Protection Of Groundwater Resources Research Articles

Assessing the future groundwater vulnerability of an urban region under variable climatic and land use conditions

Climate change and urbanization threaten groundwater resources due to over-abstraction and contamination. Groundwater vulnerability assessment aids in protecting groundwater resources; DRASTIC is the widely used groundwater vulnerability model (GVM) to assess vulnerability. This study uses an optimized DRASTIC framework to assess the impact of climate and land use change on the future groundwater vulnerability of Chennai Metropolitan Area (CMA). The frequency ratio (FR) and metaheuristic (MH) algorithms are coupled to optimize the rates and weights of GVM to reduce subjectivity. The climatic variables and land use projected for the future period 2030 and 2050 under RCP4.5 and RCP8.5 scenarios. The projected net recharge for the study region varies from 349.95 mm/yr to 458.95 mm/yr, and depth to groundwater level ranges between 4.92 and 6.42 mbgl for scenarios 1 to 4. The RCP4.5 scenario for the far future period (scenario-2) shows an increase in the vulnerability class by 41.64%, and RCP8.5 scenario for the far future period (scenario-4) exhibits a decrease in the vulnerability class by 20.67% of the total area. The integrated groundwater vulnerability analysis found that the CMA groundwater system is in critical condition of high vulnerability for near and far future periods.

Effect of mixed physical barrier on seawater intrusion and nitrate accumulation in coastal unconfined aquifers.

Physical barrier has been proven to be one of the most effective measures to prevent and control seawater intrusion (SWI) in coastal areas. Mixed physical barrier (MPB), a new type of physical barrier, has been shown to have higher efficiency in SWI control. As with conventional subsurface dam and cutoff wall, the construction of MPB may lead to the accumulation of nitrate contaminants in coastal aquifers. We investigated the SWI control capacity and nitrate accumulation in the MPB using a numerical model of variable density flow coupling with reactive transport, and performed sensitivity analysis on the subsurface dam height, cutoff wall depth and opening spacing in the MPB. The differences in SWI control and nitrate accumulation between MPB and conventional subsurface dam and cutoff wall were compared to assess the applicability of different physical barrier. The numerical results show that the construction of MPB will increase the nitrate concentration and contaminated area in the aquifer. The prevention and control efficiency of MPB against SWI is positively correlated with the depth of the cutoff wall, reaching the highest efficiency at the minimum effective dam height, and the retreat distance of the saltwater wedge is positively correlated with the opening spacing. We found a non-monotonic relationship between the change in subsurface dam height and the extent of nitrate accumulation, with total nitrate mass and contaminated area increasing and then decreasing as the height of the subsurface dam increased. The degree of nitrate accumulation increased linearly with increasing the height of the cutoff wall and the opening spacing. Under certain conditions, MPB is 46-53% and 16-57% more efficient in preventing and controlling SWI than conventional subsurface dam and cutoff wall, respectively. However, MPB caused 14-27% and 2-12% more nitrate accumulation than subsurface dam and cutoff wall, respectively. The findings of this study are of great value for the protection of coastal groundwater resources and will help decision makers to select appropriate engineering measures and designs to reduce the accumulation of nitrate pollutants while improving the efficiency of SWI control.

Preventing water inrush hazards in coal mines by coal gangue backfilling in gobs: influences of the particle size and stress on seepage characteristics.

The backfilling mining method that fills gobs with coal gangue can prevent water inrush hazards, protect groundwater resources, and protect the ecological environment of the mining area. However, initial conditions including the particle size distribution of gangue and the stress environment may affect the seepage characteristics of gangue backfill and inrush prevention ability. Taking the particle size and stress as main controlling factors, the seepage tests were designed for gangue to evaluate influences of the particle size and stress on the void ratio, permeability, and non-Darcian flow factor of gangue. In the meantime, the four stages in dynamic changes of seepage channels were studied and the impervious envelope lines of gangue backfill materials were provided. The results show that the larger the particle sizes, the stronger the crushing resistance of particles; under high stress (> 6.67MPa), seepage channels in small gangue particles (< 5mm) change in a more complex manner, and the non-Darcian flow phenomena become more significant. The particle size and stress exert significant influences on the seepage characteristics. Therefore, when reducing water inrush hazards by gangue backfilling in gobs, the particle size distribution should be optimized by combining the stress and water pressure conditions. Seepage channels in gangue backfill materials vary with changes in the particle size and stress. Their variation can be divided into four stages: shrinkage of seepage channels, reconstruction of seepage channels, dynamic equilibrium between slight expansion and shrinkage, and persistence of the impervious effect. After the first and second stages have been fully developed, the preliminary impervious conditions are met; after full development of the fourth stage, the gangue backfill materials reach an impervious state.

At the crossroad: Stakeholders’ perspectives from Thailand and Lao PDR towards a transboundary groundwater cooperation in the Khorat Plateau aquifer

To understand stakeholder perceptions from Thailand and Lao PDR in promoting and supporting transboundary groundwater cooperation, a stakeholder workshop was conducted to look into the role of scientific information, groundwater resource use, institutional and legal frameworks and challenges and opportunities within the Khorat Platea transboundary aquifer. Results showed that (1) stakeholders perceived scientific information as pivotal in exposing potential problems and facilitate transformative change among users and policy makers across border, (2) groundwater resource use in the plateau area is limited to domestic and agricultural applications but increasing resource abstraction portrays a forbidding future scenario, (3) Thailand and Lao PDR have made significant strides in the decentralization of laws and policies pertaining to groundwater use but remains weak as local authorities lack the knowledge to manage and protect groundwater resources, and (4) Thailand and Lao PDR are at the crossroad of groundwater competition and cooperation and should work together to manage and protect the Khorat Plateau transboundary aquifer system. While anticipation for a transboundary cooperation may still need more efforts to take, interests and initiatives from all stakeholders must continue as initial elements for transboundary cooperation have already been achieved.

Assessment of hydrogeochemistry in groundwater using water quality index model and indices approaches

Groundwater resources around the world required periodic monitoring in order to ensure the safe and sustainable utilization for humans by keeping the good status of water quality. However, this could be a daunting task for developing countries due to the insufficient data in spatiotemporal resolution. Therefore, this research work aimed to assess groundwater quality in terms of drinking and irrigation purposes at the adjacent part of the Rooppur Nuclear Power Plant (RNPP) in Bangladesh. For the purposes of achieving the aim of this study, nine groundwater samples were collected seasonally (dry and wet season) and seventeen hydro-geochemical indicators were analyzed, including Temperature (Temp.), pH, electrical conductivity (EC), total dissolved solids (TDS), total alkalinity (TA), total hardness (TH), total organic carbon (TOC), bicarbonate (HCO3−), chloride (Cl−), phosphate (PO43−), sulfate (SO42−), nitrite (NO2−), nitrate (NO3−), sodium (Na+), potassium (K+), calcium (Ca2+) and magnesium (Mg2+). The present study utilized the Canadian Council of Ministers of the Environment water quality index (CCME-WQI) model to assess water quality for drinking purposes. In addition, nine indices including EC, TDS, TH, sodium adsorption ratio (SAR), percent sodium (Na%), permeability index (PI), Kelley's ratio (KR), magnesium hazard ratio (MHR), soluble sodium percentage (SSP), and Residual sodium carbonate (RSC) were used in this research for assessing the water quality for irrigation purposes. The computed mean CCME-WQI score found higher during the dry season (ranges 48 to 74) than the wet season (ranges 40 to 65). Moreover, CCME-WQI model ranked groundwater quality between the “poor” and “marginal” categories during the wet season implying unsuitable water for human consumption. Like CCME-WQI model, majority of the irrigation index also demonstrated suitable water for crop cultivation during dry season. The findings of this research indicate that it requires additional care to improve the monitoring programme for protecting groundwater quality in the RNPP area. Insightful information from this study might be useful as baseline for national strategic planners in order to protect groundwater resources during the any emergencies associated with RNPP.

Water-preserved coal mining in water-shortage mining areas: a case study in the Yonglong mining area of China

Abstract Water-preserved coal mining (WPCM) in water-shortage mining areas is an important aspect of water resources management. This paper aimed at the protection of Cretaceous groundwater resources during the high-intensity mining in the Yonglong mining area, China, and carried out basic theory and practical application of WPCM. The hydrogeological structure and engineering geological characteristics were investigated on-site. On-site detection and numerical simulation were used to study the dynamic evolution laws of overburden failure and water-conducting fractured zone (WCFZ), and the seepage laws of mining-induced overburden were analyzed by the rock triaxial seepage test. The results showed that it was feasible to carry out WPCM in the Yonglong mining area. From the view of reducing the height of WCFZ and preventing water hazards, the technical measures for WPCM were proposed. The research results can provide a theoretical basis and technical approach for WPCM in the water-shortage mining areas.

Study on Groundwater Function Zoning and Sustainable Development and Utilization in Jining City Planning Area

The sustainable development and utilization of groundwater resources are of paramount importance for the progress of society, the economy, and the environment. This study focuses on the planning area of Jining City and establishes an evaluation index system for groundwater functional zoning by analyzing key factors such as resource supply function, geo-environmental stability function, and ecological environmental protection function. To evaluate the groundwater functions, this study employs the barrel effect AHP. Through the overlay analysis of different groundwater functions, the planning area of Jining City is categorized into distinct zones based on their groundwater functions. These zones include centralized development and utilization areas (5.69%), decentralized development and utilization areas (65.67%), fragile geo-environmental areas (10.44%), ecological protection areas (8.38%), and unsuitable development and utilization areas (9.82%). The comprehensive zoning map of groundwater functions in the planning area of Jining City is generated. Taking into account the challenges posed by human activities, such as groundwater pollution, this study proposes recommendations for the sustainable development of groundwater in the planning area of Jining City. By systematically examining the functional zoning and sustainable management of groundwater, this study provides a scientific foundation for the responsible development and protection of groundwater resources.

Quantitative prediction of the impact of deep extremely thick coal seam mining on groundwater

Reasonable exploitation and utilization of groundwater near coal mines in arid areas are of great significance to regional ecological and geological environment protection and sustainable mining of coal resources. It is a challenge to accurately predict the impact of deep coal mining on groundwater resources before mining. Adopting a coal mine in Inner Mongolia, China, as a case study, first, a well-fitted GA-BP neural network model was established to predict the height of the water-conducting fracture zone (WCFZ). The prediction results of WCFZ were verified by in-situ measured data of optical fiber and cable sensing systems. In Chinese coal mines, hydrogeological research generally lags behind geological exploration. Therefore, in the context of limited hydrogeological data, a variable weight model (VWM) for evaluating the potential groundwater yield of the objective aquifer (OAPGY) was established considering geological survey data before mining. Then, drilling pumping test data was used to verify the OAPGY predictions. Finally, groundwater resource protection measures were proposed according to the zoning results. The research results could provide a reference and basis for sustainable utilization of groundwater and reducing the impact of coal mining on groundwater resources.

Springs Water Quality Assessment for Drinking Purposes: A Case Study of Bsaira, Jordan

Water scarcity is one of the biggest challenges to Jordan. Jordan is considered one of the poorest countries in the world in terms of freshwater availability. The protection of freshwater springs from pollution is among the possible solutions that can help in mitigating the water scarcity problem. In this study, the quality and quantity of water flowing from three springs namely Um Sarab, Dana, and Gharandl within Bsaira area that is located in Tafilah governorate in Jordan were evaluated as potential drinking water sources. During the spring period (March to June 2021), several water samples from the springs were collected and tested for biological, physical, and chemical parameters. Spring water samples were tested for (Ni, Co, Cr, Cu, Fe, Pb, Mn, Zn, Na+, K+, Mg2+, Ca2+), pH, total dissolved solids, chemical oxygen demand, turbidity, total solids, total coliforms, and E-coli. Results indicated that all the physical and chemical parameters of water in the three springs are within the acceptable standard limits according to Jordanian standards for drinking water. However, the biological parameters (i.e. total coliforms and E-coli) exceeded the permissible limits, and this is more significant in Gharandl spring. The field investigation of the study area showed that the main sources of pollution are the presence of many septic tanks and agricultural activities in the surrounding areas of the springs. Therefore, applying Jordanian regulations for the protection of groundwater resources can significantly improve the quality of water in these springs. The total quantity of water from these springs exceeds 1300 m3/day which is considered a significant source of drinking water after local treatment and disinfection.

A Framework to Assess Natural Chloride Background in Coastal Aquifers Affected by Seawater Intrusion in Eastern Spain

The protection of groundwater resources in coastal aquifers is an increasingly important issue worldwide. To establish threshold values and remediation objectives, it is essential to know the natural background concentrations of relevant ions in groundwater. The rationale is to define the Natural Background Level (NBL) of chemical species determined by atmospheric and lithological forces. In many coastal aquifers, this evaluation worsens since atmospheric and lithological salinity combines with many other anthropogenic sources of salinity, including exogenous salinity induced by seawater intrusion (SWI). This paper presents a combination of six well-known statistical techniques and a new methodology (i.e., SITE index) in eight GWBs affected by SWI in Eastern Spain. The chloride ion was the selected conservative chemical specie to assess the qualitative status due to the variable SWI affection. The Natural Chloride Background (NCB) obtained from these methodologies at the GWB scale was compared with regional NCB data calculated with the Atmospheric Chloride Mass Balance (CMB) method in Continental Spain. The CMB method provides atmospherically derived NCB data that are not influenced by SWI or anthropogenic activities or lithological forces. This external evaluation can be considered the atmospheric fraction of NCB, which serves as a regional criterion to validate the more detailed statistical methodologies applied at the GWB scale. As a result, a conceptualization of NCB is obtained by means of a range of values between 115 mg L−1 and 261 mg L−1 in the studied coastal GWBs affected by SWI in Eastern Spain.

Development of IOT-based low-cost MEMS pressure sensor for groundwater level monitoring

Groundwater level monitoring is critical to the protection and management of groundwater resources. Properly designed and executed instrumentation can play an important role in increasing the quality and reliability of collected data and reducing total monitoring costs. The efficiency of the instrumentation depends mainly on the accuracy and reliability of the installed sensors. This study presents the testing and application of a cost-effective pressure sensor (0–689 kPa range) for water level monitoring based on microelectromechanical system (MEMS) technology and the internet of things concept. The sensor performance, in terms of accuracy, precision, repeatability, and temperature, was investigated in laboratory columns (with constant water level, increasing and decreasing water levels at various rates) and in situ conditions in an observation bore (with natural groundwater level fluctuations). The results show that the MEMS sensor is capable of providing a reliable and adequate monitoring scheme with an accuracy of 0.31% full scale (FS) (2.13 kPa).

Antimicrobial resistance and karst groundwater systems: A policy gap analysis for addressing water quality and contaminants of emerging concern

Aquifers are a significant drinking water source for the United States. Although vital to human well-being, development, and economies, these systems, specifically karst, either have minimal protections or are entirely overlooked in federal and state-level water quality policies and regulations. A lack of policies and regulations for the protection of karst groundwater resources is problematic, especially because these systems are characterized by distinctive landforms such as interconnected networks of underground rivers, sinkholes, springs and caves, and are extremely susceptible to contamination from polluted overland flows. This study considers policy approaches to improve water quality in groundwater, specifically karst systems, especially with regard to emerging contaminants of concern (CECs) and health threats, such as antimicrobial resistance (AMR). The study reviews and evaluates groundwater and karst groundwater quality and AMR policy gaps in federal water legislation (including the U.S. Clean Water Act and the Safe Drinking Water Act), and state-level programs in 44 states to provide recommendations for future policy development. Presently, there is limited federal and state-level protection for groundwater systems and minimal state-level for karst throughout the U.S. Also, there are neither federal nor state regulations for AMR mitigation in water resources. There is a need for policies and monitoring and regulatory programs that support water quality protection and management strategies for water resources with distinctive hydrology. Addressing water quality policy gaps for groundwater resources – especially karst aquifers – and prioritizing emerging contaminants in research, monitoring, and policymaking, are critical to safeguard the public against nascent public and environmental health threats.

Mapping of groundwater potential zones by integrating remote sensing, geophysics, GIS, and AHP in a hard rock terrain

Groundwater is a life-sustaining resource that provides for society's daily water needs, supports industrial development, promotes agricultural activities, and maintains ecological balance. In groundwater resource studies, integrating remote sensing, geophysical data, and GIS tools play a critical role in monitoring, analyzing, and protecting groundwater resources for water resources development and management. This study used a comparative approach since it is less labour-intensive, inexpensive, and efficient. The potential groundwater zones were determined by integrating various data sources such as remote sensing, geophysical, and collateral data and using the Analytic Hierarchy Process (AHP) method. Fifteen different thematic layers, including geology, geomorphology, lineament density, topsoil resistivity, topsoil thickness, weathered zone resistivity, weathered zone thickness, first fractured resistivity, first fractured thickness, second fractured resistivity, second fractured thickness, slope, land use/land cover, drainage density, and rainfall, were mapped in this process. The results show that the northern part of the study area has a relatively higher response of groundwater potential zones than the southern portion. Agricultural areas near surface water bodies and forests, characterized by shallow to moderately weathered pediments and pediplains, exhibit favourable groundwater potential. The study identifies five distinct groundwater potential categories based on area coverage:very low (242.44 km2), low (147.52 km2), medium (241.72 km2), high (26.35 km2), and very high (18.51 km2). The predominant factors influencing the groundwater potentiality are top soil thickness, pediment as well as pediplain (shallow to moderately weathered), lithology (charnockite and fissile hornblende biotite gneiss), slope type (gentle), and rainfall (high). A very good correlation between the groundwater potential zones and the well yield aided in validation of the above findings.

Spatial analysis of groundwater quality in Bulawayo, Zimbabwe: Geogenic and anthropogenic contributions

Over-exploitation of groundwater owing to urbanisation and industrialisation compromises its quality, spatially and temporally. The objective of this study was to analyse the spatial groundwater quality due to geogenic and anthropogenic activities in Bulawayo, Zimbabwe. Eighty boreholes were mapped and sampled for selected water quality parameters. The groundwater quality parameters that were adopted in this study were the temperature, electric conductivity, dissolved oxygen, pH, bicarbonate alkalinity, chloride, sodium, calcium, magnesium, sulphates, chlorides, potassium, iron, nitrates, fluoride, phosphates, arsenic, aluminium, zinc, strontium, barium and manganese. Groundwater samples were evaluated for drinking water suitability as per the 2011 World Health Organization (WHO) guidelines. Prediction of groundwater quality parameters at unsampled points was achieved by using the Inverse Distance Weighted interpolation method using Geographic Information Systems (GIS) software. Population, land use and geological data were superimposed onto the groundwater quality to generate integrated maps. There were noticeable distinctions in groundwater quality within different geological areas, particularly for fluoride, arsenic, sodium, calcium, chloride and strontium, signifying natural groundwater contamination. High levels of nitrate were detected near agricultural areas and in medium to high-density residential areas suggesting possible contamination from nitrogenous fertilizers and leakages from wastewater infrastructure respectively. The application of GIS to spatially map water quality, can be used by hydrogeologists and local authorities in planning, monitoring and protecting groundwater resources.

Predictive modeling and analysis of key drivers of groundwater nitrate pollution based on machine learning

Nitrate comtamination of shallow groundwater in agricultural intensification regions is a prevalent and global environment issue affecting food security, human health, and the water ecology. Developing a prediction model for groundwater nitrate contamination is crucial for protection of groundwater resources. Machine learning modeling offer potentials to predict contamination, but often fails to adequately screen input features in complex non-linear environments before modeling. Additionally, there is a tendency to overlook the interpretable description of the relationship between major water chemistry parameters and nitrate concentration after modeling, which hinders scientific decision-making by water resource managers. In this study, a dataset consisting of hydrochemical test results from 316 groundwater samples collected between 2011 and 2015 in intensive agricultural areas of Northeast China was collected. Prior to modeling, the dataset was grouped based on land use type, vadose zones types, and thickness. Based on the grouping of data sets, self-organizing map (SOM) and Spearman's coefficients were employed to identity the correlations between water chemical parameters and nitrate concentration (NO3–-N), which provided a logical basis for selecting the key input variables. A radial basis function artificial neural network (RBF ANN) prediction model and principal components regression (PCR) models was constructed using the dataset, and particle swarm optimization algorithm was applied to determine optimal parameter combinations of the RBF ANN. After conducting modeling, the advantages and disadvantages of RBF ANN and principal components regression (PCR) models were thoroughly examined and discussed, and the primary factors that impact nitrate concentrations in groundwater were analyzed using a PCR model. The results revealed that the RBF ANN model showed greater accuracy, while the PCR model offered better interpretability. Therefore, the integration of the two models is advantageous for nitrate prediction research. Human activities, rainfall, land-use types, vadose zones types and thickness are external factors that affecting nitrate concentration, and the difference between nitrification. Denitrification, and dissimilatory nitrate reduction to ammonium (DNRA) is internal driving factors for the change of nitrate concentration in the aquifer, and partially determine differences in the spatial distribution of aquifer nitrate concentrations under various land use types. This study provides a comprehensive approach for predicting nitrate pollution in groundwater under non-linear environmental conditions, supporting decision making in sustainable groundwater development, management, and conservation.

Multitechnique approach for characterizing the hydrogeology of aquifer systems: application to the Mauricie region of Québec, Canada

The Groundwater Knowledge Acquisition Project (Programme d’acquisition de connaissances sur les eaux souterraines, PACES) in eastern Mauricie, Québec, aimed to develop multiple groundwater characterization methods and provided a more comprehensive portrait of this resource across the region. The proper management and protection of regional groundwater require an accurate characterization and detailed description of regional aquifers. Here, a comprehensive summary is presented, showcasing the amalgamation of specialized investigation tools and diverse groundwater characterization methods developed throughout the Eastern Mauricie PACES project. This holistic approach unveils valuable insights into hydrogeological units while identifying the crucial parameters that define the regional aquifers. Information related to groundwater surface or subsurface distribution is presented through comprehensive thematic maps, stratigraphic sections, 3D fence diagrams, novel geophysical techniques, conceptual models, and numerical modeling. Integrating a comprehensive spatially referenced database, targeted subregional studies, and peer-reviewed research has significantly enhanced our understanding of regional groundwater. This paper offers substantial information on regional aquifers and their surrounding geology. The approach developed during the eastern Maurice PACES project will serve to better manage and protect groundwater resources in Québec and elsewhere.

Groundwater Quality Variations in Multiple Aquifers: A Comprehensive Evaluation for Public Health and Agricultural Use

Understanding hydrological and hydrochemical processes is crucial for the effective management and protection of groundwater resources. This study conducted a comprehensive investigation into hydrochemical processes and variations in groundwater quality across five distinct aquifers in Phra Nakhon Si Ayutthaya, Thailand: Bangkok (BKK), Phra Pradaeng (PPD), Nakhon Luang (NKL), Nonthaburi (NTB), and Sam Khok (SK). Utilizing various diagrams, the findings revealed that high levels of sodium and salinity in shallow aquifers (BKK and PPD) were found which can impede soil permeability and have potential consequences on crop yields. The presence of four distinct types of groundwater—Na-Cl, Na-HCO3, Ca-Cl, and Ca-HCO3—suggests the influence of rock weathering, mineral dissolution, and ion exchange reactions with the surrounding geological formations, controlling the chemistry in the groundwater basin. The research also highlights concerns regarding groundwater quality, particularly elevated concentrations of heavy metals (e.g., Zn, Hg, Pd, Fe, and Mn) exceeding safe drinking water guidelines established by the World Health Organization (WHO) in certain samples. The evaluation of water suitability for consumption and irrigation using the Water Quality Index (WQI) and Wilcox diagram reveals a predominance of “poor” or “unsuitable” categorizations. Untreated sewage discharge and fertilizer usage were identified as the primary anthropogenic activities affecting hydrochemical processes in groundwater. These findings emphasize the need for continuous monitoring, appropriate management, and remediation efforts to mitigate potential hazards.

Groundwater–surface water interaction in Denmark

AbstractThe study of groundwater–surface water interaction has attracted growing interest among researchers in recent years due to its wide range of implications from the perspectives of water management, ecology and contamination. Many of the studies shed light on conditions on a local scale only, without exploring a regional angle. To provide a broad and historical overview of groundwater–surface water interaction, a review of research carried out in Denmark was undertaken due to the high density of studies conducted in the country. The extent to which this topic has been investigated is related to Denmark's physiography and climate, the presence of numerous streams and lakes combined with shallow groundwater, and historical, funding, and administrative decisions. Study topics comprise groundwater detection techniques, numerical modeling, and contaminant issues including nutrients, ranging from point studies all the way to studies at national scale. The increase in studies in recent decades corresponds with the need to maintain the good status of groundwater‐dependent ecosystems and protect groundwater resources. This review of three decades of research revealed that problems such as the difference in scales between numerical models and field observations, interdisciplinary research integrating hydrological and biological methods, and the effect of local processes in regional systems remain persistent challenges. Technical progress in the use of unmanned aerial vehicles, distributed temperature sensing, and new cost‐effective methods for detecting groundwater discharge as well as the increasing computing capacity of numerical models emerge as opportunities for dealing with complex natural systems that are subject to modifications in future triggered by climate change.This article is categorized under: Science of Water &gt; Hydrological Processes Science of Water &gt; Water and Environmental Change Water and Life &gt; Nature of Freshwater Ecosystems

Groundwater salinization in northwestern Germany: A case of anticipatory governance in the field of climate adaptation?

Groundwater salinization due to sea-level rise is a problem that governance actors in coastal areas of the North Sea region have overseen for a long period. As an ecological problem associated with climate change, it can be severely exacerbated by careless water management. This paper studies governance processes, actor perspectives and responses to groundwater salinization and sea-level rise in the East Frisian and Frisian regions of the German North Sea coast. Due to its low-lying landscape, large areas of land remain below sea-level, making groundwater salinization an urgent concern. Our research questions are: (i) What type of anticipatory governance approach can be found with actors in the study region concerning groundwater salinization and climate adaptation challenges? (ii) How can an alternative anticipatory governance approach promote proactive governance processes addressing the complex problem of groundwater salinization in terms of awareness, preparedness, methods, strategies and policy actions? We conducted semi-structured interviews and workshops between 2017 and 2021, including a group of 15 actors from private and civil society organizations as well as authorities on municipal, inter-municipal and state levels. Our study finds that problem awareness in municipalities and regional governance levels in East Frisia and Frisia is low. Current management of groundwater salinization mainly focuses on technical response measures, while precautionary measures are given low priorities. With regard to governance approaches, our study identifies apparent societal challenges of groundwater salinization at the complex interface between water management, human activities and natural processes, and sustainable ways to manage and protect groundwater resources. However, we found indication for a defensive anticipatory governance approach prioritizing risk management and assessing plausible futures. In participatory processes, we discussed possible technical, non-technical and institutional adaptation options for future implementation. Finally, conclusions will be drawn on how knowledge and awareness building can contribute to change actors perspectives on the overseen problem of groundwater salinization and increase adaptiveness.

A Review on Process-Based Groundwater Vulnerability Assessment Methods

The unreasonable development and pollution of groundwater have caused damage to the groundwater system and environmental problems. To prevent this, the concept of “groundwater vulnerability” was proposed, and various evaluation methods were developed for groundwater protection. However, with changing climatic conditions and human activities, groundwater vulnerability is now emphasizing physical processes. This study aims to review and analyze the principles and applications of process-based groundwater vulnerability methods to achieve the source protection of groundwater resources. It introduces the assessment method and elaborates on pollutant migration processes and numerical simulation technology. Relevant articles from the past 30 years are reviewed to show the evolution of process-based groundwater vulnerability assessment. The study also discusses current research trends and proposes future development paths. It concludes that process-based groundwater vulnerability assessment will become the mainstream method, and modern technologies such as artificial intelligence will be necessary to solve challenges and achieve sustainable development.