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Abstract A simplified method has been developed for solving leaky aquifer non-Darcian flow hydraulics. The principle of volumetric approach is combined with the confined-aquifer, time-dependent drawdown equation in an observation well. The groundwater flow in the leaky aquifer is assumed to obey a non-Darcian flow law of exponential type. The results are obtained in the form of type-curve expressions from which the necessary bundles of curves are drawn for a set of selective non-Darcian flow aquifer parameters. Although application of the methodology appears as rather limited but it provides a scientific contribution and extension of leaky aquifer theory towards nonlinear flow conditions. The methodology developed herein is applied to some actual field data from the eastern sedimentary basin in the Kingdom of Saudi Arabia. 相似文献
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Abstract Monthly rainfall amounts are distributed according to different frequency distribution functions in different parts of the world. However, in extremely arid regions gamma probability distribution functions are most often found to fit the existing data well. Libyan monthly rainfall distributions are found to abide by gamma probability distribution function which is confirmed on the basis of chi-square tests. Almost all the rainfall sequences recorded for at least the last 20 years in Libya are investigated statistically and gamma distribution parameters are calculated at existing stations. The shape and scale parameters are then regionalized and hence it becomes possible to find the parameter values at any desired location within the study area and then to generate synthetic sequences according to the gamma distribution. Predictions of 10, 25, 50 and 100 mm rainfall amounts are achieved by this probability function. 相似文献
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ComprehensiveanalysesofseismicsourcelayerinXingtaiandTangshanseismicregionsandtheconditionsofmediaab
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NMＲ logging can provide the permeability parameter and abundant stratigraphical information such as total porosity,oil,gas and water saturation,oil viscosity,etc． And these physical parameters can be ob- tained by T2spectrum inversion． NMＲ inversion is an important part in logging interpretation． The authors de- scribe a multi-exponential inversion algorithm,solid iteration redress technique (SIＲT),and apply the algo- rithm in real data and compare the results with those based on singular value decomposition (SVD)． It shows that SIＲT algorithm is easier to be understood and implemented,and the time spent in SIＲT is much shorter than that of SVD algorithm． And the non-negative property of T2spectrum is much easier to be implemented． It can match the results based on SVD very well． SIＲT algorithm can be used in T2spectrum inversion for NMＲ analysis． 相似文献
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Belcheva NN Zakhartsev M Silina AV Slinko EN Chelomin VP 《Marine environmental research》2006,61(4):396-409
Seasonal and age-specific variations of cadmium (Cd) concentration in the digestive gland were investigated in the Japanese scallop Patinopecten yessoensis from Peter the Great Bay, Sea of Japan, with different degrees of Cd pollution. The seasonal changes in Cd concentrations of the digestive gland were inversely proportional to the dry weight of the gland. Concentrations of Cd and total Cd content (mug Cd per organ) increased with age (age-specific) to the same extent in contaminated and uncontaminated areas. There was also a strong positive correlation between Cd content in the whole digestive gland and shell weight and it is proposed that this relationship can be used as a new criterion for comparative evaluation of Cd levels in scallops from different areas We hypothesize that Cd is uptaken into scallops in proportion to the amount of calcium that absorbed through ion channels, and in addition, Cd in the digestive gland is in immobile forms (e.g. metal-rich granules) that accumulate with age. Moderate environmental pollution has no effect on the relationship between Cd content and shell size and the observed decrease in growth performance of the scallops from polluted areas may be due to other factors. 相似文献
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Abstract In any dam siting study in arid regions, rainfall records, runoff measurements and their greatest magnitudes are very important. Unfortunately, the data are scarce and, therefore, empirical approaches and charts obtained from similar regions in other parts of the world are necessary for complete applications. The lack of observed data presents the major problem for runoff modelling in arid regions. These regions have characteristically high rainfall intensity and consequent flash floods with large amounts of sediments. Occurrence of rainfall is sporadic, both temporally and spatially, which makes the interpretation of the rainfall-runoff relationship quite difficult. Flood estimations play a significant role in dam siting from the point of view of water availability. This paper presents the basic calculations of floods and sediment amounts that are necessary in dam siting and construction in an arid area by considering the southwestern part of the Kingdom of Saudi Arabia. 相似文献
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Abstract Monthly spatial rainfall distribution features and their effects on spatial correlation patterns are significant in any regional study. In this paper, first a number of statistical terms and properties are explained with reference to the spatial correlation functions (SCFs). This is followed by the analysis of a theoretical spatial correlation model and its parameter estimation. Monthly empirical SCFs are examined in relation to spatial rainfall characteristics. In order to obtain a definite pattern, the SCF values are averaged in successive equal-distance groups. This average spatial correlation function shows a decreasing pattern with distance. Some interpretations of these spatial correlation functions are given for Turkey with discussion of the results obtained. 相似文献
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根据二连盆地阿拉坦合力凹陷内坦参1井钻及的以红色砂泥岩为主的地层及其中分析出来的孢粉化石建立了伊和高勒组、吉尔嘎郎图组、代喇嘛庙组和沙木尔吉组4个新的岩石地层单位,根据前三个组中所包含的3个孢粉组合(从上到下为:Osmundacidites-Aratrisporites-Apiculatisporis-Cycadopites组合、Li matulasporites-Annu-lispora-Monosulcites组合和Li matulasporites-Lundbladispora-Florinites组合)可以确定伊和高勒组和吉尔嘎郎图组的时代为中三叠世,代喇嘛庙组的时代为早三叠世,二连盆地的三叠系可以和新疆、陕西、江苏及河南等地的相应地层较好地进行对比。 相似文献
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BENT FREDSKILD ULRIK RØEN 《Boreas: An International Journal of Quaternary Research》1982,11(3):181-185
Examination two peat samples collected at Kep København, Peary Land, Northgreenland, revealed the presence fo fossils of Betula nana, Menyanthes trifoliata and other plants which do not occur as fao north today. likewise, remains fo Cladocera (e.g. Alonella excisa ), beetles (e. g. Gyrinus opacus and Bembidion grapi ) and other animals, none of which live in the area today, are present. The occurrence of these fossils, coupled with a radiocarbon date giving an infinite age, suggest that the peat is an interglacials deposit. 相似文献