absorption is more difficult than heat rejection. Additionally, in continuous heating condition, the aquifer is more obvious in the initial disturbance. The reduced amplitude of cumulative heat in the second operating cycle is 57.1% of all reduced amount in 6 cycles. Thus, in the heat/cold load dominant area, it is necessary to carry on the energy recharge to the aquifer in time according to the building load, in order to ensure the system in a long-term reliable operation. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Jurassic weathered bedrock aquifer is an important gushing water disaster source in Northen Shaaxi Jurassic coalfield.Scientific prediction on its enrichment is an important issue to be resolved in mine water prevention and control.This paper aims at the problem of water enrichment prediction in weathered bedrock. Take Hongliulin Coal Mine in Shenfu mining area as an example，the paper investigates the weathered bedrock development characteristics and its influence factors of water enrichment. Then，the paper selects four factors of weathered bedrock stratum age，thickness，weathering degree，and lithological association as the evaluation indexes，and establishes the Fisher discriminant analysis model on the type of water enrichment of weathered bedrock aquifer，using the borehole measured inflow and index data. The type of water enrichment of weathered bedrock in the drill hole which has no pumping test data can be predicted using the Fisher model. The studies have shown that the prediction of weathered bedrock water enrichment based on Fisher discriminant analysis model is feasible，and it provides a new scientific prediction method for the water enrichment of weathered bedrock. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the serious problem of water environmental damage caused by coal mining, the authors put forward the theory and technology of water protection in mining on the foundation of backfilling mining technology according to the occurrence characteristics of mine roof aquifer. Using the migration law and control mechanism of roof and floor in backfilling mining, the roof aquifer stability mechanical model of backfilling mining was built and the boundary condition keeping the roof aquifer stable was found. Through the similarity simulation experiment the article the protection mechanism of roof aquifer that the backfilling mining technology act on was analyzed and verified its accuracy. The research results show that the subsidence of stable roof aquifer includes the pre-filling roof subsidence, the roof subsidence after filling and the subsidence associated with direct roof characteristics of rock mass itself. The breaking boundary conditions of the stable roof aquifer is hb ≤ Hb. With the increase of dense pack rate, the subsidence of stable roof water-resisting layer reduces. Through analyzing the measured data in Xingtai coalmine filling workface, die fact is found that the dense pack rate of filling body must be above 68% in order to ensure the integrity of the roof aquifer. [ABSTRACT FROM AUTHOR]

The mechanism of floor heave in the gob adjacent to the working face was analyzed. The aim was to understand the floor heave phenomena happened at No. 15423N working face in Jiulong Coal Mine, Fengfeng mining group. Core logging of floor strata and in-situ stress measurement near the investigated region were carried out. Moreover, the numerical simulation was used to obtain the in-situ stress of No. 15423N working face. Based on these data, a bi-directional loading similar simulation experiment was carried out to analyze the process and mechanism of floor heave of gob near working face above aquifer. A series of spring group were used to simulate the aquifer. The time-space evolution characteristics of stress and displacement field in floor strata were analyzed. The. results could be used to explain the mechanism of water inrush accidents in Jiulong Mine. [ABSTRACT FROM AUTHOR]