Age models for the Cape Blanc Debris Flow and the Mauritania Slide Complex in the Atlantic Ocean off NW Africa

Age models for the emplacement time of mass flow deposits from the Cape Blanc Debris Flow, the Mauritania Slide Complex and a levee of the Mauritania Canyon were obtained by offshore X-ray fluorescence (XRF) element stratigraphy on five gravity cores, allowing the assessment of slope instability in this part of the NW African continental margin with respect to climate-related sea-level variations during the Quaternary. The Cape Blanc Debris Flow emplaced approximately 155 kyr ago whereas deposition of the Mauritania Slide Complex is linked to the rapid sea-level rise at the Pleistocene/Holocene boundary. Turbidites on a levee of the Mauritania Canyon close to the Mauritania Slide Complex occurred at stage boundaries. These findings agree with other studies which show that the NW African continental margin has been unstable over the last Quaternary cycles, and that downslope sediment transport is frequently coupled to periods of climatic changes at stage boundaries.     

白龙江中上游泥石流形成条件与成灾模式探讨

白龙江中上游泥石流发育极为严重,危害、威胁巨大,研究该区泥石流的成灾模式和致灾模式对泥石流灾害防治、国土空间规划、生态文明建设具有重要的科学意义和实践指导价值。文中在分析白龙江流域中上游241条泥石流形成条件的基础上,对泥石流的成灾模式、致灾模式及泥石流防治进行了分析。研究结果表明：（1）泥石流受地形地貌影响显著,高差大于1 000 m占总数74.3%,主沟沟床纵比降>200‰占总数93.4%;(2)众多滑坡体物源沿着坪定-化马断裂带呈条带状分布,泥石流物源主要来源于千枚岩、变质砂岩、残坡积层、黄土等软弱地层的崩塌、滑坡体,物源分布与下伏基岩坡向关系不大;（3）该区泥石流按地貌特征分主要有沟谷型泥石流（占总数69.7%）、坡面型泥石流（占总数30.3%）,基于固体物质补给方式划分泥石流成灾模式主要有重力侵蚀补给型（占总数71%）、坡面侵蚀冲蚀补给型（占总数10%）、沟床侵蚀补给型（占总数19%）;(4)泥石流主要的致灾模式为溃决-冲毁、冲积-淤埋、爬高-堆积、侵蚀-坍塌、淤埋-掩埋、堰塞-次生灾害;（5）重力侵蚀补给型泥石流重点防治沟内重大灾害体,坡面侵蚀冲蚀补给型泥石流防治以拦...     

泥石流防治措施与冲击力研究进展

泥石流是一种世界范围内各个历史时期均普遍发生的地质灾害现象,尤其频发于地震多发的山地地区,每年均给人民的生命财产造成重大损失.为了应对这种暴发突然,来势凶猛,破坏力强的泥石流灾害,一系列防治措施应运而生.系统总结泥石流的防治措施.泥石流的防治措施可分为结构化措施和非结构化措施.其中结构化措施包括拦挡坝、拦挡网、导流渠、沉淀池和植被防护措施等,其设计依据可通过泥石流冲击力模型获取.泥石流冲击力模型可分为静力模型、动力模型.非结构化措施即建立泥石流预警和预报系统体系.      

Flood disaster in Taihu Basin,China: causal chain and policy option analyses

Taihu Lake is at the densely populated region of the eastern coast of China. Taihu Basin is one of the most developed regions of China. The frequency of flood disaster in Taihu Basin has been increasing in the recent years, resulting in more drowned areas and economic loss. It is shown that flood disaster is the most serious problems in Taihu Lake and Taihu Basin. Mitigation of flood problems and return to sustainability has now been given high attention and are prioritized in the Chinese national policies. This paper describes the state of the flood disaster in the Taihu Basin, examines the root causes for flood disaster, demonstrates by examples how these analyses known as transboundary diagnostic analysis can be used to develop policy options that can help predict and reduce the flood disaster based on past and current measures and policy.     

泥石流危险性分区及其在泥石流减灾中的应用

泥石流是一种突发性山地灾害,至今尚缺乏准确有效的预报方法。减灾工程也只能对一定规模的泥石流起到防御作用。泥石流危险性分区在泥石流减灾中具有重要作用。以泥石流运动数值模拟为基础,以数值模拟获得的流速和流深等参量为分区指标的危险性分区是泥石流危险性分区研究的重点和发展方向。其中,泥石流危险性动量和动能分区充分反映了泥石流的破坏能力,可以提供更为精确的定量化的分区结果。该类分区方法在城镇等有重要危害对象的泥石流减灾中具有广泛的应用。不仅可以应用于泥石流危险区和安全区的划定、泥石流灾害预估、泥石流临灾预案制定、泥石流抢险救灾方案制定和泥石流灾情评估等,还可以应用到山区土地利用规划、山区城镇建设规划和财产保险评估等领域,并起到防灾和减灾的作用。     

舟曲特大山洪泥石流形成机制与治理方法

通过对舟曲三眼峪＂8.8＂特大山洪泥石流灾害的发育条件、形成机制分析及对灾害发展趋势、危险性的评估,探讨舟曲泥石流灾害的防治思路、防治对策以及主要的防治工程措施,并为预防和防治类似泥石流灾害提供经验。     

琼东南盆地上新世中央峡谷物源分析及其意义

中央峡谷是南海西北部重要的沉积体之一,物源问题一直是其研究的焦点问题,并且至今没有统一的认识.为了解决中央峡谷物源问题,本文利用重矿物、稀土元素以及锆石年龄等物源分析方法,通过与潜在物源区进行对比,确定了中央峡谷的主要物源,探讨了其成因意义.研究结果表明:①红河是中央峡谷的主要物源,对中央峡谷的形成起到主导作用;②红河水系在历史时期曾经发生重大改变,这种改变可能发生在3.6 Ma至今的某个时期;③中央峡谷源于红河,其形成与大河注入相关,并在琼东南盆地中央凹陷带形成大型储集体,为其成为深水油气勘探目标提供了物质基础.     

台湾东部海域台东峡谷沉积特征及其成因

台湾东部峡谷的研究程度较低,对其沉积特征及成因缺乏系统的论述.利用近年来在台湾东部海域获得的地震剖面,对台东峡谷的形态特征、沉积充填以及成因进行了详细的分析.台东峡谷主体位于花东海盆,该部分水深在4 000~5 500 m范围内,以NE方向为主,长度约为160 km,宽度为0.2~14 km.根据峡谷的平面延伸特征,可以将台东峡谷分为3个区段:上游段为NE-NEE走向段、中游段为NE-NNW走向段、下游段为NE走向段直到峡谷嘴部;下切谷剖面形态从上游段的"V"型、中游段的复合形态（"UV"并行）逐渐过渡到下游段的"U"型.台东峡谷上游段-中游段滑塌构造发育,峡谷转弯处的侧翼可见波状沉积,其下游段则以沉积充填为主.台东峡谷的成因与构造作用、地形特征和深水沉积作用关系密切.受西南高东北低的地形特征及基底隐伏断裂控制,峡谷总体呈现NE向延伸;重力流作用为峡谷的下切侵蚀和充填提供了动力与物质来源,峡谷从上游段到下游段下切侵蚀能力减弱,谷底充填增厚;峡谷中游段受海山的阻挡,发生转向;峡谷下游段因多条峡谷携带的沉积物汇入和"喇叭状"地形的影响,输送的沉积物在出加瓜脊末端后,形成了大型深水扇.      

基于GIS的北京地区泥石流危险度区划

泥石流是北京市山区的主要地质灾害类型之一,文章将北京市以3km×3km的网格进行剖分,选取地形、地层岩性、构造、灾害因子及降水5个因素作为泥石流危险度区划的指标,基于GIS对北京市泥石流危险程度进行了区划。其结果可为北京市开展泥石流预警预报、减灾防灾规划和山区经济建设布局等提供科学参考依据。     

Characterizing the spatial distribution of typical natural disaster vulnerability in China from 2010 to 2017

Natural disaster vulnerability can intuitively reflect the susceptibility of an area to environmental changes. Better understanding the spatial distribution of natural disaster vulnerability is a critical process for taking effective adaptation and management. Although significant achievements have been made in disaster vulnerability, few studies are known about natural disaster vulnerability at the national scale, especially from the typical natural disaster events in China. In this study, with normalizing selected indicators and calculating vulnerability index, we analyzed the spatial distribution of natural disasters vulnerability during 2010–2017 using the geospatial techniques. The results showed that natural disaster vulnerability has certain spatial differences, but different natural disaster can occur in the same area during the study period. Drought disaster can occur in all regions of China, especially in Inner Mongolia. Flood disaster is mainly concentrated in the middle and lower reaches of the Yangtze River and the Yellow River Basin. The wind and storm disaster is chiefly in the northern regions in China. The freezing disaster is widely distributed in China. Furthermore, the regions with low vulnerability were primarily distributed in the eastern coastal region, indicating that the rapid development of economy and technology can resist or mitigate natural disaster to a certain extent. This study offers a solution to study natural disasters and provides scientific basis for disaster prevention and mitigation actions.

     

Debris flow hazard assessment with numerical simulation

Debris flow disasters are usually accompanied by serious loss of lives and properties. However, debris flows are also part of earth’s natural phenomenon, and so what is the reasonable budget to be spent on mitigation measures becomes an important issue for the budget allocation processes. This article utilizes economic concepts to propose a reasonable estimation of the hazard damage and the cost of proposed mitigation measures. The proposed method is composed of four steps, namely, delineating the area of the disaster with different return periods, itemizing the land use within those areas, calculating the hazard loss using official values, and computing the expected probable maximum loss with a probability distribution. The comparison between the assessment of hazard and the economic gains of any proposed mitigation measures can be used as a reference for future decision-making process.     

昆明市泥石流风险性评价研究

采用比较成熟的泥石流危险性评价模型,结合ESRI（Environment System Research Institute）公司开发的新一代GIS软件——ARCGIS9．2,对昆明市泥石流进行危险度评价,得出了昆明市各县区的危险度。易损性评价是泥石流灾害风险性评价的一部分,根据国内有关易损性的理论成果,我们建立了昆明市泥石流易损性评价模型,对昆明市以各县区为单位进行了易损性评价,得出了昆明市各县区的易损度。利用联合国给出的自然灾害风险性评价模型：R—H×V,易损度和危险度相乘,得出了昆明市的风险度。使用ARCGIS9．2的自然分级和制图输出功能,对昆明市泥石流风险性进行了分区和制图,给出了昆明市泥石流风险性评价图。结合实际情况综合评判之后发现昆明市各县区呈现出泥石流灾害易损度和危险度不均衡的现象,因此,泥石流灾害发生时,外部社会救援工作就显得特别重要。     

The occurrence laws of campus stampede accidents in China and its prevention and control measures

This research appraises how residential built environment growth influences coastal exposure and how this component of societal vulnerability contributes to tropical cyclone impact and disaster potential. Historical housing unit data and future demographic projections from a high-resolution, spatial allocation model illustrate that the area within 50 km of the US Atlantic and Gulf Coastlines has the greatest housing unit density of any physiographic region in the USA, with residential development in this region outpacing non-coastal areas. Tropical cyclone exposure for six at-risk metropolitan statistical areas (MSAs) along the US Atlantic and Gulf Coasts are assessed. All six MSAs evaluated are distinct in their development character, yet all experienced significant growth from 1940 through the contemporary period; projections from the model under various socioeconomic pathways reveal that this growth is anticipated to continue during the twenty-first century. Using a worst-case scenario framework, the historical and future residential data for the six MSAs are intersected with synthetic hurricane wind swaths generated from contemporary landfalling events. The New York City MSA contains the greatest residential built environment exposure, but Miami is the most rapidly changing MSA and has the greatest potential for hurricane disaster occurrence based on the juxtaposition of climatological risk and exposure. A disaster potential metric illustrates that all six MSAs will experience significant increases in disaster probability during the twenty-first century. This analysis facilitates a detailed spatiotemporal assessment of US coastal region vulnerability, providing decision makers with information that may be used to evaluate the potential for tropical cyclone disasters, mitigate tropical cyclone hazard impacts, and build community resilience for these and other hazards in the face of environmental and societal change.     

Strontium isotopic evidence for prehistoric transport of gray‐ware ceramic materials in the eastern Grand Canyon region,USA

Through a novel application of strontium (Sr) isotopic analysis, we evaluate geological sources for prehistoric ceramics in the eastern Grand Canyon region of northern Arizona, focusing on two gray‐ware traditions in the Upper Basin of the Coconino Plateau. Building on a conceptual framework for the general potential of Sr isotopes in the analysis of geological materials, we suggest that the eastern Grand Canyon is specifically well suited archaeologically and geologically for: (1) exploring the utility of Sr isotopes for ceramic provenance research and (2) testing long‐standing hypotheses that gray‐ware ceramics were invariably made with local materials. Sr isotopic compositions indicate that the ceramic samples represent at least three different geological sources, and that different raw materials were used in the manufacture of the two gray‐ware traditions found in the Upper Basin. One of the gray‐ware traditions is not compositionally consistent with local geology, indicating that either the ceramics or the raw materials were transported at least 20 km to the Upper Basin. © 2011 Wiley Periodicals, Inc.     

南海北部珠江口外峡谷体系沉积特征、演化及其控制因素

深水海底峡谷内部的粗粒碎屑沉积物不仅可以作为良好的油气储层,也可以较为完整地记录海洋地质环境变迁的相关信息,是目前海洋地质领域研究的热点.为揭示南海北部珠江口外峡谷体系沉积演化过程及其控制因素,利用多波束测深和高分辨率二维多道地震数据,对珠江口外峡谷体系地形特征、沉积充填特征、形成发育过程和控制因素进行研究.研究发现珠江口外峡谷呈三段式发育：上段为NW-SE走向,宽度超过30 km,侵蚀强度不大,横截面为不规则形态;中段为E-W走向,宽度开始变窄（25～30 km）,横截面呈U型;下段为NW-SE走向,宽度达到最大（25～45 km）,横截面呈U型,中段和下段以沉积作用为主.珠江口外峡谷体系沉积演化主要分为3个阶段：早期阶段（23～15.5 Ma）,水道-海底扇阶段（15.5～11.6 Ma）和峡谷-海底扇/块体流阶段（11.6～0 Ma）.揭示了该峡谷珠江口外峡谷体系的发育和演化主要受构造运动、海平面变化和沉积物供给的控制作用,通过以上分析,将对南海北部海洋灾害地质、深水沉积体系研究及油气资源勘探有重要的指导意义.     

陕西省宝鸡市地质灾害发育特征

根据近7年来陕西省宝鸡市12区县地质灾害详细调查资料,总结宝鸡地区地质灾害主要类型、空间分布规律、发育特征及其危害性。研究结果显示,宝鸡市地质灾害发育类型主要包括滑坡、崩塌、泥石流及不稳定斜坡等4类,总体发育特征具有群发性、突发性、周期性和链生性。其中,滑坡和崩塌数量多、危害大,泥石流相对发育较少,不稳定斜坡多与崩塌相伴生,大多发展为崩塌灾害。每年汛期在强降雨作用下,都可能诱发表层小型滑坡和崩塌,特别是城镇居民房前屋后的小型黄土滑坡和崩塌,以及山区公路切坡导致的残坡积层滑坡崩塌频繁发生,是宝鸡市地质灾害群测群防和减灾防灾关注的重点。     

uTshani BuyaKhuluma––The Grass Speaks: the political space and capacity of the South African Homeless People’s Federation

The point of departure for this article is the contemporary tendency towards localisation of politics in the context of neo-liberal globalisation. Mediated through institutional reforms, political discourses and localised struggles, this localisation of politics produce new and transformed local political spaces. The purpose of the article is to examine the capacity of popular movements to use and transform such political spaces within the South African housing sector. This analysis is done through a combination of conceptual examination of political space and actor capacity and a concrete case study of the political strategies and capacities of The South African Homeless People’s Federation. The article argues that the Federation has utilised political relations at different scales to mobilise resources such as land and subsidies for housing for its members. It has also influenced the formulation of housing policies through its discourses and practical experiences with people-driven housing processes. In consequence the Federation’s ability to function as a civil/political movement has granted them a certain capacity to participate in the complicated process of turning de jure rights to adequate shelter into de facto rights for the urban poor as citizens of a democratic South Africa.     

黄渚镇赵河泥石流沟特征及治理工程探析

黄渚镇位于地质灾害高频发地区——陇南山地的北部。泥石流灾害是威胁黄渚镇及厂坝安全的最主要因素。2010年8月12日,黄渚镇一带遭遇百年不遇的暴雨,形成暴洪泥石流灾害,给当地群众及厂坝铅锌矿作业区造成重大灾害与损失。本文对造成损失最严重的赵河泥石流沟特征进行分析,并提出了治理工程措施,以期为今后该地区相似灾害防治提供参考。     

震后映卧路沿线泥石流发育分布特征及防治措施

震后映卧路沿线泥石流发育分布呈面积广、发生频率高等特点。调查结果公路沿线主要发育泥石流两类57条,其中沟谷型泥石流28处,坡面型泥石流29处,沟谷型泥石流以大型—特大型为主,坡面型泥石流以小型为主;针对该区泥石流的发育特征,提出了生物防治和工程治理相结合的防治措施,对映卧路的防灾减灾工程有积极的意义。     

The last 30,000 years of faunal history within the Grand Canyon, Arizona

The vertebrate fauna of the last 30,000 radiocarbon years in the Grand Canyon is reviewed. Faunas accompanied with 92 ¹⁴C dates have been analyzed from nine cave sites (four systematically excavated) and 50 packrat middens. Reasonably precise chronological and environmental data of late Pleistocene and Holocene age were obtained through dung studies in Rampart, Muav, and Stanton's Caves; from the numerous packrat middens; and from a ringtail refuse deposit in Vulture Cave. The desert tortoise, 8 species of lizards, 12 species of snakes, 68 species of birds, and 33 species of mammals are identified. Extinct animals include the avian carrion feeder, Teratornis merriami, and the mammalian herbivores, Oreamnos harringtoni, Camelops cf. hesternus, Equus sp., and Nothrotheriops shastense. There is no apparent abrupt end to the late Pleistocene as observed in the Grand Canyon fossil faunal or floral record. Animal and plant taxa of the Grand Canyon responded individually to the changes in climate of the last 30,000 yr. Both animal and plant fossil assemblages indicate that a pre-full glacial, a full glacial, and a late glacial woodland community with many less dominant desert taxa were slowly replaced by a Holocene desert community. All woodland taxa were absent from the lower elevations of the Grand Canyon by 8500 yr B.P.