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81.
Natural disasters like floods, tornadoes, tropicalcyclones, heat and cold wavewreak havoc and cause tremendous loss ofproperty all over the world. Most ofthe natural disasters are either dueto weather or are triggered due toweather related processes.Extreme weather events claimed thousands oflives and caused damage on vastscale. Recent super cyclone which affectedOrissa in 1999, Bangladesh cyclone of1970 and Hurricane Andrew in 1992 areexamples of some of the more damagingtropical cyclones which affected developingas well as the developed world. Heatand cold waves are also extreme events,which cause enormous losses in terms oflives lost and human discomfort and ailmentsarising out of them. The heat waveof 1995 and 1998 are still fresh in the mindof the Indian public. The estimated lossof human lives due to heat wave in 1998 was morethan 15,000. Economic losses asa result of these disasters and in particular inassociation with tropical cyclones haveincreased enormously over the last three decades.During 1961–1991, total loss oflives from drought alone was 1,333,728 overthe whole world. In terms of economiclosses, there is 8–10 fold increase from thebase figure of 1960. The socio-economicimpact of natural disaster is complex dependingupon the vulnerability of the placeand mitigation strategies that are put in place.Meteorology plays a crucial role in forewarningpeople about the severe/extremeweather systems and a constant endeavour by themeteorological services worldover has gone a long way towards minimizing thelosses caused by natural disasters.The paper summarises the natural disasterstatistics over south Asia and the possibleprediction strategies for combating theirsocio-economic impacts. 相似文献
82.
M. Draoui J. Vias B. Andreo K. Targuisti J. Stitou El Messari 《Environmental Geology》2008,54(3):455-463
This paper presents the results of a comparative study relating to the application of four vulnerability mapping methods,
GOD, AVI, DRASTIC and SINTACS, in a pilot detritic aquifer situated in NW Morocco, known as the Martil–Alila aquifer. The
principal objective of this work is to determine the most suitable such methods for this aquifer type within a Mediterranean
context, and to show the effect of the rainfall variations that are characteristic of the Mediterranean climate on the degree
of vulnerability. The methods applied distinguish five classes of vulnerability, these being irregularly divided up in space,
with the division varying according to the method in question. The vulnerability maps obtained by the different methods strongly
suggest that the eastern half of the aquifer is more vulnerable to contamination than the western half, for all hydrological
situations. The effect of climatic conditions on the degree of vulnerability is well represented by the DRASTIC, according
to which the aquifer is moderately to strongly vulnerable during humid hydrological years and weakly to moderately vulnerable
during dry ones. For the other methods, this climatic effect is limited to the area occupied by the two predominant classes
(“High” and “Low” for GOD and “High” and “Moderate” for SINTACS) while it is null for AVI. In conclusion, DRASTIC appears
the most suitable for mapping the vulnerability to contamination of Mediterranean coastal detritic aquifers such as the Martil–Alila
aquifer. 相似文献
83.
Guan J.Wei F.Sun G.Huang J.Wang L. 《大地构造与成矿学》2015,(2):344-354
The Ningzhen metallogenic district is an important part of the Middle-Lower Yangtze River Valley metallogenic belt. LA-ICP-MS zircon U-Pb dating of the three intermediate-acid intrusions, i.e., Anjishan, Xinqiao, and Shima, in the central part of the Ningzhen district, indicates that those intrusions were emplaced in the Late Early Cretaceous, with ages of 107.0±1.1 Ma-108.0±1.6 Ma, 108.0±1.3 Ma, and 102.5±1.1 Ma, respectively. Combined with the molybdenite Re-Os isotope age (106-108 Ma) of porphyry copper deposit in this regions, the Ningzhen district exists an intensively magmatic-metallogenic-thermal event at 102.5-108.0 Ma. The age of this event is similar with the age of the third period of large scale mineralization in South China, however obviously later than the magmatic activity of other ore field (124-148 Ma) in the Middle-Lower Yangtze River Valley metallogenic belt. It is suggested that the tectonic-magmatic-thermal events in the Ningzhen area is formed under regional lithospheric extension environment, which is also consistent with the tectonic background of the third period of large scale mineralization in South China. The zircon U-Pb ages of the intrusions and the Re-Os ages of molybdenites from the porphyry deposits in the study area demonstrate that the Ningzhen district underwent intensive magmatism and hydrothermal mineralization during the period from 102.5 to 108.0 Ma, which is consistent with the third pulse of large scale mineralization in the South China. ©, 2015, Science Press. All right reserved. 相似文献
84.
High parallelization efficiency in barotropic-mode computation of ocean models based on multi-grid boundary ghost area 总被引:1,自引:0,他引:1
In general, barotropic-mode computation requires the largest communication time in ocean models because of its iterative nature, when parallel computation is performed based on regional partitioning. In this study, reduction in the overhead time included in the communication in the parallel computation of the barotropic mode is considered to achieve a high parallelization efficiency of ocean models. We verify that the reduction in the communication frequency based on the multi-grid boundary ghost area reduces the total communication time. We find that this is because the sum of several kinds of overhead time for communication occupies a fairly large part of the total communication time. We discuss the trade-off between the decrease in communication time and the increase in computation time due to increased boundary area in such cases, leading to a determination of a suitable width of the multi-grid boundary that minimizes the total required time. We also discuss the efficiencies of the one- and two-dimensional partitioning of the model domain, when a multi-grid boundary is used. In general, two-dimensional partitioning is more efficient than one-dimensional for large partitioning numbers. 相似文献
85.
中国西南及邻区上地幔P波三维速度结构/ 总被引:8,自引:0,他引:8
利用ISC报告以及中国和NEIC基本测震台网报告中的80974条P波初至到时资料(地震数为7053,台站数为165,且地震和台站都分布在研究区内),对中国西南及邻区(北纬10~36、东经70~110)的深至400km的上地幔三维速度结构进行了研究,分辨率达22.初步结果表明:①研究区速度的横向不均匀性,虽随深度增加而减弱,但至400km深度时仍很明显;②在北纬16和24的纵剖面上,可以看到与印度板块向东和欧亚板块相碰撞挤压相对应的速度结构,以及印度板块与欧亚板块速度结构的差异.在东经90的纵剖面上,与印度板块向北俯冲到欧亚板块(青藏高原)之下相对应的速度结构也比较明显;③在90km深度的横剖面上,由缅甸的密支那至越南的洞海的低速条带,可能与红河断裂带有关;④ 提出并使用了能够更为准确直观地描述分辨率好坏的图示方法. 相似文献
86.
TheQvaluevariationsinthepreparingpro┐cesofrockruptureBINWANG1)(王彬),ZHAO-YONGXU1)(许昭永),JIN-MINGZHAO1)(赵晋明)YI-LIHU2)(胡毅力)1)Sei... 相似文献
87.
本文侧重于全国性资源环境及有关自然条件等专题制图工作的现实基础和成就,作简要总结和回顾。针对提高和重新认识制图效益和重点进行讨论,提出科学效益是基础,社会效益是目的,经济效益是根本,为资源环境的合理开发利用提供依据,并提出今后发展设想。 相似文献
88.
S. Gentes 《Bulletin of Earthquake Engineering》2006,4(2):193-205
The main problem in the rescue of people buried alive in damaged buildings are pieces of rubble with a diameter less than 150 mm. Since they cover the whole site, it is neither possible to scrutinize the structure of the rubble nor to estimate the dimensions of beams, columns, and parts of ceilings. The central idea of a project at the University of Karlsruhe, Institute for Technology and Management in Construction, is the automatic removal of small pieces of rubble by a suction unit. The computer-controlled pipe which is fastened to the boom of an excavator automatically follows the structure of the heap of rubble. Therefore, it can also work in areas which are out of the driver’s visible range. The suction plant replaces the dangerous manual removal which is current standard. Furthermore, a pneumatic extraction system has been designed and constructed in combination with demolition machinery, e.g. crushers and dry wire-saw technologies, to immediately suck off the crushed material (reinforced concrete, masonry). 相似文献
89.
A Least-squares Window Curves Method for Interpretation of Magnetic Anomalies Caused by Dipping Dikes 总被引:1,自引:0,他引:1
E. M. Abdelrahman E. R. Abo-Ezz K. S. Soliman T. M. El-Araby K. S. Essa 《Pure and Applied Geophysics》2007,164(5):1027-1044
We have developed a least-squares method to determine simultaneously the depth and the width of a buried thick dipping dike
from residualized magnetic data using filters of successive window lengths. The method involves using a relationship between
the depth and the half-width of the source and a combination of windowed observations. The relationship represents a family
of curves (window curves). For a fixed window length, the depth is determined for each half-width value by solving one nonlinear
equation of the form f (z) = 0 using the least-squares method. The computed depths are plotted against the width values representing a continuous curve.
The solution for the depth and the width of the buried dike is read at the common intersection of the window curves. The method
involves using a dike model convolved with the same moving average filter as applied to the observed data. As a result, this
method can be applied to residuals as well as to measured magnetic data. Procedures are also formulated to estimate the amplitude
coefficient and the index parameter. The method is applied to theoretical data with and without random errors. The validity
of the method is tested on airborne magnetic data from Canada and on a vertical component magnetic anomaly from Turkey. In
all cases examined, the model parameters obtained are in good agreement with the actual ones and with those given in the published
literature. 相似文献
90.
荣代潞 《地震地磁观测与研究》2014,(3):1-7
利用哥伦比亚大学 GCMT 目录给出的祁连山中东段地区中强地震震源机制资料,研究较大区域(34°-41°N,100°-106°E)的应力场;利用该地区布设的中法微震数字监测台网多年监测资料和甘肃数字监测台网资料,使用 P 波和 S 波初动及振幅比联合反演方法,反演中小地震震源机制解和发震应力场。结果表明,地区构造应力大致为北东40°-45°水平向压应力;景泰地区主压应力方向约北东45°,绝大多数地震为走滑型。天祝-古浪地区有相当部分的逆断层地震分布,主压应力方向约60°,P 轴仰角在10°左右优势分布,大致为水平应力场。这与大区域构造应力场和断层实际分布基本一致。 相似文献