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1.
This paper examines the scope and limitations of geomorphological investigation of the sites of architectural and engineering works. Various degrees of vulnerability, forms of impact, and types of applied geomorphological response are summarized. Aspects of land development and construction practice that may increase the vulnerability of buildings and structures to geomorphological hazards are discussed. Strengths and weaknesses of the geomorphological input to hazard mitigation are reviewed. Examples are described that show both negative and positive influences exerted by geomorphological site analysis on urban and regional planning for unstable terrains in Italy. It is concluded that societal choice, within the overall matrix of a society's culture (sensu largo), will influence the way in which vulnerability is managed at sites, and hence the scope for utilizing geomorphological analysis of the physical risks.  相似文献   

2.
A classification of controls of chemical elements transport is elaborated for the case of copper sulfides in alluvial fan, gravel veneer, valley flat, and lake-swamp complexes in piedmont and peneplain regions. The emphasis is placed upon topographic profile notch areas in which the energy of the water drained from the upland falls below the value at which gravel and boulders can be transported, but the finer materials remain in suspension, and various complexes in solution. The topographic feature, with its surface and ground water relationships, its soil profile, and its vegetation, is defined as an elementary environment. A classification of elementary environment is then elaborated for the purpose of mapping the geomorphologic, pedologic, hydrologic, plant-ecologic ; and to a minor extent, lithologic controls of atomic and ionic transport. The soil profile, the geomorphologic properties of the topographic feature, and the vegetation cover are the objects of especially strong emphasis.—M. E. Burgunker.  相似文献   

3.
Lower rainfall and a longer dry season appear to have characterised SE Asia during the Quaternary Glacials. This had an important effect on vegetation and on landform development, particularly on weathering, river regimen, coastal features and planation.The low Glacial sea levels are generally thought not to have caused river incision and deposition of rather coarse-textured materials is considered more characteristic. Incision was mainly tied to the Interglacial and Holocene humic tropical conditions when vegetation interfered with non-concentrated surface wash. Clay blankets were deposited off-shore and also above the waterline. This concept has consequences for the Quaternary chronology in SE Asia.  相似文献   

4.
提要:自然资源、环境本底及生态地质条件调查是城市地质调查的基础,可为城市国土空间规划、建设及精细化管理提供有效的基础地质支撑.随着雄安新区城市进程的加快,使得其自然资源与生态环境发生了翻天覆地的变化.本文基于雄安新区综合地质调查成果,明确了雄安新区自然资源与生态环境本底条件,分析了建设周期内自然资源变化趋势,探讨了未来...  相似文献   

5.
The report analyses the main properties pertaining to the durability of Finnish granitoid rocks, based upon extensive field and laboratory data collected during the past ten years. Commercial materials have been tested and compared along ten years of production and their frost resistance assessed according to European standards. Laboratory tests have been coupled with non-destructive methods most used on site assessment as ultra-pulse velocity and Schmidt hammer in order to compare the results of commercial materials with materials on construction site. Evaluation of durability has included petrographic analysis, crack density, and for site exposed material, chemical analysis, to understand the environmental effects on it. The material has generally maintained its original properties. It has natural heterogeneity, and it presents higher interlocked cracking network on the surface of the exposed materials. Site samples in some cases have shown chemical changes due to environmental actions.  相似文献   

6.
At present there is a tendency for the roles, in the economy, of the environment and natural resources to be interrelated. Economic factors have increasingly been affected by environmental impact in spatial economic organisation (ETO). The growth of production results in the constant increased consumption of natural resources. New sources (of inferior quality in the developed regions or in the regions with extreme conditions), formerly not exploited area now used. At the same time the following tendencies can be observed: increased concentration of production, more complicated branch structure, growth in number of manufacturing industries, decline in the share of mining in industrial output. This tendency is accompanied by the spatial disjunction of technologically interconnected industries (dealing with mining and processing of raw materials) and by the formation of new industrial integrations (not dealing directly with natural resources utilization). In this complicated situation the investigation of natural resources and of the environmental role in the spatial organisation of the economy is becoming of special relevance. In the author's opinion while investigating this problem the type of social system should be considered, as well as the level of development of productive forces and the combination of regional nature and economic conditions. Three aspects of investigation—branch, spatial and functional—are proposed. The analysis of natural resources and environmental impact the spatial organisation of the economy in each of mentioned aspects should be performed on different scales—local, regional, national and international levels. The approach to problem investigation is based on the analysis of data about the USSR. and exemplified. The investigators recommend the application of Soviet experience in this field by the geographers of other countries.  相似文献   

7.
A study of natural radionuclides and radon concentration of Hamirpur District of Himachal Pradesh, India is carried out using various methodologies. The activity concentration of the natural radionuclides viz. 226Ra, 232Th and 40K is measured using high-resolution-based HPGe detector. Indoor radon measurements in the dwellings of Hamirpur district is carried out using LR-115 type II cellulose nitrate films in the bare mode. The average activity concentrations of 226Ra, 232Th and 40K are 35.58, 54.95 and 580.58 Bq kg?1, respectively. The annual average indoor radon value in the study area varies from 173.90 to 198.25 Bq m?3, which is well within the recommended action level given by International Commission on Radiological Protection. The indoor radon values obtained in the present investigation are higher than the world average of 40 Bq m?3. Radon concentration in water samples is measured using RAD7, an active radon detector. The annual effective dose for stomach and lung is determined from the measured value of radon concentration in water. To assess the radiation hazard of the natural radioactivity in all samples to the people, the radium equivalent activity, external hazard index, lifetime fatality risk, absorbed dose rate and total annual effective dose is estimated. The results signify that the studied area does not possess any radiation hazards due to the presence of natural radioactivity concentration.  相似文献   

8.
成都平原放射性环境地质评价   总被引:1,自引:0,他引:1  
根据成都平原地质背景和环境放射性现状,分析了地质条件对放射性水平的影响及原因,总结了成都平原地质环境对天然放射性水平及其分布的影响规律。  相似文献   

9.
10.
赵迷迷 《城市地质》2021,16(4):432-438
天然放射性辐射是衡量优质人居环境的一项重要指标,在城市建设中开展放射性环境调查必不可少.2020年5月-10月,以(250~500)m×(50~100)m的网度布设测量点,在粤港澳大湾区某地开展1:25000环境地表γ辐射剂量率测量.结果表明,区内整体辐射环境未发生明显变化,且处于正常水平.区内环境地表γ辐射水平可分为城镇人口密集区、基岩出露区和原野区3类,其中人口密集区的环境地表γ辐射水平略高于天然本底值2.48%~13.73%;基岩出露区环境地表γ辐射水平普遍高于天然本底值3.92%~65.29%;原野区环境地表γ辐射水平普遍低于天然本底值17.65%~40.20%,共发现10处异常高数值区(点),均与区内裸露的花岗岩及断裂构造带密切相关.居民所受环境地表γ辐射所致公众人均年有效剂量平均值为0.693 mSv·a-1,与全国辐射环境质量水平相当.圈定异常区4处,区内常驻人员需做好防护措施,或减少停留时间.  相似文献   

11.
The Py-GC/MS results of the study carried out on two groups of vitrinites (perhydrous and non-perhydrous) of different age and properties and on a trimaceralic coal associated with one of the perhydrous group are discussed. Such a study provides information about the effect of natural hydrogen enrichment on vitrinite structure at the molecular level. Moreover, the influence of the different conditions in the sedimentary environment on the chemical structure of the vitrinite is also discussed. This influence is inferred through differences in the distribution and relative amount of phenolic compounds found in the pyrolysates from two samples of two different coal-beds in the same basin but formed under different paleoenvironmental conditions. For vitrinites with a high H/C atomic ratio, despite having a strong perhydrous character, their pyrolysates exhibit the highly phenolic signature typical of lignin-derived material with only minor aliphatic compounds. Thus, the major chemical structural elements in these vitrinites are simple phenols with a high contribution of para alkyl-substituted derivatives. However, there is no parallel relationship between the evolution of the oxygenated functionalities and the reflectance values. From the results obtained a coalification pathway where hydrogenation processes predominate over thermal ones is proposed. The presence of resin-like substances and/or oils (which are two of the causes of natural hydrogen enrichment) in the molecular structure of vitrinites have, therefore, affected the normal evolution of the lignin and contributed to the special properties of this type of materials.  相似文献   

12.
赵迷迷 《城市地质》2021,16(4):432-438
天然放射性辐射是衡量优质人居环境的一项重要指标,在城市建设中开展放射性环境调查必不可少.2020年5月-10月,以(250~500)m×(50~100)m的网度布设测量点,在粤港澳大湾区某地开展1:25000环境地表γ辐射剂量率测量.结果表明,区内整体辐射环境未发生明显变化,且处于正常水平.区内环境地表γ辐射水平可分为城镇人口密集区、基岩出露区和原野区3类,其中人口密集区的环境地表γ辐射水平略高于天然本底值2.48%~13.73%;基岩出露区环境地表γ辐射水平普遍高于天然本底值3.92%~65.29%;原野区环境地表γ辐射水平普遍低于天然本底值17.65%~40.20%,共发现10处异常高数值区(点),均与区内裸露的花岗岩及断裂构造带密切相关.居民所受环境地表γ辐射所致公众人均年有效剂量平均值为0.693 mSv·a-1,与全国辐射环境质量水平相当.圈定异常区4处,区内常驻人员需做好防护措施,或减少停留时间.  相似文献   

13.
《Earth》2002,57(1-2):125-176
Antimony is ubiquitously present in the environment as a result of natural processes and human activities. It exists mainly as Sb(III) and Sb(V) in environmental, biological and geochemical samples. Antimony and its compounds are considered to be priority pollutants interest by the USEPA and the EU. In this first review paper on antimony occurrence in natural waters, 420 papers on freshwaters, marine waters, estuaries, soils, and sediments have been reviewed. All data are quoted from the original sources. Typical concentrations of total dissolved antimony are usually less than 1.0 μg/l in non-polluted waters. When redox speciation determinations are performed, most studies report the dominance of Sb(V) under oxic conditions. However, the presence of significant proportions of Sb(III) is sometimes detected. This is in contrast with thermodynamic equilibrium predictions and discrepancies are often attributed to biological activity or kinetic effects but proofs are lacking. Similarly, the existence of Sb(V), although not thermodynamically predicted, is often reported under anoxic conditions. Low concentrations of methylated antimony species are mentioned in a few studies. Antimony is not considered to be a highly reactive element in oceans, with concentrations of the order of 200 ng/l. In estuarine waters, both conservative and non-conservative behaviours are reported depending on the estuaries' characteristics. Elevated concentrations of antimony in soils and sediments are either related to anthropogenic sources or associated with high arsenic concentrations in sulfidic ores. Antimony appears to be highly unreactive in soils. Low accumulation factors are reported in algae. Airborne supply of antimony to aquatic and terrestrial systems seems to be important in systems far from direct pollution sources. However, the limited available data do not allow firm conclusions to be drawn on the reactivity and cycling of the element in natural systems and a list of research priorities is given.  相似文献   

14.
Ye  Maoxin  Aldrich  Daniel P. 《Natural Hazards》2021,105(1):67-81
Natural Hazards - Much research has demonstrated that vulnerable people fare more poorly than non-vulnerable ones in disasters and crises across a variety of outcomes—including mental and...  相似文献   

15.
This paper briefly presents the research progress of the State Major Basic Research Project 2001CB309400, “Theory and Application for Retrieval and Fusion of Spatial and Temporal Quantitative Information from Complex Natural Environment”. Based on the rapid advancement of synthetic aperture radar (SAR) imagery technology, information theory of fully polarimetric scattering and applications in polarimetric SAR remote sensing are developed. To promote the modeling of passive microwave remote sensing, the vector (polarized) radiative transfer theory (VRT) of complex natural media such as inhomogeneous, multi-layered and 3-dimensional VRT is developed. With these theoretical progresses, data validation and retrieval algorithms for some typical events and characteristic parameters of earth terrain surfaces, atmosphere, and oceans from operational and experimental remote sensing satellites are studied. Employing remote sensing, radiative transfer simulation, geographic information systems (GIS), land hydrological process, and data assimilation, the Chinese land data assimilation system (CLDAS) is established. Towards the future development of China’s microwave meteorological satellites, employing remote sensing data of currently available SSM/I (special sensor microwave/imager), AMSU (advanced microwave sounding unit), MTI (microwave temperature imager), etc., with ground-based measurements, several operational algorithms and databases for atmospheric precipitation, water vapor and liquid water in clouds, and other hydrological/hydrological applications are developed. To advance China’s SAR and InSAR (interferometric SAR) technologies, the image processing and analysis of ERS (European remote sensing), Radarsat SAR, and Chinese SAR, etc., the software platforms are accomplished. Based on the researches of multi-information fusion, some simulations, identification, and information extractions of the targets from complex background clutter scenes are studied. Some experiments of radio wave propagation in anomalous atmospheric status are also carried out. Translated from Advances in Earth Science, 2007, 22(2): 111–125 [译自: 地球科学进展]  相似文献   

16.
甲烷氧化与氨氧化微生物及其耦合功能   总被引:2,自引:0,他引:2  
甲烷氧化与氨氧化过程分别对控制温室气体甲烷和氧化亚氮方面有着特殊作用,土壤及湿地等环境中的甲烷氧化菌和氨氧化菌在生态系统碳、氮生物循环中扮演着重要的角色。论述了甲烷氧化与氨氧化过程的微生物学机制,甲烷氧化菌和氨氧化菌的群落结构变化,分析了甲烷氧化菌和氨氧化菌在碳、氮循环以及它们在控制重要温室气体排放中的环境功能,阐述了甲烷氧化菌和氨氧化菌的关联作用机制。以期深入揭示甲烷氧化菌与氨氧化菌的空间分异与耦合机制,为深入探讨这类微生物的生态机制和环境功能提供科学线索。  相似文献   

17.
《Geochimica et cosmochimica acta》1999,63(19-20):3429-3441
Standard partial molal thermodynamic parameters for the aqueous chlorinated-ethylene species, perchloroethylene (PCE), trichloroethylene (TCE), 1,1-dichloroethylene (1,1-DCE), cis-1,2-dichloroethylene (cis-1,2-DCE), trans-1,2-dichloroethylene (trans-1,2,-DCE), and vinyl chloride (VC) have been estimated by using experimental gas-solubility data and correlation algorithms. The provided thermodynamic values may be used to calculate properties of reactions involving the aqueous chloroethylene species at a wide range of temperatures and pressures. Estimated values for the chloroethylenes were used, along with published values for minerals, gases, aqueous ions, and aqueous neutral organic species, to calculate the stability of chloroethylene species in equilibrium with the minerals magnetite, hematite, pyrite, and pyrrhotite in the subsurface. Estimated values for the aqueous chloroethylenes were also used to calculate reduction potentials for microbially-mediated reductive dechlorination half-reactions at elevated temperatures. Calculations indicate that all aqueous chloroethylene species are energetically favored to decompose to ethylene(aq) under a wide range of conditions in the subsurface, by both abiotic and biotic pathways. Anaerobic microbially mediated degradation is especially favored under conditions at least sufficiently reducing to promote sulfate-reduction, but not under conditions sufficient for microbial denitrification, pyrolusite reduction, or ferric-iron reduction.  相似文献   

18.
19.
Antimony is ubiquitously present in the environment as a result of natural processes and human activities. Antimony is not considered to be an essential element for plants or animals. In this third review paper on the occurrence of antimony in natural waters, the interactions of antimony with microbiota are discussed in relation to its fate in natural waters. This paper covers the following aspects: occurrence in microbiota, uptake transport mechanisms, pathways of Sb(III) removal from cells involved in antimony tolerance, oxidation and reduction of antimony by living organisms, phytochelatin induction and biomethylation. This review is based on a careful and systematic examination of a comprehensive collection of papers on the above mentioned aspects of the subject. All data are quoted from the original sources. Relatively little existing information falls within the strict scope of this review and, when relevant, discussion on the interactions of antimony with reference microorganisms, such as Escherichia coli, Saccharomyces cerevisiae and different protozoan parasites of the genus Leishmania, has been included.  相似文献   

20.
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