Some Observations on the Use of Data from Historical Documents in Debris-Flow Studies     

Lorenzo Marchi  Pia Rosella Tecca 《Natural Hazards》2006,38(3):301-320

The knowledge of past events is important for the assessment of debris-flow hazard. Amongst the sources of information, documents from historical archives are particularly important in sites where the debris flows cause damage to urban areas and transportation routes. The paper analyses the availability of historical documents on debris flows in Northeastern Italy and discusses factors that can influence the building of time series from archive data both at regional and single basin scales. An increased number of debris flows was observed in the studied region for the last decades. This could be due both to an increased frequency of the events and to a larger availability of information: the analysis carried out indicates that the latter factor is probably the most influencing. The importance of factors, which affect the collection of data, including the conservation of documents and the presence and fragility of the elements at risk, is stressed in view of a wise use of historical data on debris flows.  相似文献   

湖南及邻区地壳旋转的可能成因、对大地构造演化的影响及其与大规模成矿作用关系初探   总被引：4，自引：0，他引：4  

舒孝敬 《铀矿地质》2005,21(5):257-267

在湖南及邻区,无论从地表的地质构造还是地球物理场上,都表现出明显的环状分布特征。这种特征可能是地壳的旋转运动所造成,它对湖南及邻区大地构造的演化、大规模成矿作用等具有重大的影响。本文对这种旋转运动的可能成因,以及所伴随的一系列地质作用、与大规模成矿作用的关系等进行了初步探讨。  相似文献   

2001年影响广西的台风卫星云图特征分析     

黎声镭  陈翠敏 《气象研究与应用》2002,23(3):17-20

应用定性和定量分析方法 ,对 2 0 0 1年 4个影响广西的台风云图特征进行分析 ,发现旋转结构明显、组织结构紧密、面积大的台风云系 ,所产生的台风强度强、持续时间长、降水范围宽、过程雨量大  相似文献   

1957-1996台风对中国降水的影响   总被引：15，自引：0，他引：15  

Ren Fumin  Byron Gleason  David Easterling 《大气科学进展》2002,19(5):943-952

台风活动中国气候的重要特点之一，它能带来大量降水并造成严重的财产损失。在一些地区，台风降水甚至可以在总降水量中占很大比例。本文目的是研究那些对中国产生影响的台风并重点关注台风对中国降水的影响。文中涉及四个方面的工作。首先，研究了影响中国台风的频率，结果表明台风影响的主要季节为5－11月，尤其以7－9月频繁；在过去40年中影响台风的频率没有明显的变化趋势。第二，对台站台风降水的气候特征分析结果显示，海南和东南沿海地区受台风的影响最大，而且长江以南大部地区每年都受到台风的影响；另外，影响区域大部分地区的台风降水在过去40年中表现出下降的趋势，但是只有东北地区南部这种趋势是显著的。第三，对台风个例的分析表明，个例降水总量和影响面积之间存在着显著的线性关系。最后，对台风造成的中国范围降水总量进行了分析，初步结果显示台风降水总量在1957－1996年间显著减少。  相似文献   

云南银(铅)-锌矿开发史料与找矿探讨   总被引：1，自引：0，他引：1  

薛步高  吴良士 《矿床地质》2002,21(3):298-303

云南是银铅锌矿开发较早的省份之一，史料丰富。本文从史料的角度，阐述了与云南古代有关银（铅）－锌矿的开发概况，基本特点以及如何保护，继承这份丰富的历史遗产，进而对目前有关史料的研究和古代采矿遗址清理情况进行分析，提出今后找矿的一些想法。  相似文献   

上海数字强震观测网     

徐永林  周生良  熊里军  火恩杰  张奕麟  王炜 《地震地磁观测与研究》2002,23(6):37-43

上海市数字强震观测网是我国第1个具有一定规模的数字强震观测网，是上海市“九五”期间建设完成的，它由3部分组成；地面观测网，结构观测网和深井强震观测系统，每一部分都有不同的功能和目的，本文详细介绍该强震网的整个概况。功能及取得的部分观测成果。  相似文献   

Investigating Landslides Caused by Earthquakes – A Historical Review     

David K. Keefer 《Surveys in Geophysics》2002,23(6):473-510

Post-earthquake field investigations of landslide occurrence have provided a basis for understanding, evaluating, and mapping the hazard and risk associated withearthquake-induced landslides. This paper traces thehistorical development of knowledge derived from these investigations. Before 1783, historical accounts of the occurrence of landslides in earthquakes are typically so incomplete and vague that conclusions based on these accounts are of limited usefulness. For example, the number of landslides triggered by a given event is almost always greatly underestimated. The first formal, scientific post-earthquake investigation that included systematic documentation of the landslides was undertaken in the Calabria region of Italy after the 1783 earthquake swarm. From then until the mid-twentieth century, the best information on earthquake-induced landslides came from a succession ofpost-earthquake investigations largely carried out by formal commissions that undertook extensive ground-based field studies. Beginning in the mid-twentieth century, when the use of aerial photography became widespread, comprehensive inventories of landslide occurrence have been made for several earthquakes in the United States, Peru, Guatemala, Italy, El Salvador, Japan, and Taiwan. Techniques have also been developed for performing ``retrospective' analyses years or decades after an earthquake that attempt to reconstruct the distribution of landslides triggered by the event. The additional use of Geographic Information System (GIS) processing and digital mapping since about 1989 has greatly facilitated the level of analysis that can applied to mapped distributions of landslides. Beginning in 1984, syntheses of worldwide and national data on earthquake-induced landslides have defined their general characteristics and relations between their occurrence and various geologic and seismic parameters. However, the number of comprehensive post-earthquake studies of landslides is still relatively small, and one of the most pressing needs in this area of research is for the complete documentation of landslides triggered by many more earthquakes in a wider variety of environments.  相似文献   

黄海及其沿岸历史地震初步研究     

吴戈  刘昌森  江在雄  翟文杰  吴镝 《四川地震》2002,(2):14-22

黄海及其边缘，经历史地震资料整理，地震参数估定与编目，截至1949年8月，共有M≥3级地震2187次，其中M≥43/4级地震259次，资料显示大致有三个相对集中活跃区，16世纪曾有过历史地震活动高潮。  相似文献   

中国城市与城市发展理论的历史   总被引：7，自引：1，他引：7  

薛凤旋 《地理学报》2002,57(6):723-730

论述中国自周期以来的城市概念和理论，指出中国城市性质和城市结构的自有特点及其与西方发展经验为基础的城市概念和理论不同，将中国漫长的演变历史分为封建时代，中华人民共和国建立至1978年和1978年以后的改革开放3个时期。3个时期所形成的城市概念和理论，都有中国特色，是中国城市及城市化向前发展的重要的理解和指导基础。  相似文献   

Statistic forecast of typhoons going over the Chinese coasts     

FENG Lihua  WU Zhanghua 《地理学报》2003,13(3):305-308

According to the measured data of typhoons going over the Chinese coasts in 1949-2002, a statistic relative equation showing the relation between the central atmospheric pressure of typhoons in a certain region at a certain period of time and their accumulation of frequency is established, and the concept of recurrence interval of typhoons is put forward, which is of actual significance for typhoon disaster reduction along the coastal area.  相似文献