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1.
盘山山前地下水与矿泉水污染成因分析 总被引：4，自引：0，他引：4
文章利用主成分分析方法,结合揭示变量和样品之间在成因或空间上联系的对应分析,通过SPSS统计分析软件,对盘山山前地区地下水和矿泉水污染成因进行分析。研究表明,盘山山前存在地下水和矿泉水污染;局部范围的污染主要是由于食品厂等企业的排污引起的,污染成分主要是Cl-和NO3—N,主要污染地区是塔院地区,其次是西大佛塔至南营,污染程度与至污染源的距离有关;大部分地区存在三氮面状污染,农业氮肥的施用是其主要原因。 相似文献
2.
K. Lendering T. Schweckendiek M. Kok 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2018,12(3):203-217
Polders in the Netherlands are protected from flooding by flood defence systems along main water bodies such as rivers, lakes or the sea. Inside polders, canal levees provide protection from smaller water bodies. Canal levees are mainly earthen levees along drainage canals that drain excess water from polders to the main water bodies. The water levels in these canals are regulated. During the last decades, probabilistic approaches have been developed to quantify the probability of failure of flood defences along the main water bodies. This paper proposes several extensions to this method to quantify the probability of failure of canal levees. These extensions include a method to account for (i) water-level regulation in canals, (ii) the effect of maintenance dredging on the geohydrological response of the canal levee and (iii) survival of loads in the past. The results of a case study demonstrate that the proposed approach is capable of quantifying the probability of failure of canal levees and is useful for exploring the relative benefit of risk mitigating measures for canal levees. 相似文献
3.
Analysis of the Chiufengershan landslide triggered by the 1999 Chi-Chi earthquake in Taiwan 总被引：18，自引：0，他引：18
A disastrous earthquake rocked Taiwan on September 21, 1999, with magnitude ML=7.3 and an epicenter near the small town of Chi-Chi in central Taiwan. The Chi-Chi earthquake triggered landslide on the dip slope at the Chiufengershan. In this study, a review of the topography and geology of this area was followed by field investigations. Laboratory testing was applied to understand the geomaterial composing the slope. Then, based on a series of limit equilibrium analyses, the failure mechanism of this landslide and the risk of the residual slope were studied.
According to the stability analyses, the pre-quake slope is quite stable, with factor of safety of 1.77 (dry) to 1.35 (full groundwater level); explaining why there is no written record of a landslide here for the past 100 years. In contrast, a back analysis shows that the Chi-Chi earthquake-induced dynamic loading is far more than the dip slope can sustain, due in part to the short distance to the epicenter. A Monte Carlo type probability analysis suggests that the residual slope is more dangerous than the pre-quake slope and needs more attention. 相似文献
4.
A number of growth models have been developed and used in an attempt to project the historical pattern of oil activities to some estimate of their upper limit. Techniques are outlined for the estimation of parameters of the logistic and Gompertz curves. Factor analysis indicated a close relationship between production and demand, whereas annual discoveries and discoveries classified by year of discovery tended to comprise unique factors which were indifferent to changes in time. The growth models projected relatively high values for ultimate demand and production in comparison to the figures for ultimate reserves. Inasmuch as these trends seemed to be occurring independently, some reconciliation of the results was necessary. Using the highest projections of estimates for reserves suggests that over 420 billion barrels of oil in place will eventually be discovered in the United States, with perhaps 200 billion barrels of this eventually to be proved in the form of reserves. Projections for production were higher, corresponding to a trend indicating high levels in demand for crude oil. The only credible long-term estimate of demand was given by a bounded exponential growth model, in which ultimate cumulative demand for crude oil would reach about 416 billion barrels. These figures imply that over 150 billion barrels of oil would be imported into the United States from 1970 to 2070. Provided the time pattern for one of the variables has been determined, then estimates of the other variables probably would be facilitated because of the high interrelationship between variables. Models are suggested in which accurate pivotal forecasting in the short term might be possible—assuming the particular future trend in some of the independent variables has been predetermined.Research Council of Alberta Contribution No. 596. 相似文献
5.
Characterization and evaluation of the factors affecting the geochemistry of groundwater in Neyveli,Tamil Nadu,India 总被引：1，自引：0，他引：1
M. Jayaprakash L. Giridharan T. Venugopal S. P. Krishna Kumar P. Periakali 《Environmental Geology》2008,54(4):855-867
In order to achieve a better understanding of the nature of the factors influencing ground water composition as well as to
specify them quantitatively, multivariate statistical analysis (factor analysis) were performed on the hydrochemical data
of this area. R-mode factor analysis was carried out on the geochemical results of the 79-groundwater samples and the factor
scores were transferred to areal maps. Fundamental chemical parameters of the groundwater have been compounded together for
characterizing and interpreting a few empirical hydrogeochemical factors controlling the chemical nature of water. R-mode
factor analysis reveals that the groundwater chemistry of the study area reflects the influence of anthropogenic activities,
silicate weathering reactions, precipitation, dissolution and subsequent percolation into the groundwater. The data have been
put into few major factors and the seasonal variation in the chemistry of water has been clearly brought out by these factors.
Factor scores were transferred to contour diagrams and the factor score analysis has been used successfully to delineate the
stations under study with various factors and the seasonal effect on the sample stations. 相似文献
6.
为揭示太行山东缘小南海泉流量变化特征及规律,基于小南海泉1971-2016年的流量资料,采用R/S分析法、Mann-Kendall趋势分析法和小波分析法,探讨小南海泉流量变化规律及特征。结果表明:小南海泉年流量呈显著下降趋势,年变化幅度为0.05 m3·s-1;未来泉流量的变化趋势和过去一致,具有持续性特征,且持续性强烈;泉流量的变化存在约15、27年的主周期与6年的次周期。降水量的减少和气温的增加是导致泉流量减少的主要气象因素,且这种暖干化现象会持续发展。泉流量对降雨的响应存在一定的滞后,流量与前五个月的月降水量均呈高度相关,其中与前2月的降水相关性最高,研究成果可为小南海泉水资源合理开发和保护提供依据。 相似文献
7.
骨化学分析在古人类食物结构演化研究中的应用 总被引：1，自引：0，他引：1
古人类食物结构演化的研究,是探索人类起源和进化的重要组成部分。骨化学分析是探索古人类食物结构的主要方法,也是最为有效的方法。在概述骨化学分析原理的基础上,详细介绍了如何运用该方法了解古人类（南方古猿、人属、尼安德特人、欧洲现代人）的食物结构,并通过与现代黑猩猩的食物结构比较,揭示了从猿至人食物结构的演化过程,探讨了古人类食物结构的演变对人类进化的深刻影响。此外,提出了目前研究中尚存的2个重要问题及已有的解决方法。之后,评述了我国古人类食物结构的研究现状,并展望了古人类食物结构研究的前景。 相似文献
8.
9.
首先对被研究对象－冲击矛及土体作出若干假设，并在此基础上建立力学模型，然后找出研究对象的所有受力并对它们进行分析、简化，最后从运动学角度对可控冲击矛偏转机理进行了分析。 相似文献
10.
Ibsen Chivatá Cárdenas 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2019,13(1):53-65
In this paper, we report on the use of Bayesian networks, BNs, learnt from data generated by physical and numerical models, to overcome to a certain degree a number of complications in traditional slope stability analyses that jointly consider the mechanical and hydraulic properties of soils. Discrete Bayesian networks resulted to be useful and efficient to acquire knowledge from simulated data and to identify significant factors by the combined use of backward inference and global sensitivity analysis. Further, BNs enable decision thresholds to be estimated quickly. Along with this, backward inference and global sensitivity analysis are performed in BNs at low computation costs. Moreover, under conditions in which knowledge is scarce, we show how a practitioner can be better informed using the proposed approach. All these previously under-reported modelling features in the specialised literature encourage the further application of the proposed approach to enhance slope stability analysis. 相似文献
11.
紫金山铜金矿床为典型的高硫化型浅成低温热液矿床。文章以矿山地质调查工作为基础,通过岩相学、矿相学、岩化学分析等方法对紫金山铜金矿中的赋矿围岩以及金属矿石进行了系统研究;应用多元统计分析法对蚀变围岩的岩石地球化学数据进行分析,借助SPSS系统研究了Cu-Au元素变量与控矿微量元素变量的聚类关系,建立了Cu-Au元素变量与其它变量的回归方程,验证与解释了紫金山Cu-Au高硫化型矿床的成矿作用是由多期次的岩浆热液活动引起的。另外,通过聚类分析研究发现紫金山的成矿过程主要有中温Cu-Au矿化、低温Pb-Zn矿化以及少量高温W-Sn矿化三种矿化类型,其中W-Sn矿化形成于燕山早期的赋矿围岩形成阶段,而Pb-Zn、Cu-Au矿化为主矿化成矿阶段、形成于燕山晚期,且与富潜火山热液活动有关。 相似文献
12.
探讨了利用青铜器内残留的陶范或泥芯示踪青铜器产地的可行性。采用偏光显微镜、XRD、XRF、NAA等技术手段,测试分析了湖北九连墩楚墓青铜器内的泥芯,发现九连墩外来风格青铜器的泥芯,在物相、微观结构、化学成分、植硅体组合等方面与本地风格青铜器的泥芯有较大差异。外来风格青铜器的泥芯,其CaO含量很高,达6%以上,而Na2O的含量相对较低,这一富钙、贫钠的特点,与中国黄土的典型特征极为吻合。结合泥芯中的植硅体组合特征,推测九连墩外来风格的青铜器很可能来自中国北方黄土堆积地区,系当地铸造后输入到楚国的。本研究表明利用青铜器内的泥芯或陶范残留,可望有效地示踪青铜器的产地。 相似文献
13.
造山带复杂结构构造区遥感-构造综合解析--以南天山东段铜花山-榆树沟地区解剖为例 总被引：1，自引：0，他引：1
通过对铜花山—榆树沟地区的解析研究,阐述了造山带复杂结构构造区遥感解析与构造解析交叉互动的优势。遥感解析以区域线状构造及由它划分的块状、片状地质体为宏观骨架(对应于构造解析划分的构造单元、构造均匀区段),以地质体中的岩体、构造岩石组合,线状、带状构造,透人性、非透人性面状(原始层理、新生面理)和褶皱等构造作为解析的结构构造要素,以造山带表壳组成和结构构造解析研究为主要内容。采用野外实测构造要素与遥感图像处理技术相结合,分解造山带不同层次、不同构造单元的物质组成和结构构造,达到解析造山带内各级各类构造及其内部构造要素之间的相互关系。 相似文献
14.
The electricity generation capacity in the Limay River basin is approximately 26% of the total electrical power generation
in Argentina. Assessing the potential effects of climate change on the hydrological regime of this basin is an important issue
for water resources management. This study explores the presence of trends in streamflow series, evaluates climate sensitivity
and studies the effects on the flow regime of predicted changes in precipitation in the basin. In order to identify and quantify
changes in observed streamflow series, the Mann–Kendall test, with a modification for autocorrelated data, and an estimator
of the magnitude of the trend are applied. In order to evaluate the sensitivity of streamflow to changes in climate, the concept
of elasticity is used. Precipitation elasticity of streamflow is used to quantify the sensitivity of streamflow to changes
in precipitation and is estimated using a power law model and a linear statistical model in two sub-basins, Aluminé and Nahuel
Huapi. The effects on flow regime of the predicted changes in precipitation under different scenarios are studied. Climatic
results for different scenarios of growth in greenhouse gases from some General Circulation Models are used as inputs into
the proposed models. The analysis identifies decreasing trends in mean and minimum annual flows and in the low flow season.
The estimates of the precipitation elasticity imply that changes in precipitation produce similar changes in streamflow and
the climatic results for different scenarios show that the variations are moderate. 相似文献
15.
通过对永吉高速公路黑潭坪边坡的野外调查,详细地了解了研究区工程地质条件,探讨了边坡变形破坏机理,结合室内试验和计算反演获取岩土体强度参数,在此基础上建立三维地质模型,运用FLAC3D数值分析软件采用强度折减法对不同工况下的坡体稳定性进行详细分析并提出治理建议。研究表明:(1)边坡变形破坏是内外因素综合作用的结果,岩土体性质不良是边坡变形破坏的内在因素,坡脚便道开挖和地表水下渗是边坡变形破坏的诱导因素;(2)强度折减法应用于边坡三位稳定性分析具有较好的适用性;(3)数值模拟显示采用削坡结合锚固的综合治理措施具有明显的效果。 相似文献
16.
The Barth Island layered structure is an oval, 6 by 9 km body, consisting of rhythmically layered adamellitic rock in the center which grades outward through jotunite into troctolite. Farther outward the sequence repeats itself in reversed order, strongly reduced in magnitude and finer grained; the adamellitic zone is followed by jotunite which grades into coarse-grained leuconorite and into anorthosite of the Nain complex. The Barth Island structure, having an inverted conical base topped by a hemispherical depression, seems to represent a distorted sequence of rock layers with troctolite at the bottom, grading upward into adamellitic rocks which grade into anorthosite at the top. Trend-surface analysis demonstrates the regional variation of plagioclase and orthopyroxene compositions in the troctolite—adamellite sequence of the central part of the structure. The fits for the second- and third-degree surfaces are good and significant at the 99 percent level. The regression line for compositional variation in coexisting plagioclase and orthopyroxene in all analyzed rocks has a correlation coefficient of r2
= 0.78. The difference between the trends in the troctolite—adamellite sequence and the anorthosite—adamellite sequence is insignificant. The regression curve for compositional variation in coexisting orthopyroxene and olivine has a correlation coefficient of r2
= 0.98. The curve shows good correlation with the experimentally established partitioning curve of Medaris, which indicates that equilibrium conditions prevailed during formation of the olivine—ortho-pyroxene pairs. The results suggest that the troctolite—adamellite sequence and the anorthosite—adamellite sequence are products of fractional crystallization, possibly from the same parental magma. 相似文献
17.
针对Noah-MP模型多参数化方案、模拟结果不确定性范围难以确定的特点,选取北疆地区具有代表性的阿勒泰站气象资料作为模型驱动数据,探讨了积雪对多参数化方案的敏感性。在不考虑模型参数和驱动数据不确定性的条件下,设计了集合数为13824的多参数化方案集合模拟试验。选用Natural selection方法对物理过程的敏感性进行分析,并在敏感性分析结果的基础上进一步讨论了模拟结果的不确定性。结果表明:积雪对地表热交换、雨雪分离、土壤温度底层边界条件和第一层积雪或土壤时间方案4个物理过程敏感;在不考虑驱动数据和模型参数不确定性的条件下,多参数化方案集合模拟试验中的不确定性主要来源于敏感物理过程。去除敏感物理过程中能够明显降低模拟性能的参数化方案后,集合模拟结果的不确定性大幅减小。最后,根据分析结果构建了该站雪深和雪水当量模拟的最优参数化方案组合。 相似文献
18.
程昊 《矿物岩石地球化学通报》2005,24(2):148-152
对石榴子石冷却速率计中的几个重要参数误差分析结果表明，在慢速冷却的情况下，由测量数据误差所致的偏差可以忽略不计。但当冷却速率较大时，误差对模拟结果的影响则非常显著。然而，若采用现代分析仪器，由定位导致的模拟误差也可以完全忽略。空间测量的偏差往往使模拟得到的岩石冷却速率比实际值小得多；初始温度估计的偏差会使模拟结果产生很大的变化；扩散系数的选择对模拟结果影响也颇大。因此．具体情况下需仔细选取那些实验条件与所研究的具体地质情况最为相似的实验数据得到的模拟结果才是合理的。只有在合理的计算和选取参数以及可靠的测试技术的情况下，得到的模拟结果才具有地质意义。 相似文献
19.
R. Scott Anderson Renata B. Jass Jaime L. Toney Craig D. Allen Marcey Hess Julianna Fessenden 《Quaternary Research》2008,69(2):263-275
Chihuahueños Bog (2925 m) in the Jemez Mountains of northern New Mexico contains one of the few records of late-glacial and postglacial development of the mixed conifer forest in southwestern North America. The Chihuahueños Bog record extends to over 15,000 cal yr BP. An Artemisia steppe, then an open Picea woodland grew around a small pond until ca. 11,700 cal yr BP when Pinus ponderosa became established. C/N ratios, δ13C and δ15N values indicate both terrestrial and aquatic organic matter was incorporated into the sediment. Higher percentages of aquatic algae and elevated C/N ratios indicate higher lake levels at the opening of the Holocene, but a wetland developed subsequently as climate warmed. From ca. 8500 to 6400 cal yr BP the pond desiccated in what must have been the driest period of the Holocene there. C/N ratios declined to their lowest Holocene levels, indicating intense decomposition in the sediment. Wetter conditions returned after 6400 cal yr BP, with conversion of the site to a sedge bog as groundwater levels rose. Higher charcoal influx rates after 6400 cal yr BP probably result from greater biomass production rates. Only minor shifts in the overstory species occurred during the Holocene, suggesting that mixed conifer forest dominated throughout the record. 相似文献
20.
A. J. Parsley 《Mathematical Geology》1971,3(3):281-295
It is proposed that the variance in mapped geologic data should be formally considered to be composed of three components which arise on different geographic scales. The three components (regional, local, and residual) should be defined solely in terms of the parameters of the sample data set. A two-step analysis is required to separate three components. Applying autocorrelation criteria, trend-surface analysis has been used, in the first step, to remove the residual component and, in the second step, to separate regional and local components from the resulting noise-free data. This procedure has made it possible to quantify local components in stratigraphic thickness data from the East Midlands coalfield (central England) which can be identified in terms of the known geology. 相似文献