Current Extraction Rates Research Articles

Hobli wise hydro geomorphological evaluation of the groundwater prospects mapping

ABSTRACT Numerous studies highlight the urgent issue of groundwater depletion due to overexploitation. The United Nations’ World Water Development Report (2023) warns that if current extraction rates persist, many regions could face severe groundwater shortages in the coming decades. A 2021 study in Nature reports that about one-third of the world’s largest groundwater basins are depleting faster than they are replenished, escalating the risk of critical shortages. In Chickballapur District, excessive agricultural activity has led to an imbalance between groundwater loss and recharge. To address this challenge, a weighted overlay analysis of spatial layers in QGIS was employed to identify potential groundwater zones. This methodical approach involved mapping topographic features and integrating six spatial layers: slope, geomorphology, lithology, drainage, lineament and land use/cover. Each subcategory was ranked and scored based on expert opinion and existing literature. The Central Ground Water Board data was used to validate the resulting groundwater prospect map. The study further included an assessment of groundwater prospects across administrative units by superimposing the administrative boundaries on the final map. Calculating the percentage of land within each groundwater prospect category is crucial for effective groundwater management at the administrative level.

A numerical modelling approach to investigate the fate of brine reject of farm scale desalination plants on groundwater aquifers in arid environments

Farm-scale desalination units are gaining popularity for agricultural irrigation in arid countries, such as Kuwait to meet freshwater demands. However, less attention has been given to the management of environmentally hazardous brine reject water they produce. In this study we investigated the fate of brine water produced by the inland desalination units on the underlying aquifers using numerical modelling and field investigations. The methodology involved developing groundwater flow and solute transport models using Flex VMF-SEAWAT to simulate the movement of reject brine. The field investigations included collecting 150 water samples and conducting pumping tests on newly drilled wells. This numerical simulation considered advection, dispersion, and adsorption processes with variable groundwater density following rigorous validation and calibration of the developed numerical models. The results show that the RO reject brine will significantly increase groundwater salinity, exceeding 10,000 mg/L when accounting for advection, dispersion, and adsorption processes. The sustainable yield of the aquifer, with a salinity of <10,000 mg/L, averages 500 Mm3 but is expected to be depleted within 16 years with the current extraction rate. The resulting hydraulic properties are favourable with K about 100 m/d, T > 1000 m2/day, and Sy just >0.1. The adopted values for dispersivity and adsorption coefficients for chloride and sulphate salts in the aquifer were 10 m and 1 × 10−7 [mg/L]−1 respectively. Chemical and numerical analyses indicate a mixing ratio between the reject brine and groundwater in the study area of approximately 10 %. Uncontrolled groundwater extraction, combined with the surface disposal of RO reject brine, has led to a significant decline in groundwater levels and an increase in the salinity. The adsorption ratio of simulated brine plume was 13 %. The authors recommend to dispose the RO reject water in a safe location or transfer it to the nearest wastewater treatment plant for proper treatment and reuse.

The catastrophic effects of groundwater intensive exploitation and Megadrought on aquifers in Central Chile: Global change impact projections in water resources based on groundwater balance modeling

Central Chile is undergoing its most severe drought since 2010, affecting ecosystems, water supply, agriculture, and industrial uses. The government's short-term measures, such as increasing groundwater extraction (by 383 % from 1997 to 2022), are exacerbating the situation, leading to long-term hydrological deterioration. The objective of this research is to establish the main processes driving the water table depth evolution within Central Chile over the period 1979–2023. This is done by conducting groundwater balances on five major hydrological basins of Central Chile. For the Megadrought (MD) period (2010−2022), the groundwater level depths reflect not only the recharge variability but, especially, the forcing trend of groundwater withdrawals: they represent 35 % and 65 %, respectively, of the total phreatic level drawdown. This result underlines the dominant role played by groundwater withdrawals in the current delicate state of Central Chile's groundwater resources, while revealing that drought is a new complex phenomenon to deal with, in the midterm, to revert the current water resource trend in Central Chile. Our study moreover presents the impact of climate change in the basin in the framework of six different groundwater withdrawal scenarios. In the worst case (i.e., RCP8.5), the aquifer recharge decreases 18 % with respect to 1979–1997, which is the period assumed to be unaffected by the impact of MD and withdrawals. Such a reduction may be irrelevant in the dynamics of the aquifer system if the current extraction rate does not change. The estimated recovery time needed to reach aquifer conditions equal to those of the unaffected period is approximately 50 years.

Economic valuation from direct use of melaleuca forest at U Minh Ha National Park, Vietnam

This paper investigates the direct use values of melaleuca forests at U Minh Ha National Park. The market price method (MPM) was utilised to estimate the economic value. A semi-structured questionnaire comprising multiple-choice and open-ended questions was administered to 360 families in 2022 to collect data on the various forest products available locally, the quantity of these products collected, as well as their corresponding prices and costs. The results revealed that the total net benefits that the local people derived from the entire melaleuca ecosystem were US$ 73,022,184 per year, or an average worth of US$ 1,723 per person per year. Most of the local annual income was derived from construction pole harvesting (US$ 57,092,223), followed by wood for fishing boats (US$ 5,792,757) and fish (US$ 6,226,995). The melaleuca ecosystem was significant, contributing an average of 75% to the total annual per capita income for the local people. However, the U Minh Ha melaleuca ecosystems are threatened and predicted to disappear in 118 years if the current extraction rate of wood products (2,204 kg/person/year) remains uncontrolled. This suggests an urgent need for an integrated management plan that incorporates melaleuca preservation, as well as the commercial and local use interests in this area.

Temporally explicit abiotic depletion potential (TADP) for mineral resource use based on future demand projections

PurposeAssessing the potential impacts (characterization) of mineral resource use in life cycle impact assessment (LCIA) has long been debated. One of the most crucial challenges in the characterization models for mineral resource use is the consideration of the changing demand and availability of in-use stocks in the future, which is relevant to the global population and economy growth as well as the increasing low-carbon technologies. We propose an extended characterization model to assess the potential impacts for arbitrary time horizons, considering future demand changes and the availability of in-use stock: temporally explicit abiotic depletion potential (TADP).MethodsThe TADP was developed based on abiotic depletion potential (ADP), which is a widely used characterization model for mineral resource use. While the ADP assesses the potential impacts of mineral resource use based on a natural stock estimate and the current extraction rate, the TADP adopts an average extraction rate for arbitrary time horizons. The average extraction rate was estimated using material flow analysis considering future demand changes and recycling under the five shared socioeconomic pathways (SSPs). TADPs were calculated for six common metals: aluminum, copper, iron, lead, nickel, and zinc.Results and discussionAs a result of calculating TADPs for the term by 2050 (TADP2050), compared to iron, all other metals showed larger values of characterization factors for all SSPs than the original ADPs. The TADP2050 of copper exhibited the largest difference with ADP among the six metals (approximately 1.9 times), which is mainly attributed to future demand growth. On the other hand, for the longer time perspective, the TADP2100 of lead and zinc exhibited larger differences with ADP than copper (approximately 2.8 times for zinc), which is mainly due to a relatively shorter lifetime for lead and a lower recycling rate for zinc. This suggests that the relative significance of the characterization factors of metals varies depending on the temporal perspective.ConclusionsWith the proposed characterization model, the potential impacts of mineral resource use can be assessed reflecting future situations for the selected time horizons. The results demonstrate that the consideration of future situations greatly influences the relative significance of the potential impacts of using different mineral resources in the results of LCIA studies. By expanding the coverage of mineral resources and future scenario analysis to other relevant factors, the TADP model can improve the robustness of the assessment and further support decision-making towards sustainable resource management.

Expected spatio-temporal variation of groundwater deficit by integrating groundwater modeling, remote sensing, and GIS techniques

For the last 6 decades, the Nile Valley region has been subjected to expanding reclamation, advancing agricultural and human activities. Extreme changes in the groundwater regime and land cover have been detected. Evaluation and mapping of groundwater and its controlling factors as important environmental factors have been assessed and managed based on their Spatio-temporal distribution and effect on the hydrologic properties. Visual MODFLOW and GIS database modeling are applied to simulate and predict the future aquifer response due to increased pumping rates to match the continuous need for water resources. Two pumping scenarios are proposed. The first scenario assumes that the current extraction rates continue without modification over the next 50 years. The second scenario assumes to increase the pumping rates by 50% from those of the first scenario. An obvious decline in groundwater heads is resulting in both scenarios. It reaches 20 m in the first scenario while it exceeds 30 m in the second one. Results obtained from the model have been merged with remote sensing data under GIS framework. GIS model using the weighted overlay approach is applied to produce the groundwater potentiality map, classified to five potential zones; very good, good, intermediate, poor, and very poor, the model showed that zone of very good recharge will decrease with time and disappear with increase pumping rate by 50% while the poor and very poor zones increase with time. There is a reciprocal relationship between the human and geological factors on the efficiency of the aquifer.

Orthodontic extraction practices: a cross-sectional survey of orthodontists in Australia

Abstract Objective To survey Australian-based orthodontists regarding their opinions on their extraction practices. Method A pilot-tested electronic-questionnaire was distributed to 465 members of the Australian Society of Orthodontists. Questions pertained to their demographic details, current extraction rates, changes in prescribed orthodontic extraction patterns over the past 5 to 10 years and the factors that may have influenced decisions. Results A response rate of 35.05% was recorded. Orthodontists estimated that they extracted permanent teeth in 21.03% and 22.06% of recently treated adults and children/adolescents presenting with a Class I malocclusion. Respondents were less comfortable carrying out non-extraction treatment in child/adolescent patients (15.4%) than in adult patients (34.7%) when crowding was greater than 6 mm. Most orthodontists (55.89%) who had practiced for more than 5 years believed that the number of patients that were treated by extractions was unchanged over the past 5 to 10 years while 34.55% believed that the proportion had decreased. More experienced orthodontists tended to report increased rather than decreased extraction rates (p = 0.0102). Most of those (88.1–93.17%) who reported decreased extraction rates considered facial aesthetics had a moderate/major influence on their extraction decisions. The increased use of ‘combined’ interproximal reduction (IPR) and arch lengthening in children/adolescents (55.8%) and IPR in adults (85%) was reported by those whose extraction rates had decreased. Conclusions Orthodontists extracted permanent teeth in just over 20% of their patients who presented with a Class I malocclusion. Most orthodontists considered that their extraction rates had not changed over the past 5 to 10 years. The increased use of IPR with or without arch lengthening procedures, was reported by those whose extraction rates had decreased over the same time period.

Evaluation of Groundwater Potential and Safe Yield of Heterogeneous Unconsolidated Aquifers in Chiang Mai Basin, Northern Thailand

Chiang Mai basin has an escalating population growth resulting in high demand for water consumption. Lack of surface water supply in most parts of the basin gives rise to the increasing use of groundwater which leads to a continuous decline in groundwater level in the past decades. This study is the first long-term groundwater monitoring and modeling study that aims at developing a transient, regional groundwater flow model of heterogeneous unconsolidated aquifers based on the MODFLOW program. Long-term groundwater monitoring data from 49 piezometers were used in model calibration and validation. The pilot points technique was used to account for the spatial variability of hydrogeologic parameters of heterogeneous aquifers. The simulation results and statistics showed that most sensitive and significant model parameters were spatially variable hydraulic conductivities and recharge rates. The Chiang Mai basin’s unconsolidated aquifers do not have high potential. The water table and/or potentiometric surface in the southeast and southwest areas of Chiang Mai city were continuously decreasing with no sign of recovery indicating critical groundwater condition and careful management must be considered. Safe yield calculation, based on a 2-m average drawdown threshold, suggested that unconsolidated aquifers of the Chiang Mai basin can sustain overall abstraction rates up to 51.2 Mm3/y or approximately 214% of the current extraction rates.

Understanding Oil Cycle Dynamics to Design the Future Economy.

In this work, we make the ansatz that economic production is reduced to the energy made available to the economy. In (Illig and Schindler, BioPhys Econ Resour Qual 2(1):1, 2017) the price of oil was expressed as a function of the size of the economy, the cost share of oil, and the quantity of oil extracted. We clarify assumptions needed to use this explicit price equation to study prices. Using the current extraction rate, the previous year’s extraction rate, and interest rates of the Federal Reserve we use linear regression to give a model for oil prices from 1966 to 2018. The model verifies that deductions made from the explicit price equation are consistent with empirical data over the given time period. Our analysis indicates that the contraction phase of world oil extraction began in 2020 and that it will be characterized by relatively low oil prices. We present some challenges and opportunities for building a future economy if our assumptions prove valid.

Abiotic depletion and the potential risk to the supply of cesium

The petroleum exploration industry is the largest end user of cesium where it is employed in oil well drilling fluid. It has recently been broadly reported that the inclusion of cesium into perovskite for photovoltaics and optoelectronics significantly improves their properties. If this element is eventually incorporated into commercial perovskite photovoltaic devices, this usage will add to the amount of Cs required. Herein, mineral resources and the extraction rate of Cs are collected, despite the scarcity and uncertainty of the data. Considering only the Cs resources currently known, as well as assuming the current extraction rate as constant, Cs resources will be completely depleted by 2056. The abiotic depletion potential impact category factor for Cs is calculated to be 1.25·10-4 kg Sbeq. The supply risk of Cs is obtained considering that either a) Canada and Zimbabwe are the main producers or b) China controls all production. The results concur that there is an increase in the supply risk when all Cs production is concentrated in a single place.

Assessment of age, origin, and sustainability of fossil aquifers: A geochemical and remote sensing-based approach

An integrated approach was developed to assess the sustainability, origin, age, evolution, and groundwater potential of large fossil aquifers using the Mega Aquifer System (MAS) (area: 2 × 106 km2) in the Arabian Peninsula as a test site. A two-step exercise was adopted, the sustainability of the MAS was first investigated through the analysis of GRACE data and land surface model (LSM) outputs. Then, integrated geochemical, remote sensing, and field studies were conducted to address the age, origin, hydrogeological setting, and evolution of the southern sections of the MAS (Rub Al Khali Aquifer System (RAKAS)), the area identified from the analysis of GRACE and LSMs as being the most suited for sustainable development. Analysis of GRACE and LSMs revealed: (1) the MAS central and northern sections are experiencing high groundwater extraction (6.6 km3/yr) and depletion rates (−2.8 ± 0.8 km3/yr) with minimum balancing potential through aquifer capture processes, yet sustainability could be achieved by reducing annual extraction by 2.8 km3, and (2) the MAS southern sections (Rub Al Khali Aquifer System (RAKAS)) are experiencing low groundwater depletion rates (eastern RAKAS: −1.8 ± 1.4 mm/yr) to steady-state conditions (western RAKAS: −0.73 ± 1.4 mm/yr). Geochemical, remote sensing, and field investigations over the RAKAS revealed: (1) the presence of west to east trending drainage networks and large-scale groundwater flow systems consistent with a meteoric source (precipitation over Red Sea Hills); (2) increasing 36Cl model ages along groundwater flow directions (up to 970,000 years), indicating aquifer recharge in wet Pleistocene periods; (3) progressive depletion in the O and H stable isotopic compositions of aquifers with increasing distance from the Red Sea Hills basement outcrops, indicating modest recharge during prevailing dry conditions; and (4) the presence of relatively fresh (TDS: 800–2800 mg/L) and non-radioactive (226Ra + 228Ra < 0.185 Bq/kg) water in western RAKAS. Findings suggest that sustainable agricultural development is achievable at current extraction rates in western RAKAS and provide a replicable and cost-effective model.

Which factors influence orthodontists in their decision to extract? A questionnaire survey.

BackgroundTo evaluate the relative influence of different criteria in the choice between extraction and nonextraction treatment in current orthodontics, and to assess how the percentage of extractions has evolved over time.Material and MethodsPre-treatment records (panoramic radiograph, lateral cephalogram, study casts and photographs) of fourteen cases in permanent dentition (adult or adolescent) with class I molar relationship and moderate anterior crowding were evaluated by 28 orthodontists. For each case, each orthodontist filled out a questionnaire reporting his treatment plan proposal (extraction or nonextraction) and the importance of specific parameters in his decision-making process, using categorical scales. Orthodontists practicing for more than 15 years were also asked to compare this decision with the one they would have taken at the beginning of their professional career.ResultsThe two most important factors in the decision-making were the soft tissue profile and the amount of crowding. The least important factor was the presence of third molars. In cases of nonextraction treatment, the lack of space was managed mostly by dental expansion and stripping. Twenty percent of the case evaluations revealed extraction(s) decisions. Among the orthodontists practicing for more than 15 years, the current extraction rate reached 24%, whereas the same orthodontists reported they would have extracted in 39% of the cases in the past.ConclusionsThe present study suggests that soft tissue profile has a higher impact than traditional criteria such as cephalometric measurements in the extraction decision. This is associated with a decreased extractions rate compared to the past. Key words:Orthodontics, extractions, survey, treatment planning.

Molybdenum resources: Their depletion and safeguarding for future generations

Comparison of the current extraction rate of molybdenum with the globally extractable resources of molybdenum shows that exhaustion of molybdenum within fifty to hundred years will be a reality. Unless measures are taken to reduce the use of primary molybdenum resources, the transition to a fossil-free energy world could be jeopardized. This study argues that the global use of primary molybdenum resources needs to be substantially reduced at short notice, if humanity wishes to take the interests of future generations into account. We investigated how this goal can be achieved. The study shows that the focus should be on increasing molybdenum recycling, because there is little or no substitution potential for molybdenum in its major applications. It will be necessary to increase the recycling rate of molybdenum from end-of-life products from the current rate of 20% to more than 80%. This ambitious goal can only be achieved by introducing a dedicated molybdenum waste collection, separation, and recycling system. It is highly uncertain that the free market price mechanism will work in time and sufficiently to preserve molybdenum resources for future generations.

Modeling the energy future

AbstractA bare‐bones dynamic model of an island economy is constructed for the purpose of discovering “socially optimal” fossil fuel depletion schedules. An entire family of candidates is identified, all members being significantly more gradual than the one currently in force. The active ingredient in the model is a real‐valued function of two real variables―the current extraction rate and the quantity extracted to date―which quantifies the need to expend energy in the course of delivering it to end users. The main conclusions are that fossil fuels are currently being extracted far too fast for the common good, while a wide variety of socially preferable schedules are overlooked.Summary for ManagersConsider conservation! Several methods have proven successful in the past. Before World War I, Standard Oil did it by monopolizing the industry. During the 1930s, the Texas Railroad Commission invoked martial law. OPEC has achieved intermittent success by forming a cartel. The proposed carbon tax may be the fairest alternative. Any method of slowing the extraction of fossil fuels will encounter resistance, as the public has long been addicted to cheap energy. Yet conservation will slow global warming, even as it economizes an increasingly scarce resource. Expect no painless alternative―there is none!

Ownership of parrots in Madagascar: extent and conservation implications

AbstractThe trade of live parrots is a threat to wild populations but is understudied. Madagascar is home to three parrot species listed on CITES Appendix II: Coracopsis nigra, Coracopsis vasa and Agapornis canus. Prior to this study there were no data on the ownership of parrots in Madagascar. We therefore aimed to investigate the extent of the domestic pet trade in this group. Our objectives were to quantify the prevalence, spatial extent, and timing of ownership. We collected data in July and August 2016 in nine urban towns across Madagascar, using semi-structured household surveys (n = 440). We found that the ownership of pet parrots is widespread in time and space; 37% (95% CI 26–48%) of interviewees had seen, and 8% (95% CI 3–13%) had owned, a Coracopsis sp. Fewer interviewees (4.5% of all interviewees) had seen A. canus in captivity, and only one individual reported having previously owned an A. canus. We estimate that 1,290 Coracopsis spp. individuals were held in captivity in the towns surveyed, in the 1.5 years prior to our interviews. It is likely that much of this ownership is illegal, although we did not examine this explicitly. Additional research is needed to determine whether current extraction rates are sustainable. This study adds to a growing body of evidence that the domestic regulation of the trade of wild species is not being addressed adequately in Madagascar.

Spatio-temporal analysis of the impact of climate, cropping intensity and means of irrigation: an assessment on rice yield determinants in Bangladesh

Rice (Oryza sativa) is the most important staple food for almost half of the global population. Improvement of rice yield is of global concern and is influenced by a wide variety of regional factors including climate and agricultural management. This research addresses the need to understand the relative influence of these factors and develop geographically explicit determinants of rice yield across Bangladesh. The specific objectives of this study were (a) to assess spatial and temporal variation in rice yield, cropping intensity and means of irrigation, and (b) to evaluate the relative importance of spatio-temporal change in climate, cropping intensity and means of irrigation on rice yield. A database on rice yield, management practices (cropping intensity and means of irrigation) and climate was collected from the Bangladesh Bureau of Statistics and Bangladesh Meteorological Department, respectively, for the years of 1981–2010. Linear mixed models were used to assess the influence of different determinants on rice yield. The results indicate that irrigation, particularly groundwater irrigation, had a stronger influence on rice yield than climatic conditions and cropping intensity in Bangladesh during the study period. Temperature and rainfall showed negative impacts on yield. Rice yield also declined when cropping intensity increased. Both climate and groundwater extraction need to be considered in future policy development. However, the current extraction rate of groundwater may not be sustainable in the future to increase rice yield. The study concludes that spatio-temporal differences in observed yield allow interpretation of potential determinants that are important for food policy development in Bangladesh.

Groundwater modeling as a precursor tool for water resources sustainability in Khatt area, UAE

Groundwater is the main source of irrigation in the Khatt area located in the northeastern part of the United Arab Emirates. The excess pumping of groundwater for irrigation during the last three decades has decreased the average groundwater flow by one tenth. Water resources in the region are of strategic national importance. Therefore, the main objective of this paper is to establish an accurate groundwater budget model that will enable assessment of water availability in the Khatt Basin. The well-known software MODFLOW is used to simulate groundwater in the study area. Several simulations for different periods were conducted including a steady state calibration simulation for 1969, a transient calibration simulation from 1970 to 1986, and a verification simulation that represents current conditions. Additionally, future scenarios were simulated till 2035. Results show that the current extraction rates are not sustainable and need to be reduced by at least 25 % to mitigate the present severe groundwater depletion and to achieve sustainable development in the area.

How can we adapt to geological scarcity of antimony? Investigation of antimony's substitutability and of other measures to achieve a sustainable use

Antimony is an element that is applied in many useful applications for mankind. However, antimony resources are very scarce, when comparing the current extraction rates with the availability of antimony containing ores. From an inter-temporal sustainability perspective, current generations should not deprive future generations from extractable ores. The extraction rate of a mineral resource is defined sustainable, if such a rate can be sustained for 1000 years assuming the same consumption per capita in all countries of the world. To achieve a sustainable extraction of antimony, it is necessary to reduce the current extraction with 96% compared to the primary antimony extraction in 2010. We have investigated whether such an ambitious extraction reduction goal would be technically feasible, without losing any of the current services that are provided by antimony. Reduction of the use of primary antimony can be achieved through (a combination of) substitution, improved material efficiency and recycling. Because the potential of material efficiency and recycling are limited in the case of antimony, the focus is on substitution of antimony in its applications.The major application of antimony (more than 50%) is in flame retardants. It appears that about 95% of antimony in flame retardants can be replaced by other components or systems. Overall, the substitutability of antimony in all its applications is estimated at around 90%.The required additional extraction reduction needs to be realized by improved material efficiency and further recycling, especially from the remaining antimony containing flame retardants and from lead-alloys.

Towards a sustainable use of primary boron. Approach to a sustainable use of primary resources

The sustainable use of raw materials does not only concern the environmental impacts of their production and consumption, but also the intergenerational distribution of access to the raw material or the services provided by that material. From this sustainability perspective, current generations should not deprive future generations from economically accessible ores, but they have the responsibility to assure that a sufficient quantity of enriched deposits of primary materials continues to be available for future generations.Comparing the extraction rate of different primary materials to their current use, some materials are scarcer than others. Elements like aluminum, magnesium, titanium and vanadium are relatively abundant and cannot be considered critical from a geological point of view. From a point of view of availability for future generations, action is not really urgent for these elements. However, other elements, like antimony, rhenium, gold, zinc and molybdenum are relatively scarce from a geological perspective. The current extraction rate of these elements is not sustainable.Boron is also a relatively scarce element, comparing the current extraction rate to the geological availability. The accessible ores may be depleted within two hundred years. This may affect future generations negatively in securing services provided by boron. Therefore, we investigated whether the use of primary boron could be reduced to a sustainable level) without losing any of the services currently provided by boron. In this framework we have designed a generally applicable approach for investigating whether and to what extent a combination of substitution, material efficiency and recycling could reduce the use of a primary material to a sustainable level.

Grid-enabled Monte Carlo analysis of the impacts of uncertain discharge rates on seawater intrusion in the Korba aquifer (Tunisia)

The Korba aquifer, located in the north of Tunisia, suffers heavily from salinization due to seawater intrusion. In 2000, the aquifer was exploited from more than 9000 wells. The problem is that no precise information was recorded concerning the current extraction rates, their spatial distribution, or their evolution in time. In this study, a geostatistical model of the exploitation rates was constructed based on a multi-linear regression model combining incomplete direct data and exhaustive secondary information. The impacts of the uncertainty on the spatial distribution of the pumping rates on seawater intrusion were evaluated using a 3-D density-dependent groundwater model. To circumvent the large amount of computing time required to run transient models, the simulations were run in a parallel fashion on the Grid infrastructure provided by the Enabling Grid for E-Science in Europe project. Monte Carlo simulations results showed that 8.3% of the aquifer area is affected by input uncertainty. Citation Kerrou, J., Renard, P., Lecca, G. & Tarhouni, J. (2010) Grid-enabled Monte Carlo analysis of the impacts of uncertain discharge rates on seawater intrusion in the Korba aquifer (Tunisia). Hydrol. Sci. J. 55(8), 1325–1336.