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1.
斜坡类型描述岩层产状与斜坡的角度关系,很大程度上决定了斜坡岩土体变形的方式和强度,对地质灾害分布具有重要作用。斜坡的顺向坡、反向坡与地形的阳坡、阴坡概念相似,可以利用改进的太阳辐射地形因子计算模型(TOBIA指数)对斜坡类型进行定量化表达。计算TOBIA指数需要斜坡坡度、坡向、岩层倾角、倾向4个参数。以三峡库区顺向坡基岩滑坡多发地段青干河流域为例,通过区域地质图上产状点获取离散岩层倾角和倾向数值,经空间插值得到空间连续分布的倾角和倾向参数;通过数字高程模型获取坡度和坡向参数,得到区内TOBIA指数分布。在此基础上进一步研究指数和滑坡发育关系。结果表明,TOBIA指数值与区内斜坡类型密切相关,根据TOBIA指数值能很好地区分斜坡类型。以二分类变量逻辑回归模型对坡度和指数两个变量进行分析,发现引入TOBIA指数后,回归模型对已知滑坡拟合度由55%提高到71.5%,能有效提高区域滑坡灾害危险性区划结果精度。 相似文献
2.
滑坡危险度评价的地形判别法 总被引：10，自引：1，他引：10
选取影响滑坡发育的坡度、坡形、坡向、坡体的相对高度和地形与地层产状的组合关系5个主要地形因素，结合三峡库区重点滑坡段(云阳-巫山)205个滑坡统计资料，利用地形判别法，对典型滑坡危险度进行评价。将各地形判别因子在区域滑坡发育上的贡献率作为评价典型滑坡危险度的评价值，利用层次分析法，建立典型滑坡危险度判别矩阵。将判别矩阵的归一化特征向量作为判别因子的权重，得到典型滑坡的危险度。通过建立典型滑坡危险度评价表，对滑坡进行有效的管理。此研究方法有效地避免了对评价因子赋值的主观性，并提出了对不同危险度等级的滑坡管理措施。 相似文献
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基于正交设计的滑坡运动参数模型试验 总被引：1，自引：0，他引：1
《山地学报》2016,(1)
运动距离和速度是滑坡致灾区域和致灾强度的主要评价指标。颗粒级配、体积、斜坡坡度、下垫面摩擦系数、含水率等是影响这些参数的主要因素,按照正交试验原理设计模型试验研究这些因素对滑坡运动参数的影响特征。在试验基础上,采用极差和方差分析等手段,以滑坡的最大运动距离、最大运动速度为评价指标,对影响滑坡运动参数的5种因素进行了分析。结果表明:影响滑坡最大运动距离的诸因素中,斜坡坡度是最主要的因素,以下依次为下垫面摩擦系数、滑坡体积、颗粒级配、含水率,其中,斜坡坡度、下垫面摩擦系数和体积是影响最大运动距离的决定性因素;在滑坡最大运动速度的影响因素中,斜坡坡度也是最主要影响因素,以下依次为下垫面摩擦系数、含水率、颗粒级配和体积,其中,仅斜坡坡度是影响滑坡最大运动速度的决定性因素,其他因素的影响不显著。由此表明滑坡的运动距离是滑坡体规模与运动场地条件耦合作用的结果,而最大运动速度受控于斜坡坡度。 相似文献
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基于SINMAP模型的区域滑坡危险性定量评估及模型验证 总被引：1，自引：0，他引：1
武利 《地理与地理信息科学》2012,28(2):35-39,113
利用稳定态水文学理论与无限斜坡稳定性模型,构建分布式斜坡稳定性定量评估模型SINMAP,以坡体滑塌十分发育的陕西省略阳县为试验区,利用Grid DEM提取坡度、流向、地形湿度指数和有效汇水面积等流域地形水文数据,将GIS专题图、遥感数据等作为模型输入数据,获得地表斜坡稳定性分级专题图,实现滑坡危险性定量评估;将模型模拟结果与目前国内最具有权威性的中国县(市)地质灾害调查结果进行对比分析,发现两者在稳定性分级标准划分、滑坡点定性评价、滑坡危险性分区等方面都具有很好的相似性和可比性,说明模型的模拟结果能够客观反映研究区地表滑坡危险性,对可能出现的滑坡具有一定的预测精度。因此,该模型的研究有望为定量分析区域滑坡与环境因子的关系、区域滑坡预测等工作奠定基础。 相似文献
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本文通过对广东省丰顺县海拔高度、斜坡高度、地形坡度与滑坡和崩塌两种自然灾害的统计数据分析,以及地质构造、地层岩性及岩土体类型、降雨和人类工程活动与地质灾害关系的研究,初步分析了形成地质灾害的多方因素,为后续该地区的防灾减灾工作提供一定的理论和实践基础。 相似文献
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GIS支持下三峡库区秭归县滑坡灾害空间预测 总被引：3，自引：1，他引：2
基于GIS空间分析和统计模型相结合进行区域评价与空间预测是滑坡灾害研究的重要方向之一。以三峡库区秭归县为研究区,选择坡度、坡向、边坡结构、工程岩组、排水系统、土地利用和公路开挖作为评价因子。为提高模型的预测精度、可信度和推广能力,利用窗口采样规则降低训练样本之间的空间相关性。建立Logistic回归模型,对滑坡灾害与评价因子进行定量相关性分析。计算研究区滑坡灾害易发性指数,对其进行聚类分析,绘制滑坡易发性分区图,其中高、中易发区占整个研究区面积的38.9%,主要分布在人类工程活动频繁和靠近排水系统的区域。经过验证,该模型的预测精度达到77.57%。 相似文献
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《山地学报》2021,(2)
堰塞湖的泄流会对下游河谷边坡造成严重的冲刷,对下游居民的生产生活及基础设施的安全造成威胁。为了研究堰塞湖泄流对下游河谷边坡的影响,选取了具有足够代表性的金沙江白格滑坡下游一定范围(50 km)的河谷边坡为代表区域,将遥感信息提取技术、GIS技术与空间分析等方法相结合,定量地研究了堰塞湖泄流对河谷边坡的影响;并综合考虑了河流形态发育中的重要影响因素,从地形、地貌和地质三个方面分析了不同影响因素对冲刷效果的影响。结果表明:(1)冲刷面积在河流弯曲度较大的地方普遍较大;(2)坡度与冲刷面积呈幂律分布,且在坡度35°～40°范围内冲刷作用最强;(3)地质岩性对冲刷面积的影响作用显著,受风化作用影响,花岗岩分布的区域相较于大理岩冲刷面积普遍较大;(4)在当前研究的尺度和精度下,地貌要素与冲刷面积具有一定的相关关系。本研究成果可对该区域滑坡灾害的预防以及大型工程选址建设提供参考。 相似文献
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《山地学报》2016,(6)
现场调查的数据分析表明:同等规模体积的中、小型滑坡碎屑流的运动参数存在较大的差异,这些参数的差异源于滑坡体积、岩土体特性和地形条件耦合作用的结果,理论分析和数值计算常常不能完全解释其机理。因此,在模型试验的基础上,运用极差、方差分析等方法,探讨了滑坡碎屑流的体积、颗粒级配和斜坡坡度对坡脚下的水平运动距离、等效摩擦系数的影响。研究表明:滑坡碎屑流体积在同等规模等级和相同的落差条件下,3种因素对坡脚下水平运动距离的影响大小依次为颗粒级配、斜坡坡度和体积。颗粒级配对碎屑流坡脚下的水平运动距离的影响非常显著,而同等规模内变化的体积的影响不显著。因素对等效摩擦系数的影响大小顺序为斜坡坡度、颗粒级配和体积。坡度对碎屑流等效摩擦系数的影响非常显著,而同等规模内变化的体积的影响不显著。 相似文献
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采用本底因子贡献率法的三峡库区滑坡危险度区划 总被引：9，自引：0，他引：9
在不考虑触发因素的情况下对滑坡本底因子定量化处理,分析与滑坡发育的关系,进行滑坡本底因子危险度区划。采集参加区划的本底因子包括地层岩性(U_1)、坡度(U_2)、坡形(U_3)、高差(U_4)、坡向(U_5)共五种。通过危险度区划,研究区约4650 km~2中,极高危险度区57．44 km~2,高危险度区2 305．15 km~2,中危险度区1241．6 km~2,低危险度区1045．31 km~2。采用的方法：①数据库反演统计；②贡献率与权重分析；③危险度模糊判别。 相似文献
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2011-06-06贵州省望谟县北部普降百年一遇暴雨,引发大规模群发性泥石流灾害,给当地居民生活及交通造成严重损害。其中以打蒿沟泥石流灾害尤为突出,该流域内支沟发育,沟床比降相对较缓,但陡峻的岸坡和较大的汇水面积为泥石流的发生提供了良好的水动力条件。打蒿沟地处碎屑岩发育地区,松散堆积体较厚,并受岸坡坡度影响浅层滑坡发育,现场调查共19处。另外流域内人为破坏严重,村民沿沟垒筑大量梯田也为泥石流活动提供了特殊的人工物源。通过对其4条支沟的研究发现,泥石流形成特征并不一致,其中坡度较缓的2#支沟浅层滑坡发育,为浅层滑坡型泥石流;而坡度较陡的其他3条支沟浅层滑坡发育较少,以沟床物源为主,为沟床启动型泥石流。通过对沟道两侧斜坡坡度的调查统计和分级得出流域内25°～40°的岸坡最易形成浅层滑坡,且当山坡呈上缓下陡时,更利于滑坡的形成。打蒿沟在强降雨条件下依然可暴发泥石流,规模会有所减小,但在类似2011-06-06这类稀遇暴雨作用下仍可造成较大危害。 相似文献
11.
《The Journal of geography》2012,111(5):205-213
Students in U.S. geography programs face particular challenges that may discourage them from taking advanced GIScience courses and considering geospatial careers. This article provides a preliminary discussion of the development, delivery, and evaluation of a University of Colorado Colorado Springs sophomore-level, required geography course designed to address this concern. The course, Digital Earth (DE), introduces students to the principles, concepts, and applications of major geographic information technologies (GITs) early in their academic careers. The success of DE is evaluated by examining the extent to which the course excited students about GIScience and motivated them to take higher level elective geospatial courses. Results suggest that DE generates considerable student interest in GIScience, prepares students reasonably well for elective courses, and greatly inspires them to seek a geospatial career. 相似文献
12.
沙漠化已是世界性的严重生态环境问题。沙漠化土地的整治是一门复杂的生态环境工程学科。中国沙漠化治理的成就和经验受到国际社会的重视, 中国科学院兰州沙漠研究所受国际组织委托为发展中国家举办了七期国际沙漠化治理讲习班, 取得了很好效果。当前发展中国家更需要对抗沙漠化的人才, 因此为对抗世界沙漠化培养人才的继续教育工程是当前一项迫切的任务, 期望得到国际社会的重视和支持。 相似文献
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Brazil seeks to rapidly increase its agricultural production to meet future demands, especially for sugarcane, which is an agricultural commodity and a biofuel source. In this paper, we explore how to achieve this increase without compromising existing forestlands. We propose that it is possible to substantially expand sugarcane production in Brazil while avoiding further environmental losses and the indirect land use changes often associated with them, such as deforestation. This task could be accomplished by converting existing pasturelands with agricultural potential into cropland. A great deal of pastureland exists in Brazil. Thus, we addressed the following questions in this study: (1) where are the most suitable pasturelands for sugarcane located geographically and (2) what potential do these pasturelands have for sugarcane production regarding their physical suitability and other significant factors, such as infrastructure availability and socioeconomic factors. We conducted a land suitability analysis using a spatial location model based on multicriteria decision-making and geographic information systems (GIS) to identify the cultivated pasturelands most suitable for conversion to sugarcane production in Brazil. “What if” scenarios were built to determine how changes in the subjectively derived weights of the priority criteria would modify the spatial distribution of the suitability classes relative to the MCDA model and demonstrate the robustness of the crop suitability assessment. The most suitable pastureland areas for conversion to sugarcane production were predominantly located in Minas Gerais, São Paulo, Paraná, Goiás, Mato Grosso do Sul, Mato Grosso and Pará. These zones have large contiguous areas of pasture with moderate and high agricultural potentials for sugarcane production. The total estimated area of cultivated pasturelands with moderate or high suitability for sugarcane production was 50 million hectares, which is much larger than the area currently used for sugarcane production in Brazil. 相似文献
16.
Takeshi Shirabe 《International journal of geographical information science》2014,28(2):314-325
This paper considers the problem of planning a path in a circumstance where its origin is given, but its destination is not specified and is to be selected from among a set of candidate destinations during a trip. A situation like this may be experienced by a group of people who have different preferred destinations, as well as by an individual who is simply indecisive about where to go. To resolve such an uncertainty, one may stay at the origin until he decides on a destination, or choose to proceed on some path that does not overly deviate from a shortest path, whichever destination is eventually chosen, and make a decision on the way. The latter action is sensible when the risk of traveling longer is outweighed by the benefit of buying more time for a better destination decision. The problem of finding such a time-buying path is formulated and a simple algorithm is developed for its solution. Some extensions and applications are also discussed. 相似文献
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《寒旱区科学》2013,(5)
正1.Aims and scope Sciences in Cold and Arid Regions(SCAR)is a bimonthly journal that publishes in English the latest research achievements in processes and the patterns of the Earth surface system in cold and arid regions.Researches in cold regions emphasize particularly on the cold-region-characterized physical,chemical and biological processes and their interactions,and on the response of cryosphere to global change and human activities as well as their effects on environment and the acclimatizable strategies;focus on the objects of glacier,snow,river,lake,sea ice,permafrost and seasonal frozen ground,and periglacial geomorphology,etc.;and think much of cold regions 相似文献
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《寒旱区科学》2014,(3):I0002-I0003
1. Aims and scope Sciences in Cold and Arid Regions （SCAR） is a bimonthly journal that publishes in English the latest research achievements in processes and the patterns of the Earth surface system in cold and arid regions. Researches in cold regions emphasize particularly on the cold-region-characterized physical, chemical and biological processes and their interactions, and on the response of cryosphere to global change and human activities as well as their effects on environment and the acclimatizable strategies; focus on the objects of glacier, snow, river, lake, sea ice, permafrost and seasonal frozen ground, and periglacial geomorphology, etc.; 相似文献
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《寒旱区科学》2014,(4):I0002-I0003
1. Aims and scope
Sciences in Cold and Arid Regions （SCAR） is a bimonthly journal that publishes in English the latest research achievements in processes and the pattems of the Earth surface system in cold and arid regions. Researches in cold regions emphasize particularly on the cold-region-characterized physical, 相似文献
Sciences in Cold and Arid Regions （SCAR） is a bimonthly journal that publishes in English the latest research achievements in processes and the pattems of the Earth surface system in cold and arid regions. Researches in cold regions emphasize particularly on the cold-region-characterized physical, 相似文献