共查询到20条相似文献,搜索用时 15 毫秒
1.
From radon hazard to risk prediction-based on geological maps,soil gas and indoor measurements in Germany 总被引:3,自引:0,他引:3
Mapped geological units can be regarded as proxies standing for a complex series of subsoil geochemical and physical properties
including the assigned radon activity concentration in soil gas, which is taken as best estimator of the regional geogenic
radon potential. Areal distribution of measuring sites for soil gas in Germany is adapted to spatial variation of geology.
A grid-based and distance-weighted interpolation procedure is applied, following geologically defined neighbourhood relations
of measuring sites and accounting for isolated outcrops of known geology but without measurements. To investigate the statistical
relationship between indoor radon, house type and building ground specifications, measurements of the indoor radon concentration
have been carried out in more than 10,000 dwellings in different regions of Germany. Multiple regression analyses of variance
reveal that besides region-specific geological properties and building characteristics, various house type and living style
variables significantly contribute to the explained variance for ground floor radon concentrations. These parameters are also
dominant in controlling the radon transfer relation from soil gas to indoor air. Risk prediction maps for radon in houses
indicating the probability to exceed certain indoor threshold values can be useful especially for regions with no or only
a few measurements of indoor radon. 相似文献
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L. M. O. Martins M. E. P. Gomes L. J. P. F. Neves A. J. S. C. Pereira 《Environmental Earth Sciences》2013,68(3):733-740
The region of Amarante (Northern Portugal) is composed of Hercynian tardi-tectonics granites and Paleozoic metasediments. Petrographic observations and SEM studies show that uranium is mainly contained within the rock in heavy accessory minerals such as apatite, zircon, monazite, uraninite, thorite and thorianite. The geological, geochemical and radiological data obtained suggest that the radon concentrations in dwellings of the studied area are mainly related with the uranium content of the rocks. Indeed, the highest contents were observed in granite AT2 of Padronelo (18.2 ppm) and the granite AT1 of Telões (10.3 ppm), with metasediments showing much lower uranium contents of 1.6 ppm; radon concentrations were evaluated in dwellings, using CR-39 passive detectors, and the results obtained in winter conditions suggest that the most productive geological units are the granites AT2 and AT1, with geometric means of 430 and 220 Bq/m3, respectively, while the metasediments show the lowest value of 85 Bq/m3. Some moderate radiometric anomalies, where uranium contents can double typical background values, were found in relation with specific fault systems of the region affecting granitic rocks, thus increasing radon risk; this is an indication of uranium mobility, likely resulting from the leaching of primary mineral supports as uraninite. Groundwater radionuclide contents show a wide range of results, with the highest activities related with granitic lithologies: 2,295 Bq/l for radon, 0.83 Bq/l for gross α and 0.71 Bq/l for gross β, presenting metasediments much lower values, in good agreement with other results obtained. Absorbed dose measured with gamma spectrometers in direct contact with the rocks is directly related with the uranium contents of the rocks, and thus works as a fast proxy for radon risk. It is concluded that radon risk is moderate to high in the granitic areas of the Amarante region and low in the metasediments of the same region. 相似文献
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Douglas G. Brookins 《Environmental Geology》1991,17(3):209-217
High indoor radon in approximately 30 percent of private dwellings in the Albuquerque, New Mexico area has been reported previously. The present study explains the areas of high indoor radon as a function of different soil and/or bedrock in the area. Soils were sampled during summer and winter periods using alpha track radon detectors. The values range from 40 to 890 pCi/I air at a depth of 38 cm. The gross mean average is 360 pCi/I for the area for summer readings and 200 pCi/I for winter readings; both values are well over the average U.S. soil radon values of approximately 100 pCi/I. Analyses of soil uranium show a range in values of 1–6 ppm, with a mean of 3.1 ppm. Thorium values range from 3.3 to 28.8 ppm, and Th/U ratios range from 2.9 to 4.6.These values for U, Th, and Th/U suggest that soil U and Th are close to the values reported for the Sandia granite, the source of most of the pediment on which Albuquerque is built. Soil infiltration rates range from ~6 × 10–4 to 4.5 × 10–3 cm/sec for the samples, and soil moisture content ranges from 1.4 to 7.2 percent. A fair correlation of summer soil radon with infiltration rate is noted. Correlation of soil radon with moisture content and/or with percent silt, silt + clay, clay size fraction material is not established by this study. Soil radon values do correlate with regions in the Albuquerque area where high indoor radon is common. A better correlation of high indoor radon values with soils developed immediately over bedrock is observed. Furthermore, all values of average soil and indoor radon increase significantly with proximity of the stations to the Sandia Mountains. Soil uranium also shows this trend. The data argue that regions of potentially high radon can thus be identified. 相似文献
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Douglas G. Brookins 《Environmental Geology》1988,12(3):187-196
Radon buildup in homes is now recognized throughout the world as a potentially major health hazard. The U.S. Nuclear Regulatory
Commission and the U.S. Environmental Protection Agency estimate 8,000–30,000 fatalities per year in the United States due
to indoor radon.
The Albuquerque, New Mexico area was chosen for study because it is representative of metropolitan areas in the southwestern
United States where slightly uraniferous source rocks (Sandia granite) have provided the very immature soil for much of the
area. The granite contains 4.7 ppm U, and limestone capping the granite 5.7 ppm U. Soils in the area average 4.24 ppm U, and
Th/U ratios average 3.2. These data suggest some removal of U from the source rocks, but fixation of the U in the soils (that
is, as opposed to widespread removal of the U by solution), thus providing a ready source for soil radon. A pilot study of
soil radon in the area in winter of 1983–1984 shows high values, 180 pCi/l, relative to the U.S. average (about 100 pCi/l).
In the winter of 1986–1987, 180 dwellings were surveyed for their indoor radon levels, including 20 that had been surveyed
in summer of 1986. Twenty-eight percent of those in the winter study yielded indoor radon above the EPA suggested maximum
permissible level of 4 pCi/l air, well above the EPA estimate of 10–15 dwellings for the U.S. The indoor radon levels show
positive correlation with closeness to the Sandia Mountains, to soil radon, to excess insulation, to homes with solar capacities,
and other factors. Building materials may provide a very minor source of some indoor radon. Summer readings are lower than
winter readings except when the houses possess refrigerated air conditioning. 相似文献
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The relationship of soil gas radon Rn222 and indoor radon was studied within the Quaternary fluvial sediments of the Czech Republic. The processing of data selection
from the radon database of the Czech Geological Survey and indoor radon data (database of the National Radiation Protection
institute) has proved the concentration dependence of radon in Quaternary fluvial sediments on deeper bedrock. The ArcGIS
processing was accompanied by the field verification in five profiles, intersecting the granitoid Central Bohemian Plutonic
Complex and its rim rock types. Both theoretical and experimental results show dependence of soil gas radon and indoor radon
concentrations in Quaternary fluvial sediments on deeper geological basement, thus leading to the conclusion that the lateral
transport of Quaternary sediments does not play such a dominant role in radon concentrations, as was thought previously. This
fact will enable to determine precisely the radon index of Quaternary sediments (in the Czech radon mapping classified as
an intermediate index) into three categories according to the lithology of their geological basement. 相似文献
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中国信息研究工作经过几十年的发展,已经形成了具有中国特色的、多层次多方式的信息服务系统.中国国情决定了信息研究是该系统的一个组成部分,这也是中国信息工作的一大特点.中国地矿信息研究工作经过多年发展已取得了许多进展.信息研究工作作为一项专门的社会职能,必须有自己的理论认识作为指导,这种认识是在实践中形成和发展的.在新形势下,中国信息研究工作正在由"供给驱动型"向"需求驱动型"转变,这对信息研究工作的发展来说,既是挑战,又是机遇. 相似文献
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中国信息研究工作经过几十年的发展,已经形成了具有中国特色的、多层次多方式的信息服务系统。中国国情决定了信息研究是该系统的一个组成部分,这也是中国信息工作的一大特点。中国地矿信息研究工作经过多年发展已取得了许多进展。信息研究工作作为一项专门的社会职能,必须有自己的理论认识作为指导,这种认识是在实践中形成和发展的。在新形势下,中国信息研究工作正在由“供给驱动型”向“需求驱动型”转变,这对信息研究工作的发展来说,既是挑战,又是机遇。 相似文献
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The study illustrates the critical role of accurate geological structural mapping to delineate crystalline aquifer zones more prone to high health risk due to elevated dissolved As in drinking wells.The analysis revisits the results from more than 1200 groundwater samples collected over ten years from domestic wells across the Tampere region(Finland).It is demonstrated that the highest dissolved As concentrations in the region(up to 2230 μg/L)are exclusively found near major faults and deformation zones(FDZs)detected via geophysical and geological surveys,and that a clear correlation exists between dissolved concentrations and the distance from the FDZs(r).Almost all values exceeding the drinking water limit(10 μg/L)occur at r8 km,while concentrations above 100 μg/L occur at r4 km.Solidphase As concentrations in bedrock show less dependency on FDZ than aqueous concentrations.This behavior is explained considering different mechanisms,which include enhanced sulfide oxidation and fracture connectivity,promoting preferential transport of dissolved As to FDZs and mixing of waters from different redox zones,mobilizing preferentially As(Ⅲ)or As(V).Fe hydro-oxides may also precipitate/dissolve preferentially because of FDZs,while residence time may influence the contact time between water and As-bearing minerals.It is concluded that the accurate mapping of FDZs,and in general of structural geology,provides an important preliminary information to identify where localized,sitespecific characterization of hydrogeology and geochemistry is more urgent to reduce As-related health risk from groundwater intake. 相似文献
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M. Shakir Khan M. Zubair Deepak Verma A. H. Naqvi Ameer Azam M. K. Bhardwaj 《Environmental Earth Sciences》2011,63(2):279-282
Radon and its progeny have been recognized as one of the major contributors to the natural radiation and health hazards in
the human dwellings. Even lung cancer is expected if it is present in enhanced levels beyond maximum permissible limit. This
paper reports the measurements of indoor radon and its progeny in the urban dwellings of the Etah district of Uttar Pradesh
province in Northern India using the cellulose nitrate (LR-115 type-II) plastic track detectors. It is found that the values
of radon concentration vary from 3.52 to 248.64 Bq m−3 with a standard deviation of 69.19. The values of radon progeny concentration vary from 0.38 to 26.88 mWL with a standard
deviation of 7.48. The effective dose has been calculated and found to vary from 0.05 to 3.76 mSv year−1 with a standard deviation of 1.05. The lifetime fatality risk is found to vary from 0.04 × 10−4 to 2.90 × 10−4. The results have been compared with the results reported in the rural areas of the same district. 相似文献
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地质图是一个区域地质研究的重要成果,也是前人留下的宝贵资料,更融合了地质专家的丰富知识。本研究的目的是通过新的思路将彩色地质图信息提取出来,使其结果能直接进行数据分析,并用于决策和分析。以机器学习为指导,在分析半结构化(栅格)地质图特征的基础上,根据图例信息,提出一种彩色地质图信息提取新思路,对彩色地质图进行分层信息提取,并结合数学形态学和多层前向反馈式神经网络,探索半结构化数据转换为结构数据的有效技术方法。利用图像信息提取技术将半结构化地质图转化为结构化数据,可用于成矿预测等研究。这一变化将改变传统地质数据的结构,地质研究的信息基础和来源将会增加,对于获取更多的数据源和信息源,进一步开展地质分析研究具有重要意义。 相似文献
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The Middle Jurassic Walloon Subgroup is a prolific coal seam gas (CSG) resource in the Surat Basin, Queensland. Sedimentary framework models constrain stochastic reservoir models of the geological heterogeneity, but there is limited basin analysis information in the public domain. Here we present a regionally consistent stratigraphic framework model for the Walloon CSG play in the eastern Surat Basin. Lithostratigraphic correlation of open-file industry and government wireline logs supports the interpretation of six subunits in the eastern Surat Basin (oldest–youngest: Durabilla Formation; Taroom Coal Measures; Tangalooma Sandstone; and Juandah Coal Measures, informally divided into three members named the lower Juandah Coal Measures, Juandah sandstone and upper Juandah Coal Measures). Important findings are that subunits within the Walloon Subgroup do not correlate along the entire CSG play area; in many places, the overlying Springbok Sandstone (Upper Jurassic) has incised to the lower Juandah Coal Measures level, removing the upper coal seam groups. The Walloon Subgroup thins to the south through a combination of depositional thinning and truncation. Lithofacies analysis and isopach maps support deposition in a southerly prograding fluvial system or clastic wedge. This stratigraphic and depositional interpretation informs models for hydrogeological studies of the Walloon Subgroup and underpins a regional assessment of controls on microbial methane distribution. 相似文献
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我国即将完成1: 2 500 000全月球数字地质图编制,为便于成果数据存储管理和集成共享,需要建立完备合理的空间数据库。本文基于本次编图工作实践,对月球地质图空间数据库要素内容进行了全面整理和归类。月球地质图空间数据库要素包括物质要素、构造要素、其他特殊符号、注记共4个大类,在大类基础上细分为13个中类及40个小类,并据此设计了具有可扩展性的要素分类代码。空间要素采用分层的方式进行组织管理,图层名前4位为所属图幅号,第5位为比例尺代码,其后为图层英文名称的缩写。每个要素图层与一张属性表关联,对属性表所有字段的字段名称、别名、类型、能否为空、长度、小数位及单位进行了定义和规范。本文选取月表撞击坑坑物质、月海岩石、撞击断裂及高程点要素详细阐述了其属性表结构。属性表主键为“要素标识号”,用于唯一标识某一个图元,其由图幅号、比例尺代码、要素分类代码、图元顺序码四层14位层次码构成。数据库设计遵循可扩展原则,特定区域或其他比例尺的月球地质图空间数据库建设也可参照执行,本文以月球冯·卡门撞击坑及邻区地质图为例进行了空间数据库设计。科学合理的数据库设计是数据库建设的前提,将为编图成果存储管理、集成共享与国际合作提供重要支撑。 相似文献
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地质信息服务体系框架研究 总被引:9,自引:3,他引:9
信息服务已经成为21世纪各国地质工作的战略重点,基于Internet和信息技术及时有效地为用户提供综合、客观的地质信息服务已列入了各国地质调查机构的战略计划。完善的信息服务体系是信息服务健康发展的必要条件。本文在明确相关概念的基础上,分析了现代信息服务的特点,提出了较为完整的地质信息服务体系框架,阐述了体系框架中各组成部分的主要内容和相互关系。 相似文献
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Xiaojing Liu Jiquan Zhang Donglai Ma Yulong Bao Zhijun Tong Xingpeng Liu 《Natural Hazards》2013,65(3):1393-1409
The traditional studies on drought disaster risk were based on the ground point data, which were unable to realize the continuity of space and the timeliness. It is shown that the monitoring and evaluation precision on drought were reduced significantly. However, remote sensing data in adequate spatial and temporal resolution can overcome these limitations. It can better monitor the crop in large area dynamically. This study presents a methodology for dynamic risk analysis and assessment of drought disaster to maize production in the northwest of Liaoning Province based on remote sensing data and GIS from the viewpoints of climatology, geography and disaster science. The model of dynamic risk assessment of drought disaster was established based on risk formation theory of natural disaster, and the expression of risk by integrating data came from sky, ground and space. The risk indexes were divided into four classes by data mining method, and the grade maps of drought disaster risk were drawn by GIS. It is shown that the spatial and temporal risk distributions of maize at each growth stage changed over time. The model has been verified against reduction in maize yield caused by drought. It demonstrated the reasonability, feasibility and reliability of the model and the methodology. The dynamic risk assessment of regional drought disaster for maize can be used as a tool, which can timely monitor the status (the possibility and extent of drought) and trends of regional drought disaster. The results obtained in this study can provide the latest information of regional drought disaster and the decision-making basis of disaster prevention and mitigation for government management and farmers. 相似文献
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随着经济社会的发展和科学技术的进步,以及地质工作服务领域的空前扩展,地质图件作为地质工作成果的集中体现和地质工作服务于经济社会发展的主要工具,受到各国政府及国际地质组织的高度重视,并出现一些明显的特点和发展趋势,主要表现为:由专业性地质图件向更多实用性图件发展;由单一地质类图件向多学科系列图件发展;由地区性、国家级图件向洲际性及全球性图件扩展;由地表地质图件向反映深部地壳结构构造图件发展;并在图面结构、表现形式上进行了诸多改革,提供了更多地质信息。 相似文献