植物特征与某滑坡坝形成时间和稳定性关系

植物生长受其生长环境的影响，一定的生长情况，反映了其生活环境。在环境、生物、地质等学科，通过对植物种属、生长形态等分析，可以表明其生活环境的某些特征。在地质上，马刀树的存在是滑坡存在一个典型证据，生存时间较长的树，是其生活地区的活化石，对其进行分析，可以论证地质体的稳定性，在自然风景区和国家保护区，这种方法是非常具有应用价值的。本文通过对某一保护区的滑坡坝顶部生长的树木分析，确定其形成时间，这同其它调查结果是一致的。计算分析表明滑坡坝在形成后处于稳定状态，它同植物生长特征符合。表明这种分析方法是一种简易实用的方法，对其它工程也有借鉴意义。     

5·12汶川地震青川县木鱼镇滑坡坝稳定性分析

滑坡坝及其形成的堰塞湖是山区常见的一种地质灾害,在强地震发生时,滑坡坝形成的堰塞湖的数量多,规模大.汶川5·12地震发生时,就形成了多个堰塞湖,这些滑坡坝一旦发生溃坝,将会对下游灾民和抢险人员生命安全构成很大的威胁.文中对汶川大地震发生期间木鱼镇滑坡坝进行研究.通过地质分析和计算表明,这个滑坡坝在发生和强降雨和地震期间是稳定的,不会对下游构成威胁,因此,可以不对此滑坡坝采取防治措施.此研究结果已在实践中证明是正确的,其研究方法可以为类似工作提供参考.     

5·12汶川地震青川县木鱼镇滑坡坝稳定性分析

滑坡坝及其形成的堰塞湖是山区常见的一种地质灾害,在强地震发生时,滑坡坝形成的堰塞湖的数量多,规模大。汶川5·12地震发生时,就形成了多个堰塞湖,这些滑坡坝一旦发生溃坝,将会对下游灾民和抢险人员生命安全构成很大的威胁。文中对汶川大地震发生期间木鱼镇滑坡坝进行研究。通过地质分析和计算表明,这个滑坡坝在发生和强降雨和地震期间是稳定的,不会对下游构成威胁,因此,可以不对此滑坡坝采取防治措施。此研究结果已在实践中证明是正确的,其研究方法可以为类似工作提供参考。     

四川宝兴大板桥堵江滑坡作坝的可行性分析

针对四川宝兴县大板桥堵江滑坡堆积体,在现场调查分析的基础上,对其作坝存在的主要工程地质问题及作坝的可行性进行了分析研究,为开展堵江滑坡作坝提供参考。     

美国的区域政策及其对我国西部开发的启示

本文分析了美国区域政策的特点：区域政策的核心是提高受援地区的社会福利;致力于改善落后的投资环境;突出重点,实施增长中心战略;注重培育欠发达地区的自我发展能力;依靠法制化管理,保障援阻工作顺利进行。在此基础上,提出解决我国地区发展不平衡问题的一些措施。     

初始含水率对黄土滑坡堰塞坝溃决影响研究

黄土区各类地质灾害伴随着极端降雨频繁发生,然而当前针对黄土滑坡堰塞坝溃决机制的相关研究成果较少,尤其是初始含水率、密实度、来水流量等参数对堰塞坝溃决的影响仍缺乏系统研究,其灾害机理尚不清晰.在影响堰塞坝溃决的众多因素中,初始含水率对黄土滑坡堰塞坝的稳定性有着重要影响,本文基于室内模型试验,初步探究了0％ ～25％含水率...     

典型滑坡的研究方法

对一个典型滑坡的研究可以通过勘察到观测，由经验判断、GPS地表和DIP地下观测、数据统计、仿真模拟组成综合研究系统。本文讨论了一个由古、老、新滑坡构成的典型滑坡研究方法。     

永胜金沙江寨子村古滑坡和古堰塞湖的发现

在滇西北地区永胜南部金沙江的右岸,发现了总方量为2.5×108 m3的超大型古滑坡.滑坡后缘及两侧断壁为近直立的石灰岩峭壁,高5 ～30 m.滑床发育有规模不一的冲沟,覆盖有发育植被的坡积物、倒石堆和巨石.该滑坡曾造成过严重的堵江事件,在金沙江左岸仍然可以看到垄岗状残留滑坡坝,坝体方量约180×104 m3,滑坡坝和坝体后侧基岩界限清晰,两者之间岩性区别较大.滑坡堵江事件在上游形成了沿江连续分布长度约46 km的古堰塞湖沉积,沉积物主要由粉土、粉质粘土及粉细砂构成,偶夹卵石层,以水平层理为主,粉细砂层中见有小型交错层理,湖相沉积特征显著,而沉积物的树枝状平面分布进一步证实其形成于堰塞湖环境.     

张溪滑坡--台风诱发滑坡成因分析

14号台风“云娜”造成我国东部沿海地区发生多处滑坡地质灾害,张溪滑坡便是其中个案。通过对张溪滑坡成因进行分析,得出了张溪滑坡是在一定厚度覆盖层、特定地形条件、植被条件下,台风风力加载作用及暴雨的淘蚀、软化、增重等一系列过程共同作用下滑动失稳的滑坡。它与暴雨型滑坡的形成机理有显著不同,这一分析成果对类似滑坡的研究和防治具有一定的意义。     

TERRESTRIAL VERTEBRATES AND VEGETATION STRUCTURE IN THE WESTERN UNITED STATES

Terrestrial vertebrates in the western United States are functionally linked to environmental settings, as revealed by principal components analyses. Species number in five major vertebrate feeding guilds increases as vegetation structure becomes more complex and environmental conditions become more varied, and as evolutionary history has promoted species richness. Two other major vertebrate feeding guilds increase with temperature and evolutionary factors. Results support the view of animals as adapted parts of deterministic environmental systems, although complete explanations of species distributions require consideration of evolutionary history and stochastic processes.     

REGIONAL DEMOGRAPHIC STRUCTURE OF THE UNITED STATES

This paper analyzes the surprisingly great variation in demographic character across the states, utilizing data on fertility, mortality, age, sex, mobility, household character, abortion, race and ethnicity. A fairly simple regional pattern is revealed that is less related to levels of economic development than to long-standing historical cultural differences.     

WHY WAS HUMBOLDT FORGOTTEN IN THE UNITED STATES?*

ABSTRACT. In the nineteenth century Alexander von Humboldt was acclaimed as “the second Columbus” and “the scientific discoverer of America.” His prestige and fame were such that on 14 September 1869, the hundredth anniversary of his birth, a grand celebration was held with parades, speeches, concerts, and the unveiling of memorials in cities across the country. Humboldt's popularity in the United States endured for the remainder of the nineteenth century, but he dropped from public consciousness in the twentieth century. To account for the eclipse of Humboldt's fame in the United States three hypotheses are discussed: a shift in the character of scientific endeavor; the quality of Humboldt's written work; and the rise of anti‐German sentiment with a concurrent rush to “de‐Germanize” the United States in the early twentieth century.     

INCIDENTS OF TERRORISM IN THE UNITED STATES, 1997–2005

ABSTRACT. The geography of terrorism remains underexplored. By focusing on the spatial patterns of terrorist attacks, the settings and land uses in which attacks occur, and the methods used to perpetrate violence, this analysis helps build a theory of terrorism geography. Between 1 January 1997 and 11 September 2005, 178 terrorist incidents occurred in the United States. Analysis of these incidents suggests three insights. At the national scale, terrorism in the United States clustered in large urban areas, with regional differentiation of terrorist motives and targets. At the scale of individual attack sites, terrorist motivations pinpointed offices, clinics, and public spaces; right‐wing violence, military, government, and infrastructural targets; and religious terrorism, commercial and special land uses. At the scale of individual interactions, terrorists crossed paths with victims in various ways. For example, the 2001 anthrax‐attack letters and lone‐wolf terrorism created alternative intersections of perpetrators with victims.     

RELIGIOUS AFFILIATION AND ALCOHOL CONSUMPTION IN THE UNITED STATES*

ABSTRACT. Levels of alcohol consumption are a major public health issue. This study aims to gain a better understanding of how geographical patterns of religious affiliation in the United States relate to geographical patterns of alcohol consumption. We explored state‐level correlations between alcohol consumption and religious adherence. Although we found no statistically significant correlation between overall religious adherence rates and current or binge drinking rates, states with higher adherence rates were significantly more likely to have high proportions of binge drinking among current drinkers. Yet, regionally, we found a strong inverse correlation in the Southeast and a strong positive correlation in the Midwest and Northeast between adherence rates and current and binge drinking rates. These geographical differences were largely explained after stratifying by major religious denominational groupings. States with high Catholic adherence rates tended to have higher drinking rates, whereas states with high Evangelical Protestant adherence rates tended to have lower drinking rates. These findings suggest that the relationship between religion and alcohol may be denomination‐specific and challenge the lay perception that religious adherence per se is associated with less alcohol consumption and less excessive drinking among those who drink.     

AN INTEGRATED APPROACH TO AIR MASS CLASSIFICATION IN THE NORTH CENTRAL UNITED STATES

Both subjective and objective schemes for air mass classification offer advantages to climatological studies. An integrated approach is developed and applied to 850 mb level data in the north central United States. Each air mass type was initially delimited by a subjective analysis. Final limits were then determined with an objective technique that separates temperature curves into normal components based on interpretation from the subjective method. Continental air was most frequent in all seasons except summer. The methodology also allows estimation of classification error.     

WESTERN RANGE BOUNDARIES OF FLOODPLAIN TREES IN THE SOUTHEASTERN UNITED STATES

Forest vegetation in the southeastern United States extends westward beyond the Ozark and Ouachita plateaus in Arkansas and Missouri into the Central Plains. Along this transect, luxuriant forests give way to mixed forests and grasslands that include smaller trees and progressively fewer tree species and eventually to grassland‐dominated landscapes in central Kansas, Oklahoma, and Texas. This transition is directly related to decreasing precipitation with distance to the west of the Mississippi River valley. Many species, however, have abrupt western range boundaries related to physiography and hydrogeomorphic processes. The western range limits for many trees correspond to Coastal Plain boundaries that at a regional scale impose sharper range boundaries than would be expected on the basis of decreasing precipitation. Also, riparian habitats within stream valleys extending westward from the Coastal Plain provide suitable habitats for trees in the dry regions of the Great Plains. The presence of riparian trees in this region is determined largely by the presence or absence of groundwater conditions necessary for survival. For floodplain trees, then, it is primarily habitat—not climate—that determines the location of range boundaries.     

美加两国北极主题博士论文的调研与分析

利用国外博、硕士论文数据库PQDT,对美国和加拿大地区研究北极主题的博士学位论文进行收集,并将收集到的学位论文按照各年文献量、授予学位机构、学科和关键词等方面进行文献计量分析。通过分析得到结论：美加北极主题的博士学位论文稳步增长;美加环北极机构是北极研究的主要机构;地质学、大气学、生态学、海洋学是美加北极研究的优势学科;海洋、岛屿、气候成为美加北极研究的焦点。     

泛珠三角区域合作背景下的广东东西两翼经济发展思路探究

“泛珠三角”区域政府间合作为广东东西两翼加速经济发展带来了机遇,通过分析两翼在泛珠三角区域中的地位、经济发展面临的挑战与机遇;提出了泛珠三角背景下两翼实现经济跨越式发展的思路.     

AVOIDING THE DEMISE OF GEOGRAPHY IN THE UNITED STATES

This is the second of two articles about challenges that confront geography departments in a changing academic environment. College enrollment trends and tightening budgets are placing geography programs in jeopardy because the discipline is not considered by society to be indispensable. Departmental survival in a period of retrenchment may depend upon successfully demonstrating utility and quality, identifying unfilled niches in individual institutions, developing new interdisciplinary organizational arrangements, or finding ways to strengthen geography's position in governmental definitions of useful academic training.