Mapping of groundwater prospective zones integrating remote sensing,geographic information systems and geophysical techniques in El-Qaà Plain area,Egypt     

Sara M. Abuzied  Hamed A. Alrefaee 《Hydrogeology Journal》2017,25(7):2067-2088

The geospatial mapping of groundwater prospective zones is essential to support the needs of local inhabitants and agricultural activities in arid regions such as El-Qaà area, Sinai Peninsula, Egypt. The study aims to locate new wells that can serve to cope with water scarcity. The integration of remote sensing, geographic information systems (GIS) and geophysical techniques is a breakthrough for groundwater prospecting. Based on these techniques, several factors contributing to groundwater potential in El-Qaà Plain were determined. Geophysical data were supported by information derived from a digital elevation model, and from geologic, geomorphologic and hydrologic data, to reveal the promising sites. All the spatial data that represent the contributing factors were integrated and analyzed in a GIS framework to develop a groundwater prospective model. An appropriate weightage was specified to each factor based on its relative contribution towards groundwater potential, and the resulting map delineates the study area into five classes, from very poor to very good potential. The very good potential zones are located in the Quaternary deposits, with flat to gentle topography, dense lineaments and structurally controlled drainage channels. The groundwater potential map was tested against the distribution of groundwater wells and cultivated land. The integrated methodology provides a powerful tool to design a suitable groundwater management plan in arid regions.  相似文献   

Biostratigraphy and seismic data analysis to detect the sequence stratigraphic depositional environment of the Miocene succession: Gulf of Suez (Egypt)     

Ahmed Abd El Naby  Wafaa Abd-Elaziz  Mohamed Hamed Abdel Aal 《Swiss Journal of Geoscience》2017,110(3):777-791

This work comprises a study of the sequence stratigraphy, seismic-facies analysis, biostratigraphy and depositional environments of the northern part of the Gulf of Suez, Egypt, using a set of 24 3D seismic profiles, composite logs and sonic logs from ten wells. The syn-rift formations in the studied ten wells are described lithologically and interpreted based on investigating two seismic profiles. Biostratigraphically, the Miocene fossils are identified to correlate the five planktonic foraminiferal biozones in the examined boreholes (RB-A1, RB-B1, RB-B3, EE85-2 and RB-C1). The sequence stratigraphic analysis suggests that the Miocene succession can be subdivided into two major third order depositional sequences (S1 and S2) separated by the three major sequence boundaries (DSB1, DSB2 and DSB3).  相似文献   

Mapping thermal comfort in Iran based on geostatistical methods and bioclimatic indices     

Hamzeh Ahmadi  Fariborz Ahmadi 《Arabian Journal of Geosciences》2017,10(15):342

The cognition of thermal comfort plays a pivotal role in human life and activities. Recognizing thermal comfort based on climatic parameters is substantially significant. The main objective of the present study is to map thermal comfort using statistics from 43 meteorological stations, from 1970 to 2013. Initially, according to temperature and relative humidity, annual and seasonal thermal comfort conditions were mapped, and later bioclimatic human thermal comfort conditions in line with spatial factors were zoned based on bioclimatic indexes of Temperature Humidity Index (THI), effective temperature (ET) and Relative Strain Index (RSI). Among geostatistical methods, empirical Bayesian kriging (EBK) method with less RSME is more efficient. The annual distribution of temperature changes according to spatial factors of rugged topography and elevation, and latitude affects relative humidity. Thermal comfort in the northern and western half of Iran is higher than the southern and eastern areas of the country. Spatial factors of latitude and altitude reduce bioclimatic uniformity and create small areas with or without thermal comfort conditions. Bioclimatic indicators based on air temperature and relative humidity range of bioclimatic zones show. The results of ET and THI divide the whole country into six zones, from lack of thermal comfort to having thermal comfort conditions. Areas of southern strip as well as central and southeastern parts of the country do not have any human thermal comfort conditions in most of the year.  相似文献   

Nature of serpentinization and carbonation of ophiolitic peridotites (Eastern Desert,Egypt): constrains from stable isotopes and whole-rock geochemistry     

Mohamed M. Hamdy  Hamed M. Gamal El Dien 《Arabian Journal of Geosciences》2017,10(19):429

Serpentinites are widespread in the Arabian-Nubian Shield (ANS) of the Eastern Desert of Egypt and usually enclose a tremendous carbonate alteration. Combined investigation of the stable isotope compositions of both O-H in serpentines and O-C in the whole-rock and the chemistry of the fluid-mobile elements (FMEs) in whole-rock serpentinites from Wadi (W.) Alam, Gabal (G.) El-Maiyit, and W. Atalla (Eastern Desert of Egypt) allowed to better understand the subsequent fluid sources of serpentinization and carbonation, as well as impact of these processes on the geochemistry of protolith ultramafic rocks. δ ¹⁸O values of W. Alam and W. Atalla serpentine minerals are close to the unaltered mantle and propose a lower temperature serpentinization if compared with those of G. El-Maiyit rocks. Moreover, δD values of W. Alam and W. Atalla serpentines (? 94 to ? 65‰) correspond to an igneous source that might be hydrothermal solutions mixed with the seawater in the mid-ocean ridge-arc transition setting. On the other hand, G. El-Maiyit serpentine is more depleted in ¹⁸O (with lower δ ¹⁸O values = 4.08–4.85‰), and its δD values (? 73 to 56 ‰) are most probably caused by an interaction with metamorphic fluids, acquired during on-land emplacement of oceanic peridotites or during burial in fore-arc setting. In addition, the oceanic oxygen isotope composition of most studied ophiolitic serpentinites points to the preservation of the pre-obduction δ ¹⁸O signatures and thus local-scale fluid flow at low water/rock ratios. Serpentinization fluids were CO₂-poor and the carbonation of the serpentinites resulted from infiltration of externally derived fluids. δ ¹⁸O_VSMOW values of carbonates in the studied serpentinites vary between heavier oxygen isotope composition in G. El-Maiyit samples (av. = 25.32‰) to lighter composition in W. Alam samples (av. = 19.43‰). However, δ ¹³C values of all serpentinites point mantle source of carbon. This source might have been evolved in mid-ocean ridge (W. Atalla) and subduction zone (W. Alam and G. El-Maiyit) settings. The studied serpentinites are usually enriched in FMEs, particularly Pb, Sr, Cs, and U. These enrichments were most probably the result of serpentinization and/or carbonation.  相似文献   

Plasma‐Based Indoor Air Cleaning Technologies: The State of the Art‐Review          下载免费PDF全文

Mitra Bahri  Fariborz Haghighat 《洁净——土壤、空气、水》2014,42(12):1667-1680

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基于深度学习的区域生态安全时空模拟与预测     

陈工  李琦  金玲艳  梁贺明  莫玉琴 《地球信息科学学报》2017,19(7):915-923

区域作为人类、自然、社会共同作用和互相影响的复杂系统,对区域进行生态量化建模与模拟仿真,是实现区域可持续发展战略的关键。传统机器学习方法对区域生态系统建模取得了一定的成果,但难以确定学习特征和实现时空模拟。深度学习不需事先确定训练特征,具有优异的特征学习能力,能够提高模型预测精度,因此利用深度学习进行建模具有显著优势。本文使用植被净初级生产力（NPP）、气溶胶光学厚度（AOD）和人口格网数据,充分利用深度学习的优点,采用最优深度神经网络时空模拟,得到了河南省2007-2014年3 km分辨率的生态赤字空间分布图和河南省2015-2020年的生态赤字时间预测结果并进行分析,为区域生态的科学管理和建设供科学依据和参考。  相似文献   

Effects of a sill on selective withdrawal through a point sink in a linearly stratified fluid     

Mirmosadegh Jamali  Hamed Haddadzadegan 《Advances in water resources》2010

Reservoir topography has significant effects on mechanism of selective withdrawal. We study selective withdrawal of a linearly stratified fluid through a point sink in a long rectangular reservoir with a sill at the bed experimentally and analytically. Experiments were conducted for various flow rates and sill heights to evaluate their effects on withdrawal layer in the inertial-buoyancy regime. Transition to the steady state is discussed in terms of dynamics of shear waves over the sill. The results show that in presence of a sill the withdrawal layer is thicker and higher in elevation. For flows controlled at the sill crest, the withdrawal layer thickness in the point-sink flow is almost equal to that in the similar line-sink flow. We propose an analytical relation for the withdrawal layer thickness in presence of a sill and confirm it by experiments.  相似文献   

Determination of mercury biogeochemical fluxes in the remote Mackenzie River Basin,northwest Canada,using speciation of sulfur and organic carbon     

Jesse Carrie  Gary A. Stern  Hamed Sanei  Robie W. Macdonald  Feiyue Wang 《Applied Geochemistry》2012

The Mackenzie River Basin (MRB) in NW Canada is one of the least human-impacted large watersheds in the world. The western and eastern sub-basins of the MRB are also marked by contrasting geology, geomorphology, hydrology, and biology. These remarkable differences in a remote river basin provide a unique opportunity to probe the biogeochemical processes governing the sources, transport, and bioavailability of Hg at the terrestrial-marine interface and ultimately in the Arctic Ocean. Based on a large dataset of the concentration and speciation of Hg, S and organic matter in surface sediments across the MRB, a source-apportioned budget was constructed for Hg in the MRB. The results indicate that the Hg flux in the basin originates primarily from the weathering of sulfide minerals in the western mountainous sub-basin (∼78% of the total), followed by the erosion of coal deposits along the mainstream of the Mackenzie River (∼10%), with the remainder split between atmospheric inputs and organic matter-bound Hg (6% and 5%, respectively). Although the Hg flux from the eastern peatland sub-basin only accounts for ∼10% of the total riverine Hg flux, Hg in this region correlates strongly with labile organic matter, and will likely have a much stronger influence on local biota.  相似文献   

Hydrogeological investigations of thermal waters in the Sfax Basin (Tunisia)   总被引：2，自引：2，他引：0  

Badia Chulli  Aysen Davraz  Jalila Makni  Mourad Bedir  Hamed Ben Dhia 《Environmental Earth Sciences》2012,66(1):1-16

The Sfax Basin in eastern Tunisia is bounded to the east by the Mediterranean Sea. Thermal waters of the Sfax area have measured temperatures of 23–36°C, and electrical conductivities of 3,200 and 14,980 μS/cm. Most of the thermal waters are characterized as Na–Cl type although there are a few Na–SO₄–Cl waters. They issue from Miocene units which are made up sands and sandstones interbedded with clay. The Quaternary sediments cap the system. The heat source is high geothermal gradient which are determined downhole temperature measurements caused by graben tectonics of the area. The results of mineral equilibrium modeling indicate that the thermal waters of the Sfax Basin are undersaturated with respect to gypsum, anhydrite and fluorite, oversaturated with respect to kaolinite, dolomite, calcite, microcline, quartz, chalcedony, and muscovite. Assessments from various chemical geothermometers, Na–K–Mg ternary and mineral equilibrium diagrams suggest that the reservoir temperature of the Sfax area can reach up to 120°C. According to δ¹⁸O and δ²H values, all thermal and cold groundwater is of meteoric origin.  相似文献   

Nitrate contamination in groundwater in the Sidi Aïch–Gafsa oases region, Southern Tunisia     

Younes Hamed  Sadek Awad  Amina Ben Sâad 《Environmental Earth Sciences》2013,70(5):2335-2348

Groundwater pumped from the semi-confined Complex Terminal (CT) aquifer is an important production factor in irrigated oases agriculture in southern Tunisia. A rise in the groundwater salinity has been observed as a consequence of increasing abstraction from the aquifer during the last few decades. All sources of contamination were investigated using hydrochemical data available from the 1990s. Water samples were taken from wells tapping both the CT and the shallow aquifers and analyzed with regard to chemistry tracers. Hydrochemical and water quality data obtained through a sampling period (December 2010) and analysis program indicate that nitrate pollution can be a serious problem affecting groundwater due to the use of nitrogen (N) fertilizers–pesticides in agriculture. The concentration of nitrate in an groundwater-irrigated area in Gafsa oases basin was studied, where abstraction from an unconfined CT aquifer has increased threefold over 25 years to 34 million m³/year; groundwater levels are falling at up to 0.7 m/year; and groundwater is increasingly mineralised (TDS increase from 500 to 4,000 mg/L), with nitrate concentrations ranging from 16 to 320 mg/L.  相似文献