Pumping Wells Research Articles

Evaluation of Project Work in a Public Service Building in East Java

In the process of implementing a project, few people find projects that go according to plan. In general, there are projects that are behind schedule, both in terms of time and schedule, but there are also projects that experience acceleration from the originally planned schedule. Project delay is a problem that arises as a result of unplanned construction implementation. Damage to the state due to additional costs and delays is one of the impacts of project delays. The purpose of this research is to track project implementation, identify factors that cause delays, calculate the cost of delays that occur, find root causes and suggest alternative solutions that can be used to anticipate project delays. Monitoring and evaluating delays require an approach that includes the use of Microsoft Project Tracking, Fishbone Charts, and Root Cause Analysis. Alternative methods are used to track performance and analyze delays in public service building projects. The results showed a lack of understanding of human resources in terms of planning/evaluating existing plans, lack of training programs related to the field of work being handled, and poor schedule planning causing a lack of lightning rods, installation in the main building, lighting in changing rooms, grounding systems, central duct/airline, less power cables than needed and original water source using PAM water converted into deep pumping wells.

Determination of Water Resources in Tube Well Using Hydrofacies for Riverbank Filtration

The reliability of water in riverbank filtration application is hard to be determined since the source of water and what happen at below ground cannot be see. These difficulties give effect for application of riverbank filtration since it is important in determination of its water quality and quantity. Due to that, this method was suggested to be used to determine the source of water in pumping well (PW) at Lubok Buntar, Kedah. The soil and water samples were taken from the PW and river water to determine the soil type and major ion (anion and cations). The results show that most of PW soil type is sandy loam (52%). Based on the piper diagram of the hydrofacies showed that the RW and PW were connected for a certain period of time. The most predominant cationin the PW was Na2+-CI-, consequently, the tube well water mostly came from groundwater rather than from river water. Therefore, this location is suitable for riverbank filtration applications as it has two reliable water sources. Due to that, for riverbank filtration water treatment, the river and groundwater water quality and quantity is important in order to make sure the system is reliable and sustainable.

Identification of Aquifer and Pumped Well Parameters Using the Data Hidden in Non-Linear Losses

During the pumping of wells, the groundwater level drawdown, as measured in the pumped well, is increased by non-linear losses caused by the water flow velocity through the well screens. This undermines the adequacy of the direct use of the measured drawdown data in the well for the purpose of the realistic identification of the effective well radius and aquifer parameters. This anomaly is avoided by reshaping the drawdown function into a function of the specific drawdown sw/Q of the pumped well. This reshaping simplifies the exclusion of non-linear losses from the sequence of measured data of the water level in the well at the position of the effective radius of the pumped well. Combining the data of linear losses and the respective pumping rate of the pumped well, a function of the specific drawdown of the radial flow sw/Q was formed. This function describes the aquifer parameter relations during the respective test pumping. A consistent sequence of the function of the specific drawdown sw/Q of the pumped well reveals the actual value of the coefficient of nonlinear losses. Moreover, the specific drawdown function enables the reliable estimation of aquifer transmissivity using only the pumped well drawdown data.

Numerical modeling as a support tool for groundwater permits in the state of Bahia, Brazil

The western region of Bahia State is an important agricultural frontier in Brazil, generating a large increase in requests for groundwater usage in the last decades, mainly through large capacity water wells tapping the Urucuia Aquifer System (UAS). This study aims to develop a groundwater numerical model using the Visual MODFLOW software and the additional packages MODPATH and ZONEBUDGET to evaluate the effects of intensive groundwater pumping in eight possible scenarios of two areas (Central and Eastern) in the Alto Grande - São Desidério rivers sub-basin. Drawdown ranging from 4 to 20 m was observed in the different areas and scenarios. The analysis of the local flow path lines showed that the wells have an area of influence that captures part of the groundwater flow. The water balance indicated that the total volume pumped in the sub-basin did not reach 10% of the recharge in any scenario, considering the entire model domain. The high concentration of irrigation pumping wells in restricted areas resulted in a significant impact on the aquifer, reaching up to 84.6% of the local recharge, a value that is far above what is considered sustainable for the region. Results show that the eastern area is more susceptible to drawdown and changes in flow path lines by pumping. The applied method has proven to be useful to predict the effects of water abstraction on the aquifer before the implementation of projects, improving water resources management. Long-range forecasts and taking into account possible climate changes are also some of the advantages of the method, though it depends on reliable field hydrological and climate data.

Numerical convergence does not mean mathematical convergence: Examples of simple saturated steady-state groundwater models with pumping wells

Groundwater numerical studies do not include H-convergence tests, contrarily to computational fluid dynamics (CFD) studies. In regional groundwater studies with pumping wells, the grids may exceed 106 nodes. The authors examine whether H-convergence tests can help to calculate the numerical errors made by using large grids with element sizes in the 10–500 m range. First, the differences between numerical and mathematical convergences are explained. Then, a method is proposed that most users may easily implement for their groundwater studies to assess the numerical error linked to the element size, ES, and the aspect ratio, AR. A single problem, forming a simple part of a regional groundwater study, was examined and solved by using many uniform grids. The results show that most regional groundwater studies make errors in the 50–500% range, considering their usual values for ES and AR. The numerical convergence domain, NCD, is shown to be larger than the mathematical convergence domain, MCD. This means that the codes can provide a numerical solution for a large range of ES values, even for many values outside the MCD, which is a risky situation for designers who are unaware of the difference between NCD and MCD and ignore the H-convergence tests.

Estimating hydrogeological parameters at groundwater level observation wells without pumping well information

Aquifer pumping is a common method of meeting human water needs, but it can also disrupt the natural flow of groundwater and cause fluctuations in groundwater levels. These fluctuations, however, can provide useful insights into hydrogeological properties when measured in an observation well. Traditional modeling methods are not well suited for analyzing such data because they lack essential details about the pumping wells, such as their number, distance from the observation well, and pumping rates. To address this issue, new impulse response function for transfer function modeling is developed that accurately describes the confined flow in such situations. The proposed function is based on the Theis solution, which uniformly distributes the effects of multiple pumping wells within a circular area around the observation well. This allows our function to accurately estimate hydrogeological parameters and pumping rates without knowing the number and specific location of pumping wells. The effects of well distance, spatial arrangement, and aquifer anisotropy on the accuracy of our function are also analyzed using synthetic experiments and Morris sensitivity analysis. The results show that the proposed function is effective in estimating essential hydrogeological parameters, such as the aquifer storativity, using only drawdown time series data from a observation well.

The Effectiveness of Slow Sand Filtration on Reduction of Iron (Fe) and Calcium (CaCO3) Levels in Water

Ground water or well water is the largest source of clean water used. The most common obstacle in using groundwater is the problem of iron (Fe) and calcium (CaC03) content in raw water. This research aims to determine the effectiveness of slow sand filtration to reduce Fe and CaCO3 levels in water. This type of research is a pure experimental study in a re-treatment design (One Group Pretest Posttest). The samples of raw water were taken from water pump wells owned by residents on JI. Datu Adam, Lere Village. Sample testing after slow sand filtering was carried out at the UPTD Laboratory of the Office of Environment, Donggala. The filter was carried out with a medium thickness of 45 cm sand, 5 cm gravel sand, 7 cm gravel and 5 cm high puddle water. Before filtering the test results Fe 0.4mg/L and CaCO3 546.37mg/L. Based on the effectiveness test of slow sand filtration with 3 treatments, it was found that the levels of substances after filtering were iron (Fe) 0.29, 0.21 and 0.I2 mg/L respectively, while calcium (CaCO3) was 273.41, 241.35 and 210.11 mg/L respectively. From these results, slow sand filtration is effective in reducing Fe and CaCO3 levels in water. The community is expected to be able to use simple filtering media such as slow sand filters to reduce iron (Fe) and calcium (CaCO3) levels in water. It is also expected to provide additional knowledge studies in the field of public health, especially environmental health.

Pump-and-treat (P&T) vs groundwater circulation wells (GCW): Which approach delivers more sustainable and effective groundwater remediation?

Pump-and-treat (P&T) is commonly used to remediate contaminated groundwater sites. The scientific community is currently engaged in a debate regarding the long-term effectiveness and sustainability of P&T for groundwater remediation. This work aims to provide a quantitative comparative analysis of the performance of an alternative system to traditional P&T, to support the development of sustainable groundwater remediation plans. Two industrial sites with unique geological frameworks and contamination with dense non-aqueous phase liquid (DNAPL) and arsenic (As) respectively, were selected for the study. At both locations, attempts were made for decades to clean up groundwater contamination by pump-and-treat. In response to persistently high levels of pollutants, groundwater circulation wells (GCWs) were installed to explore the possibility of accelerating the remediation process in unconsolidated and rock deposits. This comparative evaluation focuses on the different mobilization patterns observed, resulting variations in contaminant concentration, mass discharge, and volume of extracted groundwater. To facilitate the fusion of multi-source data, including geological, hydrological, hydraulic, and chemical information, and enable the continuous extraction of time-sensitive information, a geodatabase-supported conceptual site model (CSM) is utilized as a dynamic and interactive interface. This approach is used to assess the performance of GCW and P&T at the investigated sites. At Site 1, the GCW stimulated microbiological reductive dichlorination and mobilized significantly higher 1,2-DCE concentrations than P&T, despite recirculating a smaller volume of groundwater. At Site 2, As removal rate by GCW resulted generally higher than pumping wells. One conventional well mobilized higher masses of As in the early stages of P&T. This reflected the P&T's impact on accessible contaminant pools in early operational periods. P&T withdrew a significantly larger volume of groundwater than the GCW. The outcomes unveil the diverse contaminant removal behavior characterizing two distinct remediation strategies in different geological environments, revealing the dynamics and decontamination mechanisms that feature GCWs and P&T and emphasizing the limitations of traditional groundwater extraction systems in targeting aged pollution sources. GCWs have been shown to reduce remediation time, increase mass removal, and minimize the significant water consumption associated with P&T. These benefits pave the way for more sustainable groundwater remediation approaches in various hydrogeochemical scenarios.

Identification of Seawater Intrusion in the Dibdibba Coastal Aquifer, South of Iraq Using Chemical Indicators and Multivariate Analyses

Seawater intrusion into the groundwater is a major environmental disaster which affects the environment as well as community. This research aims to analyze the seawater intrusion in the Dibdibba coastal aquifer. In this study, researchers used statistical techniques to examine the impact of seawater intrusion in the Dibddiba coastal aquifer in southern Iraq. They collected 15 groundwater samples from pumping wells during wet and dry periods and analyzed those using multivariate statistical analyses and ionic ratios based on the GIS technique. The results showed that there was a strong linear correlation between total dissolved solids (TDS) and several other ions, including Ca2+, Mg2+, Na+, Cl− SO−2 4, and NO−3. The principle component analysis revealed two factor loadings, with the first accounting for a significant portion of the total variance and showing a high loading for TDS, Na+, Cl−, SO−2 4, Mg2+, Ca2+, and NO−3. The second factor had a high loading for K+. The seawater influence was detected in 33.33 percent of the low zone groundwater, 26.66 percent of the moderate zone groundwater, and 40 percent of the high zone groundwater that was studied. Eighty and sixty-seven percent of the groundwater samples, respectively, belonged to the seawater field as Na-Cl type, as shown by Chadha’s graphic, demonstrating the effect of seawater intrusion. Also, during the wet time, 20% of the samples belonged to the reverse ion exchange water field as Ca-Mg-Cl type, but during the dry period, 33.3% did. This is further evidence of the impact of seawater intrusion.

A robust experimental design for conceptual model discrimination based on information theory

This study introduces firm information gain for model discrimination based on Shannon entropy and worst-case scenario experimental design. Firm information gain is the minimal additional information gained by an experimental design with respect to existing information. Robust experimental design aims to maximize the firm information gain by searching for the least number of new pumping wells and observation wells. Robust experimental design includes a Bayes factor threshold to ensure that new data provide strong evidence for model discrimination. To maximize the firm information gain, a framework is proposed that combines the parallel-sequential genetic algorithm (GA) for parallel computing and the nested quadrature rule for efficiently solving multidimensional integrals. The numerical experiment involves the true model for the purpose of verification. The results show that using a full covariance matrix is imperative to avoid exaggerating firm information gain. Collecting new groundwater data is prioritized over exploring additional pumping wells. Maximizing firm information gain is able to identify the same and true model.

Assessment of river water quality improvement due to riverbank filtration (RBF) mechanism

Riverbank filtration (RBF) is a natural process where river water is induced to flow through riverbed soils to pumping wells located on the banks. It is a well-established and proven natural water treatment technology by having a series of physical and chemical processes during subsurface passage. This paper aims at the measurement of physical and chemical characteristics of river water and groundwater from riverbank filtration wells at Kg. Jenderam Hilir, Selangor and to assess the effectiveness of riverbank filtration through Water Quality Index (WQI) for both river water and groundwater. The riverbank filtration is able to improve quality of water such as reducing the turbidity to 0 NTU, Chemical Oxygen Demand (COD) to 3.67 mg/l, Suspended Solids (SS) to 6.33 mg/l and several other contents that existed in the river. In addition, the effectiveness of RBF is also proven based on the improvement of Water Quality Index (WQI) for Langat river from Class IV to Class III.

Optimal Pollution Control and Pump-and-Fertilize Strategies in a Nitro-Polluted Aquifer, Using Genetic Algorithms and Modflow

Nitro-pollution in a confined aquifer may originate from its recharge area, e.g., agricultural sites, animal feedlots, septic tanks, and other waste disposal sites or from treated wastewater recharge wells. The latter case is studied. Existing water supply pumping wells should be protected for a given period. Instead of typically investigating optimal pump-and-treat or hydrodynamic pollution control management/remediation strategies, a novel combined pollution control and pump-and-fertilize (PAF) approach is proposed: protect existing wells with additional wells, considering pumped nitro-polluted groundwater as profitable reusable fertilizer rather than a pollutant to be remediated; convey pumped polluted water to an irrigation reservoir, considering nitrogen (N) uptake by irrigated crops in nearby farmlands and proportional decrease in fertilizer application, meaning profit. Optimization entails the operation of optimally located additional pumping wells with optimal flow rates, minimizing the sum of (i) annual pumping cost, (ii) pipe network (connecting additional wells and reservoir) amortization cost, and (iii) profit from retrieved N reuse. Modflow simulates a 3D flow field and advection-dispersion mass transport, while Genetic Algorithms (GAs) handle optimization. Various scenarios are simulated concerning crops’ retrieved N root uptake percentage, fertilizer, and energy market prices. The paper provides a data-ready optimization/decision support tool that creates a pool of alternative (sub)optimal management solutions/strategies.

Forever legacies? Profiling historical PFAS contamination and current influence on groundwater used for drinking water

A wide range of PFAS residues were studied in an aquifer used for drinking water production which was affected by historical PFAS contamination from a landfill and military camp. Samples were taken at three monitoring and four pumping wells at different depths ranging from 33 to 147 m below the land surface and analysed for a series of 53 PFAS (C2-C14) and PFAS precursors (C4-C24). A comparison of results to earlier research from 2013, with a more limited range of PFAS, showed decreasing concentrations and migration of PFAS with increasing depth and distance from the contamination source.The PFAS profile and branched/linear isomer ratio are used as source characterization tools. The landfill was confirmed to contaminate the groundwater in both monitoring wells, while the military camp was indicated as a probable source for PFAS observed in the deep sampling points of one of the monitoring wells. Pumping wells used to produce drinking water are not yet affected by these two PFAS sources. In one of the four sampled pumping wells, a different PFAS profile and isomer pattern was observed, which indicated a different but yet unknown source.This work shows the necessity of implementing regular screening to identify potential (historical) PFAS sources to be able to prevent future contaminant migration nearby and towards drinking water abstraction wells.

KAJIAN PARAMETER GENETIK KARAKTER KUANTITATIF TANAMAN JAGUNG (Zea mays L.) DI LAHAN KERING

The narrow-sense heritability and expected selection response are very important to be recognized in the F2 population of maize to determine the character to be selected. This study aimed to estimate the narrow-senseheritability and the expected selection response of quantitative characters in the F2 population. The experimental method used in this study was field experiments on dry land using pumping wells for irrigation. This was conducted from April to October 2022 in Amor-Amor Hamlet, Gumantar village, North Lombok district. The experiment was carried out in two growing seasons; namely: the first growing season was to establish kinship with NC1 and the second season was to test the results of crosses by used a Randomized Block Design (RBD). The number of treatments was 105; derived from 35 male parents. Each treatment was replicated 2 times, so there were 210 experimental units. Data were analyzed using analysis of variance (ANOVA); and then calculation of narrow sense heritability and response selection expectations was conducted. The results showed that the narrow sense heritability of all the quantitative characters observed was low, while the selection response of the biomass weight per plant was high; Plant height, leaf angle, and dry cob weight per plant were moderate and other characters were low. Fresh biomass weight per plant can be used as a selection criterion for improving the stay-green character. Yield can be improved through enhancing dry cob weight per plant.
 
 Keywords: corn; heritability; response of expected selection and dry land.

3D modelling of surface spreading and underground dam groundwater recharge: Egri Creek Subbasin, Turkey.

This study investigated surface spreading and underground dam recharge methods to replenish groundwater in Turkey's Egri Creek Sub-basin of the Kucuk Menderes River Basin. A three-dimensional numerical model was employed for this purpose. Field and lab data are provided to the model for realistic simulations. Pumping test results were used to determine the aquifer parameters. The laboratory works involved sieve analysis, permeability tests, and porosity and water content prediction. The numerical model's boundary conditions were determined from the geological and hydrogeological characteristics of the study area. Initial conditions were expressed regarding water content and pressure head in the vadose zone. The numerical model was satisfactorily validated by simulating water levels in three different pumping wells in the study area. Seven different scenarios, each having a different pool size, were investigated for the surface spreading recharge method. The results showed that a pool size of 30 × 30m with a 6-m depth basin was the most optimal choice, raising the groundwater level to about 29.3m. On the other hand, it was found that an underground dam could raise the levels by an average of 9.5m, which might not be significant to warrant the construction.

Modeling Flow and Transport in Saline Aquifers and Depleted Hydrocarbon Reservoirs for Hydrogen Energy Storage

Summary Hydrogen (H2) is an attractive energy carrier, and its true potential is in decarbonizing industries, such as for providing heat for buildings and being a reliable fuel for trains, buses, and heavy trucks. Industry is already making tremendous progress in cutting costs and improving the efficiency of hydrogen infrastructure. Currently, heating is primarily provided by using natural gas and transportation by gasoline with a large carbon footprint. Hydrogen has a similarly high energy density, but there are technical challenges preventing its large-scale use as an energy carrier. Underground geologic storage of hydrogen in porous media (aquifers and hydrocarbon reservoirs) could offer substantial storage capacity at low cost as well as buffer capacity to meet changing seasonal electricity demands or possible disruptions in power supply. Underground geologic storage must have adequate capacity and ability to inject/extract high volumes with a reliable caprock. A thorough study is essential for a large number of site surveys to locate and fully characterize the subsurface geological storage sites both onshore and offshore. An isothermal compositional reservoir simulator was used to evaluate hydrogen storage and withdrawal from saline aquifers and depleted oil/gas reservoirs. The phase behavior, fluid properties, and petrophysical models were all calibrated against published laboratory data for density, viscosity, relative permeability, and capillary pressure for a given site. History-matched dynamic models of two CO2 injection field projects in saline aquifers and one natural gas storage in a depleted oil reservoir were considered as hypothetical hydrogen seasonal storage sites. A wide range of working gas volume/cushion gas volume ratios was observed, meaning that careful optimization is required for a successful storage project. For the aquifer cases, the range was 0.292 to 1.883 and a range of 1.045 to 4.4 was observed for the depleted hydrocarbon reservoir scenarios. For the saline aquifer cases, a higher injection rate, longer injection/withdrawal (I/W) cycles, and the use of pump wells to control the hydrogen plume spreading were all beneficial for improving the working gas/cushion gas ratio and the working gas volume. Plume control was important for storage in the oil reservoir in which changes in the well length location and orientation showed high sensitivity in the working and cushion gas volumes. Sensitivities to the initial gas saturation in the depleted gas reservoir scenarios suggested that both cushion and working gas volumes increased with the initial gas saturation while the ratio of working to cushion gas volumes decreased with the initial gas saturation. Finally, when comparing the ratios of working to cushion gas volumes, it was the highest for the depleted oil reservoir, followed by the depleted gas reservoir, and the aquifer.

Numerical Simulation and Analysis of the Influencing Factors of Foundation Pit Dewatering under a Coupled Radial Well and Curtain

It is crucial to use a suitable dewatering technique to prevent land subsidence and substantial decreases in groundwater levels caused by the dewatering of groundwater during the construction of underground projects. Therefore, in this study, a generalized three-dimensional numerical model of groundwater flow was implemented for an underground station pit project. The dewatering efficiency of the coupled radial well-curtain method was investigated and compared with that of a traditional method. In addition, the influence of different structures and parameters (radial pipe diameter, conductance, number of radial pipes, and shaft drawdown) on the dewatering efficiency was assessed. The results showed the following: (1) radial wells caused less disturbance to the groundwater seepage field and extracted less groundwater during the dewatering process compared with pumping wells; (2) the structure and parameters of the radial wells positively correlated with the dewatering efficiency; (3) the curtain improved the dewatering efficiency, resulting in lower amounts of groundwater discharged and less disturbance to the groundwater flow field; and (4) the coupled radial well-curtain method is an efficient dewatering method that could effectively prevent the lowering of groundwater level outside the foundation pit, thus reducing the risk of land subsidence in the surrounding area.

HORIZONTAL CIRCULAR PUMPING WELLS TO MINIMIZE SALINE WATER UPCONING: WATER RESOURCE DEVELOPMENT MEASURE FOR TROPICAL SAVANNA CLIMATIC NINH THUAN AREA, VIETNAM

Link for citation: Nguyen Van Hoang, Trinh Hoai Thu, Shakirov R.B., Syrbu N.S., Tran Thi Thuy Huong, Lee N.S. Horizontal circular pumping wells to minimize saline water upconing: water resource development measure for tropical savanna climatic Ninh Thuan area, Vietnam. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 4, рр.209-220. In Rus.
 The relevance. The Southern central region of Vietnam, including Ninh Thuan province, has a tropical savanna climate and has been heavily suffering from drought and water salinization. Ninh Thuan province has faced severe droughts in recent years because of the increase of the frequency and intensity of extreme weather conditions, the water scarcity, and the salinity of the groundwater. The distribution of fresh and saline groundwater in Ninh Thuan plain has three zones: 1) zone of entire profile with fresh groundwater; 2) zone of the upper profile's with fresh groundwater and of the lower profile's with saline groundwater, and 3) zone of entire profile with saline groundwater. The groundwater abstraction facilities in the first zone are vulnerable to salinization from surrounding saline water, while in the second zone are vulnerable to the upconing saline water from below. The aim: to determine the optimal groundwater pumping in respect to given water level drawdown, to show that the horizontal circular wells are the best for minimization of saline water upconing, to determine the relationship between the saline water upconing height and the radii of the horizontal circular wells. Objects: tropical savanna climate, coastal plain, fresh and saline groundwater, aquifer with fresh water in the upper profile and saline water in the lower profile, circular groundwater wells, saline water upconing. Methods: finite element method, dynamic programming, Dagan–Bear model of saline water upconing, superimposition principle in dealing with multiple pumping points for identification of overall saline water upconing. Results. Different schemes of pumping fields with either vertical wells or horizontal circular wells with different radii were analyzed for saline water upconing. The time of saline upconing height in all the alternative schemes were determined. A very well regression curve of the relationship between the time saline water upconing to the horizontal circular wells and the circular well radii was obtained. The analysis results are extremely useful supporting well design in terms of minimization of saline water upconing.

Forecasting of Groundwater Quality by Using Deep Learning Time Series Techniques in an Arid Region

Groundwater is regarded as the primary source of agricultural and drinking water in semi-arid and arid regions. However, toxic substances released from sources such as landfills, industries, insecticides, and fertilizers from the previous year exhibited extreme levels of groundwater contamination. As a result, it is crucial to assess the quality of the groundwater for agricultural and drinking activities, both its current use and its potential to become a reliable water supply for individuals. The quality of the groundwater is critical in Egypt’s Sohag region because it serves as a major alternative source of agricultural activities and residential supplies, in addition to providing drinking water, and residents there frequently have issues with the water’s suitability for human consumption. This research assesses groundwater quality and future forecasting using Deep Learning Time Series Techniques (DLTS) and long short-term memory (LSTM) in Sohag, Egypt. Ten groundwater quality parameters (pH, Sulfate, Nitrates, Magnesium, Chlorides, Iron, Total Coliform, TDS, Total Hardness, and Turbidity) at the seven pumping wells were used in the analysis to create the water quality index (WQI). The model was tested and trained using actual data over nine years from seven wells in Sohag, Egypt. The high quantities of iron and magnesium in the groundwater samples produced a high WQI. The proposed forecasting model provided good performances in terms of average mean-square error (MSE) and average root-mean-square error (RMSE) with values of 1.6091 × 10−7 and 4.0114 × 10−4, respectively. The WQI model’s findings demonstrated that it could assist managers and policymakers in better managing groundwater resources in arid areas.

Improvement in Operation Efficiency of Shallow Geothermal Energy System—A Case Study in Shandong Province, China

Shallow geothermal energy (SGE) is a renewable energy source that has the advantage of being low-cost, clean, and locally sourced compared to fossil fuels, and is thus significant for China to achieve its future goals of carbon peaking and carbon neutrality. However, determining how to improve the operational efficiency of SGE systems is a key factor in the sustainable development and utilization of geothermal energy. This study examined the long-term operational efficiency of SGE systems and applied numerical simulation methods of hydro-thermal coupling to a SGE utilization project in Shandong Province, China. The effect of the distribution of pumping and injection wells on the operation efficiency of the SGE system was analyzed, and the parameter of operation efficiency, defined by the ratio of the practical minable shallow geothermal energy to the theoretical shallow geothermal energy, was applied to quantify the operation efficiency of the SGE system. The simulated results show that the phenomenon of heat transfixion is significant in the current operation scheme, where one of three pumping wells is located downstream of the study area, which indicates that the local groundwater flow field mainly controls the operation efficiency of the SGE system. In the optimized operation scheme, the distribution of pumping and injection wells can be adjusted according to the feature of groundwater flow and temperature fields. The degree of heat transfixion significantly declines and the operation efficiency increases by 71.5%. In addition, further improvements in the operational efficiency of the SGE system can be considered through the running time. The findings of this paper will be useful for the construction and management of SGE systems.