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91.
Groundwater resources assessment using integrated geophysical techniques in the southwestern region of Peninsular Malaysia 总被引:2,自引:0,他引:2
Mohamed S. E. Juanah Shaharin Ibrahim Wan Nor Azmin Sulaiman Puziah Abdul Latif 《Arabian Journal of Geosciences》2013,6(11):4129-4144
Combined geophysical techniques such as multi-electrode resistivity, induced polarization, and borehole geophysical techniques were carried out on volcano-sedimentary rocks in the north of Gemas as part of the groundwater resource’s investigations. The result identifies four resistivity units: the tuffaceous mudstone, tuffaceous sandstone, the tuff bed, and the shale layer. Two types of aquifer systems in terms of storage were identified within the area: one within a fracture system (tuff), which is the leaky area through which vertical flow of groundwater occurs, and an intergranular property of the sandy material of the aquifer which includes sandstone and tuffaceous sandstone. The result also reveals that the aquifer occupies a surface area of about 3,250,555 m2 with a mean depth of 43.71 m and a net volume of 9.798?×?107?m3. From the approximate volume of the porous zone (28 %) and the total aquifer volume, a usable capacity of (274.339?±?30.177)?×?107?m3 of water in the study area can be deduced. This study provides useful information that can be used to develop a much broader understanding of the nature of groundwater potential in the area and their relationship with the local geology. 相似文献
92.
Margaret Armstrong Aziz Ndiaye Rija Razanatsimba Alain Galli 《Mathematical Geosciences》2013,45(2):165-182
Having a large number of geostatistical simulations of a mineral or petroleum deposit provides a better idea of its upside potential and downside risk; however, large numbers of simulated realizations of a deposit may pose computational difficulties in subsequent decision-making phases. Hence, depending on the specific case, there can be a need to select a representative subset of conditionally simulated deposit realizations. This paper examines and extends an approach developed by the stochastic optimization community based on stochastic mathematical programming with recourse and is discussed here in the context of mineral deposits while it is possibly suitable for other earth science applications. The approach is based on measuring the “distance” between simulations and the introduced distance measure between simulated realizations of a mineral deposit is based on the metal above a given set of cutoff grades while a pre-existing mine design is available. The approach is tested on 100 simulations of the Walker Lake data with promising results. 相似文献
93.
Muhammad Irfan Aziz Akbar Mubashir Aziz Ammad Hassan Khan 《Geotechnical and Geological Engineering》2013,31(2):729-738
Rapid urbanization and expansion of metropolitans in the developing world is pressing the need of tall structures with multiple basements. In several such projects, open land is available around excavation site and unsupported deep excavations by maintaining appropriate side slopes offer economical solution. In this research, subsoil stratigraphy of Lahore district was established to be comprising of a top clay stratum 1.5–8 m thick, followed by a sand layer. Considering subsoil data from several geotechnical investigation reports, the effect of four key parameters viz., cohesion of clay layer, friction angle of sand layer, thickness of clay layer at the top and slope inclination of underlying sand layer on safety factor of open excavations was studied. Six hundred twenty-five slope stability analyses were conducted by considering different geometries and soil properties. Based on the results of these analyses, a regression model was suggested to estimate safety factor of open excavations in similar stratigraphy which would be useful in feasibility studies and preliminary design of deep excavations. It was established that the clay layer cohesion was the most dominant contributor to safety factor. 相似文献
94.
95.
Abdul Jawad Antonio Pasqua Surajit Chattopadhyay 《Astrophysics and Space Science》2013,344(2):489-494
In this paper, we discuss cosmological application of holographic Dark Energy (HDE) in the framework of f(G) modified gravity. For this purpose, we construct f(G) model with the inclusion of HDE and a well-known power law form of the scale factor a(t). The reconstructed f(G) is found to satisfy a sufficient condition for a realistic modified gravity model. We find quintessence behavior of effective equation of state (EoS) parameter ω DE through energy conditions in this context. Moreover, we observe that the squared speed of sound $v_{s}^{2}$ remains negative, which indicates the instability of HDE f(G) model. 相似文献
96.
Assessment of Trace Metal Contamination of Drinking Water in the Pearl Valley,Azad Jammu and Kashmir
Saboor Javaid Syed Ghulam Sarwar Shah Abdul Jabbar Chaudhary Mohammad Haleem Khan 《洁净——土壤、空气、水》2008,36(2):216-221
The aim of this study was to assess trace metal contamination of drinking water in the Pearl Valley, Azad Jammu and Kashmir (Pakistan). The objectives were to determine physical properties and the dissolved concentration of five trace metals, i. e., lead, copper, nickel, zinc, and manganese, in drinking water samples collected from various sites of municipal water supply, natural water springs and wells in the valley. Concentrations of the metals in the water samples were determined by flame atomic absorption spectrometry. Results showed physical parameters, i. e., appearance, taste and odor within acceptable limits and pH was between 5.5 and 7.0. The observed concentrations of the metals varied between sources of water samples and between sampling sites. Maximum dissolved concentration observed was 4.7 mg/L for Pb and Mn, 4.6 mg/L for Zn, 2.9 mg/L for Ni and 2.8 mg/L for Cu. The observed concentrations of the metals were compared with the World Health Organization's guideline values for drinking water. Overall, the quality of water samples taken from the water springs at Mutyal Mara and Bonjosa was good; however, the water quality was unsuitable for drinking in Kiraki, Kharick, and Pothi Bala localities particularly. Finally, the authors discuss possible causes for increased concentrations of the trace metals in drinking water in the study area. 相似文献
97.
We expand both parts, the principal and indirect, of the Hamiltonian function up to the third order in the masses for the four major planets Jupiter-Saturn-Uranus-Neptune. Accordingly we write down the secular terms ofF
1,F
2,F
3 and the critical terms ofF
1,F
2 in terms of the canonical variables of H. Poincaré neglecting powers higher than the second inH, K, P, Q. 相似文献
98.
The Domingos Petrolini Swamp, located on the Southern Coastal Plain of Rio Grande do Sul, near the town of Rio Grande, constitutes an ample holocene lagoonal deposit. Events related to the holocene transgression and their diverse phases of glacial-eustatic ocillations were found through palynological analysis. Bases on these palynological data, four distinct phases to the paleoenvironmental evolution of the ecosystem were identified. It has also shown a transgressive restricted marine sequence on the base , which suggests the existence of a coastal brackish lagoon or a marisme type of environment. Later, there was a gradation for continentality conditions along with a scarce pollinical record. The third phase is characterized by the presence of marine components and halophyte vegetation, showing another transgressive event in that place. Lastly, the end of direct marine influence over the swamp was recorded and also the vegetation development as it appears these days. 相似文献
99.
Hassan Abdul Kadir Saleh Prof. 《GeoJournal》1990,21(4):337-348
This paper focuses on the process of Jewish settlement in the West Bank and its economic consequences in the period from 1967 to the outbreak of the Intifada late in 1987. It attempts to show that this process is the practical application of Israeli objectives which are based on expansion and occupation of neighbouring Arab lands, facilitated by the fashioning of a dual or bifurcate economy there.After the war of June 1967, Israeli occupation authorities started to draw up plans with a view to settling Jews in the West Bank. There has been an increase in the numbers of settlements and settlers, estimated at 122 and 52,000 respectively in 1987. The pattern of settlement distribution is randomly dispersed, although it is concentrated in a region located to the NW of Jerusalem. The settlement began in the Jordan valley and extended gradually westward in the highlands.Jewish settlement has affected economic development of the West Bank, where there were many constraints on Arab agriculture and industry. Inequality is evident between settlers and Palestinians in an economy that has been structurally bifurcated: although settlers represent about 3% of total population of the West Bank, their economic activity constitutes at least 35% of the GDP of the West Bank. 相似文献
100.
Kernel Principal Component Analysis for Efficient,Differentiable Parameterization of Multipoint Geostatistics 总被引:6,自引:5,他引:1
This paper describes a novel approach for creating an efficient, general, and differentiable parameterization of large-scale
non-Gaussian, non-stationary random fields (represented by multipoint geostatistics) that is capable of reproducing complex
geological structures such as channels. Such parameterizations are appropriate for use with gradient-based algorithms applied
to, for example, history-matching or uncertainty propagation. It is known that the standard Karhunen–Loeve (K–L) expansion,
also called linear principal component analysis or PCA, can be used as a differentiable parameterization of input random fields
defining the geological model. The standard K–L model is, however, limited in two respects. It requires an eigen-decomposition
of the covariance matrix of the random field, which is prohibitively expensive for large models. In addition, it preserves
only the two-point statistics of a random field, which is insufficient for reproducing complex structures.
In this work, kernel PCA is applied to address the limitations associated with the standard K–L expansion. Although widely
used in machine learning applications, it does not appear to have found any application for geological model parameterization.
With kernel PCA, an eigen-decomposition of a small matrix called the kernel matrix is performed instead of the full covariance
matrix. The method is much more efficient than the standard K–L procedure. Through use of higher order polynomial kernels,
which implicitly define a high-dimensionality feature space, kernel PCA further enables the preservation of high-order statistics
of the random field, instead of just two-point statistics as in the K–L method. The kernel PCA eigen-decomposition proceeds
using a set of realizations created by geostatistical simulation (honoring two-point or multipoint statistics) rather than
the analytical covariance function. We demonstrate that kernel PCA is capable of generating differentiable parameterizations
that reproduce the essential features of complex geological structures represented by multipoint geostatistics. The kernel
PCA representation is then applied to history match a water flooding problem. This example demonstrates that kernel PCA can
be used with gradient-based history matching to provide models that match production history while maintaining multipoint
geostatistics consistent with the underlying training image. 相似文献