Groundwater recharge to ophiolite aquifer in North Oman: constrained by stable isotopes and geochemistry     

Osman Abdalla  Rashid Al Abri  Khadija Semhi  Talal Al Hosni  Mansour Amerjeed  Ian Clark 《Environmental Earth Sciences》2016,75(15):1117

  相似文献   

Flow units delineation of multiple hydrocarbon reservoirs using hydraulic zonation technique via cluster analysis algorithm,Zeit Bay Field,Gulf of Suez,Egypt     

Nadia Abd Al Fattah  Mahmoud Ali Ghaleb  Omar Mohamed Mohamed Al mahdy 《Arabian Journal of Geosciences》2016,9(7):504

Investigation of hydraulic units in drilled wells through multiple reservoirs in Zeit Bay Field is the main target of this paper. Karim Limestone and Nubian Sandstone are target reservoirs in this study. Hydraulic zones provide a fundamental unit for subsequent reservoir characterization and simulation and also prove to be helpful in defining future well completion and work over practices. Hydraulic zonation by means of cluster analysis has been utilized to achieve this target. Hierarchical cluster analysis, elbow method, and k-means clustering are the main steps of this analysis. Petrophysical properties obtained from cores are utilized to perform this zonation. These properties are permeability and porosity data. Results have been validated by comparing the geological behavior of each zone against the measured permeability curve. Finally through this zonation, flow units which have the potential to extract fluids are determined more accurately. Petroleum geologists and engineers are more interested in these results. The cluster analysis flow suggesting in this paper is cost-effective due to lack of need for any commercial software.  相似文献   

Evolution of calculations of the virtual dipole moment of the Earth for reconstructing the oceanic inversion magnetic layer’s parameters     

A. A. Schreider  A. A. Ignatova  Al. A. Schreider  A. E. Sajneva  P. Varga  C. Denis 《Oceanology》2016,56(3):428-434

The VDM (virtual dipole moment) is one of the most significant characteristics describing the behavior of the time evolution of the terrestrial magnetic field. However, we have revealed that the formulas with which VDM calculations are performed often do not coincide with each other in various literature sources. Hence, results are obtained from these calculations that cannot be identical. Their correctness is verified by comparing the dimension and obtained results with the known value of the VDM for our time.  相似文献   

Biological data from sharks landed within the United Arab Emirates artisanal fishery     

RW Jabado  SM Al Ghais  W Hamza  DP Robinson  AC Henderson 《African Journal of Marine Science》2016,38(2):217-232

Landing site and market surveys of sharks landed along the Arabian Gulf coast of the United Arab Emirates were undertaken between October 2010 and September 2012 to obtain biological data from this artisanal fishery. Data were collected on the size and sex of 12 482 individuals representing 30 species. Maximum sizes of Carcharhinus sorrah, C. amblyrhynchoides and Hemipristis elongata were extended by at least 300?mm total length (TL) compared with published global maxima. The size at 50% maturity was determined for males of five species and this indicated that the males of smaller shark species (<1 000 mm maximum TL) in the fishery were largely mature. For many species, including Loxodon macrorhinus and Mustelus mosis, overall sex ratios were male-biased, indicating that sexual segregation is likely in those species. Furthermore, sex ratios for several species, such as Rhizoprionodon acutus, showed differences across seasons. Overall, the landings contained a high proportion of juveniles, causing concerns about the sustainability of this fishery. Biological parameters of a number of species differed from those recorded earlier for the region, demonstrating a need for additional local data collection to support the development of management measures.  相似文献   

Role of vegetation in shaping Early Pennsylvanian braided rivers: Architecture of the Boss Point Formation,Atlantic Canada     

Alessandro Ielpi  Martin R. Gibling  Arden R. Bashforth  Corinne Lally  Michael C. Rygel  Saif Al‐Silwadi 《Sedimentology》2014,61(6):1659-1700

Vegetation is a major driver of fluvial dynamics in modern rivers, but few facies models incorporate its influence. This article partially fills that gap by documenting the stratigraphy, architecture and palaeobotany of the Lower Pennsylvanian Boss Point Formation of Atlantic Canada, which contains some of the Earth's earliest accumulations of large woody debris. Braided‐fluvial systems occupied channel belts of varied scale within valleys several tens of metres deep and more than 12 km wide, and their deposits predominantly consist of sandy and gravelly bedforms with subordinate accretionary macroforms, high flow‐strength sand sheets and rippled abandonment facies. Discrete accumulations of clastic detritus and woody debris are up to 6 m thick and constitute at least 18% of the in‐channel deposits; they represent lags at the base of large and small channels, fills of minor channels and sandy macroforms that developed in central positions in the upper parts of channel fills. Sandstones with roots and other remnants of in situ vegetation demonstrate that vegetated islands were present, and the abundance of discrete channel fills suggests that the formation represents an anabranching, island‐braided sandbed river, the earliest example documented to date. Although some sphenopsid and lycopsid remains are present, most woody fragments are derived from cordaitalean trees, and the evolution of this group late in the Mississippian is inferred to have exerted a significant influence on fluvial morphodynamic patterns. The formation records a landscape in which active channel belts alternated with well‐drained floodplains colonized by dense, mature forests and local patches of pioneering, disturbance‐tolerant vegetation. Lakes and poorly drained floodplains dominated by carbonate and organic deposition, respectively, were also present. A large supply of woody debris triggered channel blockage and avulsion, and active channel margins and islands within the channel belts were initially colonized by pioneer vegetation and subsequently stabilized by large trees. A similar alternation of stable and unstable conditions is observed in modern braided rivers actively influenced by vegetation.  相似文献   

Impact of sewage and mining activities on distribution of heavy metals in the water-soil-vegetation system   总被引：1，自引：1，他引：0  

K. Semhi  R. Al Abri  S. Al Khanbashi 《International Journal of Environmental Science and Technology》2014,11(5):1285-1296

Several samples of groundwater and soils and plants have been collected from Sohar (Batina region, NE Oman), which is affected by various activities such as mining, agriculture, and sewage. To characterize quality of groundwater, As and Cu concentrations have been investigated in waters collected from different wells. Comparison of data with local and international standard values revealed that groundwater in Sohar region is characterized by lower concentrations in Cu and As compared with standards. In soils collected from the same area, concentrations of heavy metals have been measured in different fractions in order to investigate the mobility of such elements and risk of vulnerability in this area. A sequential extraction procedure has been applied to surface sediments to determine the partitioning of Zn, Cu, Co, Mn, Fe, Pb, Cr, Cd and Ni among (1) exchangeable and acid-soluble phases, (2) Fe–Mn oxides, (3) organic matter and sulphides and (4) resistant phases. The results showed that the mobile fraction in the sewage area accounts only for 10 % of the total concentration in sediments while in the Cu mining area, the contribution of the mobile fraction may exceed 10 %, especially for Pb, Mn, Cd, Cu and Co. Investigation of concentrations in As and Cu in plants collected from mining and sewage areas revealed an important accumulation of these elements in leaves and may explain enrichment of As in shallow groundwater relative to deep groundwater. This investigation also showed that Cu is more available in sewage area than in mining zone, as opposed to As.  相似文献   

Groundwater contamination assessment in Al-Quwy’yia area of central Saudi Arabia using transient electromagnetic and 2D electrical resistivity tomography     

Mohamed Metwaly  Eslam Elawadi  Sayed S. R. Moustafa  Nassir Al Arifi  Mohamed El Alfy  EKab Al Zaharani 《Environmental Earth Sciences》2014,71(2):827-835

Groundwater contamination is one of the most significant problems in arid countries. Al-Quwiy’yia region is an example of an area where the groundwater is contaminated as a result of infiltration of waste water in low-lying areas adjacent to inhabited zones. Such contamination poses significant environmental threats for the surrounding environment and groundwater. Surface observations and spatial distribution of contamination observed in the shallow aquifer indicate that the main contamination sources were from sewage as well as from waste water dumping. However, the main source of water supply for the whole area is groundwater abstracted from the relatively shallow aquifer. Therefore, the transient electromagnetic method (TEM) and 2D electrical resistivity tomography (2D ERT) have been applied close to the waste water dump site to characterize the response of pollution plumes. Both of these geoelectrical techniques are sensitive to electrical conductivity as well as to other physical properties, which are greatly influenced by the polluted groundwater. Therefore, it is possible to profile the contamination plumes, both vertically and horizontally, in the vicinity of the measured stations. The ERT profiles gave detailed information about the lateral distribution of the contaminated groundwater, whereas the TEM demonstrated the vertical extensions.  相似文献   

The scarp lands of Saudi Arabia     

Randolf Rausch  Theo Simon  Hussain Al Ajmi  Heiko Dirks 《Arabian Journal of Geosciences》2014,7(6):2437-2450

In central Saudi Arabia, the combination of rock types and sedimentary bedding created a unique scarp landscape. The escarpments were formed during Late Miocene through Early Quaternary times. At present, cuesta formation and migration are restricted to the actual escarpments as a consequence of negligible sediment removal. The plains between the escarpments are sealed through periodically active fluvial processes and through eolian sedimentation. In this publication, the major escarpments of central Saudi Arabia are described. The interactions between tectonics, climate, and morphogenesis which created this unique landscape are reviewed.  相似文献   

Integrated acoustic technologies form new shallow water survey system     

Al Rougeau  Larry Rosenbalm  Carl Sonnier 《Marine Geodesy》2013,36(2-3):187-198

  相似文献   

Fracture flow modelling based on satellite images of the Wajid Sandstone, Saudi Arabia   总被引：1，自引：0，他引：1  

Conny Zeeb  Daniel Göckus  Paul Bons  Hussain Al Ajmi  Randolf Rausch  Philipp Blum 《Hydrogeology Journal》2010,18(7):1699-1712

Large-scale geological features have been identified by satellite imagery and global positioning system data in the Wajid Sandstone in Saudi Arabia. The main objective is to evaluate the importance of fractures for the overall flow behaviour in this fractured rock aquifer and to estimate in-situ hydraulic apertures. Data on fractures and lineaments were available for three outcrops. By applying a “cut-out” routine on the fracture endpoint data of these fracture trace windows, three deterministic discrete fracture networks (DFN), with an area of 100 m?×?100 m, could be generated. These were used to simulate the fracture flow and to determine the hydraulic conductivity tensors. Using additional data on hydraulic pumping tests and matrix conductivities, in-situ hydraulic apertures could be determined. Average in-situ hydraulic apertures range from 1,300 to 1,700 µm. Observations from the field support these results. In addition, a hydraulic conductivity ratio between the matrix and fracture system was used to identify the contribution of the DFN to the overall fluid transport. A ratio of 10.4 was determined, which indicates that the effective flow behaviour in the Wajid Sandstone aquifer is not entirely dominated by the fracture system, though evidently strongly controlled by it.  相似文献