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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 creep-sliding 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.

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]

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]