Verknüpfung von Wasserbeschaffenheit und Wassermenge für das Grundwasser des Festgesteinsbereiches

Patterns of the typical groundwater quality for 13 hydrogeological units (lithofacies units) of the solid rock and for 5 stages of the contamination of groundwater by the agricultural production are derived from investigations carried out in six regions serving as examples and in evaluation of data series covering many years. The concentration values of the substances contained in water constituting the lower and upper limits of the typical width of variation are regarded as the quality of the groundwater reservoir (long retention time) and a fast runoff component of groundwater. On the basis of this model conception it is possible to determine one of the following four quantities from the other three quantities: groundwater quality, size of the groundwater reservoir, groundwater runoff with the shares of the slow component and of the fast one, removal of substances out of the root zone.     

非岩基厂址条件下核电厂标准化地基模型研究

核电厂标准化设计方法是节省核电建设成本的重要手段,开展非岩基厂址地基标准化设计地基模型的研究对拓宽核电厂地基适用范围有重要意义。首先,基于国内外典型软质岩和硬土厂址动参数的调研数据进行数理统计分析,归纳动参数随深度的变化规律,并通过归一化分析得到地基剪切波速剖面特征曲线,从而确定初步的标准化地基模型;进而,基于SuperFLUSH/2D Ver6.0软件开展初步标准地基模型的地震反应分析,以最大加速度随深度变化与加速度反应谱为考量指标探究动参数变化对于地震反应的影响程度及规律;最后,依据初步地基模型的剪切波速剖面的相似性及包络性,定义软质岩和硬土厂址条件下的核电厂标准化地基模型,并给出相应的动参数合理取值。该模型及研究成果可为我国“核电走出去”战略中主力堆型的核电厂标准化设计提供重要的参考。     

Geomechanical Models for Clastic Grain Packing

This study proposes a classification of sphere models for grain packing types of coarse grained clastic soft and hard rocks with special emphasis on Permocarboniferous red-beds. The classification covers the range of principal packing types and different cements. Random sphere packing models are derived from ideal symmetric packing models. The study comprises both homogeneous models with equal single grain properties and heterogeneous models with different single grain properties. For each packing type geomechanically relevant parameters like the packing density or coordination numbers are calculated and discussed. The models are correlated with results of image analysing and standard rock engineering experiments that were carried out on a variety of grain mixtures and sedimentary rocks of Permocarboniferous age. The discussion is concerned with the principles of grain packing models and the particular effects of distinct packing types on the petrophysical rock properties and the geomechanical behaviour of the examples presented.     

Hydrodynamic conditions and vertical hydrogeochemical zonality of groundwater in the Western Khatanga Artesian Basin

The results of hydrogeochemical studies of oil-and-gas bearing deposits in the western Khatanga Artesian Basin are given. The hydrogeological structure that formed during a long geological time is complicated by different types of hydrogeological sections. The boundaries of their occurrence have been established for the first time and detailed hydrogeological zoning has been carried out.     

A proposed structure–groundwater model: application to chalky media of the Paris Basin

The groundwater flow in a fissured chalky environment at the northern border of the Paris Basin depends on several geological and hydrogeological parameters. Although the studied sector of the basin presents a homogeneous rock type, it is affected by a fracture network. In this type of environment, in which the permeability is low, the groundwater flow displays significant disruption, which is localized in the Fruges region (northern France). The interconnection of the discontinuities (network of fault and/or joints) is reliant on the structural control of groundwater flow through increases in the hydraulic connection between the unsaturated and the saturated zone. The methodology developed herein makes use of microstructural and regional analysis of the fracture patterns, and allowed consideration of the piezometric variations of the chalk aquifer during periods of low and high groundwater levels (April and October 2001) and a diagraphic representation of the estimated physical parameters (electrical resistivity). This enabled us to construct a ‘flow structure’ conceptual model in which we identify two types of faults: tight walls and flow paths that control the piezometric heads and the flow rate. Model validation was carried out on a similar sector. Copyright © 2007 John Wiley & Sons, Ltd.     

Monitoring Hydrogeologlcal Conditions in Fractured Rock at the Site of Canada's Underground Research Laboratory

Atomic Energy of Canada Limited is constructing an Underground Research Laboratory (URL) at a depth of 250m in a plutonic rock body near Lac du Bonnet, Manitoba. The facility is being constructed to carry out a variety of in situ geotechnical experiments as part of the Canadian Nuclear Fuel Waste Management Program. A unique feature of the URL, in comparison to other similar facilities such as the Stripa Mine in Sweden, is that it is to be constructed below the ground water table in a previously undisturbed plutonic rock body. One of the main research objectives of the project is to develop and validate comprehensive three-dimensional models of the hydrogeology of the rock mass encompassing the URL site. These models will be used, before excavation of the URL shaft begins, to predict the hydrogeological perturbation that will be created by the excavation of the shaft and the horizontal working levels below the ground water table. As a model-validation exercise, these drawdown predictions will be compared with actual hydrogeological perturbations that will be monitored at the study area over the next several years by an extensive network of instrumented boreholes. Measurements made in an array of boreholes extending to depths of 1,000m on the 4.8 km² study area have established that the permeability distribution in three major extensive subhorizontal fracture zones controls the movement of ground water within the rock mass. Several types of multiple-interval completion systems have been installed in the boreholes to monitor the three-dimensional, physico-chemical hydrogeological conditions within the fractured rock mass. These include conventional piezometer nests and water-table wells that have been installed in shallow holes (less than 30m deep), and multiple-packer/ multiple-standpipe piezometers and multiple-interval casing systems installed in deeper holes (30 to 1,000m deep). An automated, electronic, piezometric pressure-monitoring system has been designed to collect continuous measurements from 75 isolated hydrogeological monitoring positions within the rock mass. Another 200 positions are being monitored frequently using a variety of techniques. Piezometric data have been collected from this monitoring network to establish baseline conditions prior to any excavation into the rock mass. These data have also been used to determine the steady-state, three-dimensional ground water flow regimes that exist at the URL site under natural conditions.     

Estimation of spatial variability of aquifer parameters from geophysical methods: a case study of Sindhudurg district,Maharashtra, India

Accurate estimation of aquifer parameters, especially from crystalline hard rock area, assumes a special significance for management of groundwater resources. The aquifer parameters are usually estimated through pumping tests carried out on water wells. While it may be costly and time consuming for carrying out pumping tests at a number of sites, the application of geophysical methods in combination with hydro-geochemical information proves to be potential and cost effective to estimate aquifer parameters. Here a method to estimate aquifer parameters such as hydraulic conductivity, formation factor, porosity and transmissivity is presented by utilizing electrical conductivity values analysed via hydro-geochemical analysis of existing wells and the respective vertical electrical sounding (VES) points of Sindhudurg district, western Maharashtra, India. Further, prior to interpolating the distribution of aquifer parameters of the study area, variogram modelling was carried out using data driven techniques of kriging, automatic relevance determination based Bayesian neural networks (ARD-BNN) and adaptive neuro-fuzzy neural networks (ANFIS). In total, four variogram model fitting techniques such as spherical, exponential, ARD-BNN and ANFIS were compared. According to the obtained results, the spherical variogram model in interpolating transmissivity, ARD-BNN variogram model in interpolating porosity, exponential variogram model in interpolating aquifer thickness and ANFIS variogram model in interpolating hydraulic conductivity outperformed rest of the variogram models. Accordingly, the accurate aquifer parameters maps of the study area were produced by using the best variogram model. The present results suggest that there are relatively high value of hydraulic conductivity, porosity and transmissivity at Parule, Mogarne, Kudal, and Zarap, which would be useful to characterize the aquifer system over western Maharashtra.     

Groundwater study of a volcanic area near Bandung,Java, Indonesia

A hydrogeological investigation of the Bandung area, Java, Indonesia, is described. The investigation was carried out as part of a feasibility study directed towards improvement and development of the city's water supply.The area is situated in a tropic mountainous region, dominated by pyroclastic volcanic deposits and with abundant rainfall. The main activities of the investigation were compilation and evaluation of existing climatological and hydrogeological data, testing of four existing wells, a geo-electrical survey, drilling and testing of a new test well, study of water quality by analysis of samples from both springs and wells, and measurements of spring yields.The results of the investigation indicated presence of large groundwater resources within a distance of 15–20 km from the city. The feasibility study recommended that Bandung's water supply be based on these groundwater resources and this recommendation is being implemented.During the investigation some results concerning rainfall, infiltration, aquifers, geoelectrical surveying, and groundwater quality were obtained, which may be of general interest for hydrologists and geologists working in tropical volcanic and mountainous regions. These results are summarized in the conclusion of this paper.     

Efficiency of joint use of MRS and VES to characterize coastal aquifer in Myanmar

The productivity and the water quality of coastal aquifers can be highly heterogeneous in a complex environment. The characterization of these aquifers can be improved by hydrogeological and complementary geophysical surveys. Such an integrated approach is developed in a non-consolidated coastal aquifer in Myanmar (previously named Burma).A preliminary hydrogeological survey is conducted to know better the targeted aquifers. Then, 25 sites are selected to characterize aquifers through borehole drillings and pumping tests implementation. In the same sites, magnetic resonance soundings (MRS) and vertical electrical soundings (VES) are carried out. Geophysical results are compared to hydrogeological data, and geophysical parameters are used to characterize aquifers using conversion equations. Finally, combining the analysis of technical and economical impacts of geophysics, a methodology is proposed to characterize non-consolidated coastal aquifers.Depth and thickness of saturated zone is determined by means of MRS in 68% of the sites (evaluated with 34 soundings). The average accuracy of confined storativity estimated with MRS is ± 6% (evaluated over 7 pumping tests) whereas the average accuracy of transmissivity estimation with MRS is ± 45% (evaluated using 15 pumping tests). To reduce uncertainty in VES interpretation, the aquifer geometry estimated with MRS is used as a fixed parameter in VES inversion. The accuracy of groundwater electrical conductivity evaluation from 15 VES is enough to estimate the risk of water salinity. In addition, the maximum depth of penetration of the MRS depends on the rocks' electrical resistivity and is between 20 and 80 m at the study area.     

Spatial Variability of the Depth of Weathered and Engineering Bedrock using Multichannel Analysis of Surface Wave Method

In this paper an attempt has been made to evaluate the spatial variability of the depth of weathered and engineering bedrock in Bangalore, south India using Multichannel Analysis of Surface Wave (MASW) survey. One-dimensional MASW survey has been carried out at 58 locations and shear-wave velocities are measured. Using velocity profiles, the depth of weathered rock and engineering rock surface levels has been determined. Based on the literature, shear-wave velocity of 330 ± 30 m/s for weathered rock or soft rock and 760 ± 60 m/s for engineering rock or hard rock has been considered. Depths corresponding to these velocity ranges are evaluated with respect to ground contour levels and top surface levels have been mapped with an interpolation technique using natural neighborhood. The depth of weathered rock varies from 1 m to about 21 m. In 58 testing locations, only 42 locations reached the depths which have a shear-wave velocity of more than 760 ± 60 m/s. The depth of engineering rock is evaluated from these data and it varies from 1 m to about 50 m. Further, these rock depths have been compared with a subsurface profile obtained from a two-dimensional (2-D) MASW survey at 20 locations and a few selected available bore logs from the deep geotechnical boreholes.     

Surface Soil Effects Study Using Short-period Microtremor Observations in Almería City, Southern Spain

—?In Almería city large earthquakes occurred and many buildings were completely destroyed in these historical earthquakes. The actual population of Almería city is about 200,000 people. This population is rapidly increasing and new urbanizing areas are growing to the eastern part of the city where they are located in softer soil conditions. Consequently, the evaluation of surface soil conditions is very important from a standpoint of earthquake disaster mitigation. We have obtained a landform classification map developed by analysing aerial photos, large-scale topographic maps and 80 borehole data. Eleven unit areas, which have different soil conditions, were inferred from this research. Also, S-wave velocity prospecting tests were carried out at several sites within the city. The shear-velocity values of the ground vary from 1689?m/s in hard rock to 298?m/s in soft soil. These results are useful for understanding the uppermost soil characteristics and are used for soil classification. Finally, short-period microtremor observations were densely carried out in the research area and NAKAMURA's method (1989) was applied for determining predominant periods. Microtremors were observed at about 173 sites with mainly 400?m interval in rock sites and 200?m interval in relatively soft soil sites. From the result of these microtremor measurements, the predominant period determined at rock site, in the western part of the city and historic area, is very short, about 0.1?s, and very stable. However at soft soil sites, in the center of the city, near Zapillo Beach and in the newly developed urban area, the predominant period is about 1.0?s and even larger in concordance with the geological conditions. Finally, at medium soil sites, in the eastern part of the city, the predominant period is about 0.4?s and it appears very stable in the whole region. The difference of predominant periods between hard rock and soft soil sites is very clear and it has been observed that the distribution of predominant periods depends heavily on the surface soil conditions.     

Geochemical and Isotopic Indicators of Hydrodynamic Systems in Crystalline Rock Mass

The regularities of groundwater movement in crystalline rock masses are considered. Multidimensional techniques are used to treat the hydrogeological and hydrogeochemical data collected in sites with different conditions of groundwater formation. Sets of informative indicators are chosen for the decomposition of hydrogeological systems. Approaches to assessing the information content of empiric data are proposed.     

Modeling the Transient Response of Saline Intrusion to Rising Sea‐Levels

Sea levels are expected to rise as a result of global temperature increases, one implication of which is the potential exacerbation of sea water intrusion into coastal aquifers. Given that approximately 70% of the world's population resides in coastal regions, it is imperative to understand the interaction between fresh groundwater and sea water intrusion in order to best manage available resources. For this study, controlled investigation has been carried out concerning the temporal variation in sea water intrusion as a result of rising sea levels. A series of fixed inland head two‐dimensional sea water intrusion models were developed with SEAWAT in order to assess the impact of rising sea levels on the transient migration of saline intrusion in coastal aquifers under a range of hydrogeological property conditions. A wide range of responses were observed for typical hydrogeological parameter values. Systems with a high ratio of hydraulic conductivity to recharge and high effective porosity lagged behind the equilibrium sea water toe positions during sea‐level rise, often by many hundreds of meters, and frequently taking several centuries to equilibrate following a cease in sea‐level rise. Systems with a low ratio of hydraulic conductivity to recharge and low effective porosity did not develop such a large degree of disequilibrium and generally stabilized within decades following a cease in sea‐level rise. This study provides qualitative initial estimates for the expected rate of intrusion and predicted degree of disequilibrium generated by sea‐level rise for a range of hydrogeological parameter values.     

岩体力学参数变异性及取值方法

受结构和赋存环境的制约,岩体力学性质及其力学参数具有显著的时间和空间变异性.岩体力学参数和岩体质量从不同的侧面反映了岩体力学性质,两者具有必然的关联性,故可用相对简单的岩体质量评价来选取岩体力学参数:按地质条件将岩体空间离散为若干连续微元体单元;采用Q、RMR和BQ等方法逐一对各单元开展岩体质量评价,并利用岩体质量与岩体力学参数间的关系(如Hoek-Brown经验准则)计算其力学参数;综合各单元的计算结果确定反映连续岩体空间内空间变异特征的力学参数.以某水电站地下洞室群为例,实现了工程区围岩力学参数的不连续取值.     

THE GROUNDWATER PROVINCES OF IRAN

Summary

The hydrogeological character of the various provinces of Iran is treated in the following paper.

The author puts emphasis on the combined influence of the climate, nature of rock and geological structure on the occurence, flow and quality of the groundwater and explains the difference and similarities between the hydrogeological regime of the different provinces.

Four main and distinct hydrogeological provinces are described:

1) The Central Plateau.

2) The Zagros mountain ranges.

3) The Caspian Coastal Plain.

4) The Alborz mountains.     

Determination of Porosity and Permeability out of Dispersion Analyses of Borehole Wall Displacements

Waves carried in the borehole can be measured by the use of controlled sources inside the borehole and receivers located in the same borehole as well. This article gives the theoretical background and develops a new method to determine rock-physical parameters out of such controlled measurements of waves carried inside the borehole. Theoretical dispersion curves of the group velocities are matched to dispersion analyses of registrations obtained in the borehole. This inversion process intends to determine the in situ porosity and permeability of the rock.     

Inversion of Travel Times in Weakly Anisotropic Rock Samples

Based on the perturbation theory, inversion formulae for travel time of qP and qS waves in arbitrary weak anisotropy media are presented. The inversion formulae are linear expressions of elastic parameters expressed in terms of weak anisotropy (WA) parameters. The formulae of qS₁ and qS₂ waves have the same form and they can be used without identifying which wave is considered. A synthetic experiment similar to the measurement of rock sample in the laboratory is carried out to illustrate the efficiency of the presented inversion formulae. Two data sets for qP wave travel time from rock samples in the laboratory are inverted and 15 WA parameters are obtained.     

Thermal conductive heating in fractured bedrock: Screening calculations to assess the effect of groundwater influx

A two-dimensional semi-analytical heat transfer solution is developed and a parameter sensitivity analysis performed to determine the relative importance of rock material properties (density, thermal conductivity and heat capacity) and hydrogeological properties (hydraulic gradient, fracture aperture, fracture spacing) on the ability to heat fractured rock using thermal conductive heating (TCH). The solution is developed using a Green’s function approach in which an integral equation is constructed for the temperature in the fracture. Subsurface temperature distributions are far more sensitive to hydrogeological properties than material properties. The bulk ground water influx (q) can provide a good estimate of the extent of influx cooling when influx is low to moderate, allowing the prediction of temperatures during heating without specific knowledge of the aperture and spacing of fractures. Target temperatures may not be reached or may be significantly delayed when the groundwater influx is large.     

强烈震动对山区岩石属性参数变化的影响分析

采用静力分析法分析强烈震动对山区岩石属性参数变化的影响时,忽略了岩石碎裂底部和顶部之间的相互作用,存在对岩石密度以及其他参数属性分析结果不准确的问题。因此提出强烈震动对山区岩石属性参数变化的影响分析方法。该方法通过高程控制效应能有效显示强烈震动后岩石的碎裂程度,再将碎石间存在的卸荷和碾压力融入室内、外对原岩和碎裂岩石密度的测量结果,最后采用蜡封法得到强烈震动后碎裂岩石的各种参数变化结果,实现对岩石的密度、孔隙率、天然吸水率、渗透系数以及软化系数等属性参数的有效分析。实验结果说明,所提方法对强烈震动下山区岩石属性参数变化分析结果具有较高的准确性。     

4-Dimensional Models of Deformation of the Earth's Crust and Earthquake Prediction

Traditionally, when creating 4-D models of elastic offsets in the Earth's crust, the data from geodesic and GPS monitoring of offsets on the ground surface, earthquake catalogs, monitoring of the water level and radon content in wells, sea level fluctuations, as well as gravitational and magnetic fields, etc., can be taken as bases for information. In essence, the reason for creating a 4-D model of slow elastic deformations is to approximate the process by a set of plane deformation solitons (solitary waves). The parameters of a set of deformation solitons are obtained by a two-stage inversion. First, the parameters of the model are determined in a kinematic way by the use of a modified simplification of the method. Then, a calibration of the amplitude characteristics of the model is carried out in terms of elastic dynamic offsets. Taking Ural, Northern Tianshan, Greece, and China as examples, models for these regions are created on the basis of seismological, geodesic, deformation, hydrogeological, and