Assessing groundwater vulnerability to nitrate pollution using statistical approaches: a case study of Sidi Bouzid shallow aquifer,Central Tunisia     

Ikram Jmal  Bachaer Ayed  Emna Boughariou  Nabila Allouche  Salwa Saidi  Monji Hamdi  Salem Bouri 《Arabian Journal of Geosciences》2017,10(16):364

The study region comprises the Sidi Bouzid shallow aquifer, which is located in the western part of Central Tunisia. It is mainly occupied by agricultural land with intensive use of chemical fertilizers especially nitrates. For this reason, nitrate measurement was performed in 38 water samples to evaluate and calibrate the obtained models. Several environmental parameters were analyzed using groundwater nitrate concentrations, and different statistical approaches were applied to assess and validate the groundwater vulnerability to nitrate pollution in the Sidi Bouzid shallow aquifer. Multiple linear regression (MLR), analyses of covariance (ANCOVA), and logistic regression (LR) were carried out for studying the nitrate effects on groundwater pollution. Statistical analyses were used to identify major environmental factors that control the groundwater nitrate concentration in this region. Correlation and statistical analyses were conducted to examine the relationship between the nitrate (dependent variable) and various environmental variables (independent variables). All methods show that “groundwater depth” and “land use” parameters are statistically significant at 95% level of confidence. Groundwater vulnerability map was obtained by overlaying these two thematic layers which were obtained in the GIS environment. It shows that the high vulnerability area coincides with the likelihood that nitrate concentration exceeds 24.5 mg/l in groundwater. The relationship between the groundwater vulnerability classes and the nitrate concentrations provides satisfactory results; it showed an Eta-squared correlation coefficient of 64%. So, the groundwater vulnerability map can be used as a synthetic document for realistic management of groundwater quality.  相似文献   

Algal community and pollution indicators for the assessment of water quality of Ismailia canal,Egypt     

Elshobary  Mostafa E.  Essa  Dorya I.  Attiah  Abdullah M.  Salem  Zenhom E.  Qi  Xianghui 《Stochastic Environmental Research and Risk Assessment (SERRA)》2020,34(7):1089-1103

Stochastic Environmental Research and Risk Assessment - The phytoplankton community structure is affected by both ecological and spatial factors. Influences of these two factors on phytoplankton...  相似文献   

Groundwater vulnerability and risk mapping of the Hajeb-jelma aquifer (Central Tunisia) using a GIS-based DRASTIC model   总被引：7，自引：2，他引：5  

Salwa Saidi  Salem Bouri  Hamed Ben Dhia 《Environmental Earth Sciences》2010,59(7):1579-1588

The aim of this study is to elaborate a synthetic document for the assessment of groundwater vulnerability to pollution in the Hajeb-Jelma aquifer. The specific object is to incorporate the Geographical Information System (GIS) to generate groundwater vulnerability and risk maps with DRASTIC model. Indeed, GIS could help to make the results of a complicated model more clear through visual representation, providing an applicable tool for decision makers. The vulnerability map of Hajeb-Jelma watershed shows three classes: moderate, high and very high depending on the intrinsic properties. The risk map shows a very high risk dependant on hydrogeological characteristics, land use and human impacts in major part of the Hajeb-Jelma region. These maps could serve as a scientific basis for sustainable land use planning and groundwater management in the Hajeb-Jelma region.  相似文献   

Structural Setting of Northern Tunisia Insights from Gravity Data Analysis Jendouba Case Study     

Imen Hamdi Nasr  Adnen Amiri  Mohamed Hédi Inoubli  Abdelhmid Ben Salem  AbdelHak Chaqui  Said Tlig 《Pure and Applied Geophysics》2011,168(10):1835-1849

Detailed gravity data in conjunction with available surface geology are analyzed to infer the organization of the underlying structures in Jendouba area. Gravity data analysis benefits from the gravity Bouguer anomaly, upward continuations, residual distribution, derivatives and Euler deconvolved maps. The main results display a positive amplitude gravity anomaly as the response of Triassic evaporitic bodies and important NE trending features at the boundaries between the Triassic outcrops and their enveloping strata. Integration of gravity, geological and structural maps let to the identification of major structural directions and trends of the study area. It confirms some structural elements gathered from outcrops. It defines also new ones.  相似文献   

Erratum to: Properties of geothermal resources in Kebilli region, Southwestern Tunisia     

Fatma Ben Brahim  Jalila Makni  Salem Bouri  Hamed Ben Dhia 《Environmental Earth Sciences》2013,69(6):2125-2125

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Hydrochemical analysis and evaluation of groundwater quality of a Mio-Plio-Quaternary aquifer system in an arid regions: case of El Hancha, Djebeniana and El Amra regions, Tunisia   总被引：1，自引：1，他引：0  

Fatma Ben Brahim  Salem Bouri  Hafedh Khanfir 《Arabian Journal of Geosciences》2013,6(6):2089-2102

A hydrogeochemical approach has been carried out in the Mio-Plio-Quaternary aquifer system of northern Sfax to investigate the geochemical evolution, the origin of groundwaters and their circulation patterns. The groundwater samples collected from different wells seem to be dominated by sodium chloride type to sulphate chloride type. Detail analysis of chemical data including the thermodynamic calculations was used to assess that the chemical evolution of groundwater is primarily controlled by water–rock interactions. The values of sodium absorption ratio and electrical conductivity of the groundwater were plotted in the US Salinity Laboratory diagram for irrigation water. Most of the water samples in northern Sfax fall in the fields of C4S1, C4S2 and C4S3 indicating very high salinity and medium to high sodium alkalinity hazard. Thus, groundwater quality is ranging between doubtful to unsuitable for irrigation uses under normal condition, and further action for salinity control is required in remediating such problem. Principal component analysis of geochemical data used in conjunction with bivariate diagrams of major elements indicates that groundwater mineralization is mainly controlled by (1) water–rock interaction processes, (2) anthropogenic process in relation with return flow of NO₃-rich irrigation waters and (3) domestic discharges.  相似文献   

Fate of drilling waste discharges and ecological risk assessment in the Egyptian Red Sea: an aquivalence-based fuzzy analysis   总被引：2，自引：2，他引：0  

Ahmad Agwa  Heba Leheta  Ahmed Salem  Rehan Sadiq 《Stochastic Environmental Research and Risk Assessment (SERRA)》2013,27(1):169-181

Egypt is located in the Northeast of Africa where oil and gas (O&G) are produced offshore from the Gulf of Suez and the Southeast part of the Mediterranean. The O&G production in Egypt is distributed as follows: 70% from Gulf of Suez, 16% from Western desert, 8% from the Sinai Peninsula and 6% from Eastern desert. Past O&G activities, refining and transport have resulted in chronic pollution in Egyptian offshore and numerous environmental programs have been initiated to protect new development areas from the environmental impacts. The offshore drilling process uses drilling fluids (mud) and generates waste fluids and cuttings, which could be the largest discharges going into the receiving water bodies. There are several options to manage offshore drilling wastes: offshore discharge, offshore down-hole injection and onshore disposal. Water-based drilling fluids (WBF) are commonly employed for drilling in Egyptian offshore because of their expected environmental benign behavior. The main objective of this paper is to develop a methodology to determine the fate of heavy metals associated with WBF drilling waste in the marine environment and estimate the associated ecological risks. Proposed contaminant fate model is based on an aquivalence approach, which has been integrated with fuzzy-based analysis to study the uncertainties. This research concluded that the impacts of heavy metals associated with the drilling waste discharges in the receiving waters are minimal.  相似文献   

Methodology for comparing two carrier phase tracking techniques   总被引：1，自引：0，他引：1  

Dina Reda Salem  Cillian O’Driscoll  Gérard Lachapelle 《GPS Solutions》2012,16(2):197-207

The carrier phase tracking loop is the primary focus of the current work. In particular, two carrier phase tracking techniques are compared, the standard phase tracking loop, i.e., the phase lock loop (PLL), and the extended Kalman filter (EKF) tracking loop. In order to compare these two different techniques and taking into consideration the different models adopted in each, it is important to bring them to one common ground. In order to accomplish this, the equivalent PLL for a given EKF has to be determined in terms of steady-state response to both thermal noise and signal dynamics. A novel method for experimentally calculating the equivalent bandwidth of the EKF is presented and used to evaluate the performance of the equivalent PLL. Results are shown for both the L1 and L5 signals. Even though the two loops are designed to track equivalent dynamics and to have equivalent carrier phase standard deviations, the EKF outperforms the equivalent PLL in terms of both the transient response and sensitivity.  相似文献   

Geo-environmental evaluation of Wadi El Raiyan Lakes,Egypt, using remote sensing and trace element techniques     

Hend S. Abu Salem  Atef Abu Khatita  Mamdouh M. Abdeen  Essam A. Mohamed  Ahmed M. El Kammar 《Arabian Journal of Geosciences》2017,10(10):224

Wadi El Raiyan depression represents a discharge area of excess wastewater from the Faiyum province. It comprises two lakes: the upper lake connects the lower one through a channel. The intensive agriculture in the area hazardously affects both lakes. To assess the status of these lakes, this work studies the change detection using image classification and post-classification comparison, physicochemical parameters, concentration of trace elements, and microbiological contents. The classified images indicate a maintained constant area of the upper lake from 1990 to 2012 and decreased by 1.6% in 2014. The lower lake area increased by 4.8% between 1990 and 2001, then decreased till 2014 and increased again by 8.4% in 2015. The change detection concluded that the lake could be disappeared by 2019 if the exploitation of water from the upper lake continues, or the lake could be rebounded if the government planned to increase the recharge. The factor analysis implies that the total Fe, Mn, Ni, Ba, and As are controlled by pH–Eh relationship, Cu by TDS, Pb by temperature, while Cd is attributed to anthropogenic factor. The upper and lower lake samples exhibit biological oxygen demand (BOD) and chemical oxygen demand (COD) values lower than fish farm samples. The high BOD and COD values were coupled by high nitrate contents in the studied water samples. The cultivated land drains and the fish farms samples have total coliform (TC) and fecal coliform (FC) higher than the samples collected from the upper lake.  相似文献   

Assessment of groundwater vulnerability using a specific vulnerability method: Case of Maritime Djeffara shallow aquifer (Southeastern Tunisia)     

Bachaer Ayed  Ikram Jmal  Samir Sahal  Salem Bouri 《Arabian Journal of Geosciences》2017,10(12):262

Groundwater resources are vulnerable to contamination especially in shallow aquifers. The aquifer hydrogeological parameters and the Land Uses category combinations lead to subdivide areas according to their contamination likelihood. In arid and semi-arid regions, shallow aquifers are more exposed to groundwater contamination due to high population densities (extensive uses) and agricultural activities (nitrate contamination). Moreover, these regions are characterized by low rainfall and high evaporation. Furthermore, the spread of farmland, industrial and domestic sectors, is the principal contaminant producer which threats the groundwater quality. To protect these limited resources, the groundwater vulnerability assessment was developed in Maritime Djeffara shallow aquifer (Southeastern Tunisia). The study area is essentially occupied by agricultural areas (intensive use of chemical fertilizers) in addition to the discharge of industrial zones. The main objective of this study is to assess the aquifer vulnerability using the Susceptibility Index (SI) method as a specific vulnerability model. The results show that the study area is classified into five classes of vulnerability: very low, low, medium, high, and very high (1.54, 20, 41.54, 35.9, and 1.02%, respectively) with an uneven spatial distribution. The risk results exhibit three degrees: low, moderate, and high. The validation of the vulnerability model was performed by using salinity values and nitrate concentrations with a correlation coefficient of about 57 and 55%, respectively. This study could serve as a scientific basis for sustainable land use planning and groundwater management in the study area.  相似文献