Search

In areas where urban land subsidence is frequent and significant, there are problems with heavy workload, high cost, long observation period, and difficult technical maintenance of the regional elevation reference frame in leveling measurement. In this paper, we propose a method of using continuous operation reference stations (CORSs) as nodes to perform dynamic maintenance of regional elevation reference frames. Using continuous years of Global Navigation Satellite System (GNSS) observation data and surface mass load data (land hydrology, atmospheric pressure, and sea level elevation), we calculate the normal height variation of CORSs, dynamically correct the normal height of CORSs, and verify the accuracy of the calculated CORS normal height variation results using multiperiod leveling observation data. The results showed that the average difference between the normal height variation determined using CORSs data and surface mass load data and the normal height variation of the station obtained by two-stage leveling measurement is 4.37 mm, and the calculated average accuracy of the normal height variation of CORSs is about 5.42 mm. CORSs demonstrating long-term stable continuous observation can be selected as nodes of the elevation control network to achieve the dynamic maintenance of the regional elevation reference framework using CORS data. The research results can provide exploratory experience for future elevation benchmark maintenance work in Beijing. [ABSTRACT FROM AUTHOR]

Background: Total en bloc spondylectomy (TES) is a recognized surgical approach for managing spinal tumors. With advancements in three-dimensional (3D) printing technology, the use of 3D-printed prosthetics for vertebral reconstruction post-tumor resection has gained traction. However, research on the clinical implications of these prosthetics remains limited. Methods: This retrospective study evaluated patients who underwent TES for primary and metastatic thoracolumbar tumors at the Department of Spinal Surgery, Tianjin Hospital, between October 2017 and September 2020. These patients received anterior reconstruction with 3D-printed artificial vertebral bodies. Results: 14 patients completed the surgery, with intraoperative blood loss ranging from 1,400 to 4,200 ml (mean 2,767 ± 790 ml) and operative duration between 240 and 520 min (mean 382 ± 75.9 min). The follow-up period extended from 7 to 43 months, with an average of 19.9 ± 9.5 months. Standardized prefabricated prosthetics were utilized in nine patients, while five received customized prosthetics. Throughout the follow-up, there were no reports of posterior connecting rod, 3D-printed prosthetic, or pedicle screw failures. Notably, one patient presented with significant prosthetic subsidence resulting in screw loosening, and three cases of prosthetic subsidence were observed. Conclusion: The incorporation of 3D-printed prosthetics in TES procedures yielded favorable clinical outcomes. Further research is warranted to optimize these prosthetics for enhanced postoperative stability and patient-specific applications. [ABSTRACT FROM AUTHOR]

Volcanoes in extensional environments may show gradual subsidence over decades during quiescent periods, due to various processes such as magma withdrawal, cooling, contraction, plate spreading and viscoelastic response. If significant rheological anomalies reside in volcano roots, due to the presence of magma and hot rock, they can influence the style of deformation. We use Finite Element Method (FEM) models to explore how strain localization due to extension can lead to volcano deflation. We apply rheological models comprising an elastic layer overlying a viscoelastic domain and include local up‐doming regions of low viscosity material beneath volcanic centers. The models reveal a localized subsidence above the rheological anomaly, influenced by the tectonic extension, and by the up‐doming volume and its viscosity. The models suggest that plate divergence may account for 4–5 mm/yr of observed subsidence at Krafla and Askja volcanic systems (KVS and AVS, respectively) in North Iceland. Plain Language Summary: Extensional stretching may have an important effect on the ground deformation observed at volcanic systems located along a divergent boundary. The physical properties of the crust are altered by the presence of hot material and/or geothermal activity at central volcanoes, compared to the surrounding rocks. We use a two‐layer model consisting of an elastic crustal volume overlying a viscoelastic layer, which locally reaches shallower depth (referred to up‐doming material), to investigate such crustal properties beneath volcanic systems. We explore a wide range of viscosity values in the up‐doming material and elastic layer thickness. The models, applied to investigate observed ground deformation at the Krafla and Askja volcanic systems, suggests that regional stretching with realistic material properties in the crust beneath the volcanic system, fits quite well the observed deformation satellite data at Krafla volcanic system in the 2015–2018 observations, but only a minor contributor to the Askja deformation pattern in the same period. Our modeling approach suggests that any extensive magmatic system undergoing stretching should feature subsidence in relation to the presence of hot material/magma mush beneath volcanic systems. Key Points: Gradual deflation (mm to cm per year) over decades has been observed at the Krafla and Askja volcanic systems in IcelandNumerical models show that deflation is induced by stretching across volcanic systems and dependent on their crustal rheological anomaliesFor the 2015–2018 period, an extensional model can broadly explain observed deflation at Krafla, but only ∼25%−30% at the Askja caldera [ABSTRACT FROM AUTHOR]

This study examines the combined effects of decommissioning lignite mining operations and long-term climate trends on groundwater systems and land surface movements in the Konin region of Poland, which is characterised by extensive open-pit lignite extraction. The findings reveal subsidence rates ranging from −26 to 14 mm per year within mining zones, while land uplift of a few millimetres per year occurred in closed mining areas between 2015 and 2022. Groundwater levels in shallow Quaternary and deeper Paleogene–Neogene aquifers have declined significantly, with drops of up to 26 m observed near active mining, particularly between 2009 and 2019. A smaller groundwater decline of around a few metres was observed outside areas influenced by mining. Meteorological data show an average annual temperature of 8.9 °C from 1991 to 2023, with a clear warming trend of 0.0050 °C per year since 2009. Although precipitation patterns show a slight increase from 512 mm to 520 mm, a shift towards drier conditions has emerged since 2009, characterised by more frequent dry spells. These climatic trends, combined with mining activities, highlight the need for adaptive groundwater management strategies. Future research should focus on enhanced monitoring of groundwater recovery and sustainable practices in post-mining landscapes. [ABSTRACT FROM AUTHOR]

The large-scale collapse of overlying strata in the gob directly affect the safe production of coal mines; they are also the major causes of geological disasters, such as ground cracks, surface subsidence, and ground collapse. In this paper, the movement and caved characteristics of overlying strata during coal seam excavation are studied by conducting a physical model experiment. Results show that overlying strata have different movement and caved laws during the initial, intermediate, and later mining stages. During the initial mining stage, overlying strata do not collapse, and the subsidence is extremely small. During the intermediate mining stage, overlying strata cave along the vertical direction, and caved height gradually increases. Large numbers of cavities, abscission layers, and fractures exist between caved strata. The fractured area gradually increases upward, and the subsidence increases considerably. During the later mining stage, overlying strata cave along the horizontal direction. The abscission layers between the caved strata of the central are compacted. The compacted area is surrounded by a fractured area. The compacted and fractured areas increase along the horizontal direction. The subsidence curves exhibit a horizontal variation. Overlying strata evolve from the self-equilibrium stage to the vertical collapse stage, and finally, the horizontal collapse stage. The fractured area changes from a no fractured area to a fractured area, increases vertically, and finally, increases horizontally. The subsidence curve changes from extremely small to large, and finally, changes horizontally. [ABSTRACT FROM AUTHOR]

Introduction: This study investigated stem subsidence following primary total hip arthroplasty (THA) with a Corail stem in patients who underwent two-staged bilateral THA. The second outcome of interest was to investigate whether a specific single cortical bone contact point might reduce postoperative stem subsidence. Methods: The present study was conducted following the STROBE guidelines. The records of patients who underwent THA between 2016 and 2023 were accessed. All patients who underwent two-staged bilateral THA were retrieved. The direct contact between the stem and the cortical bone was assessed at various points in the metaphysis and the distal portion of the stem (diaphysis) in both anteroposterior radiographs of the pelvis (medial and lateral bone contact) and a Lauenstein view of the hip (anterior and posterior bone contact). The following parameters were measured and compared to assess stem subsidence: distance from the proximal femur at the stem bone interface and the tip of the lesser trochanter (distance A); distance from the tip of the lesser trochanter and the tip of the femoral stem (distance B). Results: In total, 250 patients were included, 45% (149 of 250 patients) were women and 61% (153 of 250 THAs) were implanted primarily on the right side. The mean age of patients at the time of the first THA was 64.3 ± 10.0 years and the mean body mass index (BMI) was 28.0 ± 4.9 kg/m2. The mean length of the follow-up was 14.1 ± 10.8 months. The overall stem subsidence following THA was 2.8 ± 0.7 mm (P < 0.006). A direct cortical bone-implant contact did not exert a statistically significant difference in subsidence of the THA stem at the metaphysis and diaphysis (P > 0.5). Stem subsidence following THA with a collarless cementless Corail stem was approximately 2.8 mm at 14 months. Conclusions: Direct cortical bone contact of the stem at diaphysis and metaphysis seems not to influence stem subsidence following THA using the Corail stem. [ABSTRACT FROM AUTHOR]

The Heze section of the Rizhao-Lankao High-Speed Railway (RLHR-HZ) officially began operations in June 2021. Previous studies have shown that the RLHR-HZ crosses two subsidence zones. In this study, we analysed ground displacement along the RLHR-HZ using Sentinel-1A SAR data collected from June 2021 to June 2023, employing both Permanent Scatterer and Distributed Scatterer techniques. The results indicate a reduction in the displacement rate; however, subsidence continues along the RLHR-HZ, with displacement rates ranging from −16 mm/yr to −5 mm/yr. This reduction is likely due to the cessation of mining activities and the replenishment of groundwater. [ABSTRACT FROM AUTHOR]

The exploitation of coal resources has caused problems such as ground deformation, affecting the ecological environment. Spatiotemporal varying characteristics between land subsidence and ecological environmental quality (EEQ) are an important research hotspot. Using the SBAS-InSAR method, 64 Sentinel-1 images were utilized to monitor land subsidence in the Shenfu mining area, one of China's largest coal source regions. And the remote sensing ecological index (RSEI) was used to monitor and evaluate EEQ of the Shenfu mining area. Global and local spatial autocorrelation methods were used to assess the spatial aggregation degree and change patterns over time. Spatial Econometric Models were employed to explore the impacts of land subsidence on EEQ. The results showed the following: (1) The average RSEI values in the Shenfu mining area were 0.531, 0.488, and 0.523 in 2016, 2018, and 2020, respectively; there was a slight downward trend in EEQ. The permanent scatter (PS) point deformation rate ranged from −353.40 mm/year to +246.24 mm/year, with average deformation rates of 0.1642, 0.2181, and 0.2490 mm/year, respectively. (2) There was a significant correlation and spatial agglomeration effect between land surface subsidence and EEQ. Low–high, high–low, and low–low clusters were the main types of relationships, indicating that land subsidence primarily has a negative spatial impact on the ecological environment. (3) The relationship between land subsidence and EEQ varied spatially in the Shenfu mining area at 500 × 500 grid units. This research can provide scientific guidance for disaster prevention and sustainable development in mining areas by considering long-term differences in ecological environmental quality and its correlation with land subsidence. [ABSTRACT FROM AUTHOR]

Advanced statistics can enable the detailed characterization of ground deformation time series, which is a fundamental step for thoroughly understanding the phenomena of land subsidence and their main drivers. This study presents a novel methodological approach based on pre-existing open-access statistical tools to exploit satellite differential interferometric synthetic aperture radar (DInSAR) data to investigate land subsidence processes, using European Ground Motion Service (EGMS) Sentinel-1 DInSAR 2018−2022 datasets. The workflow involves the implementation of Persistent Scatterers (PS) time series classification through the PS-Time tool, deformation signal decomposition via independent component analysis (ICA), and drivers' investigation through spatio-temporal correlation with geospatial and monitoring data. Subsidence time series at the three demonstration sites of Bologna, Ravenna and Carpi (Po Plain, Italy) were classified into linear and nonlinear (quadratic, discontinuous, uncorrelated) categories, and the mixed deformation signal of each PS was decomposed into independent components, allowing the identification of new spatial clusters with linear, accelerating/decelerating, and seasonal trends. The relationship between the different independent components and DInSAR-derived displacement velocity, acceleration, and seasonality was also analyzed via regression analysis. Correlation with geological and groundwater monitoring data supported the investigation of the relationship between the observed deformation and subsidence drivers, such as aquifer resource exploitation, local geological setting, and gas extraction/reinjection. [ABSTRACT FROM AUTHOR]

Over the years, the field of landslide disaster research has amassed a wealth of data and specialized knowledge. However, these resources originate from a wide array of sources and often feature complex data structures, highlighting a persistent lack of methods to integrate multi-source, heterogeneous data. Traditional landslide monitoring methods typically focus on singular monitoring targets and data sources, which limits a comprehensive understanding of the complex processes involved in landslides. This paper introduces a landslide monitoring model based on a knowledge graph. This model employs P-Tuning to fine-tune ChatGLM2 for the extraction of triples. Differential InSAR (D-InSAR) is utilized to extract ground deformation data, which is then integrated with the knowledge graph for landslide monitoring and analysis. This study focuses on the co-seismic landslide in Jishishan, Gansu, China. By analyzing the landslide knowledge graph and the spatiotemporal deformation map, the results are as follows: (1) For this event, 106 entities and attributes were constructed, along with two recommended calculation routes. (2) The deformation at the earthquake's central region reached up to 8.784 cm, with a slightly smaller deformation zone to the northwest peaking at 9.662 cm. Significant unilateral subsidence was observed in the mountain range to the southwest. (3) The area affected by the co-seismic landslide primarily includes farmland and villages, covering an area of 0.3408 square kilometers. (4) Analysis based on the knowledge graph indicates that this landslide was primarily caused by the rapid liquefaction of water-saturated soil layers due to the earthquake, resulting in instability. This study contributes to the analysis of post-disaster losses, attribution, and impacts. [ABSTRACT FROM AUTHOR]

Soil shrinkage characteristic curves are used to describe the shrinkage behavior and hydraulic properties of unsaturated soils. To construct soil shrinkage characteristic curves, a high‐data‐density measurement method is needed that relates water content to soil volume changes. We present a fully automated soil shrinkage measurement setup, based on the simplified evaporation method, to characterize the shrinkage behavior of undisturbed natural expansive clay soils. The high data density creates the opportunity to produce soil shrinkage characteristic curves without the need for a mathematical model. The technique allows for resaturation of the samples after drying, enabling differentiation between reversible and irreversible shrinkage. The setup consists of the commercialized HYPROP2 apparatus combined with optical distance sensors to measure the horizontal and vertical dimensions of the samples, yielding data on the sample volume, weight, and soil water suction. The measurement frequency is once per 10 min, and the measurement period is up to 4 weeks, providing a detailed time series of the drying and shrinkage characteristics. The setup can capture the different shrinkage phases and offers the opportunity to relate the soil shrinkage characteristic curve to soil water suction. The measurement data acquisition rate and accuracy enable detailed interpretation of soil water retention curves for nonrigid soils and are shown to be essential for understanding and quantifying the shrinkage potential of several types of deposits. Core Ideas: We present a new fully automated setup to accurately measure soil shrinkage curves of expansive soils.The method enables the construction of soil shrinkage curves without applying a mathematical model.Establishing soil water retention curves can be improved by simultaneously measuring shrinkage during drying. Plain Language Summary: Soil shrinkage is the decrease of soil volume due to lower water levels, which can damage infrastructure, cause land subsidence, and alter soil properties. To predict soil shrinkage accurately, it should be monitored either in the field or on natural samples in the lab, requiring high data density. We developed and tested a method to capture the shrinkage behavior of natural soil samples. Our results show that this method allows us to describe shrinkage without relying on mathematical models and also study the effects of soil wetting. This study enhances our ability to measure and understand soil shrinkage, which is crucial for predicting soil behavior in various environmental and engineering scenarios. [ABSTRACT FROM AUTHOR]

Based on a compilation of widely available climate analysis products, we show evidence for a significant variation in the spatial pattern of the large-scale vertical zonal atmospheric circulation patterns across the equatorial Indo-Australasian domain of the Eastern Hemisphere during the major 2023–24 El Niño event. The region of large-scale subsidence and its associated teleconnection patterns that are usually centered across Indonesia (the "Maritime Continent") were displaced to the west over the equatorial Indian Ocean. In the record of El Niño events with readily available online dynamical tropospheric fields (one source from 1947 and the other from 1979), this has only been seen two other times, during the strong 1997–98 El Niño and the weaker 1977–78 event. These three events may well be consistent with internal variability, but at present, the reason for such occurrences has not been established. [ABSTRACT FROM AUTHOR]

The subsidence caused by coal mining could cause the destruction of roads and houses, and even the failure of infrastructures. Understanding of the mechanism of coal mining subsidence may provide early protecting to infrastructures on coming failure, but dynamic analysis of subsidence due to coal mining is currently needed. In this study we apply particle image velocimetry (PIV) method to reveal strata movement and subsidence according to the prototype and indoor physical model similarity experiment of Henan. Our result shows magnitude of the subsidence of overlying strata during the coal mining at different excavation thickness, that more coal mining thickness may produce more subsidence, and that shallower coal may cause more significant subsidence. Our result suggests that further PIV test combined with field monitoring data may be an effective measure to study subsidence mechanism and pattern helping to predict disaster caused by subsidence. [ABSTRACT FROM AUTHOR]

Accurate monitoring of mining three-dimensional deformation plays an important role in analyzing the subsidence mechanism and assessing potential geological hazards in the mining area. This paper combines TerraSAR-X and RADARSAT-2 heterogeneous SAR images employing MSBAS technology to obtain the three-dimensional time-series of deformation of the 132 610 working face in the Fengfeng mine from December 2015 to February 2016. The monitoring results show that the maximum surface subsidence and the subsidence rate during the monitoring period were –243 mm and 4.42 mm/day, and the maximum east-west horizontal movement was –80~30 mm. The surface subsidence basin is in the active stage, which is prone to pose a threat to the safety of the surrounding structures. Comparison with the leveling data shows that the root-mean-square deviation of the vertical deformation obtained by MSBAS technology is 10.7 mm, and the accuracy can reach the centimeter level. Meanwhile, based on the vertical deformation obtained by MSBAS technology, combined with the proportionality relationship between horizontal movement and tilt, the north-south horizontal movement was estimated as –80~70 mm, which provided a solution for obtaining the north-south horizontal movement of the mining area by InSAR. Analysis of the three-dimensional time-series of the surface deformation at the main sections shows that the surface deformation features during the mining process of the 132610 working face match well with the general model of mining subsidence, but the working face inclination angle has an influence on the surface deformation. [ABSTRACT FROM AUTHOR]

A high-precision and high-resolution vertical velocity for the Chinese mainland is obtained by integrating precise levelling and Global Navigation Satellite System data, using a Helmert joint adjustment method. The results show that the surface vertical rates range between −3.0 and 3.9 mm yr−1 with continuous deformation in most areas, except the obvious subsidence at the rates of −15.0 to −94.2 mm yr−1 induced by groundwater exploitation in the North China Plain. Particularly, the central and southern Tibet, Tien Shan, Alashan, Ordos, eastern Cathaysia and Northeast China uplift at the rates of 0.5–3.9 mm yr−1; the southeastern Tibetan Plateau, Sichuan basin and Yangtze block are dominated by surface subsidence at the rates of −3.3 to −0.5 mm yr−1. Furthermore, the vertical rates vary little between the eastern and western regions of the Chinese mainland despite their pronounced differences in horizontal deformations. The effects of gravity isostasy and non-tectonic factors, including the environmental mass loads, Glacier Isostatic Adjustment (GIA), poroelastic expansion/compression, and mining operations have partially contributed to the vertical deformation of the Chinese mainland. Overall, this velocity reflects the complicated deformation features induced by the multiple geodynamic processes of the Chinese mainland. These geodynamic processes include isostasy, orogenic processes and geothermal anomalies associated with slab subduction/plate collision. [ABSTRACT FROM AUTHOR]

Many intracontinental basins form as broad depressions through prolonged, slow subsidence of the continental lithosphere. Such long-lived basins can record lithospheric processes over hundreds of millions of years, serving as important archives of lithospheric evolution. Since continental amalgamation in the Mesoproterozoic, the lithosphere beneath the intracontinental Canning Basin has been subject to several tectonic events, with extensive crustal reworking evidenced through different upper crust data sets. However, knowledge of the structure of the subcontinental lithospheric mantle is lacking. As a consequence, understanding the coupled evolution between surface and deep lithospheric processes, crucial to resolving basin formation, development and survival, remains problematic. Here, we combine geochemical, geophysical and petrophysical data within a thermodynamic modelling framework to determine the thermochemical properties, rheology, density and seismic structure of the lithospheric and sublithospheric mantle beneath the Canning Basin. The results indicate a thick, rigid lithosphere with a maximum thickness of 185 km and strength of ca. 1 × 1013 Pa m, and an anomalously Fe-enriched subcontinental lithospheric mantle with a Mg# of 88.6. This mantle structure is not consistent with pre-collisional fragments or a Precambrian collisional setting and may reflect magmatic refertilization during high-volume mafic magmatic events. Potential candidate events are the ∼1070 Ma Warakurna, ∼825 Ma Gairdner and ∼510 Ma Kalkarindji Large Igneous Provinces. The youngest of these is temporally and spatially correlated with and therefore interpreted to have influenced the Canning Basin formation. We propose that refertilization caused a negatively buoyant subcontinental lithospheric mantle and prolonged subsidence and preservation of the basin, while the strong lithosphere ensured lithospheric stability and longevity. [ABSTRACT FROM AUTHOR]

This paper forms part of the SINEW (sinkhole early warning) project and continues the work conducted by Möller and co-workers in 2022, where 1g experiments demonstrated the feasibility of using distributed fibre-optic sensing (DFOS) for sinkhole early warning. Their experimental campaign highlighted an order of magnitude difference in the strain between the soil and the cable that remains unexplained and weakens confidence in the technology and/or the experimental method. This paper uses three-dimensional finite-element analyses to examine further this discrepancy and the soil–cable interface. The results support the experimental findings and demonstrate that the DFOS signature strain profile is induced by the horizontal movement of the ground, and enhanced when sufficient coupling at the soil–cable interface is achieved. This result holds when modelling is scaled to realistic confining pressure, and its significance is twofold. First, this needs to be accounted for in the DFOS laying technique. Second, particles of cohesionless soils undergo relatively high horizontal displacement away from the centre of the sinkhole, and this means that DFOS cables are able to detect subsidence away from the centre of the sinkhole. The paper illustrates this result and the signature strain profile expected in this case. [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.)

Land subsidence (LS) is a geological hazard driven by both natural conditions and human activities. Traditional LS time-series prediction models often struggle to accurately capture nonlinear data characteristics, leading to suboptimal predictions. To address this issue, this paper introduces a multi-component temporal convolutional gate recurrent unit (MC-TCGRU) model, which integrates a fully adaptive noise-ensemble empirical-mode decomposition algorithm with a deep neural network to account for the complexity of time-series data. The model was validated using typical InSAR subsidence data from Kunming, analyzing the impact of each component on the prediction performance. A comparative analysis with the TCGRU model and models based on seasonal-trend decomposition using LOESS (STL) and empirical-mode decomposition (EMD) revealed that the MC-TCGRU model significantly enhanced the prediction accuracy by reducing the complexity of the original data. The model achieved R² values of 0.90, 0.93, 0.51, 0.93, and 0.96 across five points, outperforming the compared models. [ABSTRACT FROM AUTHOR]

Many cities worldwide are increasingly threatened by compound floods resulting from the interaction of multiple flood drivers. Simultaneously, rapid urbanization in coastal areas, which increases the proportion of impervious surfaces, has made the mechanisms and simulation methods of compound flood disasters more complex. This study employs a comprehensive literature review to analyze 64 articles on compound flood risk under climate change from the Web of Science Core Collection from 2014 to 2024. The review identifies methods for quantifying the impact of climate change factors such as sea level rise, storm surges, and extreme rainfall, as well as urbanization factors like land subsidence, impervious surfaces, and drainage systems on compound floods. Four commonly used quantitative methods for studying compound floods are discussed: statistical models, numerical models, machine learning models, and coupled models. Due to the complex structure and high computational demand of three-dimensional joint probability statistical models, along with the increasing number of flood drivers complicating the grid interfaces and frameworks for coupling different numerical models, most current research focuses on the superposition of two disaster-causing factors. The joint impact of three or more climate change-driving factors on compound flood disasters is emerging as a significant future research trend. Furthermore, urbanization factors are often overlooked in compound flood studies and should be considered when establishing models. Future research should focus on exploring coupled numerical models, statistical models, and machine learning models to better simulate, predict, and understand the mechanisms, evolution processes, and disaster ranges of compound floods under climate change. [ABSTRACT FROM AUTHOR]

When mineral resources are extracted using underground mining methods in hilly regions, landslides or slope failures can be induced frequently. In this study, slope collapse disasters in mountain mining areas were analyzed. The model test and numerical simulation of the slope impacted by repeated mining were carried out. The crack evolution and failure process were analyzed to reveal the instability mechanism. The results show that the rock mass would topple to the inside of the slope first, when the subsidence of overlying rock was induced by the mining of the upper coal seam. When repeated mining was performed in the lower coal seam, the mining induced macro-cracks that could connect with natural fissures, inducing the outward displacement of the slope. Then, the rock mass at the foot of the slope has to bear the upper load, which is also squeezed out by the collapsed rock mass, forming the potential slip zone. Finally, the instability is caused by the shear slip of the slope toe rock mass. Therefore, the instability evolution of the slope under underground repeated mining disturbance can be divided into four stages as follows: roof caving and overlaying rock subsidence, joint rock toppling, fracture penetration, and slope toe shearing and slope slipping. [ABSTRACT FROM AUTHOR]

Climate change, urbanization, and land subsidence are increasing risks of dangerous and costly flooding in Africa's coastal regions. As the intensity and the number of flooding occurrences increase, real-time solutions for flood risks and hazards mapping are required to assess flooding and its potential impacts on the environment and humans. Flood risk mapping has become an important tool for assessing flood risks in coastal areas to guide planning and mitigation efforts by local officials. However, this tool has not been leveraged to support flood risk analysis. Using GIS weighted sum method, this study mapped and assessed flood risk zones in Limbe, Cameroon, by utilizing a Shuttle Radar Topography Mission-Digital Elevation Model (SRTM-DEM). Flood risk zones were delineated based on several environmental factors, including precipitation, elevation, slope, soil texture, land use/land cover, and flow accumulation. The findings classified about 50% of land in Limbe as having either high or very high vulnerability to flooding. The highest risk areas were concentrated in the upstream and downstream areas of Ejengele and Limbe Rivers. Only about 9% of Limbe was classified as very low risk, suggesting that most of the land area is susceptible to flooding. The study reveals that more than 90% of the Limbe's urban areas are in flood-prone areas, which requires special attention from stakeholders to take necessary steps toward the preparation and mitigation of extreme flood events. The resulting flood risk maps provide vital information for urban and risk management planning professionals. [ABSTRACT FROM AUTHOR]

We compared elevation trajectories from 14 rod surface elevation table (RSET) stations and 60 real-time kinematic (RTK) global positioning system (GPS) transects within the Blackwater National Wildlife Refuge (BNWR) from 2010–2013. The results were similar, 7.3 ± 0.9 (mean ± standard error; RSET) versus 6.2 ± 0.6 mm year−1 (RTK) (P = 0.216), and were greater than relative sea level rise (RSLR) computed at the nearest long-term tide station (3.9 ± 0.29 mm year−1). Despite having shown elevation gain, these wetlands continue to drown and convert to open water. Episodic, multi-day GPS measurements on geodetic control marks at BNWR between 2005 and 2023 revealed a substantial vertical land motion (VLM) signal. From 2005 to 2015, three reference marks used to control the 2010–2013 RTK study lost on average 6.0 ± 0.7 mm year−1, corresponding to 80% and 94% of the elevation gain measured by the RSET and RTK techniques, respectively. The longer 18-year subsidence trend measured on one of these marks was lower, 3.9 ± 0.7 mm year−1, highlighting important interannual variability. Wetland elevation change measurements need to account for VLM occurring below the reference marks used to measure elevation change. Estimates from the nearest long-term tide station may not be applicable to the wetland if the tide station is in a different geological setting. At BNWR, VLM was higher than the VLM at the Cambridge tide station, which helps explain why wetlands at BNWR are not keeping pace with RSLR despite the measured high rates of elevation gain. [ABSTRACT FROM AUTHOR]

The western North Pacific Subtropical High (WNPSH) significantly influences East Asian weather. In the Northwest Pacific where sea‐salt aerosols (SSAs) are abundant and the large‐scale environment is dominated by the dry subsidence of the WNPSH during summer, inhomogeneous SSAs form as a product of the environment. However, the extent to which inhomogeneous SSAs affect the WNPSH remains unclear. This study investigates the radiative effects of SSAs through numerical simulations, revealing a novel mechanism for the strengthening of the WNPSH. The results demonstrate that inhomogeneous SSAs enhance the WNPSH by generating diabatic cooling in the upper troposphere and associated unstable subsidence motion. Further considering the radiative hysteresis effects of inhomogeneous SSAs, the WNPSH further strengthens under the combined dynamic and thermodynamic influences associated with upper‐level radiative cooling. Inhomogeneous SSAs not only enhance the WNPSH but also influence the location where the central area of high pressure intensifies. Plain Language Summary: Variations in the western North Pacific Subtropical High (WNPSH), including changes in its intensity and position, significantly impact weather patterns in East Asia, particularly during the summer months. At high relative humidity (RH) levels, sea‐salt aerosols (SSAs) appear as homogeneous droplets; however, in moderate RH environments (45%–70%), SSAs exist in inhomogeneous states characterized by water coatings on their core particles. The dry subsiding airflow of the WNPSH creates extensive areas of moderate RH over the western Pacific Ocean. Despite this, the potential effects of SSAs on the WNPSH through radiative processes have not been previously considered. This study demonstrates that inhomogeneous SSAs induce cooling in the upper troposphere, which contributes to an overall strengthening of the WNPSH. Additionally, these aerosols influence the position where the primary area of high pressure intensifies. This newly identified mechanism by which inhomogeneous SSAs strengthen the WNPSH offers a unique perspective for understanding the evolution of the WNPSH. Key Points: Inhomogeneous sea‐salt aerosols (SSAs) contribute to strengthening the western North Pacific Subtropical High (WNPSH)Inhomogeneous SSAs also influence the position where the main body of the high pressure intensifiesDirect radiative effects of inhomogeneous SSAs offer a distinctive perspective for exploring the dynamics of the WNPSH [ABSTRACT FROM AUTHOR]

The accuracy of Interferometric Synthetic Aperture Radar surface deformation solutions depends on the quality of the chosen interferogram subset. We present a method to select interferogram subsets based on unwrapping errors rather than temporal baseline thresholds. Using Sentinel‐1 interferograms over the Tulare Basin, California, we show that subtle phase noise can lead to up to 31.5 mm/yr line‐of‐sight (LOS) errors in short temporal baseline subset solutions, while decorrelation leads to a systematic underestimation of LOS rates (up to 92.3 mm/yr) in long temporal baseline subset solutions. Our new workflow better mitigates these noise sources at the same time. In the Eagle Ford region, Texas, our strategy better reconstructed up to 11.9 cm of cumulative LOS deformation between 2017 and 2021 over a ∼ ${\sim} $900 km2 $\mathrm{k}{\mathrm{m}}^{\mathrm{2}}$ region. This deformation feature can be linked to the total volume of produced oil and water through a linear relationship. Plain Language Summary: Surface deformation estimates derived from spaceborne imaging radar data are often impacted by weather conditions and surface vegetation changes. While it is common to select high‐quality data based on the time separation between two image passes, we designed a new data selection strategy based on measurable phase artifacts. We applied the new method to two vegetated regions that experienced land subsidence due to agricultural groundwater pumping (Tulare Basin, California) or oil and gas production (Eagle Ford region, Texas). In both cases, we show that surface deformation estimates can vary substantially depending on the choice of data subsets. Our strategy better mitigates different InSAR measurement noise terms at the same time. We showed that the observed subsidence in the Eagle Ford region is linearly proportional to the volume of produced oil and water from unconventional oil and gas resources exploitation. Furthermore, ongoing production activities have led to an increase in human‐induced earthquakes. Based on these findings, accurate surface deformation derived from InSAR data is now achievable in densely vegetated regions and can play an important role in future induced seismicity studies. Key Points: InSAR phase coherence does not always decrease with temporal baselinesChoosing interferograms based on phase unwrapping errors rather than temporal baselines better mitigates InSAR measurement noiseThe improved InSAR analysis strategy reveals up to 11.9 cm of LOS deformation signals related to oil and gas operations over the Eagle Ford [ABSTRACT FROM AUTHOR]

Predicting and understanding the phenomenon of surface subsidence caused by coal mining in working faces with faults are important issues for safe coal mining and efficient production. In numerical simulation experiments, it was found that the phenomenon of surface subsidence manifests when faults exist, and the degree of influence of faults with different dip angles on surface subsidence varies. This phenomenon is attributed to fault activation. According to the experimental results, the impact of faults with different dip angles on surface subsidence falls into three levels: level I for 35° faults, level II for 45° and 55° faults, and level III for 65° and 75° faults. Similarly, the relationship between the difficulty of fault activation and the dip angle of faults can be categorized as 35° faults prone to activation, 45° and 55° faults difficult to activate, and 65° and 75° faults not prone to activation. The probability integral correction model for fault mining, which integrates the surface subsidence values caused by fault-induced attenuation and the subsidence arising from separation spaces, was introduced, thereby constructing a surface subsidence prediction model. This proposed prediction model can accurately predict surface subsidence, with a root mean square error of 10.74 mm between the predicted and measured values, as validated using DInSAR results from the III 6301 working face in the Jincheng mining area. [ABSTRACT FROM AUTHOR]

Managed Aquifer Recharge (MAR) has been implemented in the upper alluvial plain of the Chaobai River, significantly affecting the groundwater level and causing it to rise. However, the effects of the MAR on land subsidence,remain largely unknown. To elucidate the effects of MAR on land subsidence, a comprehensive analysis was undertaken, integrating interferometric synthetic aperture radar (InSAR) data, extensometer measurements, and groundwater level observations.Our analysis revealed a discernible land rebound phenomenon, with rates escalating from 2.3 mm/a in 2015 to 20 mm/a in 2021. This rebound extends southwestward, following a dispersion pattern that aligns with pre-existing fault structures, suggesting their controlling influence. The groundwater level changes caused by the MAR can cause land rebound, especially near fault footwalls. However,low permeability in fault zones hinders groundwater flow in the hanging wall resulting in slight land deformation. Lithology also affects rebound, with sandy soils showing more significant land rebound, while low-sand areas exhibit limited or delayed rebound. These findings offer crucial insights into the interplay between MAR, groundwater dynamics, and land subsidence in the studied region. They provide a foundation for informed decision-making in groundwater replenishment strategies and precise subsidence prevention and control measures. Future research should maintain a vigilant monitoring of the long-term consequences of MAR on land subsidence to ensure sustainable regional development. [ABSTRACT FROM AUTHOR]

Unmanned Aerial Vehicle (UAV) oblique photogrammetry has been extensively employed in mining, albeit predominantly for reconstructing three-dimensional scenes and detecting changes within mining sites, lacking predictive capabilities. Leveraging 3D real scene model data, this study presents a two-stage prediction model, merging the probabilistic integral method with recurrent neural network (PIMF-RNN), to mitigate the impact of internal and external factors on surface subsidence, thereby enhancing predictive accuracy. Building upon this framework, a methodology was developed to forecast the maximum surface subsidence height and affected area under the block caving method, offering crucial data support for mitigating hazards associated with this mining technique. Analysis of surface data from Pulang copper mine during 2018–2020 demonstrates a prediction accuracy of 91.47% for maximum surface subsidence height and 87.52% for subsidence area. This research expands the potential applications of UAV oblique photogrammetry techniques within mining contexts. Furthermore, it establishes a cost-effective and efficient operational procedure for predicting mine surface subsidence. [ABSTRACT FROM AUTHOR]

It is generally believed that the Maritime Continent (MC) is rarely affected by tropical cyclones (TCs) due to its equatorial location. However, this study reveals that TCs in the tropical western North Pacific can significantly suppress rainfall over the MC and its surrounding seas, based on the composite analysis. This suppression effect of TCs exists across all phases of the Madden–Julian Oscillation (MJO). TCs greatly alleviate rainfall enhancement during the convective phases of the MJO and aggravate rainfall suppression during the suppressive phases. Particularly, TCs reduce the likelihood of extremely high rainfall in convective MJO phases from 9% to 5% and increase the likelihood of extremely low rainfall in suppressive MJO phases from 10% to 16%. The rainfall suppression is attributed to the lower-tropospheric southwesterly anomalies to the south of TCs, which result in moisture divergence over the MC. Additionally, the upper-tropospheric equatorward outflows of TCs also promote subsidence and suppress rainfall. This study introduces a new factor influencing the rainfall over the MC from a synoptic climatology perspective. [ABSTRACT FROM AUTHOR]

Introduction: Moral Intelligence (MI) as a concept has gained importance Increasing water scarcity as a result of climate change and its coincidence with population growth, economic development, and the resulting rising demand has become an important challenge in most parts of the world. In numerous nations, such as Iran, frequent occurrences of droughts, combined with the extensive utilization of surface and groundwater resources, have resulted in numerous environmental detriments, including a decrease in groundwater levels, land subsidence, deterioration of water quality, and, more recently, the emergence of dust storms due to soil erosion and desertification. In this situation, stakeholders can play an efficient role in water management and the alleviation of water scarcity and its negative environmental externalities in the context of good water governance. Method: This investigation endeavored to examine the functions and importance of individuals or groups with a vested interest in groundwater resources within the Hamedan-Bahar Plain. Additionally, it aimed to evaluate their influence and motivations through the utilization of the power-interest matrix (PIM) and important-performance matrix techniques. A total of 86 people were identified who could and were allowed to be interviewed through the snowball method. Then a 10-point scale questionnaire was used to rate the questions. To examine the power and interest of the stakeholders, the IPM test was carried out using the smart pls.3 software, and the results were classified based on the average values and the overall impact. The results reveal that 20 institutions and agencies have an effective role in the governance of groundwater resources in the Hamedan- Bahar plain. Furthermore, the analysis of the PIM revealed that the most powerful organizations that play the most important role in the management of the groundwater resources of the studied area are the regional water organization, the representatives of the parliament, and the governor, respectively. Results and discussion: Based on the research findings, the governance "power" index of organizations and institutions with power (39.77%) and total impact (0.516) is higher and more effective than the value of benefits with power (36.13%) and total impact (0.48). Accordingly, paying attention to the role and influence of the power of stakeholders will be an important and effective point in the plans and strategies for groundwater resources in the Hamadan-Bahar plain. In the end, strategies are suggested to each stakeholder for better implementation of the programs and strategies. [ABSTRACT FROM AUTHOR]

The rapid construction of high-speed railways in China has forced more and more routes to pass through slow subsidence zones caused by groundwater extraction or underground mining. It is crucial to carry out deformation monitoring and prediction those areas along high-speed railways to ensure the safe operation. Twenty-nine periods of Sentinel-1A data between Taiyuan South Station and Taigu East Station were first processed using the PS-InSAR technique, and the ground subsidence sequences at ten typical points were selected. Then the Variational modal decomposition (VMD) was combined with the Adaptive Boosting Algorithm (AdaBoost), and the VMD-LSTMAda-LSTMAda model was constructed by combining the long short-term memory (LSTM) model for the prediction of regional ground subsidence along the high-speed railway. The results show that the cumulative subsidence within the 200 m buffer of the line centreline is − 37.58 − 89.19 mm, and the annual average subsidence rate is − 26.57 − 82.63 mm/y. The proposed model can reduce the complexity of the deformation sequence and combines with AdaBoost to improve the prediction accuracy of the LSTM model. It performs well in terms of RMSE, MAE, MAPE, and R2 at the two feature points (3703: RMSE = 0.82 mm, MAE = 0.25 mm, MAPE = 6.31%, and R2 = 0.94; 522: RMSE = 1.32 mm, MAE = 0.46 mm, MAPE = 4.92%, R2 = 0.95). The model improves the accuracy of regional subsidence prediction along the high-speed railway. [ABSTRACT FROM AUTHOR]

The adverse combination of excessive mining practices and the resulting land subsidence is a significant obstacle to the sustainable growth and stability of regions associated with mining activities. The Lakhra coal mines, which contain some of Pakistan's largest coal deposits, have been overlooked in land subsidence monitoring, indicating a considerable oversight in the region. Subsidence in mining areas can be spotted early when using Interferometric Synthetic Aperture Radar (InSAR), which can precisely monitor ground changes over time. This study is the first to employ the Small Baseline Subset (SBAS)-InSAR and stacking-InSAR techniques to identify land subsidence at the Lakhra coal mines. This research offers critical insights into subsidence mechanisms in the study area, which has never been previously investigated for ground deformation monitoring, by utilizing 150 Sentinel-1A (ascending) images obtained between January 2018 and September 2023. A total of 102 deformation spots were identified using SBAS-InSAR, while stacking-InSAR detected 73 deformation locations. The most extensive cumulative subsidence in the Lakhra coal mine was −114 mm, according to SBAS-InSAR, with a standard deviation of 6.63 mm. In comparison, a subsidence rate of −19 mm/year was reported using stacking-InSAR with a standard deviation of 1.17 mm/year. The rangeland covered 88.8% of the total area and exhibited the most significant deformation values, as determined by stacking and SBAS-InSAR techniques. Linear regression showed that there was not a strong correlation between subsidence and topographic factors. As detected by optical remote sensing data, the subsidence locations were near or above the mines in the research area, indicating that widespread mining in Lakhra coal mines was the cause of subsidence. Our findings suggest that SAR interferometric time series analysis is helpful for proactively identifying and controlling subsidence difficulties in mining regions by closely monitoring activities, hence reducing negative consequences on operations and the environment. [ABSTRACT FROM AUTHOR]

Land subsidence is an environmental hazard occurring gradually over time, potentially posing significant threats to the structural stability of civilian buildings and essential infrastructures. This study presented a workflow using the SBAS-PSInSAR approach to analyze surface deformation in the Choushui River Fluvial Plain (CRFP) based on Sentinel-1 SAR images and validated against precise leveling. Integrating the InSAR results with hydrogeological data, such as groundwater levels (GWLS), multilayer compactions, and borehole loggings, a straightforward model was proposed to estimate appropriate groundwater level drops to minimize further subsidence. The results showed a huge subsidence bowl centered in Yunlin, with maximal sinking at an average 60 mm/year rate. High-resolution subsidence maps enable the quantitative analyses of safety issues for Taiwan High-Speed Rail (THSR) across the areas with considerable subsidence. In addition, the analysis of hydrogeological data revealed that half of the major compaction in the study area occurred at shallow depths that mainly included the first and second aquifers. Based on a maximal subsidence control rate of 40 mm/year specified in the CRFP, the model results indicated that the groundwater level drops from wet to dry seasons needed to be maintained from 3 to 5 m for the shallowest aquifer and 4–6 m for Aquifers 3 and 4. The workflow demonstrated the compatibility of InSAR with traditional geodetic methods and the effectiveness of integrating multiple data sources to assess the complex nature of land subsidence in the CRFP. [ABSTRACT FROM AUTHOR]

The Cerro Prieto basin, a tectonically active pull-apart basin, hosts significant geothermal resources currently being exploited in the Cerro Prieto Geothermal Field (CPGF). Consequently, natural tectonic processes and anthropogenic activities contribute to three-dimensional surface displacements in this pull-apart basin. Here, we obtained the Cerro Prieto Step-Over 3D surface velocity field (3DSVF) by accomplishing a weighted least square algorithm inversion from geometrically quasi-orthogonal airborne UAVSAR and RADARSAT-2, Sentinel 1A satellite Synthetic Aperture-Radar (SAR) imagery collected from 2012 to 2016. The 3DSVF results show a vertical rate of 150 mm/yr and 40 mm/yr for the horizontal rate, where for the first time, the north component displacement is achieved by using only the Interferometric SAR time series in the CPGF. Data integration and validation between the 3DSVF and ground-based measurements such as continuous GPS time series and precise leveling data were achieved. Correlating the findings with recent geothermal energy production revealed a subsidence rate slowdown that aligns with the CPGF's annual vapor production. [ABSTRACT FROM AUTHOR]

As a passive rift basin in the Cenozoic, the formation and evolution process of the Weihe Basin has not been well explained. Here we estimate the stretching factor and basal heat flow for each rift period along four geological profiles using a 2D multi-stage finite extension model. The modelling is based on a reconstruction of pre-rift crustal and lithospheric thicknesses, and is calibrated with the current heat flow. The Xi'an Depression had the biggest stretching factor while the Pucheng Uplift had the smallest throughout the Cenozoic period, which saw a range of stretching factors from 1.02 to 2.06. The basal heat flow in the Weihe Basin exhibits a corresponding change. At the end of the Oligocene, Miocene, and Pliocene periods, the basal heat flow varied between 58.5 ~ 64.0 mW·m−2, 59.2 ~ 67.0 mW·m−2, and 59.6 ~ 78.7 mW·m−2, respectively. Increasing stretching factor and basal heat flow indicate that the Weihe Basin is currently in a state of sustained extension. The formation and development of the Weihe Basin are analysed in the context of larger tectonic changes, and it is considered that the Weihe Basin is controlled by pre-existing faults, and formed in a regional tectonic context of sliding and pulling apart first, and tensioning and lifting up later. Since the late Miocene (7.3 Ma), anomalously rapid subsidence has occurred, induced by a new phase of rifting and depth-related lithospheric extension. The thermal genesis of the geothermal system in the Weihe Basin is also thought to be closely related to the latest phase of extension. [ABSTRACT FROM AUTHOR]

Shallow coal seam mining results in the formation of various bearing structures in key strata, leading to varying degrees of surface subsidence and severe disruption to the surface ecological environment. To investigate the coupled evolution characteristics of key strata fracture-bearing structures and surface subsidence in shallow coal seam mining, with a focus on the 1–2 coal seam mining at Longhua Coal Mine in northern Shaanxi as the research background, this study employed physical similarity simulation to establish the correlation between key strata fracture-bearing structures and surface subsidence. The study also utilized theoretical calculations to develop models for the trapezoidal hinged arch structure and the coupling between key strata-bearing structures and surface subsidence. Mechanical properties of bearing structures and the coupled evolution characteristics of surface subsidence were examined, and the scientific validity of the models was verified through field monitoring. The research reveals that the inclined section of the working face in shallow coal seam mining forms a trapezoidal hinged arch structure, where stress transmission actually resembles an arch shape. Based on the fracture characteristics of rock strata, this structure can be categorized into three types: a full-trapezoidal hinged arch structure, a semi-trapezoidal hinged arch structure, and a trapezoidal-like hinged arch structure. A mechanical calculation model for the trapezoidal hinged arch structure was constructed, and the mechanical calculation formula for this structure was derived based on mechanical equilibrium conditions. Using a masonry beam mechanical model, the formula for calculating the subsidence of key blocks in the key strata fracture was obtained. Based on the "masonry beam" mechanical model, a formula was derived to calculate the subsidence of key blocks in fractured key strata. The relationship between key strata-bearing structures and surface subsidence curves was analyzed, leading to the development of a calculation model for both. This model reveals the coupled evolution between rock movement and surface subsidence. Field measurements indicate a maximum surface subsidence of 1.93 m, with a subsidence coefficient of 0.65, showing that the surface helps suppress and reduce the overall subsidence. [ABSTRACT FROM AUTHOR]

The East African March–April–May (MAM, "long rains") precipitation decline in recent decades remains a puzzle marked by various proposed large‐scale drivers. Here, the interannual variability of the long rains and their recent drying trend are examined using global model simulations and observations. Comparison of a control simulation and re‐initialized simulations in which land‐surface feedback is suppressed shows that much of the long rains deficit experienced between 1980 and 2014 is synchronized with the warming of the Northwestern Eurasian landmass. In agreement with the modeling results, multiple observational data sets reveal a strong negative correlation between MAM mean East African rainfall amount and the surface temperature over Northwestern Eurasia. Idealized simulations further indicate that warming in Northwestern Eurasia weakens the regional Hadley Cell and diverts the monsoonal transport of moisture away from Eastern Africa toward Europe and southern Africa, highlighting the role of remote land surface warming on the observed precipitation decline. Plain Language Summary: In this article the inter‐annual variability and the observed long‐term decline of Boreal spring rainfall over Eastern Africa are examined. Previous research on the causes of these droughts focused on sea surface temperature variability over tropical oceans. In this work through extensive analysis of observations and global modeling we show that land‐surface feedbacks over Northwestern Eurasia are the primary culprit. More broadly the work highlights the importance of teleconnections between regional climates through remote impacts of land surface feedbacks. Key Points: We demonstrate a co‐variability of East African March–April–May rainfall (long rains) and surface temperature over Northwestern EurasiaAnalysis of model simulations show warming Northwestern Eurasia weakens the local Hadley cell and introduces subsidence over East AfricaThe observed decline in East African March–April–May rainfall observed during 1980–2014 can be explained by this warming [ABSTRACT FROM AUTHOR]

The fluid–solid coupling effect is an important factor which cannot be ignored to study the surface subsidence of deep coal seam mining in the area with abundant underground water. To study the influence of boundary permeability characteristics on surface subsidence in deep near‐horizontal coal seam mining under the effect of fluid–solid coupling, the pore water pressure field, vertical stress field, surface subsidence, and vertical displacement of a rock seam during deep mining under different permeability boundary conditions were analyzed based on fluid–solid coupling theory, taking the 3−1501 working face of Erdos Hongqinghe coal mine as an example. The results revealed that the permeability characteristics of different hydraulic boundaries affected the pore water pressure, vertical stress in the rock layer, and surface subsidence during deep mining. Moreover, the trends of pore water pressure, vertical stress, and surface subsidence of a fixed‐head permeability boundary were largely the same as those under impermeable boundary conditions, but the calculated results of the fixed‐head permeability boundary were lower than those for the impermeable boundary at the same depth. The maximum surface subsidence for the fixed‐head permeable boundary condition and the impermeable boundary condition was 879 and 925 mm, respectively, which were 239 and 285 mm higher than those obtained when the fluid–solid coupling effect was neglected (an increase of 37.3% and 44.5%, respectively). The field monitoring trend for the subsidence basin aligns closely with the subsidence basin trend under the influence of fluid–solid coupling. Considering the constant head permeable boundary conditions in the context of fluid–solid coupling yields accurate surface subsidence results. The results have provided a theoretical basis for the analysis and prediction of coal mining surface subsidence considering the fluid–solid coupling effect. [ABSTRACT FROM AUTHOR]

Research into land subsidence caused by groundwater withdrawal is hindered by the availability of measured heads, subsidence, and forcings. In this paper, a parsimonious, linked data‐driven and physics‐based approach is introduced to simulate pumping‐induced subsidence; the approach is intended to be applied at observation well nests. Time series analysis using response functions is applied to simulate heads in aquifers. The heads in the clay layers are simulated with a one‐dimensional diffusion model, using the heads in the aquifers as boundary conditions. Finally, simulated heads in the layers are used to model land subsidence. The developed approach is applied to the city of Bangkok, Thailand, where relatively short time series of head and subsidence measurements are available at or near 23 well nests; an estimate of basin‐wide pumping is available for a longer period. Despite the data scarcity, data‐driven time series models at observation wells successfully simulate groundwater dynamics in aquifers with an average root mean square error (RMSE) of 2.8 m, relative to an average total range of 21 m. Simulated subsidence matches sparse (and sometimes very noisy) land subsidence measurements reasonably well with an average RMSE of 1.6 cm/year, relative to an average total range of 5.4 cm/year. Performance is not good at eight out of 23 locations, most likely because basin‐wide pumping is not representative of localized pumping. Overall, this study demonstrates the potential of a parsimonious, linked data‐driven, and physics‐based approach to model pumping‐induced subsidence in areas with limited data. [ABSTRACT FROM AUTHOR]

Under Priabonian (latest Eocene) far-field compression, the major Jurassic graben systems and their proximal areas experienced domal uplift in the Netherlands and northeastern Belgium. It has been proposed that this flexural uplift was simultaneous with flexural subsidence of the surrounding areas. This hypothesis is, however, only based on the correlation of few widely spaced boreholes without supporting biostratigraphic or seismic data. For this study, a seismic line and cross-boundary borehole log correlation panel, comprising three biostratigraphically analyzed boreholes, were used to critically examine the abovementioned hypothesis. The seismic line and correlation panel run from the southern flank of the uplifted West Netherlands Basin, also known as the Voorne Trough, towards the south. They both show a gradual thickening of the Priabonian sequences towards the Voorne Trough, confirming the flexural subsidence hypothesis. The underlying Bartonian and overlying lowermost Rupelian units do not share the abovementioned thickness trend, which highlights the particularity of Priabonian basin dynamics. Within the Priabonian depocenter, plenty of reworked organic material was deposited, mostly of Bartonian age, providing further evidence of the simultaneity of subsidence and uplift in nearby regions. We consider it very likely that subsidence and uplift were part of the same vertical surface deformation process. The results of this study are consistent with the mechanism of lithospheric folding under far-field compression by the convergence between Africa and Europe. A Priabonian N-S compressional stress-field would also be consistent with fault, joint and vein analyses performed at the British Isles west of the study area. As the regional stress-field changed around the Eocene–Oligocene boundary, the vertical surface movements of the study area also changed. [ABSTRACT FROM AUTHOR]

Since aquifers deform under applied stresses, it is important to understand the interaction between fluid flow and soil deformation, as the deformation of the solid matrix affects the storage of water in the void space and may reach an extent that causes land subsidence under certain conditions. Geological heterogeneity has a major influence on groundwater movement and can therefore affect the amount of compaction. The aim of this work is, therefore, to perform a stochastic analysis of the influence of the variability of hydraulic conductivity fields on the interaction between excess fluid flow and soil deformation in heterogeneous, deformable porous media. The stress equilibrium equation and the storage equation together form a pair of coupled constitutive equations to describe the interaction of deformation (volume strain) and excess pore fluid pressure head. Using the Fourier–Stieltjes representation approach and a perturbation approximation, the coupled equations are solved analytically in the Fourier space domain for the case of unidirectional excess mean flow. Based on these solutions and the representation theorem, results are obtained for the variances of excess pore fluid pressure head and volume strain. They serve as an index of variability quantification for the evaluation of the variability of the log conductivity field and the compressibility coefficient of the soil on the variability of pressure head and volume strain fields. An illustration of the application of the proposed stochastic theory to predict the excess pore pressure and volume strain under uncertainty is also given. [ABSTRACT FROM AUTHOR]

Accommodation space governs the spatial and temporal distributions of sediments in continental margins. Mapping the sedimentation patterns, therefore, offers insights into the solid‐Earth processes that shape accommodation space. We assembled an unprecedented amount of seismic and borehole data along the Eastern North American Margin and used it to divide the margin's sedimentary package into eight chronostratigraphic intervals, identifying temporal shifts in depocenters under the continental shelf, slope, and rise. The Jurassic depocenters follow the syn‐rift structure and its thermal subsidence loci. The Long Island Platform is the only margin segment where the early post‐rift sediment thickness matches subsidence predictions from uniform‐stretching models, whereas in Georges Bank Basin (GBB) and Baltimore Canyon Trough (BCT), sediment thickness is 1.5–3 times higher than predicted, pointing to other factors at play. A margin‐wide Jurassic transient shoulder uplift is inferred from the occurrence of stratigraphic onlaps above thinned crust. Unlike the Jurassic, the Cretaceous and Cenozoic depocenters disregard the inherited subsidence pattern. The accommodation space over the shelf and coastal plain during the Cretaceous was affected by regional isostatic compensation of the sedimentary loads accumulated on the shelf and rise. Accommodation space development in the GBB was interrupted during the Cretaceous after the margin crossed the Great Meteor Hotspot track, resulting in a widespread permanent uplift, erosion, and sediment redistribution. The distribution of anomalous Neogene subsidence in the BCT challenges previous suggestions of mantle dynamic control on the accommodation space and favors flexural downwarping of the shelf by sediment accumulation on the rise. Plain Language Summary: The volume available for sediment accumulation at continental margins is key for determining where, when and how much sediments are stored. To explore the processes that determine this volume we assembled a broad geological and geophysical data set that covers the US Atlantic margin from Cape Hatteras to the US‐Canada border. Using these data, the margin's sedimentary cover was divided into eight time‐constrained intervals spanning the last ∼190 Myr. The thickness distribution of these intervals was used to investigate the processes that regulated the space available for sediment accumulation. During the first ∼50 Myr of the margin life span, most of the deposition occurred over areas that were thinned and heated during the margin's formation and later cooled and subsided. During this period, the deepest parts of the margin subsided twice as fast as predicted by conventional models whereas the margin's inland rims experienced uplift. Later, subsidence of the coastal plain by basinward sediment loading allowed sediment accumulation. The passage of the margin over a deep‐seated thermal anomaly resulted in uplift and erosion. An anomalous Neogene sediment accumulation on the continental shelf is explained by subsidence inflicted by seaward sediment loading. Key Points: We present a new stratigraphic framework for the post‐rift period of the US Atlantic marginThe syn‐rift shaping of the lithosphere is key for determining accommodation space during the post‐rift periodObserved deviations from passive thermal subsidence patterns resulted from flexure, hot spot passage, flank uplift or mantle dynamics [ABSTRACT FROM AUTHOR]

Through data collection and field investigations of a gold mine-s goaf, a 3D digital model of the mines goaf and roadways was established using 3Dmine software. This model accurately provided information on the actual boundaries and shapes of the goaf at different levels. Based on the comprehensive analysis of goaf conditions and the mine-s production reality, a management plan was proposed. The management strategy includes the following:for goaf groups/collapse pits (above the fourth level) that have interconnected, surface waste rock filling is used; for isolated goafs on the fourth level, forced roof caving through medium-long hole blasting is employed to fill the goaf with waste rock from the surface. In addition, closed-off isolation methods are applied for joint management. For other goafs where mining has ceased and access is no longer possible, the goafs are managed by sealing off the level stone doors. For goafs under mining, filling with in-pit coarse rocks and sealed isolation methods are implemented. Through the integrated application of these various measures, the risk of large-scale ground pressure activities and surface subsidence has been thoroughly eliminated, creating favorable conditions for continued underground production operations. [ABSTRACT FROM AUTHOR]

A sedimentological investigation was carried out to reconstruct the paleogeography of the Zagros Foreland Basin. Based on the study of more than 1 000 rock samples, nine carbonate microfacies and three terrigenous facies were identified. The study reveals that the Maastrichtian succession was deposited in a widespread homoclinal ramp in the High Zagros Basin. Three (Gandom Kar area), two (Ardal area), seven (Gardbishe area), five (Shirmard area), two (Kuh-e-Kamaneh area), three (Kuh-e-Balghar area), and six (Murak area) of depositional sequences (3rd order) were identified. The thickness of the lowstand systems tract (LST) due to activities of local faults and subsidence in the southeast is more than in the central and northwest of the High Zagros Basin during the Early and Early Middle Maastrichtian. During the Middle Maastrichtian, the shallow and deep marine deposits were formed during the transgressive systems tract (TST) and highstand systems tract (HST) in this basin and the rate of subsidence in the center of this basin (Gardbishe area) is higher than in other areas and the platform was drowned in this area. The falling relative sea-level due to activities of local faults led to that marine deposits were absent in all parts of the High Zagros Basin (except the south part) during the Late Maastrichtian. Paleogeographical studies on the Zagros Basin during the Late Campanian–Maastrichtian showed the following results: shallow marine environments were developed in the south-east of this basin, and the turbidite, delta, and fluvial environments in the northwest were developed more than in other areas. [ABSTRACT FROM AUTHOR]

The escalating issue of land subsidence poses a critical threat to the economic prosperity of Indonesia's North Coast in Central Java. This recurring phenomenon intensifies annual tidal floods, posing a severe threat to the infrastructure, buildings, coastal zones, land quality, and the livelihoods of local communities. Effective monitoring of land subsidence rates is essential to mitigate these impacts and implement pre-emptive measures. This study addresses this challenge by employing a two-pronged approach: measuring subsidence rates and assessing susceptibility. Over six years (2016–2021), the research utilizes SAR Sentinel-1 data coupled with machine learning algorithms to achieve these goals. The subsidence rates are generated by the time series InSAR SBAS method. Land subsidence susceptibility assessment uses algorithms such as Random Forest (RF), Gradient Boosted Trees (GTB), Classification and Regression Trees (CART), Support Vector Machine (SVM), Decision Trees with Bagging Method (MD), and K-Nearest Neighbours (KNN). An exhaustive assessment utilizing K-fold cross-validation, incorporating five folds with an 80% training and 20% validation split, effectively facilitates the identification of the model exhibiting the highest accuracy. The findings reveal significant spatial variations in land subsidence rates. Semarang, Pekalongan, and Jepara experienced the highest rates (ranging from − 13 cm/year to -5 cm/year) based on SAR Sentinel-1 data. Machine learning model evaluation yielded Overall Accuracy values of 0.761 (RF), 0.766 (GTB), 0.65 (CART), 0.456 (SVM), 0.359 (KNN), and 0.541 (MD). Based on this analysis, the RF and GTB algorithms are recommended for mapping land subsidence susceptibility. Additionally, the study identified influential factors, with distance from boreholes being the most significant influence. Other notable variables are distance to rivers, rainfall, wetness index, proximity to faults, and distance from residential areas. These valuable insights offer significant benefits to decision-makers and stakeholders, including local governments, urban planners, and disaster management agencies. These findings serve as a foundation for developing a comprehensive policy framework and strategic measures to address land subsidence in this critical region. [ABSTRACT FROM AUTHOR]

Due to a heavy reliance on groundwater, Bangladesh is experiencing a severe decline in groundwater storage, with some areas even facing land subsidence. This study aims to investigate the relationship between groundwater storage changes and land subsidence in Bangladesh, utilizing a combination of GRACE and InSAR technologies. To clarify this relationship from a macro perspective, the study employs GRACE data merged with GLDAS to analyze changes in groundwater storage and SBAS-InSAR technology to assess land subsidence. The Dynamic Time Warping (DTW) method calculates the similarity between groundwater storage and land subsidence time series, incorporating precipitation and land cover types into the data analysis. The findings reveal the following: (1) Groundwater storage in Bangladesh is declining at an average rate of −5.55 mm/year, with the most significant declines occurring in Rangpur, Mymensingh, and Rajshahi. Notably, subsidence areas closely match regions with deeper groundwater levels; (2) The similarity coefficient between the time series of groundwater storage and land subsidence changes exceeds 0.85. Additionally, land subsidence in different regions shows an average lagged response of 2 to 6 months to changes in groundwater storage. This study confirms a connection between groundwater dynamics and land subsidence in Bangladesh, providing essential knowledge and theoretical support for further research. [ABSTRACT FROM AUTHOR]

Objective: The unclear clinical outcomes of two different zero‐profile implants with different number of screws in hybrid surgery restricts the choice of patient‐specific implants. This study aims to compare two different implants on its postoperative subsidence, motion stabilization and clinical outcomes. It also provides references to the most reasonable implant choice in fusion surgery. Methods: This was a retrospective study. From February 2014 to March 2022, 173 patients who underwent hybrid surgery were included. Among them, 122 received surgery with a four screw implant, while 51 received a two screw implant. We analyzed the significance of patient‐specific factors, radiographic factors and clinical outcomes. The Wilcoxon rank sum test, t tests/analysis of variance (ANOVA) test and stepwise multivariate logistic regression were adopted for statistical analysis. Results: No statistically significant difference was observed between the two screw and four screw groups in terms of immediate, middle, and long‐term stability and fusion rate (p > 0.05). However, the two screws group had higher FSU height subsidence at 3, 6, and 12 months postoperatively and higher rates of significant subsidence at three and 6 months postoperatively (p < 0.05). Both groups showed significant clinical improvements at the final follow‐up. Conclusion: Two screw and four screw implants provide comparable stability, fusion rates and clinical outcomes. However, the two screw implant was inferior to the four screw implant in subsidence prevention. Therefore, the two‐screw implant is non‐inferior to the four‐screw implant in most patients. It can be used as the priority choice in the fusion segment by its easy manageability. However, the patients with a high risk of subsidence such as multilevel surgery, the elderly, lower BMD, bad cervical alignment should receive a four screw implant rather than a two screw implant. [ABSTRACT FROM AUTHOR]

During boreal summer, large scale subsidence and a persistent northerly flow, known as the Etesians, characterize the tropospheric circulation over the eastern Mediterranean. The Etesians bring clear skies and alleviate the impact of heat waves over the region. The intraseasonal variability of the Etesians and subsidence over the eastern Mediterranean has been thought to be influenced by the South Asian monsoon and atmospheric processes over the North Atlantic. Here, we employ causal effect networks and causal maps, obtained by applying the Peter and Clark Momentary Conditional Independence (PCMCI) causal discovery algorithm, to identify causal precursors of Etesians. We find that both wave train activity over the North Atlantic/North American region and convective activity over South Asia associated with the Indian summer monsoon (ISM) are causally related to the Etesians at 3-day time scale. Thus, intraseasonal ISM variability affects the eastern Mediterranean circulation, though its influence is conveyed via a Middle East ridge. On longer weekly time scale, the mid-latitude influence weakens, while the influence of the tropical convective activity via the Middle East ridge remains stable. Moreover, the heat low over the Arabian Peninsula, a feature strongly responsible for the development of the Etesians, is caused by a stronger Middle East ridge and not by North Atlantic wave activity. Finally, we discuss potential implication for circulation changes in the eastern Mediterranean due to anthropogenic global warming. [ABSTRACT FROM AUTHOR]

Purpose: To compare clinical and radiographic outcomes of propensity-matched patients undergoing THA using standard versus high offset stems at five years. Methods: The authors retrospectively reviewed a consecutive series of primary THAs performed between 01/09/2015–31/12/2017 using a fully-hydroxyapatite coated collared stem, with either a standard (n = 365) or high (n = 110) offset. Outcomes collected included: modified Harris Hip Score (mHHS), Oxford Hip Score (OHS), Forgotten Joint Score (FJS), and radiographic measurements including limb length discrepancy (LLD), stem subsidence, and stem radiolucencies. Results: Propensity score matching resulted in 80 hips per group. Preoperatively there were no significant differences in patient demographics, surgical data and radiographic measurements, except the standard offset group had significantly smaller femoral (40.0 ± 7.5 vs 48.4 ± 6.2, p < 0.001), acetabular (92. ± 6.3 vs 94.8 ± 7.3, p = 0.011) and global (132.0 ± 10.3 vs 143.2 ± 8.2, p < 0.001) offsets compared to the high offset group. At a minimum five years follow-up, there were no significant differences in mHHS (93.2 ± 11.0 vs 93.1 ± 10.6, p = 0.553), OHS (45.1 ± 4.1 vs 45.3 ± 4.6, p = 0.623), and FJS (85.1 ± 19.3 vs 82.7 ± 23.0, p = 0.910). There were also no differences in radiographic measurements, including LLD (1.5 ± 4.8 vs 1.1 ± 3.5, p = 0.537), stem subsidence (0% vs 0%, p = 1.000), and stem radiolucencies (severe: 6% vs 1%, p = 0.152). Conclusion: The present matched-cohort study found no significant differences between standard versus high offset straight fully-hydroxyapatite coated collared stems for primary THA in terms of clinical and radiographic outcomes at five years. These findings may suggest that uncemented collared high offset stems are not associated with an increased risk of radiolucencies and loosening compared to uncemented collared standard offset stems. [ABSTRACT FROM AUTHOR]

Global climate change highlights the significance of renewable clean energy. Geothermal energy from oilfields is abundant and can be utilized for residential heating and oil transportation. However, unreasonable heat exchange methods lead to groundwater level decline. Differences and delays between water extraction and reinjection inevitably cause land subsidence, hindering the sustainable utilization of geothermal energy resources. It is crucial to effectively monitor large-scale ground surface deformation characteristics in geothermal fields. In the research, 55 Sentinel-1A images from October 2018 to May 2022 were collected, and the ground deformation of Caofeidian new district in Bohai Bay Basin, where Nanpu Oilfield is located, in North China, was inverted by short baseline subsets-interferometric synthetic aperture radar (SBAS-InSAR) technology. The maximum subsidence velocity in Caofeidian new district exceeded 50 mm/year. Since April 2019, there has been concentrated ground subsidence in the Caofeidian new district, with a maximum cumulative subsidence exceeding 50 mm. The maximum cumulative subsidence exceeded 150 mm by May 2022. Combined with pumping and recharging tests near heating project in Caofeidian new district, the temporal subsidence mechanisms were revealed. The water extraction from the thermal reservoir caused drainage consolidation of the strata, triggering rapid subsidence in November. In April, discrepancy between water extraction and reinjection flow rate in thermal reservoir caused drainage consolidation of the strata, further exacerbating the subsidence trend. During rainy seasons, despite water reinjection and groundwater replenishment from precipitation, the strata in the Caofeidian new district underwent irreversible plastic deformation, with a slow rebound process, lagging behind urban areas without geothermal development by one month. InSAR is a reliable technology for understanding the ground deformation process in geothermal fields. Clarifying the subsidence mechanisms guides the selection of water-heat exchange methods, ensuring the sustainable development of geothermal resources. [ABSTRACT FROM AUTHOR]