Use of Electrical Resistivity Methods (2-D and VES) in Proposed Landfill Site Investigation – A Case Study of Al Fukhari Landfill, Southeastern Gaza Strip, Palestine

Electrical resistivity tomography (ERT) and vertical electrical sounding (VES) are widely used in environmental and engineering purposes. In the present study, both ERT and VES were used to investigate the suitability of a proposed landfill site area in south of Gaza Strip, Palestine to delineate the presence of any linear structure, depth and characterization of the unsaturated zone, layer resistivities, soil type, bedrock depth and subsurface structures with priority of groundwater protection. Measurements procedure for electrical imaging resistivity survey is taken along 9 spreads with Wenner-Schlumberger configuration with maximum spread length of 115m, in E-W and N-S direction, in addition to three VES points with Schlumberger configuration with electrode spacing (AB/2) ranging from 0.5 to 150 m. VES location has been selected much closed to the 2D lines and near the proposed boreholes to integrate all the data. Data from 6 drilling boreholes (up to 25m depth) and 14 drilling test pits (up to 5m depth) are also used to support the geophysical models. The proposed geoelectrical models show that resistivity values change horizontally and vertically as a result of  inhomogeneous of soil contents. Top soil layers and dry Sands are characterized by high resistivity values, whilst low resistivities reflect  a Clay or Silty Clay layers to Sandy Clay layers. Layer thicknesses and the subsurface structure proposed by the geoelectrical interpretation showed a good correlation with that of the boreholes and drilling test pits. Keywords: Electrical Resistivity Tomography, VES, Landfill Investigation, Al Fukhari , Gaza Strip, Palestine

Physico-Chemical and Microbiological Assessment of Desalination Plants in Gaza City, Palestine

Gaza Strip is an area suffers from sharp deterioration in the water situation (both in terms of quality & quantity) due to high growth of population, rain shortage, sea water intrusion, industrial and agricultural activities. The bad situation leads to establish many commercial desalination plants, in order to contribute in the solution of water problems.The goal of this study is to assess the effects of desalination plants by analyzing the desalinated water chemically, bacteriology and physically.The results indicated that there is growth in the number of desalination plants in the last seven years, about half of the desalination plants located in the west of Gaza City. All of these plants depend on private wells as water source but there were large number of these wells not closed and also not protected well.It was found that 70 % of the desalination plants located in inappropriate sites (near facilities like schools, factories...). The pipe of discharge was fixed well in 72% of the trucks and the location of the generator was suitable in 76% of the trucks. Brine water disposal in 63% of the plants was in sewage. Most of the desalination plants were not disinfect the tanks, while 40.7% of the plants add chlorine to the water tanks. There is no any problem in the physiochemical parameters of the desalinated water where all the samples were according to the WHO standards. The problems were present in the brackish water, where all the samples have physiochemical parameters higher than the WHO standards. There was bacteriological contamination in 27% of the plants with FC, while 28.3% were contaminated of E coli bacteria because of the absence of disinfection. Keywords: Water, contamination, desalination, Palestin

Evaluation of Microbiological Quality of Desalinated Water at Gaza City Schools, Palestine

Gaza Strip is an elongated strip located at southeastern coast of Palestine with total area of about 365 km2 with approximately 40 km long and the width varies from 8 km in the north to 14 km in the south. Gaza City is the biggest cities in Gaza Strip and has an area of approximately 55km2 with about 500,000 people forms about 30% of total Gaza strip residence. The Area has very limited water resources. Groundwater is the main source for domestic, industrial and agricultural purposes. Over abstraction of the groundwater leaded to sea water intrusion which increases salinity of the groundwater by time. Water resources are deteriorating in terms of quantities and quality which led to establish small business scale desalination plants to treat and distribute desalinated water by trucks for most of Gaza strip areas and schools. The aims of this research are to check if there is microbiological contamination at desalinated water at Gaza City schools, to determine the source of contamination if any, and to determine the difference between drinking water microbiological quality between schools moderated by Ministry of High Education (MOHE) and schools moderated by United Nations Relief and Works Agency (UNRWA). Some of 130 school buildings have been selected and the data evaluated for the periods from the year 2009 to 2011. Results indicated significant microbiological contamination in the desalination plants inlet and in schools water tanks. The origin of this contamination is believed to animal origin. About 50.0% of monitored schools at East Directorate, 83.3% of monitored schools at West Directorate and 60.0% of monitored schools at UNRWA were contaminated. Contaminated schools after follow-up has decreased, it were 16.7% at East, 50% at West and 40% at UNRWA schools. Keywords: Gaza Strip, Palestine, Contamination, Desalination plants

Application of Vertical Electrical Sounding for Delineation of Sea Water Intrusion into the Freshwater Aquifer of Southern Governorates of Gaza Strip, Palestine

Abstract Vertical Electrical Sounding (VES) proved to be an important tool for mapping the freshwater-saltwater interface. Seawater intrusion is serious problem especially in coastal areas. 14 Vertical electrical soundings with Schlumberger array were carried out (perpendicular to the coast) in southern part of the coastal aquifer in Gaza Strip (Khan Younis and Rafah Governorates) to study the subsurface geologic formation and delineation of seawater intrusion into freshwater aquifer. Lithology and hydrochemistry data from 12 bore holes were used to integrate the results. The results reveals that 50% of the total sounding are interpreted of 3 layer modes, while the other 50% are of 4 layers model. Interpreted 2D geoelectrical models (in two cross sections parallel to the coast line) showed that seawater intrusion with electrical resistivity less than 2Ωm is dominant along the section parallel to coast line at 400m east of it and for shallow depths (3-10m depth), while in the other section (1000m) east of the coast line seawater intrusion is detected in some places while the other parts still have brackish/fresh groundwater with resistivity more than 10Ωm at different depths (26-50m). ملخص: اثبتت طريقة المقاومة الكهربائية العمودية (VES)  فعاليتها فى تحديد الحدود الفاصلة بين المياه العذبة و المالحة . تعتبر مشكلة تداخل المياه المالحة فى مياه الخزان الجوفى العذب مشكلة ذات اهمية و خاصة فى المناطق الشاطئية. لقد تم تنفيذ 14 مجسة كهربائية عمودية بأستخدام تشكيل شلمبرجير بشكل قطاعات عمودية على على الساحل الجنوبى لقطاع غزة (محافظات خانيونس و رفح) و ذلك بهدف دراسة التركيب الجيولوجى للخزان الجوفى و تحديد مدى تداخل مياه البحر فيه . كما تم الاستعانة بالمعلومات الليثولوجية و الهيدروكيميائية من 12 بئرمياه فى مناطق الدراسة. اظهرت النتائج ان 50% من منحنيات المقاومة الكهربائية المقاسة تمثل نموذج لثلاث طبقات جيولوجية بينما 50% تمثل اربع طبقات. تم اختيار قطاعين متوازيين و موازين لشاطىْ البحر, يبعد الاول 400 م عن الشاطىْ بينما الاخر يبعد 1000م عنه لدراسة تغيرات المقاومة فى بعدين. أظهرت النتائج ان مياه الحر ذات المقاومة الكهربائية أقل من 2 أوم.متر تسود على طول القطاع القريب من الشاطىْ و لاعماق ضحلة (3-10 م), بينما فى القطاع الثانى و الذى يبعد 1000م شرقا تم تحديد أمكن تداخل مياه البحر المالحة فى بعض الاماكن و لم يتم تحديدها فى أماكن أخرى مما يفسر على انه لا زال تلك المناطق تحتوى على مياه عذبة/ مالحة ذات مقاومة كهربائية اكبر من 10 أوم.متر و على أعماق تتراوح بين 26-50 متر

Electrical Resistivity Tomography for Coastal Sea Water Intrusion Characterization along Rafah Area, South of Gaza Strip, Palestine

Resistivity methods mainly electrical resistivity tomography 2D and resistivity sounding 1D represent the main geophysical tools to delineate seawater intrusion into freshwater aquifers. Thirty 2D imaging sections were applied with Wenner-Schlumberger array (NW-SE direction), distributed on six profiles (perpendicular to the coast) in southern part of the coastal aquifer in Gaza Strip (Rafah Governorates), supported by 4 Vertical electrical soundings points with Schlumberger array, to map shallow-depth seawater intrusion into freshwater aquifer and study the subsurface geologic formation. Analysis and interpretation of the electrical resistivity tomography 2D and 1D sounding results reveal that seawater intrusion zone appears at the western part of the study area and extends along Rafah coast with a difference distance and depths. The depths are ranging between (few meters to 20 m) in the western sections, while they are betwee 40 to more than 65 m in the eastern section. The resistivity data results were correlates well with the 3 boreholes data and 3 chemical analyses water samples

Estimation of Aquifer Parameters from Vertical Electrical Sounding Measurements South Gaza Strip, Palestine

In this study quantitative interpretation of some 14 Vertical Electrical Sounding (VES) points using the Schlumberger array and data from 10 boreholes were applied to study the aquifer geoelectrical/hydrogeological parameters in the southern governorates of Gaza Strip. The quantitative interpretation of (VES) results analyzed in order to find empirical relations between different aquifer parameters. The results represent the predicted hydraulic conductivity (K), transmissivity (Tr), TDS, earth resistivity, water resistivity, porosity and Dar-Zarrouk parameters (Longitudinal conductance and Transverse resistance). The results show the earth resistivity is strongly affected by the chemistry and salinity of the groundwater. The relation between longitudinal resistivity (ρL) and groundwater salinity (TDS) was achieved for groundwater aquifer. The geoelectric (Dar-Zarrouk) parameters determined and interpreted by using the integration of the results, which indicates that longitudinal conductance has a high values at the western part of the study area represents an increase in groundwater movement horizontally, that is a strong evidence of seawater intrusion. Porosity was estimated to be in the range of 38–52% with an average value of 46%. Transmissivity values for the study area were calculated. This result helps to delineate the contact between the saline and fresh groundwater aquifer in the study area

Determining Levels of Carbon Dioxide, Carbon Monoxide And Thermal Comfort Inside IUG Offices And Its Effect on The Employees

Indoor environmental quality (IEQ) is one of the most important factors that affect the residents of the indoor locations. CO2, CO and thermal comfort is the most famous parameters, and IUG is considered as a leader in the pursuit of providing satisfaction for workers. This study aims to identify the impact of the elements of indoor environmental quality on the employees of IUG and to compare these elements with the international recognized standards. This study was conducted on 22 rooms within IUG, where employees spend more 7 hours in their offices during three seasons: winter, and summer, in two stages, the first stage: field work, by measuring the concentration of CO2, CO, Humidity and temperature by using the relevant devices, the second stage: designing a questionnaire for exploring the extent of the impact of The study shows the following results: 80% of IUG employees are satisfied with thermal comfort and the concentration of CO is appropriate and less than the standards (9ppm). CO2 is high in the rooms that rely on centralized air conditioning, and there is a negative relationship between the ventilation ratio and the concentration of CO2. There is a significant statistical difference between CO2 measurements according to seasons these factors on the employees working indoors. The university employees felt the symptoms of health issues related to carbon dioxide concentration. The study concluded that CO2, CO concentrations are varied inside the rooms of the university and the environmental awareness of these factors and their effect need to be enforced