Hydrogeochemical Processes Controlling the Water Chemistry of a Closed Saline Lake Located in Sahara Desert: Lake Qarun,Egypt   总被引：1，自引：0，他引：1  

Mahmoud S. M. Abdel Wahed  Essam A. Mohamed  Mohamed I. El-Sayed  Adel M’nif  Mika Sillanpää 《Aquatic Geochemistry》2015,21(1):31-57

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Late Miocene normal faulting beneath the northern Nile Delta: NNW propagation of the Gulf of Suez Rift     

Mohammad A. Sarhan  Richard E. Ll. Collier  Ahmed Basal  Mohamed Hamed Abdel Aal 《Arabian Journal of Geosciences》2014,7(11):4563-4571

The north Egyptian continental margin has undergone passive margin subsidence since the opening of Tethys, but its post-Mesozoic history has been interrupted by tectonic events that include a phase of extensional faulting in the Late Miocene. This study characterizes the geometry and distribution of Late Miocene normal faulting beneath the northern Nile Delta and addresses the relationship of this faulting to the north–northwestwards propagation of Red Sea–Gulf of Suez rifting at this time. Structural interpretation of a 2D grid of seismic reflection data has defined a Tortonian–Messinian syn-rift megasequence, when tied to well data. Normal fault correlations between seismic lines are constrained by the mapping of fault-related folds. Faults are evenly distributed across the study area and are found to strike predominantly NW–SE to NNW–SSE, with some N–S faults in the north. Faults are interpreted to be <10 km in length, typically in the range 3–6 km. This suggests that rifting in the northern Nile Delta did not proceed beyond a continental rift initiation phase, with distributed, relatively small-scale faults. This contrasts with the Gulf of Suez Rift, where faulting continued to a more evolved fault localization phase, with block-bounding faults >25 km in length. Results suggest that future studies could quantify fault evolution from rift initiation to fault linkage to displacement localization, by studying the spatial variation in faulting from the northern Nile Delta, south–southeastwards to the Gulf of Suez Rift.  相似文献   

Sustainable multivariate analysis for land use management in El-Sharkiya,Egypt     

W. A. Abdel Kawy  Kh. M. Darwish 《Arabian Journal of Geosciences》2014,7(2):475-487

In Egypt, major sustainability variables could be identified as scarce of soil and water resources, environmental degradation, rapid population growth, institutional arrangement that includes land tenure and farm fragmentation, agricultural administration, lack of infrastructure, and credit utilization. The main objective of the current work is to evaluate the sustainable land use management (SLM) model through biophysics and socioeconomic elements for the purpose of combating sustainability constraints that preclude the agricultural development geospatially. In this research, from the geomorphologic point of view, the obtained results showed three main landscapes. They were identified in the study area as: fluviolacustrine plain, Aeolian deposits, and flood plain. The study area was dominated by some physical and chemical degradation processes with different scales breaking down the equilibrium of soil stability. The SLM model was implemented and assessed from multivariate perspective points of productivity, security, protection, economic viability, and social acceptability. Four SLM classes were outlined as follows: class I, land management practices that did meet sustainability requirements with a score ≥0.65, which represented 31.0 % of the considered agricultural study area; class II, land management practices that were marginally above the sustainability threshold and represented 12.6 %; class III, land management practices that were slightly below the threshold of sustainability and represented 8.60 %; class IV, land management practices that did not meet sustainability requirements with index values >0.1 that represented 47.86 %. As a general conclusion, it is found that land management practices tend to be unsustainable in the area under investigation for certain constraints that play motivated roles in lowering the targeted land sustainability.  相似文献   

Origin of Some Neo-Proterozoic Ophiolites from Eastern Desert of Egypt: Geochemical Constraints     

Mohamed Metwaly ABU ANBAR  YANG Jingsui 《《地质学报》英文版》2017,91(Z1):3-4

The Neo-Proterozoic ophiolites occur in the central and southern Eastern Desert along suture zone as dismemberedmassesinvolcano-sedimentary assemblages.The ophiolite component includes ultramafic rocks mainly serpentinites,mafic rocks,minor bodies of trondhjemite,sheeted dykes,metabasalts,and pillow lavas.The Present studies include two ophiolites in Central and southern eastern Desert named Mubarak–El Mayet and Ghadir respectively(Fig.1).The first one named after wadi Mubarak and wadi El Mayet area(55 km north Marsa Alam city)and the second named after Wadi Ghadir(30 km south Marsa Alam city).The dismembered ophiolite components in MubarakEl Mayet mainly composed mainly of serpentinites,ophiolitic metagabbros,sheeted dykes and Pillow lavas.All components occur as thrusted blocks and sheets in metavolcano-sedimentary assemblages(matrix).Gabbros sometimes occur as coarse grained gabbros(appenites)whereas pillows range in size from 30 cm to 1 m(Fig.2a).The second ophiolite sequence expose in Wadi Ghadir and its tributary.It consists of serpentinized peridotites,layered gabbro,massive isotropic gabbro,1fine grained gabbro,sheeted diabase dykes,pillowed basaltic lavas and minor plagiogranites.The serpentinizedperidotites,metapyroxenitesand serpentinites occur as allochthonous dismembered blocks,fragments and sheets in highly sheered metasediments and metavolcanics(mélange)(Fig.2b,c).The massive and layered gabbros occur in the main wadi(Fig.2d,f)and in many places contain some veins and pockets from plagiogranites.The present gabbros intruded by syenogranites from the east.Pillow lavas occur between metasedimentary mélange and ophiolitic gabbros in wadi El Beda as tributary of Wadi Ghadir and sometimes occur as fragments in mélange.The pillows range in size from 40 cm to 1 m(Fig.2f)and are mainly amygdaloidal and porphyritic basalt and spilite.Sheeted dykes cut the gabbros and pillow lavas in the Wadi El Beda and composed mainly from diabase(Fig.2g,h).In the present study,47 samples for major,trace and REE elements from different rock types in Mubarak-El Mayet(18 samples)and Ghadir ophiolite(29 samples)were analyzed.The field work and the geochemical data will discussed in the present work to evaluate the tectonic setting,origin and mantle source for two ophiolite suites.  相似文献   

Fungal Decontamination of Fleshy Fruit Water Washes by Double Atmospheric Pressure Cold Plasma          下载免费PDF全文

Salama A. Ouf  Abdel‐Aleam H. Mohamed  Wael S. El‐Sayed 《洁净——土壤、空气、水》2016,44(2):134-142

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Incorporation of a Non-linear Image Filtering Technique for Noise Reduction in Seismic Data     

Jalal Ferahtia  Kamel Baddari  Nouredine Djarfour  Abdel Kader Kassouri 《Pure and Applied Geophysics》2010,167(11):1389-1404

Seismic noise is a fundamental part of seismic data which cannot be avoided when conducting any seismic survey. It consists of coherent and random noise. Noise removal or filtering is one of the major concerns in the field of seismic processing. In this paper, we introduce an image filtering technique based on a detection-estimation algorithm for Gaussian and random noise removal in seismic data, namely the trilateral filter, based on a statistic called rank-ordered absolute differences. The non-linear and adaptive behaviour of this filter makes it very robust in the presence of random and coherent noise, in addition to its computational simplicity and its ability to automatically identify noise in data. We have modified the strategy of trilateral filtering by adapting the rank-ordered absolute differences formula in order to extract the signal component. We have successfully used this filter for the removal of surface waves and random spiky noise from synthetic and field data. Results are very encouraging and show the superiority of this filter compared with other filters, particularly when used recursively.  相似文献   

Free Amino Acids Content in Some Halophytes under Salinity Stress in Arid Environment,Jordan     

Farah Al Nasir  Mufeed Batarseh  Adel H. Abdel‐Ghani  Anwar Jiries 《洁净——土壤、空气、水》2010,38(7):592-600

The variation in free amino acids concentration was examined in halophytes under salt stress conditions during spring and autumn in an arid environment, Jordan. The experiment was conducted in the southern region of the Jordan valley, using four different halophytes namely: Atriplex halimus, Atriplex nummularia, Tamarix aphylla L., and Portulaca oleracea L. Free amino acid concentrations showed changeable patterns under salinity stress conditions compared to the non‐stress (control) with respect to plant species and seasonal variation. In general, the amino acid pool during the spring experienced increases in A. halimus with increasing salinity; and decreased in A. nummularia, P. oleracea L., and T. aphylla L., respectively. Whereas, during the autumn, the overall amino acids decreased in A. halimus and A. nummularia, and increased in T. aphylla L. and P. oleracea with increasing salinity. The amino acid pool concentrations of A. halimus L. during the autumn was similar to that in spring under stress condition. Similarly, T. aphylla L. and P. oleracea showed higher rates in the autumn. In contrast, A. nummularia L. exhibited a slight increase in amino acid composition in the autumn under stress conditions. The plantation of salt tolerant plants such as halophytes in saline sodic soils showed an effective decline in soil salinity and can be recommended to be used as a bioreclamation method instead of the traditional leaching method, which requires large amount of fresh water.  相似文献   

The impact of the geologic setting on the Quaternary aquifer,El-Tur area,Southwest Sinai,Egypt     

Usama Abu Risha  Sayed Mosaad  El Sayed El Abd  Abdel Mohsen Hasanein 《Arabian Journal of Geosciences》2017,10(21):461

The groundwater extracted from the unconfined Quaternary aquifer is the main source of water supply in El-Tur area. The area is bounded from the east by the elevated basement complex of Southern Sinai and from the west by El-Qabaliyat Ridge. The wadis dissecting these highlands form effective watersheds of the Quaternary aquifer. These wadis form areas of focused recharge. Recharge also occurs directly via the Quaternary sediments covering El-Qaa Plain. Subsurface lateral groundwater flow from the fractured basement contributes significant recharge to the aquifer as well. The aquifer sediment facies affect the type and quality of groundwater. In the eastern part where the aquifer is composed mainly of gravel and coarse sand with fragments of weathered basement, the Na-Cl-SO₄ water dominates. In the west where the facies change is rapid and complex, many water types arise. The base exchange index (BEX) is positive in this part reflecting the role of clay minerals in changing the water types via cation exchange. In the east where clays are insignificant in the aquifer, the BEX is negative. In the western part next to El-Qabaliyat Ridge, the wells discharging from the calcareous sand zone have low groundwater salinities compared to the wells discharging from the alluvium. In general, the groundwater salinity increases in the direction of groundwater flow from the northeast to the southwest which reflects the dissolution of aquifer sediments. The concentration relationships between the major ions on one hand and chloride on the other reflect the dissolution of calcium carbonates, precipitation of K- and Mg-bearing minerals, and cation exchange of Ca for Na on clay minerals. The hydrochemical models support these reactions. In addition, they show that the effect of evaporation on the recharge water in the western catchment is about four times its effect on the eastern recharge water which reflects the rapid recharge through the wadis draining the fractured basement. Moreover, the contribution from the eastern catchment in sample No. 23 is more than four-folds the contribution from the western recharge area. The stable isotopes (²H and ¹⁸O) show that the Quaternary aquifer is recharging from recent rainfall. However, upward leakage of Paleogene groundwater (depleted in ¹⁸O) also occurs. The groundwater level map shows strong overpumping impact especially in the areas close to El-Tur city.  相似文献   

Removal of Tartrazine Dye onto Mixed‐Waste Activated Carbon: Kinetic and Thermodynamic Studies          下载免费PDF全文

Mohamed Abdelaty Habila  Zeid Abdullah ALOthman  Rahmat Ali  Ayman Abdel Ghafar  Mohamed Slah El‐Din Hassouna 《洁净——土壤、空气、水》2014,42(12):1824-1831

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Water and Wastewater Treatment in Africa – Current Practices and Challenges          下载免费PDF全文

Hongtao Wang  Tao Wang  Bingru Zhang  Fengting Li  Brahima Toure  Isaiah Bosire Omosa  Thomas Chiramba  Mohamed Abdel‐Monem  Mahesh Pradhan 《洁净——土壤、空气、水》2014,42(8):1029-1035

Sustainable access to safe drinking water and basic sanitation is an important part of the millennium development goals (MDGs). For most African countries, an extensive effort is needed for the last three remaining years for the achievement of the MDGs, especially in Sub‐Saharan Africa. Current practices for water and wastewater treatment in Africa are insufficient to ensure safe water and basic sanitation. To address this challenge, joint efforts are needed, including transforming to green economy, innovating technologies, improving operation and maintenance, harvesting energy, improving governance and management, promoting public participation, and establishing water quality standards.  相似文献