Numerical Groundwater Flow Model Research Articles

Numerical Modelling of Groundwater Flow and Contamination Transport (TDS) in Kaniqurzala Area- Central Basin – Erbil City- Kurdistan - Iraq

Numerical Modelling of Groundwater Flow and Contamination Transport (TDS) in Kaniqurzala Area- Central Basin – Erbil City- Kurdistan - Iraq

Integrated Three‐Dimensional Geological and Numerical Groundwater Model Development

AbstractConceptual site model (CSM) development is a foundational step for numerical groundwater model construction. Tools for reviewing and combining disparate data to develop a CSM have been furthered through software that efficiently integrates multiple data streams, especially when a large amount of information is available at complex sites. Three‐dimensional (3D) interfaces for data visualization and geological modeling are becoming commonly used to compile data, support development of a robust CSM, and create effective visuals that enable project stakeholders to understand site complexity. This article describes a 3D interface workflow applied to a geological and numerical groundwater modeling case study where numerical modeling (i.e., MODFLOW family of codes) was used to assess remedy effectiveness. Specifically, the numerical model was used to overview an in situ solidification (ISS) application, where soil mixing will be conducted with cement, for possible adverse effects to an existing groundwater treatment system. 3D geological modeling allowed for the existing numerical groundwater flow model to be reconstructed to include previously overlooked data on buried infrastructure, which led to a detailed depiction of high‐permeability channels and a more accurate representation of site conditions. Modeling showed that the ISS remedy would not adversely impact the existing groundwater treatment system. Integration of existing data within a 3D interface led to hydrogeological insights that would have been difficult to obtain from two‐dimensional visualization of information, improved numerical modeling efficiency, and informed site remedy decisions. Additionally, the 3D interface created effective visuals that increased internal and external project team conceptual understanding.

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.

Field observation and mathematical representation of the hydrogeological function of alpine landforms in the Canadian Rockies

AbstractGroundwater discharge sustains the baseflow of alpine headwater streams, which is critical for water supply and aquatic environments in mountainous regions. Periglacial landforms typical of alpine headwaters (e.g., talus, moraine, rock glacier, alpine meadows) are important aquifers in alpine watersheds. This study examines the hydrological function of an alpine aquifer complex in a small headwater basin in the Canadian Rockies. The aquifer complex consisting of talus, alpine meadow underlain by a bedrock depression, and recessional moraine provided essentially all baseflow of a 6.5 km2 watershed, even though the upper sub‐watershed containing the aquifer complex occupies only 14% of the watershed. Chemical and isotopic signatures indicated that the recessional moraine serves as a gatekeeper of the upper sub‐watershed, whereby it integrates groundwater components from multiple aquifers and controls the discharge from the outlet springs. Field observation of discharge and the water table in the moraine aquifer showed a nonlinear groundwater storage‐discharge relationship. Numerical groundwater flow models of the upper sub‐watershed showed that the transmissivity feedback resulting from a decrease in hydraulic conductivity with depth was essential for determining the nonlinear storage‐discharge relationship. A simple exponential function was proposed to represent the observed groundwater storage‐discharge relationship, which can be implemented within large‐scale hydrological models to simulate baseflow coming out of alpine headwater regions.

Urbanization effects on the groundwater potential recharge of the aquifers in the southern part of the Basin of Mexico

Abstract Collection, processing, and analysis of GIS and satellite data were performed in this work to estimate temporal groundwater recharge changes, which are needed as input in numerical groundwater-flow models. Layers of geological alignments, land use, drainage network, lithology, topography, and precipitation were collected. This information was spatialized, then layer importance was calculated using an Analytic Hierarchy Process (AHP) based on infiltration capacity to define Potential Recharge (PR) regions. A water budget equation was used to calculate PR volumes. The analysis was done every five years from 1970-19, considering average urban area changes. For all study periods, an increase in urban area was calculated from 16 to 28% of the total study area, while potential recharge decreased from 23 to 19% of the mean precipitation values for each 5-year period. The most significant urban expansion was from 1980-94 and 2010-19, which match periods of potential recharge decrease. However, a slight increase in PR from 2000-09, unrelated to urban area change, may be due to temperature variations. The results account for the spatial and temporal dynamics of the recharge in the study area and can be used as input data to calibrate the actual recharge in a groundwater numerical model.

Multi Model Approach to Study the Effect of Conceptualization and Discretization on Groundwater Model

The objective of the study is to develop multiple steady state conceptual and numerical groundwater flow models for Bhiwadi region of Alwar district of Rajasthan, India. Automated parameter estimation tool (PEST) is used for the calibration of the models. To evaluate and select the best suited conceptual flow model, several statistical criteria such as RMSE (Root Mean Square Error), R-squared (R^2), Nash-Sutcliffe efficiency (NSE), percent bias (PBIAS), multi model information criteria: Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) are used. The result of the study indicates that value R2, NSE and Pbias are almost similar for all the models, hence are insufficient to evaluate the models. Therefore, AIC and BIC statistical criteria are used for accurate evaluation. The result also indicates that grid size and orientation have immense impact on modeling output. For the study area coarse grid size has given better results as compared to finer grid size.

Groundwater discharge and saltwater-freshwater mixing in a mangrove wetland over tidal cycles: A field and modeling study

Material transport and transformations in mangrove wetlands are closely related to seawater-groundwater mixing processes, which can influence mangrove growth and development. Therefore, a clearer understanding of groundwater and salt transport dynamics in aquifers beneath mangrove wetlands is needed to accurately estimate chemical fluxes to mangrove ecosystems. We established a multi-level groundwater monitoring profile in a mangrove wetland and constructed a numerical model of tidally-driven groundwater flow and salt transport that was calibrated to salinity and pore water pressure. Model results indicated that 99% of groundwater discharge to the mangrove wetland was saltwater and that this discharge accounted for 33% of total discharge over a spring-neap tidal cycle. Tidal creeks that cross-cut the wetland received the remaining 67% of total discharge. Seawater infiltration from tidal action across the wetland formed a subsurface saltwater-freshwater mixing zone with a geometry that followed the undulation of a high permeably layer at depth. Model sensitivity tests showed that salinity distributions and groundwater discharge patterns were controlled strongly by wetland topography and anisotropy. Model cases with a gently sloping and flat mangrove platform led to substantially less salt mass in the subsurface compared to the base case with mangrove topographic relief. Models with lower anisotropy allowed salt to penetrate through the high-permeability layer to the base of the aquifer. The spatial patterns of fresh and saline groundwater discharge and mixing processes within mangrove wetlands as shown in this study may have implications for mangrove tree nutrient availability and for the prevalence and spatial distribution of mangroves along coastlines.

Simulating spatial variability of groundwater table in England and Wales

AbstractGroundwater is a vital natural resource that affects human life and the environment. Groundwater supplies drinking water, supports irrigation for food production, and helps to sustain flow of water in streams and wetlands during dry periods. Therefore, it is important to assess the variability of groundwater resources and consider it in freshwater management. Numerical modelling is widely used for understanding the variability of groundwater table. However, there is still a lack of large‐scale groundwater flow models. For instance, in the United Kingdom, groundwater modelling efforts so far have focused on aquifer to regional scales. A national scale model would aid the quantification of the available groundwater storage and the assessment of the impacts of climate change and anthropogenic activities on this crucial resource. In this study, we evaluate a numerical groundwater flow modelling approach for entire England and Wales. This model operates at 1 km spatial and 1 day temporal resolution. We force the model with precipitation and potential evapotranspiration, parameterise the subsurface using our estimation of transmissivity and specific yield based on available information, and simulate steady‐state groundwater heads over England and Wales. The results demonstrate that the model can reproduce spatial variability of groundwater table in the region. Because of a two‐dimensional numerical representation of groundwater flow, the computational demand of this model is low, facilitating multiple simulations required for calibration, sensitivity analysis, and quantification of the impacts of environmental changes on groundwater resources.

The role of Canadian research in advancing groundwater hydrology: historical sketches from the past 75 years

Canadian hydrologists have played important roles in advancing the scientific understanding of groundwater flow in the hydrologic cycle. This article highlights some of the major episodes that made fundamental contributions to groundwater hydrology, rather than attempt a comprehensive review of all Canadian advances in groundwater research. The early years of groundwater research were driven by the need to find water supplies and to evaluate the capacity of wells and aquifers using the well hydraulics theories. The research focus shifted to the understanding of groundwater flow in drainage basins in the late 1950s and the 1960s through field observations using piezometer networks, rigorous mathematical analysis, and the development of numerical groundwater flow models. These researchers established a new conceptual framework and mathematical tools to describe groundwater flow systems in the context of topographic features and geological heterogeneity. In the 1970s, Canadian researchers made important contributions in establishing the new paradigm of hillslope hydrology by field observations and numerical modelling of storm runoff generation, development of tracer-based hydrograph separation techniques, and the demonstration of the role of the capillary fringe. The groundwater research group at the University of Waterloo pioneered contaminant hydrogeology research in the 1970s and 1980s, which generated new knowledge of groundwater flow and transport processes and developed increasingly sophisticated numerical models capable of simulating coupled surface and subsurface flow and transport. The scope of groundwater hydrology diversified in the 1990s onward including the interaction of surface water and groundwater as well as the interaction between hydrological and ecological systems. Climate-change impacts on groundwater are a major topic of current and future research. To address this and other challenging problems, it is important to establish and maintain long-term monitoring sites. The history has shown that the scientific advances presented in this article would have been impossible without high-quality field data.

Acesulfame allows the tracing of multiple sources of wastewater and riverbank filtration

Aquifers providing drinking water are increasingly threatened by emerging contaminants due to wastewater inputs from multiple sources. These inputs have to be identified, differentiated, and characterized to allow an accurate risk assessment and thus ensure the safety of drinking water through appropriate management. We hypothesize, that in climates with seasonal temperature variations, the sweetener acesulfame potassium (ACE) provides new pathways to study wastewater inputs to aquifers. Specifically, this study investigates the temperature-driven seasonal oscillation of ACE to assess multiple sources of wastewater inputs at a riverbank filtration site. ACE concentrations in the river water varied from 0.2 to 1 μg L−1 in the cold season (T < 10 °C) to 0–0.1 μg L−1 in the warm season (T > 10 °C), due to temperature-dependent biodegradation during wastewater treatment. This oscillating signal could be traced throughout the aquifer over distances up to 3250 m from two different infiltration sources. A transient numerical model of groundwater flow and ACE transport was calibrated over hydraulic heads and ACE concentrations, allowing the accurate calculation of mixing ratios, travel times, and flow-path directions for each of the two infiltration sources. The calculated travel time from the distant infiltration source was of 67 days, while that from the near source was of 20 days. The difference in travel times leads to different potential degradation of contaminants flowing into the aquifer from the river, thus demonstrating the importance of individually assessing the locations of riverbank infiltration. The calibrated ACE transport model allowed calculating transient mixing ratios, which confirmed the impact of river stage and groundwater levels on the mixing ratio of the original groundwater and the bank filtrate. Therefore, continuous monitoring of ACE concentrations can help to optimize the management of the water works with the aim to avoid collection of water with very short travel times, which has important regulative aspects. Our findings demonstrate the suitability of ACE as a transient tracer for identifying multiple sources of wastewater, including riverbank filtration sites affected by wastewater treatment plant effluents. ACE seasonal oscillation tracking thus provides a new tool to be used in climates with pronounced seasonal temperature variations to assess the origins of contamination in aquifers, with time and cost advantages over multi-tracer approaches.

Data scarce modelling the impact of present and future groundwater development on Jordan multiaquifer groundwater resources

Rapidly growing demands and climate change stresses water resources worldwide and leads to highly competitive situations between the environment and socio-economic development of a region, calling for a smart and modelling driven water resources management. However, data scarcity often prevents the realisation of a comprehensive, nation-wide resources model, which provides reliable and spatially discretized results of water resources development.We present a workflow approach to set up a large-scale multi-aquifer model, overcoming data shortage by stepwise calibration and integrating hydrological and numerical groundwater flow modelling into a coupled system. The study aims to develop such a system to assess how groundwater resources react on anthropogenic impacts on the example of the Kingdom of Jordan, one of the water poorest countries on globe.Simulated heads reliably resembled the monitored ones in >70 % of the observation wells. That makes us confident, the model represents all the states well from 1970, prior to the intense development of the country until 2015. The water balance shows an annual deficit of 1.16 million cubic meter (MCM) due to an overdraft. The discharge to the Dead Sea increased from 564 MCM/yr to 696 MCM/yr over the time period. Regional drawdowns of >250 m and groundwater depression with an extension of approx.100 km are observable in both large aquifer complexes. Most severe areas in the upper calcareous aquifer are located in the north of Amman and practically in all urban and agricultural agglomerations across the country. Groundwater tables in the deeper sandstone aquifer are particularly affected in the south as well as in the wider vicinity of the Dead Sea as consequence of its continuous dropping. Simulations of the future development of the groundwater tables indicate a severe deterioration of the situation with further declines in groundwater levels of up to 70 m.

Effect of Ecological Water Supplement on Groundwater Restoration in the Yongding River Based on Multi-Model Linkage

Evaluating the effect of ecological water supplement on groundwater restoration quantitatively could produce positive contributions to both water cycle theory and surface–groundwater conjunctive management. Therefore, in this paper, a groundwater flow numerical model has been established after calculating the river section seepage rate using a fuzzy mathematical method in the Yongding River channel. The simulated results show that the model could accurately reflect the real groundwater dynamic features. Then, a data-driven random forest(RF) model has been established to quantitatively evaluate the contributions of the factors which influence the groundwater level variation. The Nash-Sutcliffe efficiency coefficient(NSE) of the RF model is 0.93. It shows excellent ability to identify the rising zone of groundwater level. The study shows that the infiltration capacity is strong in the upstream area of the Yongding River, and the seepage rate is over 0.7. The lowest seepage rate is 0.19 at the downstream end, while the seepage rate in the middle area is basically between 0.4 and 0.7. From 2018 to 2019, the ecological water supplement of the Yongding River has played a significant role in raising the groundwater level along the river channel. Additionally, its contribution analyzed by the RF model to the change of groundwater level is 25%. Groundwater exploitation is the most important variable affecting the groundwater level variation. The impact depth of groundwater level fluctuation reaches about 10 m. The impact range where the groundwater level average uplifts 1.86 m is 502.13 km2. The influence direction gradually changes from around the ecological water supplement section to along the Yongding River channel. The groundwater level variation along the tangential direction of the Yongding River is slowing down. The groundwater level would entirely uplift with 170 × 106 m3/year ecological water supplement of the Yongding River and 35.77 × 106 m3/year groundwater mining reduction in the downstream area until 2035.

Building energy consumption simulation and its application in underground-water source thermal energy management system

In order to analyze the rationality of the compound well structure and the degree of heat penetration of groundwater in a groundwater ground source heat pump project in a certain district of a city, the author proposed a method for building energy consumption simulation and groundwater flow numerical model. The variation trend of groundwater temperature under different heat transfer temperature difference is simulated and predicted. The experimental results show that the fitting points where the error between the simulated predicted temperature and the actual measured temperature does not exceed 0.5?C account for 51.7%, the fitting points where the error is 0.5~1?C account for 28.7%, the fitting points where the error is 1~2?C account for 18.1%, and the fitting points where the error is greater than 2?C account for 1.5%. The dynamic change trend of the simulated predicted temperature curve is basically consistent with that of the actual measured temperature curve. It is proved that the building energy consumption simulation and the numerical model of groundwater flow can effectively analyze the rationality of the compound well structure of the groundwater ground source heat pump project and the degree of groundwater heat penetration.

Numerical Modeling of Transboundary Groundwater Flow in the Bug and San Catchment Areas for Integrated Water Resource Management (Poland–Ukraine)

On the Polish–Ukrainian borderlands, there is the Lublin–Lviv transboundary groundwater aquifer system, which is of key importance in shaping strategic groundwater resources. Due to the particular importance of this aquifer system, the two neighboring countries are obliged to undertake joint actions to protect it. The integrated management of the Lublin–Lviv aquifer system seems difficult due to the significant spatial and temporal scale of groundwater flows in the region. To support internationally integrated management, a transboundary geological model was developed. Based on this model, a hydrogeological conceptual model has been developed, which allowed for a numerical model of groundwater flow to be calculated. The model research helped diagnose potential problems by determining the scope of the area with cross-border flows and quantifying the flows between Poland and Ukraine. In addition, the numerical model was used to define the optimal cross-border management unit and the conditions needed to sustainably exploit the Lublin–Lviv aquifer system. Basing on the research results it was concluded that groundwater flows in transboundary aquifers very on a regional scale and that the range of areas of importance for transboundary groundwater flows is much smaller than the pre-selected partial catchments of the Bug and San Rivers. The results of this study may significantly contribute to the preparation of joint water management plans.

Numerical modeling of groundwater flow and nitrate transport using MODFLOW and MT3DMS in the Karaj alluvial aquifer, Iran.

Nitrate is one of the most dangerous pollutants in groundwater, being regarded as a severe environmental hazard and a global-scale problem. The present study aims to analyze the groundwater flow and nitrate contamination in the Karaj unconfined aquifer, Central Iran. Simulation of the quantitative and qualitative status was performed using MODFLOW and MT3DMS. Sampling was done to model groundwater flow for eight seasonal time periods and nitrate pollution transport for four time periods (a total of 420days), and calibration was carried out by trial-and-error method. Due to the predominance of advection term in the transport of nitrate pollution, the total variation diminishing method was used in transport modeling. The groundwater flow modeling showed a reservoir deficit of - 33 MCUM and 67cm decrease in the water year 2016-2017 and 173cm in the entire modeling period (2016-2018) in groundwater level. Also, the RMSE in the calibration and validation stages was obtained from 24.9 to 0.72 and 0.84, respectively. The nitrate contamination transport modeling indicated that there are three nitrate contamination concentration parts with more than safe concentration of nitrate (50mg/l). The most pollution is in the urban areas in the east of the aquifer. The nitrate pollution is primarily anthropogenic due to industrial and especially domestic wastewater and then fertilizers used in agricultural activities. It can be predicted that with the full implementation of a municipal wastewater collection network, the nitrate pollution concentration in urban areas would reduce significantly to the range of 20 to 25mg/l.

Differentiating Nitrate Origins and Fate in a Semi-Arid Basin (Tunisia) via Geostatistical Analyses and Groundwater Modelling

Despite efforts to protect the hydrosystems from increasing pollution, nitrate (NO3−) remains a major groundwater pollutant worldwide, and determining its origin is still crucial and challenging. To disentangle the origins and fate of high NO3− (&gt;900 mg/L) in the Sidi Bouzid North basin (Tunisia), a numerical groundwater flow model (MODFLOW-2005) and an advective particle tracking (MODPATH) have been combined with geostatistical analyses on groundwater quality and hydrogeological characterization. Correlations between chemical elements and Principal Component Analysis (PCA) suggested that groundwater quality was primarily controlled by evaporite dissolution and subsequently driven by processes like dedolomitization and ion exchange. PCA indicated that NO3− origin is linked to anthropic (unconfined aquifer) and geogenic (semi-confined aquifer) sources. To suggest the geogenic origin of NO3− in the semi-confined aquifer, the multi-aquifer groundwater flow system and the forward and backward particle tracking was simulated. The observed and calculated hydraulic heads displayed a good correlation (R2 of 0.93). The residence time of groundwater with high NO3− concentrations was more significant than the timespan during which chemical fertilizers were used, and urban settlements expansion began. This confirmed the natural origin of NO3− associated with pre-Triassic embankment landscapes and located on domed geomorphic surfaces with a gypsum, phosphate, or clay cover.

Impacts of climate change on Swiss alluvial aquifers – A quantitative forecast focused on natural and artificial groundwater recharge by surface water infiltration

The sensitivity of future groundwater recharge and temperature development was investigated for three alluvial aquifers in the urban agglomeration of the city of Basel, Switzerland. For selected climate projections groundwater recharge and the associated temperature imprinting of aquifers, which are mainly determined by artificial groundwater recharge and infiltrating surface water, were investigated.3D numerical groundwater flow and heat-transport modeling, allowed quantifying and differentiating between natural and artificial groundwater recharge and thermal impacts. For aquifers where the infiltration of river water is an important component in the groundwater balance, the effects of climate change will be influenced by changes in river flow and thermal regimes and also by artificial groundwater recharge of surface water. Considering all climate scenarios investigated, the net heat input from river water infiltration for the Lange Erlen case study area increases by an average of 42 % by 2055 and 62 % by 2085 compared to the reference year 2000. Together with further heat inputs, particularly by artificial groundwater recharge, the temperatures of the extracted drinking water would increase by 0.4 to 1.3 K by 2055 and 0.7 to 3.1 K by 2085. In the Hardwald case study area, the most significant heat exchange occurs by artificial groundwater recharge. As a result, and considering all climate scenarios investigated, heat loss by groundwater extraction increases by an average of 38 % during the winter months from the year 2000 to the year 2085. The increased heat input, especially in the summer months, results in a temperature increase of the extracted drinking water of 0.2 to 1.0 K by 2055 and 0.6 to 4.0 K by 2085. In the Lower Birs Valley case study area, net heat input from river water infiltration increases by an average of 42 % by 2055 and 62 % by 2085. Correspondingly, the temperatures of the extracted drinking water increase by 0.9 to 3.2 K by 2055 and by 0.3 to 5.4 K by 2085.The quantitative assessment of climate change impacts on the groundwater resources presented allows to differentiate between hydraulic and thermal impacts of natural and artificial groundwater recharge processes. Accordingly, individual drinking water wells are exposed differently to the various components of groundwater recharge. Seasonal shifts in natural groundwater recharge processes and adaptation strategies related to artificial groundwater recharge could therefore be an important factor affecting groundwater resources in future. Moreover, increased groundwater recharge from artificial groundwater recharge systems in summer months and the interaction with surface waters during high runoff periods, which will occur more often in winter months, are likely to strongly influence groundwater recharge and temperatures.

The efficiency loss in groundwater heat pump systems triggered by thermal recycling

Thermal recycling occurring in groundwater heat pump systems is a major cause of efficiency loss in groundwater heat pump systems and its understanding is critical for systems design. However, the response of the systems performance to these phenomena is not easy to predict given that a negative feedback is created, as the rejected heated/cooled water injected back into the aquifer will tend to negatively affect the production well(s) of the doublet(s) starting the negative loop. This work approaches the nonlinearity of the thermal recycling problem for the first time, by making use of distributed numerical models of groundwater flow and heat transport combined with thermodynamic models of geothermal heat pumps. Simulation results showed that thermal interference between production and injection was unavoidable for the scenarios investigated. Different scenarios were found where the impact of thermal recycling was not sustainable during cooling seasons, thus resulting in the inoperability of the heat pump. Thermal recycling was found to be responsible of an increase in operation costs of up to 38.4 k€·year−1, as well as of an environmental impact due to the release of up to 76.2 t eqCO2·year−1 for a 402 kWth installation. The results of this article will allow to improve the understanding of thermal recycling as a nonlinear complex and a transient process responsible for an efficiency loss of groundwater heat pump systems.

Arnold Verruijt (1940-2022).

Arnold Verruijt (1940-2022).

Investigation of the impact of the implementation of the coastal aquifer management plan on nitrate pollution in Gaza Strip Aquifer using modeling techniques

Groundwater is the principal source of public water supply and for satisfying the daily water needs. The Gaza strip coastal aquifer is suffering from salinity and contamination due to human activities especially agriculture activities. Although, the nitrate is necessary for agriculture activities it can affect the groundwater quality if leached nitrate from the soil into freshwaters after some time. The main objective of this research is to evaluate the current situation of the Gaza strip coastal aquifer and to predict the nitrate concentrations resulting from agriculture activities over the next twenty years using modelling approach. 3D Numerical groundwater flow modeling was developed to simulate the impacts of transport of nitrate loading from agricultural land on groundwater system using finite difference method GMS 10.4 software (MODFLOW 2005 code and MT3DMS package). Five management scenarios were considered to study the effect of pumping and recharge parameters on the groundwater flow system and the impacts of transport of nitrate loading from agricultural areas on the aquifer. Ten different wells were selected to investigate the impact of management scenarios on the nitrate concentration. All management scenarios indicated that there is a relationship between the water level and nitrate concentration in aquifer therefore the rates of nitrate concentration in the southern regions of Gaza strip is more than the northern regions.