Ground water

m.almasri's picture

Implications of On-Ground Nitrogen Loading and Soil Transformations on Ground Water Quality Management

Journal Title, Volume, Page: 
Journal of the American Water Resources Association (JAWRA) 40(1):165–186
Year of Publication: 
2004
Authors: 
Mohammad N. Almasri
Utah State University, Utah Water Research Laboratory, 8200 Old Main Hill, Logan, Utah 84322–8200
Current Affiliation: 
Department of Civil Engineering, College of Engineering, An-Najah National University, P. O. Box 7, Nablus, Palestine
Jagath J. Kaluarachchi
Utah State University, Utah Water Research Laboratory, 8200 Old Main Hill, Logan, Utah 84322–8200
Preferred Abstract (Original): 
This 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 100,000 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.
m.almasri's picture

Assessment and management of long-term nitrate pollution of ground water in agriculture-dominated watersheds

Journal Title, Volume, Page: 
 Journal of Hydrology (295): 225–245. doi:10.1016/j.jhydrol.2004.03.013
Year of Publication: 
2004
Authors: 
Mohammad N. Almasri
Utah Water Research Laboratory, Department of Civil and Environmental Engineering, Utah State University, Logan, UT 84322-8200, USA
Current Affiliation: 
Department of Civil Engineering, College of Engineering, An-Najah National University, P. O. Box 7, Nablus, Palestine
Jagath J. Kaluarachchi
Utah Water Research Laboratory, Department of Civil and Environmental Engineering, Utah State University, Logan, UT 84322-8200, USA
Preferred Abstract (Original): 
The 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.
m.almasri's picture

Modular neural networks to predict the nitrate distribution in ground water using the on-ground nitrogen loading and recharge data

Journal Title, Volume, Page: 
Environmental Modelling and Software (20): 851–871. doi:10.1016/j.envsoft.2004.05.001
Year of Publication: 
2005
Authors: 
Mohammad N. Almasri
Department of Civil and Environmental Engineering and Utah Water Research Laboratory, Utah State University, Logan, UT 84322-8200, USA
Current Affiliation: 
Department of Civil Engineering, College of Engineering, An-Najah National University, P. O. Box 7, Nablus, Palestine
Jagath J. Kaluarachchi
Department of Civil and Environmental Engineering and Utah Water Research Laboratory, Utah State University, Logan, UT 84322-8200, USA
Preferred Abstract (Original): 
Artificial 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 input–output data. The basic premise followed in developing the MNN input–output 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.
Nidal Zatar's picture

Quantitative Determination of Three Textile Reactive Dyes in Ground Water, Sewage Water and Soil Using Voltammetric and HPLC Techniques

Journal Title, Volume, Page: 
An-Najah Univ. J. Res. (N. Sc.), 18(2) (2004) 173-
Year of Publication: 
2004
Authors: 
Nidal Zatar
Department of Chemistry, Faculty of Science, An-Najah National University, Nablus
Current Affiliation: 
Department of Chemistry, Faculty of Science, An-Najah National University, Nablus
Ali Abu Zuhri
Al-Aqsa University, Gaza, Palestine
Naser Tayem
Preferred Abstract (Original): 
Differential-pulse adsorptive cathodic stripping voltammetric (DP-AdCSV) and high performance liquid chromatography (HPLC) techniques were developed for quantitative determination of Reactive Blue 19, Reactive Red 198 and Reactive Orange 107 textile dyes. The calibration curves using the DP-AdCSV method were found to be linear over the ranges 0.05-1.0 ppm, 0.10-1.10 ppm and 0.05-1.0 ppm, respectively. The HPLC method is based on using a mobile phase consisting of acetonitrile:water (60:40, v/v) containing 0.45 M N-Cetyl-N,N,N-trimethylammonium bromide (CTAB) and buffered to pH 7.92. Reverse phase RP C18 column was used with a flow rate of 0.6 ml/minute. The retention times for Reactive Blue 19, Reactive Red 198 and Reactive Orange 107 were found to be 5.4 min, 7.8 min and 2.3 min, respectively. The calibration curves were found to be linear over the ranges 0.1-5.0 ppm, 0.1-1.2 ppm and 0.05-1.5 ppm, respectively.
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