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To address the prevailing scenario where comprehensive susceptibility assessments of ground deformation disasters primarily rely on knowledge-driven models, with weight judgments largely founded on expert subjective assessments, this study initially explores the feasibility of integrating data-driven models into the evaluation of urban ground collapse and subsidence. Hangzhou city, characterized by filled soil and silty sand, was selected as the representative study area. Nine pertinent evaluation factors were identified, and the RF-BP neural network coupling model was employed to assess the susceptibility of ground collapse and subsidence in the study area, the results indicate that the stacked model achieved a 7% increase in AUC value compared to the single model. Subsequently, this study utilized the advanced large language model (LLM), ChatGPT-4, to supplant expert judgment in the weight determination of ground deformation disasters. The advantages of ChatGPT-4, such as its ability to process vast amounts of data and provide consistent, unbiased judgments, were highlighted. ChatGPT-4's assessments were validated by geological experts in the study area through the analytic hierarchy process. The results show that, by analyzing the same textual materials, the weights determined by experts differed by only 3% from those judged by ChatGPT, demonstrating the reliability and human-expert-like logic of ChatGPT-4's judgments. Finally, a comprehensive susceptibility assessment of ground deformation disasters was conducted utilizing ChatGPT-4's judgment results, yielding favorable outcomes. [ABSTRACT FROM AUTHOR]

An investigation of the distribution and control factors of groundwater is significant for the rational exploitation and utilization of groundwater resources. This study analyzes the hydrogeochemical processes and control factors of shallow groundwater in the Guohe River Basin. A hydrogeological survey was conducted, and hydrochemical and hydrogen–oxygen isotopic data of 125 samples of surface water and groundwater were analyzed. The results showed that the total dissolved solid (TDS) content in shallow groundwater was 138–2967 mg/L, with an average of 831 mg/L. A decline in the TDS was observed from the upper to the lower reaches. The contents of the anions and cations in the shallow groundwater were in the order HCO3− > Cl− > SO42− and Na+ and K+ > Mg2+ > Ca2+, respectively. The cation exchange increased the aqueous concentrations of Na+ and K+, and the TDS content was highly correlated with the contents of Na+, Cl−, and SO42− ions. The δD and δ18O values in shallow groundwater increased from the upper to the lower reaches, with the mean δD values being −59.72‰, −53.58‰, and −47.17‰ and the mean δ18O values being −8.33‰, −7.37‰, and −6.43‰. The contribution rates of the recharge source, evaporation, and water–rock interaction to the groundwater TDS concentration were 20.4%, 29.5%, and 50.1%, respectively. The water–rock interaction dominated the formation of shallow groundwater in the Guohe River Basin. The dissolution of salt rock and gypsum contributed to ion formation in shallow groundwater. The research findings can be used to improve the groundwater quality in the Guohe River Basin. [ABSTRACT FROM AUTHOR]

Water resources and water environmental issues have emerged as significant constraints on the socio-economic development of Wuxi City. Based on the mechanism of mutual feedback within this system, a coupled model of the social-economy-water resources-water environmental was developed by means of spatial system dynamics. Subsequently, this model was employed to study the spatiotemporal dynamic characteristics of water resources and water environment carrying capacities in each subregion of Wuxi, considering various climate and socio-economic development scenarios. The results show that: (1) Both water resources carrying capacity coefficients and water environmental carrying capacity coefficients of each administrative district display in following order under different scenarios: Binhu District> Xishan District > Huishan District> Xinwu District> Liangxi District. (2) There are distinctions of water resources carrying capacity and water environment carrying capacity under different settings. Compared with B3 scenario (a developing society in a dry climate), the monthly average values of water resources carrying capacity coefficients and water environmental carrying capacity coefficients in Liangxi District, Binhu District, Xishan District, Huishan District, and Xinwu District under CI scenario (a water saving and emission reduction society in a wet climate) are 2.23 and 2.36, 2.13 and 3.22, 2.13 and 2.55, 2.12 and 2.53, 1.58 and 1.74 times, respectively. The practice shows that the spatial system dynamics model effectively harmonizes the relations between social economy and resource environment in both time and space, modelling simulation results that closely align with actual conditions. Thus, it provides a robust scientific foundation for regional water resource management in similar areas. [ABSTRACT FROM AUTHOR]

To enhance the resilience of Nanchang’s water supply system and ensure a dependable emergency water supply. Taking youkou emergency groundwater source field as an example, a flow simulation model was developed through an analysis of the hydrogeological conditions in the study area. Additionally, an optimization model based on the genetic algorithm (GA) technique was constructed and integrated into the flow simulation model. Subsequently, various water supply schemes were simulated with the minimum cost of groundwater extraction as the objective function. The results show that the values of the objective function were reduced by 4.92%, 15.67%, and 42.35% for the three different optimization schemes, namely pumping rates, joint pumping rates and the number of wells, and joint pumping rates, number of wells and well location. Ultimately, the optimal emergency water supply scheme was determined by considering a comprehensive range of factors. These factors encompassed considerations such as the area of the water level depression funnel, the dewatering thickness of the aquifer and the recovery of the groundwater level. The practice shows that the simulation–optimization model could effectively simulate complex groundwater flow systems, meeting the objective function and constraints toachieve the optimal exploitation scheme. [ABSTRACT FROM AUTHOR]

Conducting quantitative research on the microstructure of soft clay can reveal the essence of its soil mechanical behavior, which is of important practical significance for geological disaster risk assessment and prevention. To quantitatively investigate the microscopic properties of natural structured clay, soft clay soils from various sedimentary environments in the Hangzhou Estuarine Bay area were chosen as the research subject in this study. Subsequently, a comprehensive investigation into the microstructure of clay was conducted, involving X-ray phase analysis and SEM imaging analysis. The results revealed the following: (1) In comparison to the deep clay deposited in fluvial-lacustrine environments, the shallow mucky clay in marine sediments had a higher clay mineral content, accounting for 48%. Illite makes up the majority of it, with minor levels of kaolinite and montmorillonite being present. (2) The shallow mucky clay in the Hangzhou Estuarine Bay area had a typical agglomerate-flocculated structure. In contrast, the deeper clay showed a flocculated structure with less uniform particle sizes, strong stacking randomness, poor directional alignment of soil pores, and tends to form arrangements where edges are adjacent to faces or edges are adjacent to other edges. (3) Compared to the deep clay deposited in fluvial-lacustrine environments, the marine-deposited shallow mucky clay displayed orderly pore arrangements, strong directional alignment, significant pore shape variability, and minimal pore size changes between adjacent pores. The microstructure of soil plays a crucial role in determining the physical, mechanical, and other engineering properties of the soil. This study provides insightful information about the relationship between clay microstructure and geotechnical characteristics in Hangzhou and the surrounding areas. [ABSTRACT FROM AUTHOR]

The Shunyi fault in the Beijing Plain region is a significant late Pleistocene active fault. The Beijing Capital International Airport ( BCIA) is situated within the central segment of the Shunyi Fault. Since 2010, ground fissures on the airport's runway have progressively worsened, with a maximum vertical displacement difference of up to 20 cm, severely affecting airport safety. Presently, the impact of Shunyi fault activity on the ground fissures at the BCIA is primarily described qualitatively. This paper, based on research regarding the geometric structure of the Shunyi Fault, Quaternary activity, and investigations of the ground fissures at the Capital Airport, employs the fault dislocation model to quantitatively analyze the influence of the Shunyi Fault's creepsliding activity as well as the 1996 Shunyi ML 4.5 earthquake on the formation of airport ground fissures. The study also discusses the increasing risk of ground fissure hazards in the event of a potential strong earthquake along the Shunyi fault in the future. The preliminary results suggest that with a vertical activity rate of 0.6 mm / year, 46 years of Shunyi Fault's creep-sliding activity results in differential subsidence of no more than 2.5 cm on both sides of the airport ground fissures, contributing to approximately 20% of the formation and development of these fissures. The impact of the Shunyi ML 4.5 earthquake on the formation of airport ground fissures is minimal. However, if a future M 7.0 earthquake occurs on the Shunyi fault, the estimated maximum land differential subsidence between two sides of the fault could reach 104 cm, increasing the risk of airport ground fissure disasters by a factor of five. Ground differential settlement due to groundwater extraction from the upper and deeper layers of the Shunyi fault's hanging wall contributes about 70% to the formation and development of airport ground fissures, remaining the primary factor. The study's results provide essential scientific references for precise prevention and control of ground fissure disasters at BCIA. Furthermore, to further reveal the causes and mechanisms of delayed geological disasters along the Shunyi fault, such as ground fissures and land differential subsidence, it is recommended to implement dynamic monitoring of cross-fault crustal displacement or deformation at crucial segments. [ABSTRACT FROM AUTHOR]

This work aims to investigate the hydrochemical characteristics and formation mechanisms of shallow groundwater in a part of the Nanchang section of Ganfu plain. The hydrochemical data from 90 groundwater samples were interpreted by the methods of mathematical statistics, Piper diagrams, Gibbs plots, ratio graphs of ions, and geochemical modeling. The results show that shallow groundwater is weakly acidic, the average concentration of cation in groundwater decrease in Ca2+ > Na+ > Mg2+ > K+, and the abundance is in the order HCO3− > NO3− > SO42− > Cl− for anions. The hydrochemical type of groundwater was dominated by HCO3-Na·Ca·Mg, HCO3·Cl-Na·Ca·Mg, and HCO3-Na·Ca. Moreover, the main controlling factor of groundwater hydrochemistry is water-rock interactions. Na+ and K+ mainly originate from the dissolution of halite. Ca2+ and Mg2+ are mainly controlled by carbonate dissolution, while the main anions come from the dissolution of evaporite and carbonate. The groundwater chemical evolution is affected by the dissolution and precipitation of the mineral phase and cation exchange. [ABSTRACT FROM AUTHOR]

Coastal engineering construction suitability evaluation methods are too empirical and difficult to quantify. Considering these weaknesses, in order to determine the weight of each factor reasonably, and to analyze the suitability of coastal zone construction comprehensively, the theory of establishing a coastal zone construction suitability evaluation model based on a Rough Set (RS) and an Analytic Hierarchy Process (AHP) is proposed. In total, 20 typical coastal areas of Putian are selected, and the main impact factors are determined according to a port dock, pollution-prone industry, and an electric power plant. The contribution rate and weight of each factor for the construction of a coastal zone are analyzed by the combination evaluation model, and the final evaluation result is consistent with the actual investigation situation. Finally, 52 evaluation units of the Putian coastal zone are evaluated by Neural Networks (NNs). The weight of the impact factors is made more objective by using the training sample set of the combination evaluation model as the sample set of the neural network. The learning speed and accuracy of the network are improved, and the and the evaluation result is consistent with the actual investigation situation. In a word, it is effective to perform the suitability evaluation of the coastal zone construction using the RS-AHP-NN proposed model, and it can be applied in practical engineering. [ABSTRACT FROM AUTHOR]

Due to large-scale geological deposition processes, slope structures are often stratified, which means that the spatial distribution of the parameters involved in slope reliability evaluation is statistically anisotropic. This paper studies the effect of the statistical anisotropy of undrained shear strength on the probability of slope failure (pf) based on the Monte Carlo simulation. The results show that for the horizontally layered slope, the larger the horizontal correlation scale of undrained shear strength (λx) is, the larger pf is, especially when λx is smaller than the slope length; for the vertically layered slope, the larger the vertical correlation scale (λy) is, the smaller pf is, especially when λy is smaller than the slope height. Additionally, the mechanism of the above results is discussed by analyzing the displacement distribution at different correlation scales. The findings indicate that in the reliability evaluation of undrained slopes in stratified structures, either underestimation of λx or overestimation of λy leads to an unconservative estimate of pf, resulting in an overestimation of the slope stability. [ABSTRACT FROM AUTHOR]

Urban underground space (UUS) utilization is essential for urban sustainable development, and UUS geological suitability evaluation (UGSE) is crucial for safe and rational UUS utilization and for minimizing development risk. This paper presents a three-dimensional (3D) UGSE framework based on integrated weighting and improved technique for order preference by similarity to an ideal solution (TOPSIS), which enhances the evaluation rationality and accuracy. Analytic network process (ANP) was applied to calculate the subjective weights of the evaluation index. Criteria importance through intercriteria correlation (CRITIC) model improved by the coefficient of variation was applied to calculate the objective weights. The combination weights were further calculated by the game theory (Nash equilibrium model), which can coordinate the conflict and determine the consistency and compromise between subjective and objective weights. Based on the combination weights, the grey correlation analysis (GRA) model was used to refine the TOPSIS model, and combined the Euclidean distance (with the grey correlation) to construct a more reasonable closeness index. This allows the improved TOPSIS model to retain the benefit of better objectivity, while taking advantage of the grey correlation theory with little information. We took the central area of Future Sci-Tech City in China as a case study, and conducted UGSE (based on the above model), together with 3D visualization and analysis. The results support that the combined weighting and improved TOPSIS models can well reflect the varying 3D geological suitability and make the evaluation more robust, which facilitate decision-making in UUS development. [ABSTRACT FROM AUTHOR]

Now ground source heat pump is a more efficient way to develop and utilize shallow geothermal energy because it is clean and environmentally friendly and has a relatively low energy cost. In order to optimize the planning layout and geographical space development in the eastern new town of Anqing city, which can realize the transformation and upgrading of real space and urban sustainable development, the exploration for shallow geothermal energy will be carried out in this area, so as to find out the comprehensive thermophysical parameters of the shallow rock-soil body and the heat transfer capacity of the vertical heat exchanger, etc. This paper takes the CBD in the eastern new town of Anqing as an example to provide the basis for the feasibility construction of the ground source heat pump project in the study area and evaluate the economic and environmental benefits of the expected project. According to the simulation test data of 5 working conditions of 4 geothermal exploration holes in the study area, we can clearly know that the energy cost per square meter of the ground source heat pump is 11.8 yuan for a building of one hundred thousand square meters in which the heat removal power is expected to be 9481 kW in summer and 3070 kW in winter. And the annual emission of carbon dioxide, sulfur dioxide, nitrogen oxides, suspended dust, and other air pollutants to the atmosphere can be reduced by 1442.5 t, and the solid waste ash and slag can be reduced by 59.7 t. The annual environmental treatment cost will be saved by 166000 yuan. [ABSTRACT FROM AUTHOR]

To guarantee the sustainable development and utilization of shallow geothermal energy and avoid heat accumulation problems during the operating period of ground-source heat pump, a three-dimensional coupled numerical model of unsteady groundwater seepage and heat transfer was established. This model was applied to the demonstration project of the buried-pipe heat pump system in Danyang, Jiangsu Province. The model was based on the principles of groundwater seepage and heat transport and was combined with the future operating conditions of the ground-source heat pump system, to forecast the thermal equilibrium development trend of underground temperature field. A design scheme was determined on this basis. The district was divided into five development and utilization zones (I–V), and we changed the minimum heat transfer hole spacing from 5 to 14, 17, 18, 21, and 19 m. From the results, according to the actual situation we adopted, the simulation optimization scheme effectively slowed the heat transfer and resolved the heat accumulation problem, which can easily occur during the operation of a ground-source heat pump system. The three-dimensional coupled numerical model of unsteady groundwater seepage and heat transfer is an effective way to optimize and determine the sustainable development and utilization plan of a ground-source heat pump for shallow geothermal energy. [ABSTRACT FROM AUTHOR]

Plenty of mathematics researches provide feasibility to calculate the weights of geothermal controlling factors and have been applied in geothermal potential assessment. In order to avoid the disadvantages of subjective and objective weighting calculation methods, an extension theory integrated weighting method was put forward, by combining with the process of AHP and mean variance method. The improved method can reach an agreement on subjective understanding of impact factors’ roles and data-based calculation weights. Then by replacing the point values with intervals, the extension theory was used in classification of geothermal assessment, according to extension judgment matrix. The evaluation results showed perfect performance in classification of impact factors, especially in Wudalianchi area, where 10 out of 11 selected impact factors agreed well with the actual evaluation grades. The study can provide a guidance for primary stage of geothermal investigation including the impact factor selection, weights calculation for impact factors, and the factors’ classification in geothermal assessment. [ABSTRACT FROM AUTHOR]

The Jiangnan Orogen is located at a key tectonic position along the junction between the Yangtze and Cathaysia blocks. We obtained detailed major and trace elements, whole-rock Nd + zircon Hf isotope data, and U–Pb age data from several Mesozoic granites, including the Fuling (FL), Taiping–Huangshan (TH), Lingshan (LS), Sanqingshan (SQS), and Baijuhuajian intrusions in order to investigate their sources and petrogeneses related to extension in South China. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analyses of zircon from the FL, TH, SQS, and LS bodies yield Early Cretaceous ages of 124–135 Ma. These plutons are alkali-feldspar granites to syenogranites–monzogranites, and show A-type affinities. They have high K2O and total alkali contents, and are enriched in rare earth elements (except for Eu), Zr, and other high-field-strength elements as well as high Ga/Al ratios, and are depleted in Ba and Sr. These granites are metaluminous to weakly peraluminous (ACNK from 0.81 to 1.27). The whole-rockϵNd(T) values of −5.34 to −0.96 are coupled with zirconϵHf(T) values (from −5.3 to +4.24), and all samples plot along the mantle array. Field observations, geochronology, geochemistry, Nd isotopic, and zircon Hf isotopic compositions suggest that they formed by the partial melting of Mesoproterozoic metamorphic basement, with input from juvenile, mantle-derived materials in the shallow (<30 km) crust at high temperatures (756–965°C). These melts underwent crystal fractionation of biotite, plagioclase, and K-feldspar. The upwelling of asthenosphere triggered partial melting of the metamorphic protolith in a back-arc or intra-arc rift setting, reflecting rollback of the Pacific plate. Our research adds new geochronologic constraints on Cretaceous (135–120 Ma) A-type granites from the NE sector of the Jiangnan Orogen. Combined with previous research, we suggest that three main episodes of late Mesozoic extensional tectonism took place in South China: (1) 190–170 Ma (mainly inland), (2) 165–120 Ma (including 165–150 Ma in SE Shi-Hang, 135–120 Ma in NE Shi-Hang, and ∼125 Ma in the Lower Yangtze River Belt), and (3) 100–90 Ma (coastal area), showing an oceanwards younging trend due to the subduction of the Palaeo-Pacific plate. [ABSTRACT FROM AUTHOR]