Rising Groundwater Levels Research Articles

An Analysis of Rainfall-Derived Infiltration and Inflow Using Water Level-to-Flow Conversion

During rainfall, the rise in groundwater levels, coupled with defects in pipe connections and manhole joints, increases Rainfall-Derived Infiltration and Inflow (RDII) in separate sewer systems. This results in exceedances of planned wastewater volumes and a surge in Separate Sewer Overflows (SSOs). To implement effective measures in the sewer system, it is crucial to monitor the long-term sewage flow under both dry and wet weather conditions to identify RDII sources within the sub-basins. However, because of the cost disparity between installing flow meters and water-level sensors, many municipalities opt for the latter, which is more economical but limits the accuracy of flow measurement. Therefore, this study developed a methodology to estimate flow rates based on measured water-level data, which were validated using adjacent flow measurement data. This water level-to-flow conversion method is expected to be utilized through the installation of water-level sensors owing to their ease of deployment, in addition to budgetary constraints that limit the use of flow meters. This approach enables the application of water-level data for flow estimation.

Investigating steeply inclined abandoned mines for unlocking the secrets of water level recovery

With the growing emphasis on environmental protection, many coal mines in northern China were closed. However, the cessation of pumping operations in those closed mines has caused a rise in groundwater levels, giving rise to various safety and environmental concerns. Understanding the patterns of water level recovery is vital for effectively managing abandoned mine sites and ensuring the uninterrupted production of adjacent coal mines. While the groundwater hazards in goaf areas have been extensively studied by scholars, there is a notable scarcity of research on water level recovery in closed coal mines. To address this knowledge gap, this study focuses on investigating the water level recovery patterns in abandoned mine sites, using the Zhaogezhuang Mine as a case study. Based on these research findings, we will conduct future studies of the impact of water level recovery on local communities, the ecological environment, and the geological environment.

SBAS DInSAR and in situ monitoring of the Šumljak landslide (SW Slovenia) dynamics driven by rainfall and piezometric-level fluctuation

AbstractThis paper presents the first attempt at establishing the dynamics of the Šumljak debris slide by using a multidisciplinary approach, including long-term inclinometer and piezometer measurements and a time-series analysis of SAR images for displacement vector estimation. The Šumljak landslide is located in the Rebrnice area, SW Slovenia, where the regional highway Razdrto-Nova Gorica runs through and poses a threat to the highway viaduct’s stability. By combining both ascending and descending Sentinel-1 data, we have estimated 3D displacement vectors for the landslide, providing insights into the usability of the technique for this kind of slow-moving landslides. Furthermore, we have combined and compared the SBAS DInSAR results to the displacements measured by inclinometer to evaluate the rate of displacement of the landslide and the viaduct. The inclinometer measurement results show that the landslide has a single sliding plane between the flysch colluvium and the slope deposits and provide the proof of the enlargement of the sliding area above its main scarp. The displacement vectors are spatially heterogenous, suggesting that different sites have different velocities and slightly different directional vectors. These results partly comply with the InSAR results. We further discussed the estimated vectors of displacement and the possible mechanism of movements. By using the piezometric data, we studied the groundwater level fluctuation in relation to daily rainfall and its influence on the displacements. Our findings show a correlation between the movements and the wet/dry season, indicating that the landslide is driven by rainfall and consequently groundwater level fluctuation. In 2020, the groundwater level rise was smaller than in the years before due to less rainfall, resulting in lower velocity of the landslide (5.5 mm/year) than in 2019 (7 mm/year).

Study on the deformation mechanism of chair-like bedding rock landslides under the coupling effect of geological and hydrological factors

Chair-like bedding rock landslides are prevalent in the Three Gorges Reservoir area (TGRA), necessitating further investigation into their inducing mechanisms. This study focuses on the Muyubao and Tanjiahe landslides, conducting a comparative analysis of their deformation characteristics and mechanisms while comprehensively considering geological and hydrological factors. The findings indicate that the Muyubao landslide was primarily triggered by the combined effects of rainfall during the water storage period and the rise of the reservoir water levels (RWL), with a threshold of approximately 165 m. In contrast, the Tanjiahe landslide was influenced by a rapid drawdown in RWL, heavy rainfall, and a high RWL, with a threshold of around 175 m. Both landslides exhibited a clear response to the rise in groundwater levels in the steep sections, with significant deformation occurring when groundwater levels reached 175 m (Muyubao landslide QSK1) and 245 m (Tanjiahe landslide QSK2). Notably, variations in landslide morphology, permeability coefficients, and fluctuations in groundwater levels can facilitate the mutual conversion between different landslide types (seepage-driven and buoyancy-driven). To investigate the influence of chair-like slope morphology on landslides, eight landslide models were constructed, featuring a range of dip angles for the rock formation (15° to 30°) and varying length ratios of gentle to steep sections (2:8 to 5:5). The UDEC Code was employed to simulate and analyze the governing effects of slope morphology on landslide deformation and evolution. Through a comparative analysis of the Muyubao, Tanjiahe, Jiuxianping, and Qianjiangping landslide cases, we examined the significant influence of landslide morphology and permeability coefficients on landslide behavior. The results indicate that the length ratio of gentle to steep section is a crucial parameter. When this ratio exceeds 2:8, the landslide is characterized by pushing deformation; conversely, when the ratio is lower, it tends to exhibit overall movement. Additionally, geological factors affect groundwater seepage and water level variation under the influence of rainfall and reservoir water, resulting in distinct deformation characteristics and mechanisms across different landslide types. Factors such as slope angle and the length of the gentle section influence the extent of the submerged area, leading to varied landslide responses to rise of the RWL.

Waterlogging, rising groundwater levels and flooding of dry pastures and meadows on Hailuoto Island (Finland) and ways to solve the problems

Waterlogging, rising groundwater levels and flooding of dry pastures and meadows on Hailuoto Island (Finland) and ways to solve the problems

Groundwater Response to Snowmelt Infiltration in Seasonal Frozen Soil Areas: Site Monitoring and Numerical Simulation

Spring snowmelt has a significant impact on the hydrological cycle in seasonally frozen soil areas. However, scholars hold differing, and even opposing, views on the role of snowmelt during the thawing period in groundwater recharge. To explore the potential recharge effects of spring snowmelt on groundwater in seasonal frozen soil areas, this study investigated the vadose zone dynamics controlled by soil freeze–thaw processes and snowmelt infiltration in the Northeast of China for 194 days from 31 October 2020 to 12 May 2021. Responses of groundwater level and soil moisture to snowmelt infiltration show that most snowmelt was infiltrated under the site despite the ground being frozen. During the unstable thawing period, surface snow had already melted, and preferential flow in frozen soil enabled the recharge groundwater by snowmelt (rainfall), resulting in a significant rise in groundwater levels within a short time. The calculated and simulated snowmelt (rainfall) infiltration coefficient revealed that during the spring snowmelt period, the recharge capacity of snowmelt or rainfall to groundwater at the site is 3.2 times during the stable thawing period and 4.5 times during the non-freezing period.

Physical Model Experiments and Numerical Simulation Study on the Formation Mechanisms of Landslides on Gently Inclined Loess–Bedrock Contact Surfaces—A Case Study of the Libi Landslide in Shanxi Province

Landslides on gently inclined loess–bedrock contact surfaces are common geological hazards in the northwestern Loess Plateau region of China and pose a serious threat to the lives and property of local residents as well as sustainable regional development. Taking the Libi landslide in Shanxi Province as a case study (with dimensions of 400 m × 340 m, maximum thickness of 35.0 m, and volume of approximately 3.79 × 104 m3, where the slip zone is located within the highly weathered sandy mudstone layer of the Upper Shihezi Formation of the Permian System), this study employed a combination of physical model experiments and numerical simulations to thoroughly investigate the formation mechanism of gently inclined loess landslides. Via the use of physical model experiments, a landslide model was constructed at a 1:120 geometric similarity ratio in addition to three scenarios: rainfall only, rainfall + rapid groundwater level rise, and rainfall + slow groundwater level rise. The dynamic changes in the water content, pore water pressure, and soil pressure within the slope were systematically monitored. Numerical simulations were conducted via GEO-STUDIO 2012 software to further verify and supplement the physical model experimental results. The research findings revealed that (1) under rainfall conditions alone, the landslide primarily exhibited surface saturation and localized instability, with a maximum displacement of only 0.028 m, which did not lead to overall instability; (2) under the combined effects of rainfall and rapid groundwater level rise, a “sudden translational failure mode” developed, characterized by rapid slope saturation, abrupt stress adjustment, and sudden overall instability; and (3) under conditions of rainfall and a gradual groundwater level rise, a “progressive translational failure mode” emerged, experiencing four stages: initiation, development, acceleration, and activation, ultimately resulting in translational sliding of the entire mass. Through a comparative analysis of physical model experiments, numerical simulation results, and field monitoring data, it was verified that the Libi landslide belongs to the “progressive translational failure mode”, providing important theoretical basis for the identification, early warning, and prevention of such types of landslides.

Storm surge, seawater flooding, and sea-level rise paradoxically drive fresh surface water expansion

Abstract Coastal storms and sea-level rise (SLR) are expected to increase seawater flooding in low-elevation coastal zones. High sea levels and seawater flooding can drive groundwater table rise via ocean-aquifer connections. These dynamics are often overlooked but can cause groundwater flooding and salinization hazards, increasing freshwater security challenges for coastal communities and driving ecosystem transgressions. Field data and numerical modeling were used to evaluate how heavy rainfall, storm surge, and seawater flooding and infiltration during Hurricane Fiona (September 2022) and projected SLR impact groundwater levels, inland surface waters, and saltwater intrusion on Sable Island National Park Reserve, Canada. During the passage of Hurricane Fiona, precipitation increased groundwater and pond levels before seawater flooded the beach. Seawater flooding and infiltration caused a sharp rise in beach groundwater levels, which in turn caused inland pond levels to rise without coincident direct inputs from precipitation or seawater. Model simulations reveal that seawater infiltration on beaches flooded the subsurface and drove the observed inland groundwater rise and freshwater pond expansion. Simulations of projected SLR show that seawater flooding will only inundate a small area of land along the coast; however, inland groundwater rise and flooding, which is less well-studied, may inundate up to 30 times more land area. Further, groundwater flooding driven by rising sea levels decreases hydraulic gradients and increases saltwater intrusion via freshwater lens (FWL) contraction. Findings demonstrate that seawater flooding from coastal storms and SLR paradoxically cause concurrent fresh surface water expansion but FWL contraction. This study provides new insights into the spatiotemporal dynamics of island freshwater resources and highlights that unseen and often overlooked groundwater-surface water exchanges are critical to consider when evaluating coastal flooding and groundwater salinization hazards and management strategies for low-elevation coastlines.

Assessing Potential Groundwater Storage Capacity for Sustainable Groundwater Management in the Transitioning Post‐Subsidence Metropolitan Area

AbstractMany major cities worldwide have inevitably experienced excessive groundwater pumping due to growing demands for freshwater in urban development. To mitigate land subsidence problems during urbanization, various regulations have been adopted to control groundwater usage. This study examines the transition in the post‐subsidence stage, especially in metropolitan areas, to adaptively adjust subsidence prevention strategies for effective groundwater management. Taking the Taipei Basin as an example, historical data reveals significant subsidence of more than 2 m during early urban development, with subsidence hazards largely mitigated over decades. However, the rising groundwater level poses a risk to the stability of engineering excavations. In this study, 29 X‐band Cosmo‐Skymed constellation (CSK) images were utilized with the Persistent Scatterer InSAR (PSInSAR/PSI) technique to monitor surface displacements during the construction of the Mass Rapid Transit system. Correlating groundwater levels helps identify the heterogeneous hydrogeological environment, and the potential groundwater capacity is assessed. PSI time‐series reveal that approximately 2 cm of recoverable land displacements correspond to groundwater fluctuations in the confined aquifer, indicative of the typically elastic behavior of the resilient aquifer system. The estimated groundwater storage variation is about 1.6 million cubic meters, suggesting this potential groundwater capacity could provide available water resources with proper management. Additionally, engineering excavation safety can be ensured with lowered groundwater levels. This study emphasizes the need to balance groundwater resource use with urban development by adjusting subsidence prevention and control strategies to achieve sustainable water management in the post‐subsidence stage.

Integrated GIS-hydrologic-hydraulic modeling to assess combined flood drivers in coastal regions: a case study of Bonita Bay, Florida

Flooding poses a severe global threat, necessitating advanced methodologies to assess and manage its risks effectively. This study introduces a novel approach that integrates Geographic Information System (GIS) with hydrologic-hydraulic modeling to evaluate the combined drivers of current and future flood risks. The method is applied to the development Bonita Bay in southwest Florida. It occurs in a region highly susceptible to flooding due to its low elevation and proximity to tidal waters. The innovative integration of GIS with hydrologic-hydraulic models enables detailed assessment and visualization of flood inundation areas under multiple flood drivers including design storms, land use changes, groundwater rise, and sea-level rise. This allows for the seamless simulation of complex flood interactions with only minor adjustments to the model for the identified drivers. The results indicate significant increases in initial water storage caused by sea and groundwater level rise and amplified storm runoff from land use changes. A 2% increase in flooded areas is projected with stronger design storms, and a 5% increase by 2,100 compared to 2024. This approach provides a robust framework for developing tailored flood mitigation strategies and can be adapted to various coastal regions globally.

Groundwater dynamics clustering and prediction based on grey relational analysis and LSTM model: A case study in Beijing Plain, China

Study regionBeijing Plain, China Study focusThe traditional zoning of groundwater systems relies on lithological characteristics and hydraulic connections. However, the influence of climate change and human activities has led to the emergence of diverse dynamic patterns within these systems. Additionally, the differences in groundwater dynamic characteristics are often ignored when modeling with machine learning methods. In this study, a new clustering method named GRA-CLU was proposed to classify dynamic types of groundwater. Then, regional models are built using LSTM based on the dynamic zoning, aiming to incorporate hydrogeological significance into the pure data-driven model.New hydrological insights for the region: The GRA-CLU method classified the study area into six groundwater dynamic types. Compared with the traditional hydrogeological units, the new zoning result identified two dynamic types that have never been considered: urban influence zone and mountain-plain junction zone where surface water interacts with groundwater. Through analysis, the significant rise of groundwater levels in 2021 was more influenced by heavy rainfall events rather than human activities. This study further explored the performance of LSTM regional models based on the six dynamic zones. The results indicated that the NSE of models increased by 5.7–50.0 %, the improvement was more obvious in zones with irregular fluctuations. The RMSE decreased by 31.5–59.8 %, particularly noticeable in zones with regular annual fluctuations and large samples.

Analysis of the Response of Shallow Groundwater Levels to Precipitation Based on Different Wavelet Scales—A Case Study of the Datong Basin, Shanxi

The rise in shallow groundwater levels is typically triggered by precipitation recharge, exhibiting a certain lag relative to precipitation changes. Therefore, identifying the response mechanism of shallow groundwater levels to precipitation is crucial for clarifying the interaction between precipitation and groundwater. However, the response mechanism of groundwater levels to precipitation is complex and variable, influenced by various hydrogeological and geographical conditions, and often exhibits significant nonlinear characteristics. To address this issue, this study employs methods such as continuous wavelet transform, cross wavelet transform, and wavelet coherence to analyze the response patterns of groundwater levels to precipitation at different wavelet scales in the Datong Basin from 2013 to 2022: (i) At short wavelet scales (10.33~61.96 d), the groundwater level dynamics respond almost instantaneously to extreme rainfall; (ii) At medium wavelet scales(61.96~247.83 d), the precipitation-groundwater recharge process shows characteristics of either rapid recovery or significant delay; (iii) At long wavelet scales (247.83~495.67 d), three potential groundwater processes were identified in the Datong Basin, exhibiting long-term lag responses throughout this study period, with lag times of 11.18 days, 148.75 days, and 151.49 days, respectively. Furthermore, the results indicate that the lag response time of shallow groundwater levels to precipitation is not only related to the wavelet scale but also to the identified depth conditions of different groundwater regions, groundwater extraction intensity, precipitation intensity, and aquifer lithology. This study distinguishes the temporal and spatial response mechanisms of shallow groundwater to precipitation at different wavelet scales, and this information may further aid in understanding the interaction between precipitation and groundwater levels.

Groundwater level rise and geological structure influences on land deformation dynamics: insights from managed aquifer recharge operations in Beijing, China

Groundwater level rise and geological structure influences on land deformation dynamics: insights from managed aquifer recharge operations in Beijing, China

Sustainable groundwater regulation in typical irrigation areas of inland river basins based on ecological indicators and the MIKE-SHE hydrological model

Study regionThe study area is located in the Nukus irrigation area on the lower reaches of the Amudarya River in Uzbekistan. Study focusThe extensive agricultural land development has introduced a substantial amount of water resources into the irrigation area, leading to a significant rise in regional groundwater levels. Quantifying regional groundwater resource issues and achieving sustainable groundwater management under conditions of high spatiotemporal heterogeneity are key scientific issues for regional ecological protection. Thus, this study used the concept of ecological water level to quantify groundwater issues, used the MIKE-SHE hydrological model to conduct scenario simulations, formulated and subsequently evaluated a groundwater regulation plan with spatiotemporal attributes. New hydrological insights for the regionRegional sustainable development groundwater level should be within the range of 1.78–2.78 m. During the irrigation and non-irrigation periods, the groundwater levels in approximately 84.3 % and 72.2 % of the study area respectively exceeded the upper and lower ecological water level limits. Under the background of gradually increasing groundwater fluctuations, it will pose a serious threat to regional ecology. Therefore, this paper established a monthly-scale groundwater zoning control plan, which can make the area of regional groundwater within the ecological water level reach 87.53 %. All research not only contributes to the protection of the local ecological environment but also provides valuable insights for water resources management in other regions.

A multi-objective optimization and evaluation framework for LID facilities considering urban surface runoff and shallow groundwater regulation

Currently, the goals of sponge city construction mostly focus on urban surface water, with few considerations of groundwater indicators, and there is a lack of simulation methods that consider the interaction between surface water and groundwater under low impact development (LID) scenarios. Taking a sponge campus in Xi'an as the research object, this paper proposes a method to realize the interaction between surface water and groundwater at different spatial and temporal scales, so as to construct a SWMM-MODFLOW coupled numerical model to carry out the analysis of hydrological effect of sponge city comprehensively taking into account both surface water and groundwater. Simultaneously, the SWMM is coupled with the NSGA-III algorithm for multi-objective optimization of LID facility configurations, aiming to identify a globally optimal solution set for LID facility configurations under both long and short-duration rainfall scenarios. A novel framework for a comprehensive evaluation system of surface water-groundwater benefits is also developed to comprehensively assess LID facility optimization schemes that meet the goals of stormwater runoff infiltration and reduction, pollution interception and purification, and groundwater recharge conservation. The simulation results show that after optimization, the LID scheme has good surface runoff regulation effects and pollution reduction capabilities, reducing the runoff peak from 2.297 m3/s to 2.128 m3/s, significantly lowering the risk of inundation and effectively reducing the total suspended solids (SS) load by 42.38 kg at the outfall. Meanwhile, the groundwater recharge effect is particularly significant in September. Compared to the baseline scenario, the average groundwater levels from June to September were raised by 3.966 cm, 5.120 cm, 6.743 cm, and 7.639 cm, respectively. The maximum daily groundwater level rise reached 7.82 cm, while the average groundwater level for the whole year of 2023 increased by 2.61 cm. The maximum transport area of pollutants decreased from 2359.44 m2 to 1796.54 m2, and the maximum transport distance reduced from 79.985 m to 69.977 m. Additionally, the central concentration of pollutants also decreased. This optimization evaluation framework will aid decision-makers in selecting LID facility management strategies that balance the dual benefits of surface water runoff and groundwater regulation.

NON-DESTRUCTIVE METHODS OF ESTABLISHING A CAUSE-AND-EFFECT RELATIONSHIP BETWEEN WATER SUPPLY NETWORK ACCIDENTS AND THE CONDITIONS FOR PRESERVING ARCHITECTURAL HERITAGE

Accidents on water supply networks have the most significant negative consequences on the state of the historical and architectural heritage, which was formed over many centuries. The paper analyzes the cause-and-effect relationship between accidents of water-carrying networks and the conditions of architectural heritage preservation using the example of the Kyiv-Pechersk Lavra. The results of determining waterlogging zones and their factors by non-destructive monitoring methods on the territory of the Metropolitan Garden of the Upper Lavra are given. This area combines complex engineering and geological conditions and technogenic mastering, creating conditions for developing dangerous engineering and geological processes and emergency situations. In terms of danger, the garden’s territory belongs to unstable areas for preserving historical monuments of the UNESCO world heritage. The last accident on the water supply networks occurred in October 2022. It caused sinkholes on the surface, rising groundwater levels, significant destruction of an underground structure of historical importance – the Metropolitan Cellar. The research was carried out using the methods of electrotomography and natural electric field. The results of electrotomography were interpreted using two- and three-dimensional models. The existence of an anomalous dome (soils of low resistance), which is observed in the central part of the site, is probably the focus of waterlogging of the soil massif as a result of an accident on the heating network. The analysis of the adapted 3D model based on the results of non-destructive methods of monitoring the geological environment made it possible to indirectly establish the places of unsatisfactory technical condition of engineering networks (cold water supply), where a wetted section with low values of apparent resistance was recorded. Research has confirmed the presence of an inflow of man-made waters (leaks) from main water supply networks in the western part of all profiles as a constant source and factor of waterlogging of the array of soil bases of architectural monuments – Monastyrski walls, Kushnyka tower, etc. Based on the research results, the need to develop compensatory measures to strengthen part of the fortress walls was proposed, and a safe distance for moving networks from historical objects was substantiated to preserve them.

Influencing Factors, Design Methods, and Buoyancy Reduction Measures for Basement Anti-Flotation Engineering

Basement anti-flotation design is crucial in modern urban construction. An increase in groundwater buoyancy can cause basement structures to uplift, leading to structural instability or even damage. To ensure the stability and safety of underground structures under various hydrogeological conditions, anti-flotation design must comprehensively consider factors such as construction, design, supervision, structure, and hydrology. During construction, improper dewatering measures or unreasonable construction progress may lead to an abnormal rise in groundwater levels, increasing the risk of anti-flotation. Design considerations must include sufficient safety margins, supervision must fully recognize the impact of groundwater, and the structural dead load must be adequate. Anti-flotation stability verification includes both overall and local anti-flotation, involving the calculation of groundwater buoyancy, structural self-weight, and overburden, and selecting appropriate anti-flotation stability safety factors. The assessment and selection of the anti-flotation design water level are also critical. Common anti-flotation measures include adding counterweights, tension-resistant piles, compression and tension-resistant piles, and hydro-pressure reduction methods, while reinforcement and repair methods include epoxy resin grouting and steel plating reinforcement. Through systematic analysis and comprehensive research, scientific basis and technical support are provided for anti-flotation design, enhancing design efficiency and reliability and ensuring the safety and stability of underground spaces. Future research will develop more accurate calculation methods, improve design standards, and explore new anti-flotation technologies and materials.

Causes of the Groundwater Levels Rise in the Absheron Peninsula and the Ways of its Regulation

In connection with the growth of Baku city and its adjacent regions located in the Absheron Peninsula, this territory is the most densely populated part of our republic. The waste from industrial enterprises and oil and gas fields, a significant part of which is also located within the Peninsula, has a negative influence on the ecological situation of the studied area. This article provides an overview of the hydrogeological conditions of various areas of the object under study and identifies changes in the level of groundwater in these areas while establishing the reasons for its rise. Physical and chemical analyses of water samples taken from drilled wells and dug wells throughout the region were carried out. The reasons for the increase in the level of underground water were established, which lead to flooding, swamping, and recurrent salinization of the soil in the Absheron Peninsula. Measures and recommendations were developed to restore the ecological balance of the study area. In addition, groundwater, phreatimetric data, and water reservoir strikes in cities, villages, and settlements located on the peninsula were studied. The physico-chemical composition of underground waters and their mineralization levels were studied in laboratory conditions. The groundwater levels in drilled and dug wells across the peninsula were established and compared with data from historical records and literature. The studies conducted allowed for the evaluation of the suitability of groundwater for various national and economic uses. It has been established that, simultaneously with natural factors, anthropogenic factors have had a significant influence on the rise in the level of groundwater, including the absence of central sewage and drainage systems, the discharge of water from industrial enterprises, and household water, among others. To eliminate the environmental emergency, it is recommended to carry out priority temporary measures in some areas of the Absheron Peninsula at the initial stage.

Experimental study on controlling basement leakage for urban flooding mitigation

Intense summer rainstorms can result in short-term urban flooding, leading to localized groundwater level rise and subsequent floor cracking and leakage in basements. Rational control of the surrounding water level is crucial for addressing existing basement leaks caused by short-term urban flooding. In this study, a combined approach of interception and seepage control using waterproof curtains and negative-pressure wells is proposed. Four different scenarios were considered, and experimental and numerical investigations were conducted on a 1.2 m × 1.2 m × 1.1 m model. The study analyzed the influence of factors such as water content, pore water pressure, soil properties, waterproof curtain insertion depth, and length of the filter section in the negative-pressure well on controlling the upward water level in the basement.The results showed that the installation of waterproof curtains alone can impede rainwater infiltration into the basement, delaying its penetration by approximately 48 h. The combined approach of interception and seepage control outperformed the sole use of waterproof curtains, with the reduction in water level becoming smaller as the insertion depth of the waterproof curtain increased. The reduction in water level decreased at a slower rate with increasing waterproof curtain insertion depth. The recommended waterproof curtain insertion ratio was equal to or greater than 83.5 %, while the filter section length ratio in the negative pressure well should be less than 64 %. Compared to natural seepage drainage, negative-pressure pumping could maintain the basement floor's water content within the initial range 32 h earlier. The water-blocking and depressurization effect is best in sandy soil and worst in clay. Water-blocking and depressurization provide a new approach for controlling the uplift caused by summer urban waterlogging, especially offering a new method for controlling leaks in the basement.

Hydrochemical Evolution Process and Mechanism of Groundwater in the Hutuo River Alluvial Fan, North China

Due to extensive groundwater exploitation, a groundwater funnel has persisted in the Hutuo River alluvial fan in Shijiazhuang since the 1980s, lasting nearly 40 years and significantly impacting the groundwater chemical characteristics. In this study, based on the groundwater level and chemistry data, the hydrochemical evolution processes and mechanisms of the groundwater during the 1980 groundwater funnel period and the post-2015 artificial governance period were investigated using traditional hydrogeochemical methods and inverse hydrogeochemical simulations. The results show the following: (1) The ion concentrations gradually increased along the groundwater flow path, where they displayed a pattern of lower levels in the northwest and higher levels in the southeast. From 1980 to 2021, the concentrations of major ions were increased. (2) In 1980s, the groundwater hydrochemical type predominantly exhibited HCO3—Ca. From 1980 to 2015, the hydrochemical types diversified into HCO3·Cl—Ca, HCO3—Ca·Mg, and HCO3·SO4—Ca types. Following the artificial governance, the groundwater level rise led to an increase in the concentrations of SO42− and Mg2+. Post-2015, the prevailing hydrochemical type changed to HCO3·SO4—Ca·Mg. (3) The changes in the groundwater level and ion concentrations were quantitatively strongly correlated and exhibited spatial similarity. (4) In the 1980s, the groundwater hydrochemical composition was primarily controlled by the dissolution of albite, dolomite, halite, and quartz; reverse cation exchange; and groundwater exploitation. Since 2015, the hydrochemical composition has mainly been influenced by the dissolution of albite, calcite, and quartz; positive cation exchange; river–groundwater mixing; and industrial activities, with increasing intensities of both water–rock interactions and human activities.