Groundwater Consumption Research Articles

System Dynamic Simulation to Determine The Effect Of Water Consumption on Land Subsidence During Covid-19 Pandemic in Jakarta

Excessive groundwater extraction is believed to be one of the main factors for land subsidence which may be caused by tidal flooding due to the position of the surface which is lower than sea level. Covid-19 pandemic that has occurred in Indonesia since March 2020 has caused changes in water consumption patterns which derives from piped water and groundwater. There are many offices and industries that implement work from home (WFH) makes many buildings have a declining occupancy rate. With the decrease in the occupancy rate of the WFH policy, there will be a possibility that groundwater consumption from high-rise buildings that draw groundwater from deep aquifers can be reduced. This research is in the form of modelling and simulation that is used to build a level of understanding on a whole system as well as the interrelationships and interactions between its constituent variables. The purpose of this research was to determine the effect of groundwater consumption during Covid-19 pandemic on land subsidence in Jakarta using the dynamic system simulation method. The results showed that the work from home policy reduces groundwater consumption by 64.7%. In addition, the reduction in groundwater consumption during the Covid-19 pandemic caused land subsidence in Jakarta slows down and the rate of land subsidence in Jakarta decreased from 3.7 cm/year to 1 cm/year.

Soil-Mulching Influence on Spearmint Oil Yield, Ecophysiological Activities and Essential-Oil Content in Rainfed Environment of Southern Italy

The application of soil mulching is widely used to improve crop productivity within semiarid regions of Mediterranean environments. A field study was conducted during two consecutive cycles of spearmint (Mentha spicata L.) within the rainfed region of Southern Italy to evaluate the effects of straw mulch cultivation practices on crop yields and ecophysiological activities. Four treatments were evaluated: (1) rainfed with straw mulch (RM), (2) rainfed without straw mulch (R), (3) well-watered control plants (W) and (4) well-watered with straw mulch (WM). The rainfed mulch treatment (RM) significantly improved oil yields and ecophysiological activity of the spearmint in comparison with rainfed (R). The rainfed mulch treatment (RM) showed lower inhibition of photosynthesis and smaller diffusive limitations than control treatment, while in rainfed plants (R) photosynthetic activity and diffusive limitations strongly decreased at the end of crop cycle. The average essential-oil content was significantly lower under the W, WM and RM treatments, in comparison to the R treatment, during the full-bloom stages (40 DAT). Instead, at the end of crop cycle, the mulching practice (RM and WM) insignificantly changed the essential-oil content compared with non-mulched well-watered treatment (W), while in rainfed plants (R) the essential-oil content strongly decreased. In addition, rainfed conditions affected the percentage of the three major monoterpenes and decreased the formation of carvone from limonene. Therefore, the current study concluded that straw mulch is an effective management practice to improve growing conditions by decreasing groundwater consumption and to increase oil yields in spearmint within this Mediterranean rainfed region.

Groundwater Quality Assessment Using Groundwater Quality Index and Multivariate Statistical Methods and Human Health Risk Assessment in a Coastal Region of the Vietnamese Mekong Delta

This study aimed to evaluate the suitability of groundwater for drinking purposes and assess the associated human health risks for different age groups in a coastal province of Mekong Delta, Vietnam. Twenty groundwater samples were collected in Soc Trang Province, and various water quality parameters were analyzed. The data were employed to calculate entropy-weighted groundwater quality index (EWQI), principal component analysis (PCA), cluster analysis (CA), and non-carcinogenic and carcinogenic risks for adult and children health. The results revealed that groundwater in some locations, especially in GW19, was polluted by hardness, total dissolved solids, NH4+, Cl-, Fe, total coliform, and E. coli. In addition, 5 principal components from the PCA results could explain 84.5% of the total variation of groundwater quality, which also suggested that the potential groundwater pollution sources were geochemical processes, agricultural activities, domestic and industrial wastewater, seawater intrusion, and excessive nitrogen fertilizer application. The CA results showed that monitoring locations can be divided into 4 clusters based on their similarities in groundwater quality, and the most polluted group was found at cluster IV (GW19). The computed EWQI values ranged from 20.05 to 738.52, with approximately 45% of total samples classifying good to excellent water quality. The sampling points with undrinkable quality are mainly located in the northeast and center of the province. The ratio of children and adults under the threat of adverse health effects due to drinking groundwater contained non-carcinogenic substances (NH4+, NO2-, NO3-, Cd, Cu, F-, Mn, and As) ranged from 5 to 40%, and children had higher risks compared to adults. Additionally, the consumption of As-contaminated groundwater also poses carcinogenic risks for children, female and male adults ranging from 4.80×10-6 to 1.33×10-4. The findings of this study can provide helpful information for policymakers in the development of long-term water management strategies to protect community health.

Nitrate in groundwater and agricultural products: intake and risk assessment in northeastern Iran

The suitability of groundwater and agricultural products for human consumption requires determining levels and assessing the health risks associated with potential pollutants. Here, particularly pollution with nitrate still remains a challenge, especially for those urban areas suffering from insufficient sewage collection systems, resulting in contaminating soil, endangering food safety, and deteriorating drinking water quality. In the present study, nitrate concentrations in the commonly consumed fruit and vegetable species were determined, and the results, together with the groundwater nitrate levels, were used to assess the associated health risks for Mashhad city residents. For this assessment, 261 water samples and 16 produce types were used to compute the daily intake of nitrate. Nitrate in groundwater was analyzed using a spectrophotometer, and produce species were examined using High-Performance Liquid Chromatography. Ward’s hierarchical cluster analysis was applied for categorizing produce samples with regard to their nitrate content. Additionally, to account for the sanitation hazards associated with groundwater quality for drinking purposes, total coliform and turbidity were also assessed using the membrane filter (MF) technique and a nephelometer, respectively. Nitrate concentrations exceeded the prescribed permissible limits in 42% of the groundwater wells. The outcomes also exhibit significantly higher nitrate accumulation levels in root-tuber vegetables and leafy vegetables compared to fruit vegetables and fruits. Using cluster analysis, the accumulation of nitrate in vegetables and fruits was categorized into four clusters, specifying that radish contributes to 65.8% of the total content of nitrate in all samples. The Estimated Daily Intake (EDI) of nitrate and Health Risk Index (HRI) associated with consumption of groundwater exceeded the prescribed limit for the children’s target group in Mashhad’s south and central parts. Likewise, EDI and HRI values for produce consumption, in most samples, were found to be in the tolerable range, except for radish, lettuce, and cabbage, potentially posing risks for both children and adult consumers. The total coliforms in groundwater were found to violate the prescribed limit at 78.93% of the sampling locations and were generally much higher over the city’s central and southern areas. A relatively strong correlation (R2 = 0.6307) between total coliform and nitrate concentrations suggests the release of anthropogenic pollution (i.e., sewage and manure) in the central and southern Mashhad.

Recognition method for the health risks of potentially toxic elements in a headwater catchment

The spatial association of potentially toxic elements (PTEs) in soil–crop–groundwater systems is poorly recognised. In this study, the contents of arsenic (As), cadmium (Cd), copper (Cu) and lead (Pb) in paddy soils, rice and groundwater in the Xiancha River catchment were determined. The intrinsic effects of PTEs in soils on their spatial distribution in groundwater and rice were explored. Also, the potential sources and health risks of PTEs in multi-media were investigated. Results showed that the mean contents of As and Cd in soils were 23.86 and 0.26 mg kg−1, respectively. In groundwater, the maximum (average) content of As reached 6.55 (1.84) μg L−1. Moreover, As contents in soils and groundwater showed a sound spatial correlation (q = 0.81), and this is supported by the result of the soil column experiment, indicating homology and the strong vertical migration capacity of As. The non-homologous patterns of Pb, Cu and Cd contaminations in soil–groundwater system suggested that geogenic processes influenced the distribution of these PTEs. Cd presented a poor spatial correlation in soil–rice system, as multiple factors controlled its transfer process. Multivariate statistical analysis results demonstrated that As, Cu and Pb in soils mainly came from agricultural sources, whereas high Cd levels were from mining activities. Additionally, direct consumption of As-contaminated groundwater and Cd-contaminated rice posed significant health risks to local residents. This study, which proposes a risk recognition method used to investigate target PTEs in multi-media, may serve as a valuable reference for further research involving catchments.

Geochemical Modeling Source Provenance, Public Health Exposure, and Evaluating Potentially Harmful Elements in Groundwater: Statistical and Human Health Risk Assessment (HHRA).

Groundwater contamination by potentially harmful elements (PHEs) originating from the weathering of granitic and gneissic rock dissolution poses a public health concern worldwide. This study investigated physicochemical variables and PHEs in the groundwater system and mine water of the Adenzai flood plain region, in Pakistan, emphasizing the fate distribution, source provenance, chemical speciation, and health hazard using the human health risk assessment HHRA-model. The average concentrations of the PHEs, viz., Ni, Mn, Cr, Cu, Cd, Pb, Co, Fe, and Zn 0.23, were 0.27, 0.07, 0.30, 0.07, 0.06, 0.08, 0.68, and 0.23 mg/L, respectively. The average values of chemical species in the groundwater system, viz., H+, OH−, Ni2+, Mn2+, Mn3+, Cr3+, Cr6+, Cu+, Cu2+, Cd2+, Pb2+, Pb4+, Co2+, Co3+, Fe2+, Fe3+, and Zn2+, were 1.0 × 10−4 ± 1.0 × 10−6, 1.0 × 10−4 ± 9.0 × 10−7, 2.0 × 10−1 ± 1.0 × 10−3, 3.0 × 10−1 ± 1.0 × 10−3, 1.0 × 10−22 ± 1.0 × 10−23, 4.0 × 10−6 ± 2.0 × 10−6, 4.0 × 10−11 ± 2.0 × 10−11, 9.0 × 10−3 ± 1.0 × 10−2, 2.0 × 10−1 ± 2.0 × 10−3, 7.0 × 10−2 ± 6.0 × 10−2, 5.0 × 10−2 ± 5.0 × 10−2, 2.0 × 10−2 ± 1.5 × 10−2, 6.0 × 10−2 ± 4.0 × 10−2, 8.0 × 10−31 ± 6.0 × 10−31, 3.0 × 10−1 ± 2.0 × 10−4, 4.0 × 10−10 ± 3.0 × 10−10, and 2.0 × 10−1 ± 1.0 × 10−1. The mineral compositions of PHEs, viz. Ni, were bunsenite, Ni(OH)2, and trevorite; Mn viz., birnessite, bixbyite, hausmannite, manganite, manganosite, pyrolusite, and todorokite; Cr viz., chromite and eskolaite; Cu viz., CuCr2O4, cuprite, delafossite, ferrite-Cu, and tenorite; Cd viz., monteponite; Pb viz, crocoite, litharge, massicot, minium, plattnerite, Co viz., spinel-Co; Fe viz., goethite, hematite, magnetite, wustite, and ferrite-Zn; and Zn viz., zincite, and ZnCr2O4 demarcated undersaturation and supersaturation. However, EC, Ca2+, K+, Na+, HCO3−, Cr, Cd, Pb, Co, and Fe had exceeded the WHO guideline. The Nemerow’s pollution index (NPI) showed that EC, Ca2+, K+, Na+, HCO3−, Mn, Cd, Pb, Co, and Fe had worse water quality. Principal component analysis multilinear regression (PCAMLR) and cluster analysis (CA) revealed that 75% of the groundwater contamination originated from geogenic inputs and 18% mixed geogenic-anthropogenic and 7% anthropogenic sources. The HHRA-model suggested potential non-carcinogenic risks, except for Fe, and substantial carcinogenic risks for evaluated PHEs. The women and infants are extremely exposed to PHEs hazards. The non-carcinogenic and carcinogenic risks in children, males, and females had exceeded their desired level. The HHRA values of PHEs exhibited the following increasing pattern: Co > Cu > Mn > Zn > Fe, and Cd > Pb > Ni > Cr. The higher THI values of PHEs in children and adults suggested that the groundwater consumption in the entire region is unfit for drinking, domestic, and agricultural purposes. Thus, all groundwater sources need immediate remedial measures to secure health safety and public health concerns.

Distribution and transport of microplastics in groundwater (Shiraz aquifer, southwest Iran)

Despite the significance of groundwater to the hydrological cycle and as a source of potable water, very little information exists on microplastics (MPs) in this environment. In the present study, MPs have been determined in ten well samples obtained from an alluvial aquifer in a semi-arid region (Shiraz, Iran) following filtration, digestion and inspection under a binocular microscope. A total of 96 MPs were identified, and concentrations ranged from 0.1 to 1.3 MP L−1 (mean and median = 0.48 and 0.43 MP L−1, respectively) and exhibited a complex distribution across the area that reflected differences in land use and local hydrology and geology. The majority of MPs (about 70%) were fibres of ≤ 500 μm in length, but fragments and films were present at some sites, and the dominant polymers were polystyrene, polyethylene and polyethylene terephthalate. Coupling meteorological and water table monitoring data from the regional water organization and published information on aquifer hydrology, we estimate a lag time from precipitation to water table intrusion of between one and five months and groundwater velocity flows of between 0.01 and 0.07 m d−1. Although the extent of retardation of MPs within the pores of groundwater is unknown, by considering empirical data and theoretical predictions on particle flow through porous media in the literature we surmise that MP residence times in the aquifer are likely to range from years to decades, thereby impeding any clear means of source identification. Nevertheless, and more generally, the consumption of potable groundwater may make to a contribution to MP exposure through ingestion.

Frequency Analysis on Groundwater Consumption and Water Billed to the Community in Kelantan

Groundwater use in Malaysia is natural due to its high frequency. The survey study was conducted in northern Kelantan because the problem in this area is the increased use of groundwater, specially sourced from shallow aquifers among the local community. As a result, the purpose of this study is to evaluate the elements that influence the frequency of groundwater consumption and the projected expenses that the community will be responsible for paying in the state. The population of Kelantan was 1.88 million in 2019[1]. The number of people who participated in this survey is 89 people from 10 districts. Statistical Package for the Social Sciences (SPSS) manages and analyses social science data obtained from the study. Studies show that the frequency of using groundwater is high (94.4%) among the community. The cost of electricity bills is low when getting a high percentage value (98.9%) which supports the statement. The “Chi-square” test was used to determine some of the relationships studied, such as groundwater knowledge in the community, frequency of groundwater use, electricity bills charged to each home, and groundwater quality. The results show that the p-value is more effective than 0.05, referring to the relationship between groundwater knowledge and groundwater use. The p-value is also more significant than 0.5, referring to the relationship between groundwater quality and groundwater use.Meanwhile, the relationship between groundwater consumption and electricity bill, knowledge of groundwater benefits with groundwater consumption, and the relationship between groundwater color and odoris less than 0.05. With the study done, it can be proven that groundwater is very high in the community and the bills charged are very cheap and affordable. Therefore, groundwater use needs to be highlighted for its widespread use throughout Malaysia.

Health implications of selected heavy metals around hydrocarbon impacted sites in the Niger Delta: A preliminary investigation

This study appraises the levels of Heavy metals and health implications in Khana and Gokana LGAs of Rivers State, Nigeria. A random sampling approach was employed for groundwater sampling and samples were collected from a total of twenty-two (22) boreholes in the area. A total of ten (10) residential boreholes were sampled in Khana LGA and twelve (12) in Gokana LGA. Iron (Fe) in Khana area showed concentration exceeding WHO and NSDWQ regulatory limits of 0.3mg/l in BH2, BH4, BH5, BH7, BH8, BH9 and BH10 while in Gokana area, BH11, BH12, BH14, BH17, BH19 and BH20 had Fe concentration exceeding the regulatory requirements. The result shows that Fe concentration in groundwater in the study area is significantly high to render the groundwater unsuitable for oral ingestion. Manganese concentration in samples from Khana showed concentrations above WHO standard in BH3, BH6 and BH9 while only BH16 exceeded the regulatory limit in Gokana area and then all other samples concentrations were within WHO regulatory limit for potable drinking water. Copper (Cu) and Lead (Pb) concentration showed levels below permissible limits in all samples analyzed. The results of hazard index from oral ingestion of water from boreholes in the area ranged from 0.30 to 1.13, with an average of 0.69. Based on USEPA classification, apart from BH9 and BH16 where harmful effect from groundwater consumption is recognized, there is no non-carcinogenic harmful effect that may arise from oral ingestion of most of the groundwater sources in the area. The spatial map revealed that the southern central area is a hot spot that needs urgent attention. The results of hazard index from dermal contact with groundwater in the area ranged from 0.02 to 0.36, with an average of 0.18. Carcinogenic health risk from oral ingestion of groundwater in the area ranged from 1.07 to 16.69, with an average of 8.69. Similarly, cancer risk from dermal contact with groundwater in the area ranged from 0.02 to 0.25 with an average of 0.13. Based on USEPA guidelines as revealed in this study, oral ingestion or dermal contact with groundwater from any borehole cited in Gokana and Khana areas are associated with possible cancer risk. The results and of this study will serve as a baseline data in the investigation of the suitability of groundwater in oil producing areas of Khana and Gokana LGAs of Rivers State for human consumption. Thus, the study has revealed the need of an urgent remediation of oil impacted areas in the study area to mitigate further impact on human health.

Arsenic Contamination in Soil, Vegetable, Groundwater, and Riverine Fish Species in Joypurhat, Bangladesh

Arsenic contamination is one of the major concerns today in Bangladesh. Various potential and threatening health risks for humankind could be occurred due to the consumption of Arsenic which has mixed with the food chain like fish and vegetables. Therefore, in this study, we analyzed 100 samples of deep tube well water, sediment, soil, vegetable, and fish samples, collected from five different Upazila of Joypurhat district in Bangladesh. The farming process, unplanned groundwater consumption, etc. could be marked as the main culprit for arsenic contamination in a region. However, Arsenic concentrations were determined by atomic absorption spectroscopy followed by the wet digestion method. From this analysis, a shocking result has been found that almost every sample contains arsenic and its level crossed the permissible limit set by WHO guidelines for water and food samples (vegetable and rice) which is an alarming issue for southeast Asian countries.

Health risk assessment of toxic elements in groundwater in a major industrial and agricultural basin, (East of Ergene Basin, Turkey)

ABSTRACT Ergene Basin is an important agricultural and industrial region and an important water resource. In this current research, groundwater quality of east of Ergene Basin was evaluated using water quality index (WQI), and health risk due to groundwater consumption was assessed with HQ, HI, and CR. Multivariate statistical analyses were performed to evaluate the multiple effects of pollutants on groundwater. Uncertainty and sensitivity analyses were also performed. All samples were in the “excellent” WQI category. Health risk values for adults and children were below the safe limit, both from digestion and dermal exposure. CR values of As in some samples exceeded the threshold value, both for adults and children. Sensitivity analysis revealed that ingestion rate and exposure frequency for adults and exposure duration and concentration of toxic metal for children were the most sensitive variables affecting probabilistic health risk.

Quantifying water footprint of winter wheat – summer maize cropping system under manure application and limited irrigation: An integrated approach

Recycling of livestock manure in agroecosystems can promote resource utilization and reduce negative environmental consequences from intensive crop-livestock systems. However, the interaction effect of manure application and irrigation strategy on the water footprint (WF) of crop production still remains incomplete. Here, we estimated the WF of the winter wheat – summer maize cropping system based on a three-year field experiment under limited irrigation and manure application by combining the hydrological water balance and the life-cycle assessment. Four fertilization strategies were chemical fertilizer (Fc), manure (Fm), the combination of chemical fertilizer and manure (Fc+m), and no fertilizer input (F0). Two irrigation regimes were irrigation (W1) and no irrigation (W0) at the jointing stage of wheat. W1 increased the blue WF (groundwater consumption per unit of grain yield) of the wheat-maize system by 46–95% compared to W0. The annual blue WF of Fm was 6% lower than that of Fc+m under W0 in 2016–2017, while that of Fc+m was lowest under W1 in 2016–2017 and 2017–2018. Fm had a higher annual yield under W0, while Fc+m yielded better under W1. Notably, the combination of limited irrigation and manure application decreased annual blue WF by benefitting annual grain yield through improving soil water storage. The indirect water consumption per unit grain yield of Fc+m and Fm were 57% and 17% of Fc for wheat and maize, respectively. Our findings highlight the great reductions in blue water footprint and indirect water consumption through limited irrigation and manure application, suggesting an effective way to balance freshwater conservation and crop production.

GCMs simulation-based assessment for the response of the Mediterranean Gaza coastal aquifer to climate-induced changes

AbstractIn the Eastern Mediterranean countries, groundwater contained in coastal aquifers is the predominant water source for supplying water. The Mediterranean Gaza coastal aquifer in Palestine is showing alarming signs of depletion due to climate change and human-caused influences that substantially impact the hydraulic performance of the Gaza coastal aquifer. The climate statistical modeling and the downscaling of the ensemble global climate model under the representative concentration pathway (RCP) scenarios of RCP 2.60, 4.50, and 8.50 refer to a future decreasing trend in the precipitation and an increasing trend in the temperature. The stochastic model refers to an average decrease of −5.2% in the rainfall every 20 years that coincides with the RCP scenarios that show a decrease in precipitation between 0 and −5%. The rate of temperature increase over the next 20 years is defined at +1 °C, which closely matches the RCP results. As a result of human fast-paced activities, groundwater consumption is expected to rise by nearly 55% by the end of 2040, to around 193 million cubic meters, with a substantial withdrawal trend in southern provinces of the Gaza Strip. Consequently, the aquifer model predicts that subsurface water levels might fall at a rate of −2.50% per year, reaching a level of around −27.77 m below the mean sea level (MSL) by 2040. Alternative water supplies, such as desalinated seawater and treated wastewater, with annual maximum volumes of 110 and 16.5 million cubic meters, respectively, are expected to perfectly recharge groundwater resources of the Gaza coastal aquifer at an annual rate of about +3.65% to meet a groundwater table level of around −5 m below the MSL by 2040.

Highly efficient size-sieving-based removal of arsenic(III) via defect-free interfacially-polymerized polyamide thin-film composite membranes

Serious health problems have been linked to the consumption and exposure of arsenic-contaminated groundwater. In comparison to As(V), As(III) is smaller and predominantly present in its neutral form in groundwater, which hinders its efficient removal by conventional nanofiltration and reverse osmosis membranes. In this study, the removal of As(III) was investigated at different pH conditions using three defect-free interfacially polymerized thin-film composite (TFC) membranes made by an optimized in-house developed interfacial polymerization process (KRO). The membranes were fabricated from aromatic para-phenylenediamine (PPD) or meta-phenylenediamine (MPD) and cycloaliphatic piperazine (PIP) by reaction with trimesoyl chloride (TMC). The PPD-KRO, MPD-KRO, and PIP-KRO polyamide membranes were tested with a feed containing 5 ± 1 mg L−1 (ppm) As(III). Two commercial TFC membranes, a seawater (Sepro RO4) and a nanofiltration (DOW NF270) membrane, were also evaluated for comparison. At natural conditions (pH 6–8), the defect-free fully aromatic TFC membranes demonstrated unprecedented size-sieving performance for As(III) removal with a rejection of ∼99.5 and > 99.8% for PPD-KRO and MPD-KRO, respectively, in comparison to ∼95% for the commercial Sepro RO4 seawater membrane tested under the same conditions. In contrast, As(III) rejection of semi-aromatic piperazine-based TFCs, PIP-KRO and NF270, showed a strong dependence on the charge-exclusion mechanism with maximum As(III) rejections of 69.5 and 46.3% at pH 10, respectively. Most notably, we demonstrated that the MPD-KRO membrane achieved an As(III) concentration ∼5 μg L−1 in the permeate (less than the WHO permissible arsenic standard level of 10 μg L−1), whereas PPD-KRO achieved a slightly higher value of ∼14 μg L−1. Our results are very promising considering the arsenic standard level in highly As(III) contaminated groundwater in Bangladesh and India is set at 50 μg L−1.

Policy-Making toward Integrated Water Resources Management of Zarrine River Basin via System Dynamics Approach under Climate Change Impact

In terms of having a comprehensive vision toward supplying the water requirements, a multi-criteria decision-making approach was employed on the Zarrine River Basin (ZRB) in the northwest of Iran. First, the climate change impacts were analyzed with the Long Ashton Research Station Weather Generator (LARS-WG) downscaling approach by using General Circulation Models (GCMs) including the European Consortium Earth System Model (EC-EARTH), Hadley Centre Global Environment Model version 2 (HADGEM2), Model for Interdisciplinary Research on Climate, version 5 (MIROC5), and Max Planck Institute Earth System Model (MPI-ESM), from Coupled Model Intercomparison Project 5 (CMIP5) under Representative Concentration Pathway (RCP4.5, RCP8.5) scenarios for 2021–2080. Afterward, the downscaled variables were utilized as inputs to the Artificial Neural Network (ANN) model to predict future runoff under the climate change impact. Finally, the system dynamics (SD) model was employed to simulate various scenarios for assessing water balance utilizing the Vensim software. The results of downscaling models suggested that the temperature of the basin will increase by 0.47 and 0.91 °C under RCPs4.5 and 8.5 by 2040, respectively. Additionally, the precipitation will decrease by 3.5 percent under RCP4.5 and 14 percent under RCP8.5, respectively. Moreover, simulation results revealed that the water demand in various sectors will be enormously increased. The contribution of the climate change impact on the future run-off was a seven percent decrease, on average, over the basin. The SD model, according to presented plausible scenarios including decreasing agriculture product and shifting irrigation efficiency, cloud-seeding, population control, and household consumption reduction, reducing meat and animal-husbandry production, and groundwater consumption control, resulted in a water balance equilibrium over five years. However, the performance of individual scenarios was not effective; instead, a combination of several scenarios led to effective performance in managing reduced runoff under climate change.

Cyclic use of groundwater: An innovative way to improve performance of a groundwater source heat pump system during a cooling period

The building sector is a large user of energy and thus a large emitter of CO2. Replacing traditional energy with renewable energy in buildings can effectively reduce greenhouse gas emissions and global warming effects. This paper introduces a new groundwater source heat pump (GWSHP) system installed for air-conditioning of an official room. The main innovation of the new GWSHP system is the cyclic use of groundwater to save the electricity consumption of the lifting pump that pumps the groundwater from a well and also to reduce the amount of groundwater needed by the GWSHP system. The cyclic use of groundwater was realized by adding a circulating pump and a tank in the GWSHP system and intermittently running the lifting pump according to the water temperature in a groundwater heat exchanger. The performances of the new GWSHP system for four different operation modes of the lifting pump were evaluated and compared based on measurements of representative days in 2017 and 2019. The results show that the cyclic use of groundwater with an optimal operation mode can not only effectively improve the performance of the GWSHP system but also significantly reduce groundwater consumption. Specifically, the coefficient of performance of the GWSHP system was increased from 3.6 for conventional operation mode with no cyclic use of groundwater to 4.3 for the optimal operation mode, and the groundwater consumption per working day was significantly decreased from 9.2 m3 for conventional operation mode to 4.0 m3 for the optimal operation mode. Moreover, the long-term performance for three consecutive years from 2018 to 2020 was also evaluated based on measurements, and the results show that the long-term performance is almost the same as the performance of the representative day, which means that the representative day method used in this paper to evaluate the performance of the GWSHP system is feasible and reliable. The operating experience of this study can provide an important reference for the design and selection of GWSHP systems in areas with a different abundance of groundwater.

Evapotranspiration partitioning for winter wheat with shallow groundwater in the lower reach of the Yellow River Basin

Accurately partitioning evapotranspiration (ET) remains one of the key research gaps in agro-ecosystem water research. The interaction of shallow groundwater with winter wheat increased the complexity of ET partitioning. Here we proposed a cutting method to partition ET into soil evaporation (E) and transpiration (T). Field multiple lysimeter experiments under 4 different watertable conditions were conducted at the Yucheng Experimental Station to investigate the partitioning of ET for winter wheat under shallow groundwater. Results showed that the cutting method is applicable and could obtain reasonable ratio of T to ET for crop land of winter wheat. Moreover, the T/ET could be generalized into a curve for representing the ratio of T to ET (i.e. K=T/ET) at the mid- and late-season stages of winter wheat. The maximum value of generalized T/ET curve (Kmax) increased with the increase of groundwater table depth (DTW), and was 0.651, 0.768, 0.771 and 0.869 for the depth of 0.4 m, 0.7 m, 1.1 m and 1.5 m, respectively. The higher transpiration proportion corresponded to the higher yield of winter wheat, which indicated that increased groundwater depth was benefit to enhance the groundwater consumption by transpiration and hence yield when watertable depth was within 1.5 m. Moreover, the lower evaporation proportion might lower the soil salinization risk due to less soil evaporation. It is important for the understanding of the interaction between evapotranspiration components of crop with shallow groundwater and the sustainable management in the lower reach of the Yellow River Basin.

Changes in the Invasion Rate of Prosopis juliflora and Its Impact on Depletion of Groundwater in the Northern Part of the United Arab Emirates.

Prosopis species were introduced to the United Arab Emirates (UAE) region for desert greening. However, the species now pose a great threat to the native plant diversity. This study used high-resolution satellite imagery (1990–2019) to understand the history and current distribution of Prosopis species and their impact on fresh groundwater. The results show that the Prosopis invasion in the study area reached its maximum expansion rate in 2019 and covered an area of about 16 km2 compared to 0.2 km2 in 1990. The areas near Sharjah Airport, Umm Fannan, and Al Talla, located at a lower elevation of the sand dune area, are heavily invaded. Prosopis groundwater requirement derived using evapotranspiration shows that groundwater consumption has changed drastically after 2010 and consumed about 22.22 million m3 of groundwater in 2019, which is about a 7372% increase in groundwater consumption from the year 1990 to 2019. The results can be useful for setting up a management plan for the sustainable use of this species in the UAE region in particular and other similar countries in the arid land regions that are suffering from freshwater depletion because of Prosopis invasion.

Arsenic Contamination in Groundwater and Potential Health Risk in Western Lampang Basin, Northern Thailand

This research aimed to investigate the spatial distribution of arsenic concentrations in shallow and deep groundwaters which were used as sources for drinking and domestic and agricultural uses. A geochemical modeling software PHREEQC was used to simulate equilibrium geochemical reactions of complex water–rock interactions to identify arsenic speciation and mineral saturation indices based on groundwater quality and hydrogeochemical conditions. In addition, the potential health risk from arsenic-contaminated groundwater consumption was assessed based on the method developed by the U.S. Environmental Protection Agency. The study area is located at the western part of the Lampang Basin, an intermontane aquifer, Northern Thailand. The area is flat and situated in a floodplain in the Cenozoic basin. Most shallow groundwater (≤10 m depth) samples from dug wells were of Ca-Na-HCO3 and Ca-HCO3 types, whereas deep groundwater from Quaternary terrace deposits (30–150 m depth) samples were of Na-HCO3 and Ca-Na-HCO3 types. High arsenic concentrations were found in the central part of the study area (Shallow groundwater: <2.8–35 mg/L with a mean of 10.7 mg/L; Deep groundwater: <2.8–480 mg/L with a mean of 51.0 mg/L). According to geochemical modeling study, deep groundwater contained toxic As(III), as the dominant species more than shallow groundwater. Arsenic in groundwater of the Lampang Basin may have been derived from leaching of rocks and could have been the primary source of the subsurface arsenic in the study area. Secondary source of arsenic, which is more significant, could be derived from the leaching of sorbed arsenic in aquifer from co-precipitated Fe-oxyhydroxides in sediments. Quantitative risk assessment showed that the average carcinogenic risk values were as high as 2.78 × 10−3 and 7.65 × 10−3 for adult and child, respectively, which were higher than the acceptable level (1 × 10−4). The adverse health impact should be notified or warned with the use of this arsenic-contaminated groundwater without pre-treatment.

Health Risk Assessment From Heavy Metals Derived From Drinking Water and Rice, and Correlation With CKDu

Rice is the staple food of most Asians, including Sri Lankans. It is cultivated extensively in the dry zonal regions in Sri Lanka such as the Polonnaruwa district, where the prevalence of chronic kidney disease of unknown etiology (CKDu) is higher. We investigated the concentrations of potentially toxic heavy metal(loid)s in groundwater and locally produced rice and correlated their exposure with the prevalence of CKDu. We studied human health exposure risks such as total daily intake (TDI), hazard quotient, hazard index, and carcinogenic risk (CR) from the consumption of groundwater and rice. In well-water, the concentrations of heavy metal(loid)s, cadmium (Cd), arsenic (As), and lead (Pb) were below the World Health Organization (WHO) stipulated allowable limits. Except for Pb, contents of other heavy metal(loid) in all rice samples were lower than maximum permissible limits by the WHO (0.02 mg/kg). Twenty-three per cent (23%) of rice samples analyzed exceeded the permissible limit for TDI of Pb, and analysis of hazard index for Cd, As, and Pb revealed 26% of rice samples could result in a health risk through the consumption of rice in this population. Further, the outcome depicted no CR of Cd, As, and Pb by consuming rice in this study area. We recommended further studies and investigations to minimize or eliminate potential risks from chronic Pb exposure to consumers.