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91.
Natural Hazards - This study estimates the relative efficiency of disaster relief organizations that participated in the relief activities following the Marmara and Düzce earthquakes that took... 相似文献
92.
Prediction of groundwater resources potential is a spatial decision problem that involves a set of multiple evaluation parameters. In order to produce a groundwater resources potential prediction model of higher reliability and precision in a given study area, the effects of all the important parameters that can contribute to the groundwater occurrence in the area must be integrated. However, the methodology of integrating these parameters such that the relative importance of each is reflected is still a challenge that has not been efficiently handled. In this study, the principle of multi-criteria decision analysis in the context of the analytical hierarchy process is proposed as a technique that can yield a prediction model of higher reliability and precision. The proposed technique was applied to geoelectric and geologic parameters, derived from the results of the interpretation of 2D resistivity imaging data acquired from the study area. The advantage of the proposed technique is that it reduces bias in decision making. The main objective of the study is to produce groundwater potential map for the area. Furthermore, an attempt was also made in the study to characterize the aquifer of the area by estimating the Dar-Zarrouk parameters, using the integration of borehole and 2D resistivity data. The success rate (accuracy) of the prediction was established to be 80 %. Furthermore, the regression line fitted to the aquifer transmissivity and transverse resistance data shows linear relationship with a high regression coefficient of 0.79. The prediction success rate obtained showed that the method proposed in this study is reliable, accurate, and an improved technique of integrating multiple parameters for holistic evaluation of groundwater resources. 相似文献
93.
Khalid Al-Ahmadi Sharaf Al-Ahmadi Abdullah Al-Amri 《Arabian Journal of Geosciences》2014,7(9):3871-3879
Al-Ahmadi et al. (Arab J Geosci doi:10.1007/s12517-013-0974-6, 2013) applied spatial pattern analysis techniques to a seismic data catalogue of earthquakes beneath the Red Sea in order to explore and detect global and local spatial patterns in the occurrence of earthquakes over the years from 1900 to 2009 using a geographical information system (GIS). They found that the techniques of spatial pattern analysis that they applied could detect global and local clusters and broader spatial patterns in the occurrence of earthquakes and concluded that earthquakes with higher magnitudes were notably concentrated beneath the central and southern areas of the Red Sea, while earthquakes with low and moderate magnitudes were concentrated beneath the northern area of the Red Sea. The aim of this paper is to report on the application of logistic regression models to explore the associations between the likelihood of the occurrence of an earthquake beneath the Red Sea and four selected variables, namely: (1) proximity to the boundary of the African–Arabian plates, (2) proximity to transform faults, (3) proximity to the mid-Red Sea ridge and (4) the stage of rift evolution. The study was undertaken to evaluate the potential of logistic regression modelling for research exploring potential associations between earthquakes and geological and tectonic variables. The results revealed that none of the assumptions underpinning the logistic regression models had been violated for the three logistic regression models that were used in this research. The authors inferred that the occurrence of the earthquakes beneath the Red Sea was statistically significantly associated with the proximity to the African–Arabian plate boundary. We concluded that earthquakes of moderate magnitudes occurred in the zone which represents the late evolutionary stage of the Red Sea rift, including the transition zone beneath the central area and the late-stage continental rift zone beneath the northern area of the Red Sea. In contrast, earthquakes with high magnitudes tended to occur in close proximity to the mid-ridges of the Red Sea. 相似文献
94.
Utilization of supervised classification in structural and lithological mapping of Wadi Al-Marwah Area,NW Arabian Shield,Saudi Arabia 总被引:1,自引:0,他引:1
Adel Zein Bishta Abdullah Rasheed Sonbul Wuadee Kashghari 《Arabian Journal of Geosciences》2014,7(9):3855-3869
Wadi Al-Marwah area is located in the northwestern part of the Arabian Shield, Saudi Arabia. It is mainly covered by Precambrian igneous and sedimentary rock units. This area was not subjected to previous detailed lithological or structural mapping. This study aims to apply supervised classification technique of remotely sensed digital satellite data of Landsat 7 for detailed lithological and structural mapping of the area. The fusion between multispectral Enhanced Thematic Mapper (ETM)+ data and high-resolution panchromatic ETM+ band-8 produced a color composite fused image for the study area, scale 1:50,000. The structural lineaments of the study area were extracted and interpreted from the digital imageries data. Little discrepancies or improvements were detected when combining the supervised classification results with the Landsat ratios or principal component analysis. These highlighted the benefits of multispectral classification, especially in terms of lithologic discrimination. The overall results of image processing techniques, applied in this work, were excellent and succeeded in the performance of a more detailed and accurate lithological and structural maps (scale 1:50,000) than the previous published maps for the investigated area. 相似文献
95.
Md. Farhaduzzaman Wan Hasiah Abdullah Md. Aminul Islam 《Journal of the Geological Society of India》2014,83(4):433-446
Surma Group is the most important geological unit of Bengal basin, Bangladesh, because petroleum resources occur within this group. It is mainly composed of alternation of shale and sandstone and the shale fraction has long been considered as source rocks and the sandstone fraction as reservoir. These source and reservoir rocks have been studied by different authors by different approach but none of them adopted organic geochemistry and organic petrology as a means of study of source rock and their possible depositional environment. A total of thirty shale core samples have been collected from eight different gas fields to fulfill the short coming. The collected samples have been subjected to Source Rock Analysis (SRA) and/or Rock-Eval (RE) followed by pyrolysis gas chromatography (PyGC), gas chromatography mass spectrometry (GCMS), elemental analysis (EA) and organic petrological study such as vitrinite reflectance measurement and maceral analysis. The analyzed organic matter extracted from the shales of Surma Group consists mainly of Type III along with some Type II kerogen. The studied shales are mostly organically lean (TOC ±1%) and the extracted organic matter is fair to moderate. Based on these results, the analyzed shales have been ranked as poor (mostly) to fair quality source rock. The organic matter of the analyzed shale samples is thermally immature to early mature for hydrocarbon generation considering their Tmax and measured mean vitrinite reflectance values. The hopane 22S/(22S + 22R), moretane/hopane ratio and sterane parameters are also in good agreement with these thermal maturity assessments. The predominance of odd carbons over even carbons (most common) and/or even carbons over odd carbon numbered n-alkanes, moderate Pr/Ph ratio, low to high Tm/Ts ratio, comparative abundance of sterane C29 (i.e., C29 >C27>C28), Pr/nC17 — Ph/nC18 values, C/S ratio and dominance of vitrinite macerals group with the presence of liptinite macerals demonstrate that the organic matter has derived mainly from terrestrial inputs with an insignificant contribution from the marine sources. The condition of deposition alternates from oxic to anoxic. 相似文献
96.
Earth Fissures in Wadi Najran,Kingdom of Saudi Arabia 总被引:1,自引:0,他引:1
Ahmed M. Youssef Abdullah A. Sabtan Norbert H. Maerz Yasser A. Zabramawi 《Natural Hazards》2014,71(3):2013-2027
The formation of earth fissures due to groundwater depletion has been reported in many places in North America, Europe, and Asia. Najran Basin is in the southern part of the Kingdom of Saudi Arabia, and agricultural activities and other groundwater uses have caused significant groundwater depletion there. The basin recently experienced a sudden appearance of numerous earth fissures. An interdisciplinary study consisting of an evaluation of land-use changes, and hydrological, hydrogeological, and geophysical investigations was conducted to determine the reason for the formation of the earth fissures. The hydrological analysis strongly revealed that the groundwater level is decreasing with time. Groundwater depletion would lead to the accumulation of subsurface stress, causing soil hydro-consolidation which creates the ideal condition for the formation of earth fissures. Electrical resistivity, data indicated that there are anomalies in the profiles, which are most probably due to the presence of subsurface topography, another key factor for the formation of the earth fissures. 相似文献
97.
98.
Abdullah Kaygusuz Ferkan Sipahi Nurdane Ilbeyli Mehmet Arslan Bin Chen Emre Aydinakir 《地学前缘(英文版)》2013,4(4):423-438
A series of Cretaceous plutons is present in the eastern Pontides of northeastern Turkey.The Turnagl intrusion is the least studied and,thus,the least understood plutons in the orogen.This intrusion consists of hornblende-biotite granodiorites emplaced at 78 Ma based on LA-ICP-MS U-Pb zircon dating.It is of sub- alkaline affinity,belongs to the medium- to high-K calc-alkaline series,and displays features typical of Itype granites.The rocks of the intrusion are enriched in large-ion lithophile elements and light rare earthelements with negative Eu anomalies(Eu/Eu*= 0.69-0.82),but are deficient in high-field-strength elements.They have a small range of (87Sr/86Sr)i(0.7060-0.7063),εNdi(-2.6 to -3.1),and δ18O(+8.1 to +9.1) values.Their Pb isotopic ratios are 206Pb/204Pb = 18.63-18.65,207Pb/204Pb = 15.62-15.63,and 208Pb/204Pb = 38.53-38.55.The fractionation of plagioclase,hornblende,and Fe-Ti oxides had key functions in the evolution of the Tumagl intrusion.The crystallization temperatures of the melts ranged from 758 to 885℃ as determined by zircon and apatite saturation thermometry.All these characteristics,combined with the low values of K2O/Na2O and(Na2O + K2O)/(FeOt+MgO + TiO2),as well as the high values of (CaO + FeOt + MgO + TiO2).suggest an origin by dehydration melting from a metabasaltic lowercrustal source. 相似文献
99.
Ghunaim T. Al-Anezi Abdullah M. Al-Amri Haider Zaman 《Arabian Journal of Geosciences》2012,5(6):1347-1358
Five seismic refraction and five high-resolution seismic reflection (HRSR) profiles were carried out in northeastern part of Riyadh city to investigate depth of the weathering layer. Results obtained from seismic refraction survey reveal the depths of weathering layer at 12, 25, 17, 12, and 16?m, respectively. On the other hand, HRSR stack sections illustrate the depths of weathering layer at 14, 28, 20, 13, and 18?m, respectively. The weathering layer is composed of alluvial sediments and gravel, which is underlain by a sequence of limestone and dolomite layer. Seismic results from site no. 2 have been found to be in good agreement with lithological information reported from the adjacent water well. The HRSR data generally reveal better signal-to-noise ratio and enhanced resolution compared to the refraction data. Although, the HRSR data failed in achieving high-quality common midpoint (CMP) stacking profile at site no. 3, it provide an improved image of the subsurface features than the refraction data, recognizing it as a potential seismic technique. 相似文献
100.
Sarva Mangala Praveena Mohd Harun Abdullah Kawi Bidin Ahmad Zaharin Aris 《Environmental Earth Sciences》2012,66(3):719-728
Numerical models are capable of simulating various groundwater scenarios and relate it towards groundwater management. This
paper focuses on numerical modeling and water balance approaches in the search for a sustainable management plan in Manukan
Island. The impacts of pumping and recharge rates represented by groundwater scenarios were investigated by means of hydraulic
heads, chloride concentrations and water balance components. Overpumping and inconsistency in recharge rate are the stresses
shown in Scenario A. Scenario B involved with reduction pumping rate by 25% has shown an increase in groundwater levels, chloride
concentration and groundwater storage. Scenario C showed the most promising finding compared with Scenarios A and B. Highest
hydraulic heads, lowest chloride concentration (1,552.2 mg/L) and positive groundwater storage (254.3 m3/day) were obtained in Scenario C. Chloride concentration in pumping wells still exceeds World Health Organization International
Standard limit in Scenario C which illustrates an additional water treatment is needed. Nevertheless, in view of a compromise
groundwater management plan in study area, Scenario C is the best plan so far to protect the groundwater resources in the
study area. More understanding of the artificial recharge method (percolation tank) and study site by means of modeling studies
is needed. Additionally, further progress is needed in obtaining the water usage data from each part to determine the best
pumping rate. A sustainable groundwater management plan is crucial to maintain the natural resources and social benefits as
well as to protect the ecological balance of Manukan Island. 相似文献