Groundwater Level Research Articles

Exploring AI approaches for predicting groundwater levels in coastal agro-climatic zones: a case study in Cuttack District, Odisha

Groundwater level (GWL) prediction across various time scales is essential for efficient management and governance of water resources especially in regions characterized by arid and semi-arid climates, and it holds great significance. Within certain coastal regions, agro-climatic zones give rise to challenges like water scarcity in summer and waterlogging during the rainy season, resulting in reduced GWL during scarcity periods and saltwater intrusion that contaminates groundwater. This study emphasizes on application of diverse AI methodologies, encompassing Artificial Neural Networks (ANN), Adaptive Neuro-Fuzzy Inference Systems (ANFIS), Support Vector Regression (SVR), Long Short-Term Memory (LSTM), and Wavelet Transform-based ANN (W-ANN), ANFIS (W-ANFIS), SVR (W-SVR), and LSTM (W-LSTM) models for quantitative assessment of groundwater in Odisha's Cuttack District, aiming to comprehend GWL fluctuations across the region. The investigation leverages historical groundwater data from monitoring wells, incorporating monthly datasets of rainfall, temperature, relative humidity, and GWLs. Through comparative assessment using statistical methods namely Pearson’s R (R), co-efficient of determination (R2), Root Mean Squared Error (RMSE), and Sum of Squared Error (SSE), the most precise and robust AI approach for groundwater estimation in the area is identified. The W-LSTM (R2-0.78196, RMSE- 0.09254, R-0.88428 and SSE-2.66357) and W-ANFIS (R2-0.74068, RMSE-0.08229, R-0.86063 and SSE-2.10596) hybrid algorithms consistently achieved the most accurate predictions for GWLs followed by W-SVR, W-ANN hybrid models and LSTM and ANN for all stations. Overall, this study demonstrated promising outcomes, offering a dependable foundation for water resources planners to guide future investigations into groundwater resources.

Multiparametric stations for real-time monitoring and long-term assessment of natural hazards

The present work would like to illustrate a new concept of multiparametric stations to characterize the crustal fluids-tectonic interaction in specific geological contexts. The dynamics of crustal fluids in relation to tectonics is a complex and sometimes intricate issue. Several factors act and mutually influence themselves, so that in each tectonic and geological context they follow a specific behavior, and a comprehensive cause-effect rule is hard to find. Changes in water chemistry and levels and in soil flux regimes (e.g., CO2, CH4, radon) are just a few examples well documented in the literature as being pre-, co- and post-seismic modifications as well as being markers of the local tectonic stress acting in the crust. A regional study combined with a long-lasting multiparametric monitoring is needed to prepare to a seismic sequence in a given place. The field infrastructure was set up starting from the end of 2021, and multiparametric stations have been installed in correspondence of active seismogenic sources initially located in Northern Italy. Data are transmitted in real-time and archived in an ad hoc developed relational database. Monitoring is mainly focused on groundwater parameters (water level, temperature, and electrical conductivity) of aquifers showing distinct degrees of confinement and lithologies. Sites are also equipped of meteorological sensors (pressure, temperature, rain, humidity, wind speed and direction), radon sensors and surface and borehole seismic stations providing accelerometric and velocimetric data. A mud volcano field is also monitored and holds the installation of a permanent CO2 soil flux station. A statistical analysis working flow is also proposed for a preliminary evaluation of the acquired time-series. In particular, a couple of tools to detect, and thus filter, anthropogenic and meteorological effects on a groundwater level series is described. We wish to provide a model of approach to analogous study cases in other potentially seismic areas.

Ground Deformation Monitoring Using InSAR and Meteorological Time Series and Least-Squares Wavelet Software: A Case Study in Catania, Italy

Abstract. Persistent Scatterers Interferometric Synthetic Aperture Radar (PS-InSAR) is an advanced satellite remote sensing technique which allows an effective monitoring of ground movement. In this work, PS-InSAR time series as well as precipitation and temperature time series in a region in Catania, Italy are utilized during 2018–2022, and their possible interconnections with land subsidence/uplift due to groundwater level change are investigated. First, the potential jumps in the displacement time series are removed, and then the Sequential Turning Point Detection (STPD) is applied to estimate the times when the velocity of the displacement time series changes. The results show a significant correlation between the frequency of turning points in displacement time series and precipitation trend change, particularly during the winter season. Furthermore, the Least-Squares Cross Wavelet Analysis (LSCWA) is applied to estimate the coherency and phase delay between the displacement and weather cycles in the time-frequency domain. The annual cycles of displacement and temperature show more coherency than the ones of displacement and precipitation across the study region. The results presented herein are important for infrastructure and water management planning.

Assessing the Groundwater Quality in Urban Areas Using the DEMATEL Method

The Dhanbad area in Jharkhand, India, is a significant coal mining region located in the middle of the Damodar River basin. The geological composition of the area ranges in age from to Recent, encompassing, granites, pegmatite, and gneisses. These rocks are accompanied by bands of s and amphibolites. In this particular region, groundwater occurrence and movement are primarily restricted to semi weathered/weathered and fractured rocks. The movement of groundwater depends on various factors, including the thickness, size, extent, and openness of the weathered zone, as well as the interconnections of fractures within the rocks. Due to the dynamic nature of groundwater resources, it is susceptible to various factors that can impact its availability and quality. The expansion of irrigation activities, industrialization, and urbanization in the area can have significant implications for the groundwater resources. These activities can lead to increased water demand, contamination risks, and changes in the hydrological balance. Given the importance of groundwater as a vital resource, it becomes crucial to monitor and conserve it effectively. Monitoring techniques, such as hydrological studies, geophysical surveys, and groundwater level measurements, can provide valuable information about the status and behavior of groundwater resources. Conservation efforts may involve implementing sustainable water management practices, promoting water-use efficiency, and controlling pollution sources. By utilizing GIS and available physic-chemical data, the study seeks to generate a comprehensive water quality index map that can assist in making informed decisions regarding water resource management and protection in the Dhanbad area. This understanding can help in developing sustainable strategies to ensure the availability and quality of groundwater in areas like, where natural resources are intricately linked to human activities and industrial development. The variations in the resistivity of water-bearing weathered/fractured rocks in the Dhanbad area depend on the specific geological characteristics of the rocks and their water content. The resistivity refers to the rock's ability to resist the flow of electric current and can provide insights into the rock's porosity and permeability, which are crucial factors for groundwater movement. The depth to groundwater in the area can vary and is typically measured from below ground level. This depth is influenced by factors such as local topography, rainfall patterns, and geological conditions. The presence of active and abandoned coal mines, waste dumps, coal washeries, coking coal plants, and thermal power plants can introduce pollutants into the environment. These pollutants have the potential to contaminate groundwater, affecting its quality and usability. It is important to address these environmental concerns and prioritize the implementation of effective measures to mitigate the impact of coal mining and related activities on groundwater resources. Alternative parameters taken as Total dissolved solid, total hardness, Nitrate, ammonia nitrogen, Fluoride, Fluoride. the first ranking training is obtained with the lowest quality of compensation.

Increasing The Bearing Capacity of Foundations on Sandy Soil with High Water Levels Using Mini-pile

In the Kediri Regency area, it is planned to build a 3-story shophouse as one of the supporting facilities and the community’s economic needs. This area has sandy soil conditions and a high-water table. The purpose of this study was to calculate the carrying capacity of the soil in constructing a 3-story shophouse using the Terzaghi, Mayerhof, and Hansen methods. The condition of the soil with a relatively high groundwater table made the implementation of the footplate foundation less effective, so a modification of the foundation was made, which added three mini-piles measuring 0.4x0.4x1.5m, with a design load supported by the foundation of 100 t/m². Calculations with the Mayerhof and Hansen methods have nearly identical results but have not fulfilled the planned load. At a foundation depth of up to 3 m with an SF value of 3, for the Terzaghi method: 107.75 t/m2, the Mayerhof method: 92.51 t/m2, and the Hansen method: 94.68 t/m2. The results can be used as an alternative in constructing a 3-story shophouse with sandy soil conditions and high groundwater levels. This research can also be a reference for other regions facing similar problems.

Cover collapse sinkhole formation is delayed in time and uncorrelated to distance from quarry in a long-term study of a karst basin

Collapse sinkholes are problematic for the hazards they bring to property, infrastructure, and human life but the prediction of their formation in time and space remains elusive. We make use of long-term data gathered in a small, highly monitored, hydrologically constrained basin; Primrose Creek, Bucks County, Pennsylvania, USA, to examine the relation between groundwater extraction, precipitation, terrain position, and cover collapse sinkhole development. The selected site is unique as a natural laboratory to explore induced sinkhole processes in that it is a clearly demarcated topographic basin with geological structural and lithologic boundaries; the stressor is extreme, has been plainly identified, and effectively captures all upstream runoff and groundwater; the groundwater withdrawals and water-level elevations have been closely monitored over a period of 20 years; and the general record of land conditions goes back more than a century. We evaluated the history of a carbonate-rock quarry, its development and expansion over many decades, as well as associated precipitation and ground-water level data, and cover collapse sinkhole occurrence within the basin. Interception of discrete high conductivity zones in the Paleozoic carbonate rocks by quarry expansion was an important factor in propagating collapse occurrence. Collapses occurred mainly, though not exclusively, along drainageways and at lithologic boundaries. They formed in time-based clusters with delay of up to several years. Surprisingly, distance of collapse formation from the pumping area was not directly correlated with time elapsed; i.e., collapses did not begin to form close to the quarry, and then later form farther away. Monitoring wells were unsuccessful in delineating the pumping zone of influence although some documented water table decline and response to weather and anthropogenic events. This comprehensive study shows that in order to successfully monitor and control impacts from quarry dewatering in Paleozoic carbonate rocks it is critical to 1) develop a detailed conceptual model of groundwater pathways, 2) try to avoid excavating into high permeability zones, 3) clearly document karst features when exposed, and 4) carefully site a suitable number of monitoring wells and collect data at short intervals.

Spatial and temporal forecasting of groundwater anomalies in complex aquifer undergoing climate and land use change

Monitoring groundwater (GW) level variations, or anomalies in multiple wells, over long periods of time is essential to understanding changes in regional groundwater resource availability. However, it is challenging to predict these GW anomalies over the long term in agricultural areas due to complicated boundary conditions, heterogeneous hydrogeological characteristics, and groundwater extraction, as well as nonlinear interactions among these factors. To overcome this challenge, we developed an advanced modeling framework based on a recurrent neural network of long short-term memory (LSTM) as an alternative to complex and computationally expensive physical models. GW anomalies were forecast two months in advance (t + 2) based on the evaluation of drivers that influence GW dynamics in densely irrigated agricultural regions. An application and evaluation of this new approach was conducted in the Wisconsin Central Sands (WCS) region in the U.S., one of the most productive agricultural regions. The modeling framework was developed for the period 1958–2020 by utilizing easily accessible dynamic and static variables to represent hydrometeorological and geological characteristics. GW anomaly observations were acquired from 26 piezometers (wells) installed in the sandy aquifer in WCS over 10–60 years. The subset of GW observations from ∼ 10–60 years, not used in model training, can forecast GW anomalies two months out with a coefficient of determination R2 ∼ 0.8. Additionally, MAE was less than 0.34 m/month across the study region for both temporal and spatial modeling frameworks. Groundwater anomalies showed high spatiotemporal variability, and their responses are influenced differently by boundary conditions, catchment geology, climate, and topography across locations. Sites with higher autocorrelation with previous two-months GW anomalies reduced bias by increasing R2. Land use change and irrigation pumping have interactive effects on GW anomalies forecasting. The novelty of this study is identifying the regional drivers of GW fluxes. This case-specific information and location-related simplification, modification, and assumption of LSTM is a unique contribution to the existing literature. Our framework can be used as an alternative method of simulating water availability and groundwater level changes in areas where subsurface properties are unknown or difficult to determine.

Drivers of barrier island water-table fluctuations and groundwater salinization

Barrier islands are threatened by climate change as sea-level rise and higher frequency storm surge lead to more flooding and saltwater intrusion. Vegetation plays a vital role in preventing erosion of barrier islands due to aeolian and hydrological forces. However, vegetation on barrier islands is threatened by rising water tables causing hypoxic conditions and storm-surge overwash introducing saline water to the root zone. To better protect barrier island ecosystems, it is critical to identify the relative influence of different hydrological drivers on water table elevation and salinity, and understand how this influence varies spatially and temporally. In this study, three barrier island sites were instrumented with groundwater wells monitoring water level and specific conductance. Using these data, a set of transfer function noise models were calibrated and used to determine the relative influence of hydrologic drivers including precipitation, evapotranspiration, bay and ocean water levels, and wave height on groundwater levels and specific conductance. We found that drivers of water-level change and specific conductance vary strongly among sites, depending primarily on the surface water connectivity and the geology of the island. Sites with close connection to inlets showed more salinization and responded to a larger number of drivers, while sites that were poorly connected to the ocean responded to fewer drivers.

Evaluation of sand subgrade seepage erosion caused by buried pipeline leakage

Leakage from buried pipelines can lead to an increase in the water content of the subgrade soils and a rise in the water table, leading to soil loosening, erosion and ultimately the formation of hidden voids and roadway collapses. This study presents a discrete-element method and validates its accuracy by utilising cavity data from model experiments. It investigates the mechanism of seepage erosion resulting from pipe leakage and analyses the development of the soil arch effect. Furthermore, it discusses the influence of sand void ratio and particle size on sand seepage erosion. The results indicate that the erosion area is primarily affected by the void ratio and particle size. In comparison to soil particles ranging from 0.1 to 5 mm and from 2 to 5 mm, those with sizes between 0.1 mm and 2 mm generate areas of erosion and loosening that are approximately 40% larger. The proposed model offers a precise analysis of the developmental process and the extent of seepage erosion, thereby contributing to the prediction of potential road cavity areas based on dynamic changes in key factors such as subgrade soil type and groundwater level.

The general patterns of water flow in loess slope system and implications for slope geological security

Loess regions face significant challenges in quantifying hydrological processes and assessing geological environmental risks due to the prevalent development of preferential pathways and the limitations of existing monitoring technologies. To advance this knowledge, this study presents an improved electrical resistivity tomography (ERT) device, specifically designed for loess moisture observations. By refining the testing principle, power supply mode, and data collection method within the existing ERT framework, the new device offers unmanned operation, automatic data acquisition, remote transmission, and cost efficiency. It effectively tracks water movement and groundwater level fluctuations across various hydrological conditions, supporting long-term online monitoring of hydrological processes of loess slopes. Through the analysis of monitoring data and classification of 12 observed preferential flow types, water movement in loess systems can be generalized into four general patterns: uniform infiltration, preferential infiltration, inflowing diffusion, and lateral flow. This generalized scheme provides a simplified modeling approach for other researchers to quantify slope hydrodynamics and to assess geological safety risks involving preferential flow. Based on these insights and field investigations, a conceptual framework is proposed to elucidate the seepage-structure synergistic initiating mechanism of loess landslides. This framework suggests that water entry and movement patterns within the slope depend on the slope geological structure related to preferential pathways and the prevailing hydrological scenarios. Landslide occurs as the result of the progressive failure and reciprocal evolution between the slope hydrological environments and geological structure, which may also pose potential eco-hydrological risks. The outcome advances the development of slope hydrological monitoring technology and enhances the understanding of water movement laws and the associated geological environmental risks in loess slope systems, which is of vital importance to the early warning methods of loess landslides that account for preferential flow and for theoretical modeling of preferential flow in related disciplines.

Survival and Growth Performance of Calophyllum inophyllum L. Seedlings in Peat Soil and at Different Levels of Groundwater

Selecting proper tree species for revegetation is important for restoring tropical peatland. Tamanu (Calophyllum inophyllum L.) has been suggested one of the promising native species in Indonesia for the revegetation of tropical peatland; however, there is a lack of understanding of its growth in peat soil with different groundwater levels. We investigated the survival rate, plant height, number of leaves, root collar diameter, and dry biomass of tamanu seedlings grown in peat soil with different groundwater levels using a randomized block design in a water tank. The study involved five groundwater level treatments and 12 tree-level replicates each: M0 (non-groundwater level, control); M1 (−15 cm below the soil surface); M2 (−10 cm); M3 (−5 cm); and M4 (0 cm, soil surface level). The results showed that all tamanu seedlings survived in every treatment. However, their plant height, number of leaves, and root collar diameter growth were significantly inhibited in the highest groundwater level condition (M4, 0 cm) at 81 days after sowing, while their growth in −15 cm of groundwater level (M1) was as good as the growth in the fully drained conditions in M0 (control). This result indicates that the groundwater level should not be higher than −15 cm for the growth of tamanu. Considering that peatlands in Indonesia are assessed to be degraded when the groundwater level is lower than −40 cm, this study suggests that maintaining groundwater levels between −40 cm and −15 cm in peatland is the best condition for rapid growth of early tamanu seedlings while protecting peatlands. Further studies are needed to extend the range of water levels and water treatment duration.

Shallow vs. Deep Learning Models for Groundwater Level Prediction: A Multi-Piezometer Data Integration Approach

Shallow vs. Deep Learning Models for Groundwater Level Prediction: A Multi-Piezometer Data Integration Approach

Decoding uranium variation over the Indian peninsula through leveraging standardized precipitation evapotranspiration indices and groundwater level fluctuations

The present study aims to predict the concentration of uranium (U) in groundwater in India by utilizing water quantity indicators, such as Standardised Precipitation Index (SPI), Standardised Precipitation Evapotranspiration Index (SPEI), and Gravity Recovery and Climate Experiment (GRACE) based groundwater levels. The study adopts a multi-scale approach, ranging from state-level to agroclimatic zones. The findings indicate that the highest levels of U (101–500 μg.L−1), which surpass the World Health Organization (WHO) prescribed limit of 30 μg.L−1 for drinking water, are primarily concentrated in India's plateau and hills regions. The GRACE data map portrays a downward trend in groundwater levels throughout India, with the mid-Gangetic plains experiencing the most significant decline. The meteorological aspect of the study, as indicated by SPI and SPEI, reveals that the plateau and hills region is experiencing a decline in rainfall. The SPEI further underscores the grim picture of decreasing precipitation in northern India. Additionally, the study employs cluster analysis to cluster states according to the division of agro-climatic zones. Lastly, the study employs a random forest algorithm to assess the relative importance of each predictor and predict U concentration under the trinity of precipitation, extraction, and evaporation. The most significant contribution of this work is to identify the hotspots in India that require the most attention in terms of U toxicity owing to groundwater decline. Overall, this study highlights the need for immediate attention to mitigate the adverse impacts of U contamination and aims at sensitizing the stakeholders towards the compelling need to fulfil SDG-3 (health aspects due to U hazard) and SDG-6 (groundwater over-exploitation and deteriorating water quality).

THE INFLUENCE OF WASTE ACCUMULATION SITES FROM MINING AND PROCESSING PLANTS ON THE HYDROSPHERE OF ADJACENT TERRITORIES

The nature and directions of changes in the state of water bodies of the territory, for a long time (50 60 years) adjacent to the storage areas of mining waste (dumps) and enrichment (tailings) of iron ore raw materials, have been studied. It has been established that dumps and tailings are sources of the adjacent territories’ intense hydrosphere chemical pollution with highly mineralized filtrates. The most intense pollution and increase in groundwater levels at all horizons occurs in the first 10-15 years.In the future, in proportion to the service life of man-made structures, the area and level of chemical pollution of surface and underground water bodies increases, hydrogeological processes are increasing: flooding of lands, landslides, sinkholes.

Correction: Prediction of monthly groundwater level using a new hybrid intelligent approach in the Tabriz plain, Iran

Correction: Prediction of monthly groundwater level using a new hybrid intelligent approach in the Tabriz plain, Iran

A STUDY OF THE HYDROGEOLOGICAL REGIME OF THE NATURAL AND TECHNICAL GEOSYSTEM: THE CASE STUDY OF THE DNIESTER GES

The primary objective of the study is to analyse changes in the hydrogeological regime before and after the facility's commissioning, taking into account the impact of human activity on water resources. To solve this problem, it is necessary to regularly measure groundwater levels. This process was carried out by systematically measuring the water level in piezometers for the period from 2010 to 2023 with a frequency of twice a week. To achieve this goal, it was necessary to analyse the geological structure and hydrogeological characteristics of the unconfined aquifers in the soil strata, as well as to investigate the permeability of rocks. Changes in the hydrogeological regime can be caused by both rock compaction due to changes in the stressed deformation state and activation of geodynamic processes, which, in turn, contribute to drainage through faults in the rock mass. The research in the article allows us to more accurately assess changes in the hydrogeological regime of the rock mass, in particular, in the reduction of the water-holding capacity of a certain horizon. The study reveals the possible causes of these changes, such as soil compaction and activation of geodynamic processes, and indicates potential consequences for the hydrogeological environment and water use, when planning and operating other energy facilities in similar conditions. The practical significance of this study is that it helps to understand changes in the hydrogeological environment and their potential impact on water resources. This is important for the development of effective strategies for managing water resources individually and preserving ecosystems in general. Studies indicate that during the period from 2010 to 2023, significant changes occurred in the hydrogeological regime of non-pressure horizons #1 and #2. The analysis of groundwater levels indicates that in certain local areas there is a decrease in the water level, which indicates the degradation of the soil massif. These changes may be related to the effects of drainage, which caused the disruption of structural bonds in soils and their transition to a loose state. In the case when the clay soil, which serves as a waterproofing layer for non-pressure horizon No. 1, loses its waterproofing properties, it can be explained with the help of the Coulomb-Mohr law, which reveals the dependence of the angle of internal cohesion (φ) on the coefficient of internal grafting (С) in soils. In simple language, when structural bonds are destroyed in clayey soils, the filtration coefficient increases [30, p. 240; 15, p. 223; 34, p. 170; 28, p. 2]. The potential cause of the destruction of structural bonds in the soil is described in works [36, p. 3]. Therefore, it can be concluded that the dynamics of groundwater levels indicates the influence of hydrogeological processes on the physical properties of the soil environment, which is important for the further management of water resources and the preservation of ecological sustainability of the region. The practical significance of this study is that it helps to understand changes in the hydrogeological environment and their potential impact on water resources. This is important for developing effective strategies for managing water resources separately and preserving ecosystems as a whole. For example, it is possible to develop models that will predict soil deformations depending on the level of groundwater, which will avoid possible destructive consequences for infrastructure and construction objects. Such data can also be used to improve hydrotechnical structures and determine optimal water resources management strategies in conditions of changing hydrogeological regime. Keywords: Geoecology, constructive geography, geosystems, river-basin systems, river-valley landscape, river natural and technical systems, landscape technical systems, landscape engineering systems, GIS technologies, Dniester PSPP, oolitic limestone, piezometer, aquifer, piezometric surface, soil base, infiltration, Neogene, aquifer.

An Unsaturated Soil Mechanics-Based Numerical and Experimental Method to Assess Soil Settlement Due to Ground Water Level Rise

An Unsaturated Soil Mechanics-Based Numerical and Experimental Method to Assess Soil Settlement Due to Ground Water Level Rise

Time-Series Analysis of Mining-Induced Subsidence in the Arid Region of Mongolia Based on SBAS-InSAR

Mongolia’s substantial mineral resources have played a pivotal role in its economic progress, with mining activities significantly contributing to this development. However, these continuous mining operations, particularly at the Oyu Tolgoi copper and gold mine, have induced land subsidence that threatens both production activities and poses risks of geological and other natural disasters. This study employs the Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technique to monitor and analyze time-series surface subsidence using 120 Sentinel-1A datasets from 2018 to 2022. The findings reveal that the SBAS-InSAR method successfully captures the subsidence and its spatial distribution at Oyu Tolgoi, with the maximum cumulative subsidence reaching −742.01 mm and the highest annual average subsidence rate at −158.11 mm/year. Key drivers identified for the subsidence include variations in groundwater levels, active mining operations, and changes in surface stress. This research underscores the ongoing subsidence issue at the Oyu Tolgoi mining area, providing crucial insights that could aid in enhancing mining safety and environmental conservation in the region.

Deformation Monitoring Based on SBAS-InSAR and Leveling Measurement: A Case Study of the Jing-Mi Diversion Canal in China.

The Jing-Mi Diversion Canal is a large-scale water diversion project in Beijing. Routine monitoring is crucial for the reliability and stability of urban water supply. Compared with traditional monitoring methods, interferometric synthetic aperture radar (InSAR) has the advantages of large scale and high accuracy. Based on the small baseline subset InSAR, 187 ascending and 102 descending SAR images obtained from Sentinel-1 were used to detect the deformation along the diversion canal from 2017 to 2023. The results show that there was a sinking trend along the diversion canal. The subsidence was serious in the first half of the canal, and continued to sink from 2019 to 2020. The subsidence was alleviated in 2023. Combined with leveling measurements, the InSAR deformation monitoring results of important pumping station buildings were verified. The measurement accuracy of InSAR can reach the millimeter level. We extracted the groundwater level time series and subsidence for risky canal segments. Through pixel-by-pixel comparison, it was found that fluctuations in groundwater level would have some impact on surface deformation. Severe local subsidence or uplift deformation occasionally occurred. To ensure the safety of water diversion, the monitoring and maintenance of relevant pump station buildings in risky areas should be increased in the future.

Centrifuge modeling of loess slope failure induced by rising water level utilizing intact sample

Understanding the failure process of bottom-saturated loess slopes is of great significance in loess areas where flood irrigation is commonly utilized to alleviate the scarcity of precipitation. In this study, the failure process of a loess slope with an increased groundwater level was recreated and the multiple failure modes of loess landslides were revealed. A centrifugal model test was conducted using a groundwater-recharge device. An intact loess sample retrieved from the Heifangtai Loess Terrace was employed in the test. The model test was monitored using a video recorder, high-speed camera, and soil/pore water pressure sensors, and the results were validated by utilizing an intermittently investigated field landslide. Based on the monitored data and acceleration, the test was divided into three periods: the initial acceleration period with no water inlet (0–40 g), bottom saturation period (40–60 g), and failure occurrence period (60–80 g). The soil/pore water pressure and degree of deformation were relatively low, with a steadily increasing trend during the first two periods. With the enrichment of the soil water content, retrogressive sliding, deep subsidence, and surface sinkhole failures occurred successively up to areas with relatively high pore water pressure during the last period. The results of the field landslide investigation showed multiple failure modes, as observed in the model test. The results suggest that the coexistence of multiple failure modes could gradually evolve into croplands and promote water infiltration into the deep loess, increasing the groundwater level and accelerating the failure process of the slope. Despite the overall effects of multiple failure patterns on the evolution of the slope, each failure pattern had a relatively independent evolutionary process within a certain area, which could be further analyzed for the early recognition of loess landslides. This study also indicates that the challenges of centrifuge modeling for water-related materials with intact soil samples are the boundary conditions and data monitoring within the model.