An-Najah Blogs :: Mohammad N. Almasri http://blogs.najah.edu/author/mohammadalmasri An-Najah Blogs :: Mohammad N. Almasri en-us Thu, 23 Nov 2017 01:48:10 IST Thu, 23 Nov 2017 01:48:10 IST webmaster@najah.edu webmaster@najah.edu Assessment of nitrate contamination of groundwater using lumped-parameter modelshttp://blogs.najah.edu/staff/mohammadalmasri/article/Assessment-of-nitrate-contamination-of-groundwater-using-lumped-parameter-modelsPublished ArticlesIn this paper lumped-parameter models LPMs were developed and utilized to simulate nitrate concentration in the groundwater of Gaza City and Jabalia Camp GCJC in the Gaza Coastal Aquifer GCA in Palestine In the GCJC area nitrate levels exceed the maximum contaminant level MCL of 10mgL NO3-N 45mgL NO3 in many wells Elevated nitrate concentrations in the groundwater of GCJC area are due to the disposal of untreated wastewater the existence of heavy agriculture in the surrounding areas and the use of cesspits for wastewater disposal The developed LPMs utilize monthly time steps and take into consideration all the sources and sinks of water and nitrate in the study area The main outcomes of the LPMs are the average temporal water table elevation and nitrate concentration In order to demonstrate LPMs usability a set of management options to reduce nitrate concentration in the groundwater of the study area were proposed and evaluated using the developed LPMs Four broad management options were considered where these options tackle the reduction of nitrate concentration in the lateral inflow rehabilitation of the wastewater collection system reduction in cesspit usage and the restriction on the use of nitrogen-based fertilizers In addition management options that encompass different combinations of the single management options were taken into account Different scenarios that correspond to the different management options were investigated It was found based on the LPMs that individual management options were not effective in meeting the MCL of nitrate However thecombination of the four single management options with full rehabilitation and coverage of the wastewater collection network along with at least 60 reduction in both nitrate concentration in thelateral inflow and the use of nitrogen-based fertilizers would meet the MCL constraint by the end of the management period Trends and occurrences of nitrate in the groundwater of the West Bank, Palestinehttp://blogs.najah.edu/staff/mohammadalmasri/article/Trends-and-occurrences-of-nitrate-in-the-groundwater-of-the-West-Bank-PalestinePublished ArticlesGroundwater is the major source of water to the Palestinians Efficient management of this resource requires a good understanding of its status This understanding necessitates a characterization of the quality of the utilizable volumes This paper focuses on the assessment of nitrate concentrations in the aquifers of the West Bank Palestine A preliminary statistical analysis is carried out for the spatial and temporal distributions of the nitrate concentrations GIS is utilized to facilitate the analysis and to efficiently account for the spatiality of nitrate concentrations The analysis was carried out at different spatial levels and key parameters including soil type watersheds depth population and rainfall It is observed that elevated nitrate concentrations in the groundwater greatly coincide with increasing rainfall particularly in the last few years Results confirm that the annual mean nitrate concentration in the Western groundwater basin has an increasing trend over the period from 1982 to 2004 indicating its vulnerability to contamination This result can be attributed to the agricultural activities along with the high groundwater recharge However leaking septic and sewer systems are considerably causing nitrate contamination of groundwater in populated areas Overall the recommendations call for an immediate intervention to manage the quality problems in the West Bank aquifersAssessment of intrinsic vulnerability to contamination for Gaza coastal aquifer, Palestine http://blogs.najah.edu/staff/mohammadalmasri/article/Assessment-of-intrinsic-vulnerability-to-contamination-for-Gaza-coastal-aquifer-Palestine-Published ArticlesGaza coastal aquifer GCA is the major source of fresh water for the 15 million residents of Gaza Strip Palestine The aquifer is under deteriorating quality conditions mainly due to the excessive application of fertilizers The intrinsic vulnerability of GCA to contamination was assessed using the well-known DRASTIC method Detailed analysis of the intrinsic vulnerability map of GCA was carried out and did consider different relationships between the vulnerability indices and the on-ground nitrogen loadings and land use classes In addition correlation between vulnerability values and the nitrate concentrations in GCA was studied Based on the vulnerability analysis it was found that 10 and 13 of Gaza Strip area is under low and high vulnerability of groundwater contamination respectively while more than 77 of the area of Gaza Strip can be designated as an area of moderate vulnerability of groundwater contamination It was found that the density of groundwater sampling wells for nitrate concentration is high for the moderate and high vulnerability zones The highest first quartile median mean and third quartile of nitrate concentrations are reported in the high vulnerability zones Results of sensitivity analysis show a high sensitivity of the high vulnerability index to the depth to water table Journal of Environmental Management Volume 88 Issue 4 September 2008 Pages 577-593 http:dxdoiorg101016jjenvman200701022Discussion of “Groundwater Flow and Contaminant Transport Simulation with Imprecise Parameters” by Ram Kailash Prasad and Shashi Mathurhttp://blogs.najah.edu/staff/mohammadalmasri/article/Discussion-of-ldquoGroundwater-Flow-and-Contaminant-Transport-Simulation-with-Imprecise-Parametersrdquo-by-Ram-Kailash-Prasad-and-Shashi-MathurPublished ArticlesAbstract not availableAnalysis of Nitrate Contamination of Gaza Coastal Aquifer, Palestinehttp://blogs.najah.edu/staff/mohammadalmasri/article/Analysis-of-Nitrate-Contamination-of-Gaza-Coastal-Aquifer-PalestinePublished ArticlesThe ongoing degradation of the water quality of the Gaza Coastal Aquifer GCA is of a great concern for the different authorities and agencies involved in the water sector in the Gaza Strip Palestine The GCA is almost the only source of fresh water to over 15 million residents where it is utilized extensively to satisfy agricultural domestic and industrial water demands The aquifer is currently being overpumped where pumping largely exceeds total recharge In addition manmade sources of pollution endanger the water resources supplies in the major municipalities of the Gaza Strip Many water quality parameters in the GCA presently exceed the maximum contaminant level MCL of the US Environmental Protection Agency drinking water standards especially for nitrate and chloride This case study analyzes nitrate concentration distribution for the GCA at different levels such as land use classes and sampling depth Nitrate concentration data from 1990 and from 2000 to 2004 were compiled and assembled into a single composite database A geographic information system was used to assess the spatial and temporal variability of nitrate occurrences in the aquifer Results show that the first quartile of nitrate concentration for the years 1990 and 20002004 exceeds the MCL In addition the analyses demonstrated a generally increasing trend in groundwater nitrate concentration The areas with the most elevated nitrate concentrations are areas characterized by heavy agricultural activities and urban areas Elevated nitrate concentrations in the GCA indicate anthropogenic contamination sources J Hydrologic Engrg Volume 13 Issue 3 pp 132-140 March 2008 http:dxdoiorg101061ASCE1084-0699200813:3132Modeling nitrate contamination of groundwater in agricultural watershedshttp://blogs.najah.edu/staff/mohammadalmasri/article/Modeling-nitrate-contamination-of-groundwater-in-agricultural-watershedsPublished ArticlesThis paper presents and implements a framework for modeling the impact of land use practices and protection alternatives on nitrate pollution of groundwater in agricultural watersheds The framework utilizes the national land cover database NLCD of the United State Geological Survey USGS grid and a geographic information system GIS to account for the spatial distribution of on-ground nitrogen sources and corresponding loadings The framework employs a soil nitrogen dynamic model to estimate nitrate leaching to groundwater These estimates were used in developing a groundwater nitrate fate and transport model The framework considers both point and non-point sources of nitrogen across different land use classes The methodology was applied for the SumasBlaine aquifer of Washington State US where heavy dairy industry and berry plantations are concentrated Simulations were carried out using the developed framework to evaluate the overall impacts of current land use practices and the efficiency of proposed protection alternatives on nitrate pollution in the aquifer Journal of Hydrology Volume 343 Issues 3-4 20 September 2007 Pages 211-229 http:dxdoiorg101016jjhydrol200706016Nitrate contamination of groundwater: A conceptual management frameworkhttp://blogs.najah.edu/staff/mohammadalmasri/article/Nitrate-contamination-of-groundwater-A-conceptual-management-frameworkPublished ArticlesIn many countries public concern over the deterioration of groundwater quality from nitrate contamination has grown significantly in recent years This concern has focused increasingly on anthropogenic sources as the potential cause of the problem Evidence indicates that the nitrate NO3 levels routinely exceed the maximum contaminant level MCL of 10mgl NO3-N in many aquifer systems that underlie agriculture-dominated watersheds Degradation of groundwater quality due to nitrate pollution along with the increasing demand for potable water has motivated the adoption of restoration actions of the contaminated aquifers Restoration efforts have intensified the dire need for developing protection alternatives and management options such that the ultimate nitrate concentrations at the critical receptors are below the MCL This paper presents a general conceptual framework for the management of groundwater contamination from nitrate The management framework utilizes models of nitrate fate and transport in the unsaturated and saturated zones to simulate nitrate concentration at the critical receptors To study the impact of different management options considering both environmental and economic aspects the proposed framework incorporates a component of a multi-criteria decision analysis To enhance spatiality in model development along with the management options the utilization of a land use map is depicted for the allocation and computation of on-ground nitrogen loadings from the different sources Environmental Impact Assessment Review Volume 27 Issue 3 April 2007 Pages 220-242 http:dxdoiorg101016jeiar200611002Optimal Management of Nitrate Pollution of Groundwater in Agricultural Watersheds Considering Environmental and Economic Constraintshttp://blogs.najah.edu/staff/mohammadalmasri/article/Optimal-Management-of-Nitrate-Pollution-of-Groundwater-in-Agricultural-Watersheds-Considering-Environmental-and-Economic-ConstraintsPublished ArticlesGroundwater pollution due to nitrogen species from various land use activities and practices is a common concern in most agricultural watersheds Minimization of nonpoint source nitrogen pollution can be achieved by appropriate changes to land use practices to the extent of not affecting local economies that depend heavily on agricultural activities Most prior research work focused on predicting nitrogen loading andor fate and transport of nitrate in groundwater due to various agricultural activities In this work however we propose to present a broad integrated methodology for the optimal management of nitrate contamination of ground water combining environmental assessment and economic cost evaluation through multi-criteria decision analysis The proposed methodology incorporates an integrated physical modeling framework accounting for on-ground nitrogen loading and losses soil nitrogen dynamics and fate and transport of nitrate in ground water to compute the sustainable on-ground nitrogen loading such that the maximum contaminant level is not violated A number of protection alternatives to stipulate the predicted sustainable on-ground nitrogen loading are evaluated using the decision analysis that employs the importance order of criteria approach for ranking and selection of the protection alternatives The methodology was successfully demonstrated for the Sumas-Blaine aquifer in Washington State The results showed the importance of using this integrated approach that predicts the sustainable on-ground nitrogen loadings and provides an insight to the economic consequences generated in satisfying the environmental constraints The results also show that the proposed decision analysis framework within certain limitation is effective when selecting alternatives with competing demandsModular neural networks to predict the nitrate distribution in ground water using the on-ground nitrogen loading and recharge datahttp://blogs.najah.edu/staff/mohammadalmasri/article/Modular-neural-networks-to-predict-the-nitrate-distribution-in-ground-water-using-the-on-ground-nitrogen-loading-and-recharge-dataPublished ArticlesArtificial neural networks have proven to be an attractive mathematical tool to represent complex relationships in many branches of hydrology Due to this attractive feature neural networks are increasingly being applied in subsurface modeling where intricate physical processes and lack of detailed field data prevail In this paper a methodology using modular neural networks MNN is proposed to simulate the nitrate concentrations in an agriculture-dominated aquifer The methodology relies on geographic information system GIS tools in the preparation and processing of the MNN inputoutput data The basic premise followed in developing the MNN inputoutput response patterns is to designate the optimal radius of a specified circular-buffered zone centered by the nitrate receptor so that the input parameters at the upgradient areas correlate with nitrate concentrations in ground water A three-step approach that integrates the on-ground nitrogen loadings soil nitrogen dynamics and fate and transport in ground water is described and the critical parameters to predict nitrate concentration using MNN are selected The sensitivity of MNN performance to different MNN architecture is assessed The applicability of MNN is considered for the Sumas-Blaine aquifer of Washington State using two scenarios corresponding to current land use practices and a proposed protection alternative The results of MNN are further analyzed and compared to those obtained from a physically-based fate and transport model to evaluate the overall applicability of MNN Environmental Modelling Software Volume 20 Issue 7 July 2005 Pages 851-871 Statistical Analysis of Long-Term Spring Yield in a Semi-Arid Watershed a Case Study from Palestinehttp://blogs.najah.edu/staff/mohammadalmasri/article/Statistical-Analysis-of-Long-Term-Spring-Yield-in-a-Semi-Arid-Watershed-a-Case-Study-from-PalestinePublished ArticlesArid and semi-arid regions are generally characterized by water scarcity and low per capita water allocation This situation is further exacerbated when such areas are agriculturally dominated with high-density residential areas Faria watershed located in the northeastern part of the West Bank Palestine is one of these semi-arid watersheds where recently the prolonged drought periods in the watershed and the high population growth rate have negatively affected the existing obtainable surface water and groundwater resources Springs are a major water resource in the watershed where more than 50 of the water needs of the Palestinians in the study area is furnished by these springs Most of the springs of Faria watershed are located in the upper and middle parts of the watershed There are 11 fresh water springs in the watershed which can be divided into three groups: Faria Bathan and Miska in addition to other two springs that are entirely utilized by the City of Nablus Discharge data for the springs show high spring discharge variability Annual discharge from these springs varies from less than 4 to almost 42 MCM with an approximate average amount of 135 MCM Due to the fact that the available water resources in Faria watershed have sustainable-yield limits that cannot be surpassed and owing to the fact that water demand is increasing to fulfill the agricultural and residential requirements reliability assessment of water availability in Faria watershed is of great importance in order to optimally manage the local water resources This situation has compelled the motivation for conducting a statistical analysis of long-term spring yields in the watershed This analysis is essential to better understand the behavioral trends in spring yields in the area to comprehend the uncertainty associated with spring yields and the influential explanatory parameters and to enable the development of optimal water allocation policies and management option measures under drought conditions such that the economic revenue is maximized This paper employs the fundamental statistical parameters and concepts to analyze the long-term spring yields in Faria watershed in or20 der to evaluate the seasonality and variability of the yields Thereafter the relationship between spring yield and explanatory parameters such as precipitation is investigated Such relationship can be utilized in the development of best management practices that can be adopted to manage the scarce water resources in the watershedMulti-criteria decision analysis for the optimal management of nitrate contamination of aquifershttp://blogs.najah.edu/staff/mohammadalmasri/article/Multi-criteria-decision-analysis-for-the-optimal-management-of-nitrate-contamination-of-aquifersPublished ArticlesWe present an integrated methodology for the optimal management of nitrate contamination of ground water combining environmental assessment and economic cost evaluation through multi-criteria decision analysis The proposed methodology incorporates an integrated physical modeling framework accounting for on-ground nitrogen loading and losses soil nitrogen dynamics and fate and transport of nitrate in ground water to compute the sustainable on-ground nitrogen loading such that the maximum contaminant level is not violated A number of protection alternatives to stipulate the predicted sustainable on-ground nitrogen loading are evaluated using the decision analysis that employs the importance order of criteria approach for ranking and selection of the protection alternatives The methodology was successfully demonstrated for the SumasBlaine aquifer in Washington State The results showed the importance of using this integrated approach which predicts the sustainable on-ground nitrogen loadings and provides an insight into the economic consequences generated in satisfying the environmental constraints The results also show that the proposed decision analysis framework within certain limitations is effective when selecting alternatives with competing demands Journal of Environmental Management Volume 74 Issue 4 March 2005 Pages 365-381 Decision Support System for Integrated Water and Land Management in Agriculture-Dominated Watersheds: A conceptual study to Faria watershed, Palestinehttp://blogs.najah.edu/staff/mohammadalmasri/article/Decision-Support-System-for-Integrated-Water-and-Land-Management-in-Agriculture-Dominated-Watersheds-A-conceptual-study-to-Faria-watershed-Palestine-1Published ArticlesArid and semi-arid regions are generally characterized by water scarcity and low per capita water allocation This situation is further exacerbated when such areas are agriculturally dominated and encounter a high population growth rate Faria watershed Palestine is one of these semi-arid regions where the recent prolonged drought periods in the watershed have negatively affected the existing obtainable surface water and groundwater resources This situation has compelled the motivation for developing optimal water allocation policies that consider the available water resources under the dramatic climatic changes in the watershed such that the economic revenue is maximized Since the available water resources in the watershed have a sustainable-yield limits that should not be exceeded and owing to the fact that water demand is increasing to fulfill the agricultural and residential requirements alternative water resources need to be utilized including the use of wastewater effluent and brackish water In addition possible changes in land use classes and associated practices impact the water resources availability spatially and temporarily The utilization of wastewater and brackish water though economically feasible yet leads to the long-term degradation of water resources accompanied with possible serious harmful health ramifications and the likelihood of negatively affecting the land productivity especially when dealing with brackish water Therefore decision criteria have to be developed to account for the economic ramifications environmental consequences and water resources availability This paper conceptually demonstrates a decision support system to integrate different work plans and components in order to assess the conjunctive use of the different water resources in the watershed under different management scenarios driven by climatic changes and land use planning The framework involves diverse modules for the development of scenarios and management options a GIS technology to facilitate processing and visualization mathematical models of surface water and groundwater quantity and quality an economic model to evaluate the economic ramifications for different management options and a multi-criteria decision analysis module Decision Support System for Integrated Water and Land Management in Agriculture-Dominated Watersheds: A conceptual study to Faria watershed, Palestinehttp://blogs.najah.edu/staff/mohammadalmasri/article/Decision-Support-System-for-Integrated-Water-and-Land-Management-in-Agriculture-Dominated-Watersheds-A-conceptual-study-to-Faria-watershed-PalestinePublished ArticlesArid and semi-arid regions are generally characterized by water scarcity and low per capita water allocation This situation is further exacerbated when such areas are agriculturally dominated and encounter a high population growth rate Faria watershed Palestine is one of these semi-arid regions where the recent prolonged drought periods in the watershed have negatively affected the existing obtainable surface water and groundwater resources This situation has compelled the motivation for developing optimal water allocation policies that consider the available water resources under the dramatic climatic changes in the watershed such that the economic revenue is maximized Since the available water resources in the watershed have a sustainable-yield limits that should not be exceeded and owing to the fact that water demand is increasing to fulfill the agricultural and residential requirements alternative water resources need to be utilized including the use of wastewater effluent and brackish water In addition possible changes in land use classes and associated practices impact the water resources availability spatially and temporarily The utilization of wastewater and brackish water though economically feasible yet leads to the long-term degradation of water resources accompanied with possible serious harmful health ramifications and the likelihood of negatively affecting the land productivity especially when dealing with brackish water Therefore decision criteria have to be developed to account for the economic ramifications environmental consequences and water resources availability This paper conceptually demonstrates a decision support system to integrate different work plans and components in order to assess the conjunctive use of the different water resources in the watershed under different management scenarios driven by climatic changes and land use planning The framework involves diverse modules for the development of scenarios and management options a GIS technology to facilitate processing and visualization mathematical models of surface water and groundwater quantity and quality an economic model to evaluate the economic ramifications for different management options and a multi-criteria decision analysis module A Conceptual Framework for Managing Nitrate Contamination of the Gaza Coastal Aquifer, Palestinehttp://blogs.najah.edu/staff/mohammadalmasri/article/A-Conceptual-Framework-for-Managing-Nitrate-Contamination-of-the-Gaza-Coastal-Aquifer-PalestinePublished ArticlesPublic concern over the groundwater quality of the Gaza Aquifer has grown significantly in recent years and has focused increasingly on anthropogenic sources for the problem The Gaza Aquifer is an important source of water to over 11 million residents and is utilized extensively to satisfy agricultural domestic and industrial water demands Evidence indicates that the nitrate levels routinely exceeded the maximum contaminant level MCL of 10 mgL NO3-N in 90 percent of the drinking water supply wells A recent survey shows that 124 out of 640 infants children under the age of 6 months have methemoglobin levels above 20 percent Degradation of groundwater quality in the Gaza Aquifer due to nitrate pollution and the continuously increasing demand for potable water motivated the restoration of the aquifer Restoration efforts have intensified the need for developing protection alternatives and management options such that nitrate concentrations at the critical receptors are below the MCL Protection alternatives include a restriction on the use of fertilizers and proper treatment and disposal of wastewater In order to develop efficient protection alternatives the aquifer response to these alternatives should be simulated correctly perhaps through the use of mathematical models This paper presents a generic conceptual framework for an inclusive approach to modeling and management of groundwater contamination from nitrate for Gaza Aquifer The framework incorporates an assessment of the existing data and future monitoring needs conceptual models of groundwater flow and nitrate fate and transport and characterization of model related uncertainties In addition the proposed framework utilizes optimization and decision-making tools to study the impact of different management alternatives considering both environmental and socio-economic aspects Assessment and management of long-term nitrate pollution of ground water in agriculture-dominated watershedshttp://blogs.najah.edu/staff/mohammadalmasri/article/Assessment-and-management-of-long-term-nitrate-pollution-of-ground-water-in-agriculture-dominated-watershedsPublished ArticlesThe objectives of this paper are to document and evaluate regional long-term trends and occurrences of nitrate in the ground water of agricultural watersheds In Whatcom County Washington elevated nitrate concentrations in ground water are of great concern Whatcom County is recognized by heavy agricultural activities especially an intensive dairy farm industry Historical nitrate concentration data from 1990 to 2000 were compiled from different agencies and assembled into a single composite database A geographic information system was used to assess the spatial and temporal variability of nitrogen data The analysis was conducted for the whole area as well as for individual watersheds and for different land use classes In addition nitrate concentration variability with descriptive parameters such as sampling depth ground water recharge dissolved oxygen and on-ground nitrogen loadings was also investigated The analysis showed that the areas with nitrate concentrations above the maximum contaminant level are areas characterized by heavy agricultural activities The shallow surficial aquifers of the study area were found to contain high mean nitrate concentrations when compared to non-surficial aquifers The analysis showed that high nitrate presence corresponds to areas with both high ground water recharge and high on-ground nitrogen loadings In addition the nitrate concentration decreased with increasing sampling depth In general the trend of long-term nitrate concentration remained elevated in shallow aquifers due to the persistent on-ground nitrogen loadings produced by agriculture-related land use practices Finally the watersheds were prioritized for management intervention alternatives and data monitoring based on a number of decision variables Journal of Hydrology Volume 295 Issues 1-4 10 August 2004 Pages 225-245 http:dxdoiorg101016jjhydrol200403013 Applicability of Statistical Learning Algorithms in Groundwater Quality Modelinghttp://blogs.najah.edu/staff/mohammadalmasri/article/Applicability-of-Statistical-Learning-Algorithms-in-Groundwater-Quality-ModelingPublished ArticlesFour algorithms are outlined each of which has interesting features for predicting contaminant levels in groundwater Artificial neural networks ANN support vector machines SVM locally weighted projection regression LWPR and relevance vector machines RVM are utilized as surrogates for a relatively complex and time-consuming mathematical model to simulate nitrate concentration in groundwater at specified receptors Nitrates in the application reported in this paper are due to on-ground loadings from fertilizers and manures The practicability of the four learning machines in this application is demonstrated for an agriculture-dominated watershed where nitrate contamination exceeds the maximum allowable contaminant level at many locations Cross-validation and bootstrapping techniques are used for both training and performance evaluation Prediction results of the four learning machines are rigorously assessed using different efficiency measures to ensure their generalization ability Prediction results show the ability of learning machines to build accurate models with strong predictive capabilities and hence constitute a valuable means for saving effort in groundwater contaminant modeling and improving modeling performance Implications of On-Ground Nitrogen Loading and Soil Transformations on Ground Water Quality Managementhttp://blogs.najah.edu/staff/mohammadalmasri/article/Implications-of-On-Ground-Nitrogen-Loading-and-Soil-Transformations-on-Ground-Water-Quality-ManagementPublished ArticlesThis paper presents a modeling approach based on a geographic information system GIS to estimate the variability of on-ground nitrogen loading and the corresponding nitrate leaching to ground water The methodology integrates all point and nonpoint sources of nitrogen the national land cover database soil nitrogen transformations and the uncertainty of key soil and land use-related parameters to predict the nitrate mass leaching to ground water The analysis considered 21 different land use classes with information derived from nitrogen sources such as fertilizer and dairy manure applications dairy lagoons septic systems and dry and wet depositions Simulations were performed at a temporal resolution of one month to capture seasonal trends The model was applied to a large aquifer of 376 square miles in Washington State that serves more than 100000 residents with drinking water The results showed that dairy manure is the main source of nitrogen in the area followed by fertilizers It was also seen that nitrate leaching is controlled by the recharge rate and there can be a substantial buildup of soil nitrogen over long periods of time Uncertainty analysis showed that denitrification rate is the most influential parameter on nitrate leaching The results showed that combining management alternatives is a successful strategy especially with the use of nitrification inhibitors Also change in the land use pattern has a noticeable impact on nitrate leaching