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1.
黄土高原区地形与植被分布规律对滑坡发生概率的影响 总被引：1，自引：0，他引：1
黄土高原区自然斜坡的地形与植被条件对滑坡的发生有一定的促进和抑制作用。通过将研究区划分为31 418个自然斜坡单元,利用ArcGIS区域统计功能提取斜坡单元的地形和植被参数,分析研究区斜坡的坡体形态和植被空间分布规律。依据区内292处滑坡调查点的资料,统计分析不同坡体形态下的滑坡发生概率。分析结果表明,研究区正向类的凸型和直线型斜坡发生滑坡的概率明显高于负向类的凹型和阶梯型边坡;随着斜坡坡度和坡高增大,发生滑坡的概率增大;阳坡发生滑坡的概率明显高于其他坡向的边坡;随着NDVI增大,滑坡发生概率显著降低。 相似文献
2.
为了在斜坡危险性区划中考虑岩体结构的控制作用,将粗糙集和模糊模型识别理论用于区域斜坡岩体结构识别,并结合信息量法对斜坡单元进行空间危险性预测。尝试在指标中考虑深部岩体结构特征和岩层变形构造（断层、岩层曲率）,将该方法应用于巴东新城区库岸斜坡危险性区划。结果表明：巴东新城区滑坡的主要影响因素有坡向和岩层倾向关系、坡角和岩层倾角关系、构造条件,可将斜坡分为3种结构类型。不同结构类型斜坡在危险性评价时各指标的影响程度或权重不同,可将巴东新城区划分为4个危险性等级,与现有滑坡比较验证了结果的合理性。 相似文献
3.
4.
Alan Yong Susan E. Hough Michael J. Abrams Christopher J. Wills 《Journal of Earth System Science》2008,117(2):797
Estimation of the degree of local seismic wave amplification (site effects) requires precise information about the local site conditions. In many regions of the world, local geologic information is either sparse or is not readily available. Because of this, seismic hazard maps for countries such as Mozambique, Pakistan and Turkey are developed without consideration of site factors and, therefore, do not provide a complete assessment of future hazards. Where local geologic information is available, details on the traditional maps often lack the precision (better than 1:10,000 scale) or the level of information required for modern seismic microzonation requirements. We use high-resolution (1:50,000) satellite imagery and newly developed image analysis methods to begin addressing this problem. Our imagery, consisting of optical data and digital elevation models (DEMs), is recorded from the ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) sensor system. We apply a semi-automated, object-oriented, multi-resolution feature segmentation method to identify and extract local terrain features. Then we classify the terrain types into mountain, piedmont and basin units using geomorphometry (topographic slope) as our parameter. Next, on the basis of the site classification schemes from the Wills and Silva (1998) study and the Wills et al (2000) and Wills and Clahan (2006) maps of California, we assign the local terrain units with V s 30 (the average seismic shear-wave velocity through the upper 30m of the subsurface) ranges for selected regions in Mozambique, Pakistan and Turkey. We find that the applicability of our site class assignments in each region is a good first-approximation for quantifying local site conditions and that additional work, such as the verification of the terrain’s compositional rigidity, is needed. 相似文献
5.
Soil erodibility is one of the most important factors used in spatial soil erosion risk assessment. Soil information derived from soil map is used to generate soil erodibility factor map. Soil maps are not available at appropriate scale. In general, soil maps at small scale are used in deriving soil erodibility map that largely generalized spatial variability and it largely ignores the spatial variability since soil map units are discrete polygons. The present study was attempted to generate soil erodibilty map using terrain indices derived from DTM and surface soil sample data. Soil variability in the hilly landscape is largely controlled by topography represented by DTM. The CartoDEM (30 m) was used to derive terrain indices such as terrain wetness index (TWI), stream power index (SPI), sediment transport index (STI) and slope parameters. A total of 95 surface soil samples were collected to compute soil erodibility factor (K) values. The K values ranged from 0.23 to 0.81 t ha?1R?1 in the watershed. Correlation analysis among K-factor and terrain parameters showed highest correlation of soil erodibilty with TWI (r 2= 0.561) followed by slope (r 2= 0.33). A multiple linear regression model was developed to derive soil erodibilty using terrain parameters. A set of 20 soil sample points were used to assess the accuracy of the model. The coefficient of determination (r 2) and RMSE were computed to be 0.76 and 0.07 t ha?1R?1 respectively. The proposed methodology is quite useful in generating soil erodibilty factor map using digital elevation model (DEM) for any hilly terrain areas. The equation/model need to be established for the particular hilly terrain under the study. The developed model was used to generate spatial soil erodibility factor (K) map of the watershed in the lower Himalayan range. 相似文献
6.
石漠化景观生态优化途径初探——以贵州清镇王家寨小流域为例 总被引：1，自引：1，他引：0
以治理石漠化、维护喀斯特景观生态安全和土地资源的可持续利用为目标,以景观生态学理论为指导,选择西南典型喀斯特石漠化地区— — 贵州清镇王家寨流域为研究区,并建立了源于最小累计阻力模型的生态恢复耗费表面模型,其步骤如下: 首先以2005年SPOT影像为基础,依托遥感和地理信息系统软件,对研究区土地类型进行分类,同时从数字高程模型中提取两种地形因子(坡度和坡向) ,并按其对生态的影响进行分级;其次对土地利用类型、坡度、坡向进行综合优先级评价;最后在IDRI SI软件中建立生态恢复耗费表面模型。随后通过景观功能分区和生态廊道(这些廊道可组成一个生态网络)的构建,探讨了本小流域土地利用空间格局优化的途径和生态恢复模式。 相似文献
7.
Estimation of spectral reflectance of snow from IRS-1D LISS-III sensor over the Himalayan terrain 总被引：1，自引：0，他引：1
The sensor onboard the satellite views the earth as a plain surface and consequently the satelliteobtained spectral radiances
cannot represent true values over a mountainous terrain. The relative magnitudes of terrain slope and its aspect with respect
to the sun's position will determine the amount of direct solar radiation incident on an undulating surface. Estimation of
spectral reflectance from satellite data forms an important component in many of the snow and glacier studies. The spectral
reflectance of snow is influenced by its various parameters. The changes in snowpack characteristics as a result of various
metamorphic processes, with age, can cause variations in its spectral reflectances. Since, the terrain geometry also modifies
the amount of reflected radiation from a rugged surface, one has to correct the estimated spectral reflectances for terrain
topography so as to use them in deriving the snowpack characteristics accurately. Also, the amounts of melt runoff originating
from glaciers having different slopes and orientations will not be the same. Considering these aspects, a model has been developed
to estimate the terrain corrected spectral reflectances over the Himalayan terrain using the Linear Imaging Self Scanner-III
data of the Indian Remote Sensing Satellite. The model computes spectral reflectances from satellitebased radiance measurements
and includes the effect of the terrain topography on the incident solar radiation. The terrain slope and its aspect are generated
from the digital elevation model of the region. The analysis carried out over the Beas Basin, Himachal Pradesh, India, indicated
a variation of 22% in the amount of incident solar radiation for an increase of 10‡ in terrain slope. Further, the terrain
with south-east aspect received maximum amount of solar radiation. The large differences observed between the uncorrected
and terrain corrected reflectances in the shortwave infrared band (B5), which is not saturated over the snow covered region,
suggest that the terrain slope and its aspect cannot be neglected in estimating the accurate spectral reflectances over the
Himalayan terrain. 相似文献
8.
Using multiple logistic regression and GIS technology to predict landslide hazard in northeast Kansas, USA 总被引：60，自引：0，他引：60
Landslides in the hilly terrain along the Kansas and Missouri rivers in northeastern Kansas have caused millions of dollars in property damage during the last decade. To address this problem, a statistical method called multiple logistic regression has been used to create a landslide-hazard map for Atchison, Kansas, and surrounding areas. Data included digitized geology, slopes, and landslides, manipulated using ArcView GIS. Logistic regression relates predictor variables to the occurrence or nonoccurrence of landslides within geographic cells and uses the relationship to produce a map showing the probability of future landslides, given local slopes and geologic units. Results indicated that slope is the most important variable for estimating landslide hazard in the study area. Geologic units consisting mostly of shale, siltstone, and sandstone were most susceptible to landslides. Soil type and aspect ratio were considered but excluded from the final analysis because these variables did not significantly add to the predictive power of the logistic regression. Soil types were highly correlated with the geologic units, and no significant relationships existed between landslides and slope aspect. 相似文献
9.
在地形、岩体结构、坡度、岩层倾角以及河流的作用下,澜沧江某水电站边坡已明显变形。鉴于边坡开挖后可能出现大变形问题,使用三维离散元数值计算软件建立相应的计算模型,对边坡开挖后的位移变形特征进行计算分析。结果表明,边坡开挖后浅表层岩体变形位移较大,可能产生剪切滑移破坏,对边坡稳定不利。 相似文献
10.
Implementation of reconstructed geomorphologic units in landslide susceptibility mapping: the Melen Gorge (NW Turkey) 总被引：6，自引：2，他引：4
In the international literature, although considerable amount of publications on the landslide susceptibility mapping exist,
geomorphology as a conditioning factor is still used in limited number of studies. Considering this factor, the purpose of
this article paper is to implement the geomorphologic parameters derived by reconstructed topography in landslide susceptibility
mapping. According to the method employed in this study, terrain is generalized by the contours passed through the convex
slopes of the valleys that were formed by fluvial erosion. Therefore, slope conditions before landsliding can be obtained.
The reconstructed morphometric and geomorphologic units are taken into account as a conditioning parameter when assessing
landslide susceptibility. Two different data, one of which is obtained from the reconstructed DEM, have been employed to produce
two landslide susceptibility maps. The binary logistic regression is used to develop landslide susceptibility maps for the
Melen Gorge in the Northwestern part of Turkey. Due to the high correct classification percentages and spatial effectiveness
of the maps, the landslide susceptibility map comprised the reconstructed morphometric parameters exhibits a better performance
than the other. Five different datasets are selected randomly to apply proper sampling strategy for training. As a consequence
of the analyses, the most proper outcomes are obtained from the dataset of the reconstructed topographical parameters and
geomorphologic units, and lithological variables that are implemented together. Correct classification percentage and root
mean square error (RMSE) values of the validation dataset are calculated as 86.28% and 0.35, respectively. Prediction capacity
of the different datasets reveal that the landslide susceptibility map obtained from the reconstructed parameters has a higher
prediction capacity than the other. Moreover, the landslide susceptibility map obtained from the reconstructed parameters
produces logical results. 相似文献
11.
In the Vipava Valley (SW Slovenia), various types of mass movements occur in a geologically and geomorphologically diverse setting. These comprise various types of landslides, creep, and Quaternary slope deposits of carbonate blocks and recent scree deposits. A general geological setting is represented as Mesozoic carbonate overthrust on Paleogene flysch (alternations of mostly sandstones and marlstones), resulting in steep slopes and mass movements. Our study is based on the automatic classification of various litho-geomorphological units including slope deposits, alluvial deposits, steep carbonate cliffs, flysch, two carbonate plateaus, and Quaternary deposits, based on supervised Maximum Likelihood Classification. Several polygons were used for training in the broader valley area, and later, the method was applied to automatically classify the complete area into the abovementioned six units. For input layers, we used data for elevation, slope, terrain ruggedness index (TRI), and curvature. Results show that generally, the method is suitable for classification of the litho-geomorphological units including slope deposits. However, comparison with a more detailed map, comprising mapped various mass movements indicated that the method correctly predicts high Trnovo plateau carbonates, steep carbonate slopes, translational carbonate blocks, and fossil rock avalanche deposits, and alluvial deposits, but is not able to clearly distinguish between flysch and more recent slope deposits of gravel and breccia due to their similar elevation, TRI, and slope values. The Slano blato mudflow and Stogovce landslide are not recognized. Therefore, this automatic classification can be carefully used to create a guidance map of general occurrences of litho-geomorphological units including slope deposits before going to the field, with the aim of delineation of slope deposits so they can be further studied in detail later in the field. However, such a map cannot be used as a direct substitute map for the geological and geomorphological map obtained in the field due to impossibility in distinguishing among the units with the same properties (elevation, slope, and TRI values). 相似文献
12.
Landslide susceptibility mapping using LiDAR and DMC data: a case study in the Three Gorges area, China 总被引：2，自引：0，他引：2
The objective of this study is to map landslide susceptibility in Zigui segment of the Yangtze Three Gorges area that is known as one of the most landslide-prone areas in China by using data from light detection and ranging (LiDAR) and digital mapping camera (DMC). The likelihood ratio (LR) and logistic regression model (LRM) were used in this study. The work is divided into three phases. The first phase consists of data processing and analysis. In this phase, LiDAR and DMC data and geological maps were processed, and the landslide-controlling factors were derived such as landslide density, digital elevation model (DEM), slope angle, aspect, lithology, land use and distance from drainage. Among these, the landslide inventories, land use and drainage were constructed with both LiDAR and DMC data; DEM, slope angle and aspect were constructed with LiDAR data; lithology was taken from the 1:250,000 scale geological maps. The second phase is the logistic regression analysis. In this phase, the LR was applied to find the correlation between the landslide locations and the landslide-controlling factors, whereas the LRM was used to predict the occurrence of landslides based on six factors. To calculate the coefficients of LRM, 13,290,553 pixels was used, 29.5 % of the total pixels. The logical regression coefficients of landslide-controlling factors were obtained by logical regression analysis with SPSS 17.0 software. The accuracy of the LRM was 88.8 % on the whole. The third phase is landslide susceptibility mapping and verification. The mapping result was verified using the landslide location data, and 64.4 % landslide pixels distributed in “extremely high” zone and “high” zone; in addition, verification was performed using a success rate curve. The verification result show clearly that landslide susceptibility zones were in close agreement with actual landslide areas in the field. It is also shown that the factors that were applied in this study are appropriate; lithology, elevation and distance from drainage are primary factors for the landslide susceptibility mapping in the area, while slope angle, aspect and land use are secondary. 相似文献
13.
GIS支持下基于CF方法的2013年芦山地震滑坡因子敏感性分析 总被引：1，自引：0，他引：1
本文依据研究区现有地形因子(高程、坡度、坡向、斜坡曲率)、地质因子(岩性、距深大活动断裂距离)和地震因子(PGA、距震中距离)等相关影响因子资料并结合地震区基本情况,以GIS技术作为操作平台,采用确定性系数法,开展较为详细的芦山地震区地震滑坡影响因子敏感性分析工作。首先,以GIS技术作为操作平台将地震滑坡的8个影响因子据研究区特征进行分级,构建不同影响因子分级的栅格图层进行地震滑坡分布相关参数统计; 其次,采用确定性系数法计算8个地震滑坡影响因子分级区间对应的CF值,分别提取出地震滑坡最为敏感分级区间以进行地震滑坡影响因子敏感性分析,从而衡量不同影响因子分级区间对地震滑坡易发性敏感程度。地震滑坡影响因子敏感性分析结果表明,除斜坡曲率因子与距震中距离因子对地震滑坡易发性不敏感外,其他6个影响因子对地震滑坡易发性均很敏感,分别是影响滑坡发生的主要地形、地质和地震因子。针对斜坡曲率因子和距震中距离因子对滑坡的易发性不是很敏感是否受内部其他影响因子限制所进行的分析与讨论结果表明,SW向很可能限制了斜坡曲率对地震滑坡易发性的敏感程度,地层岩性对距震中距离因子限制作用更为明显,除奥陶系、志留系外的地层岩性对距震中距离因子敏感性程度都有限制。文章所得成果具有一定的方法理论意义,对于防震减灾工作也具有一定参考意义。 相似文献
14.
《Engineering Geology》2007,89(1-2):129-143
The objective of this paper is to present a new rock mass classification system which can be appropriate for rock slope stability assessment. In this paper an evaluation model based on combining the Analytic Hierarchy Process (AHP) and the Fuzzy Delphi method (FDM) was presented for assessing slope rock mass quality estimates. This research treats the slope rock mass classification as a group decision problem, and applies the fuzzy logic theory as the criterion to calculate the weighting factors. In addition, several rock slopes of the Southern Cross-Island Highway in Taiwan were selected as the case study examples. After determining the slope rock mass quality estimates for each cases, the Linear Discriminant Analysis (LDA) model was used to classify those that are stable or not, and the discriminant functions which can determine failure probability of rock slopes were carried out by the LDA procedure. Afterward, the results may be compared with slope unstable hazards occurring actually, and then the relation and difference between them were discussed. Results show that the proposed method can be used to assess the stability of rock slopes according to the rock mass classification procedure and the failure probability in the early stage. 相似文献
15.
以地震滑坡作为研究对象,选取"4·20"芦山地震中芦山县为研究区,结合多源数据,在相关分析后选取10个评价因子,分别是地面高程、坡度、坡向、斜坡形态、地层、斜坡结构、断层平均距离、水系平均距离、植被指数和地震峰值加速度,在数字高程模型基础上采用集水区重叠法划分斜坡单元,再对各评价因子重采样,进而利用基于遗传算法的神经网络算法构建地震滑坡危险性评价模型,完成地震滑坡危险性区划。将基于斜坡单元的危险性区划结果和基于格网单元的区划结果进行比较,结果显示滑坡正确率分别为96.6%和92.6%,斜坡单元的正确率较高;同时通过多组数据的受试者工作特征曲线分析本评价模型的不确定性,每组曲线位置及曲线下面积大小相当。 相似文献
16.
蠡县斜坡是冀中饶阳凹陷西部的一个大型宽缓斜坡,以倾向上的小坡降和走向上的古地形差异相对较显著为特征,自北而南呈现出台地区和单斜区等不同的地貌单元。区内古近系沙河街组沙二段和沙一段下亚段发育“浅水型”三角洲和滨浅湖滩坝两种沉积相类型,构成了斜坡带的主要储集体。根据斜坡带走向上的古地貌、沉积相类型等基本因素的差异,可归纳为两种类型的砂体发育区：1）斜坡南段单斜区的三角洲相砂体发育区和2）斜坡北段台地区的滩坝相砂体发育区。通过隐蔽油藏勘探方向分析,认为这两种不同类型砂体发育区的隐蔽油藏形成条件各异。以台地区的滩坝相砂体发育区最为有利,是隐蔽油藏勘探的主要方向。在斜坡的内带、中带和外带等不同部位,隐蔽油藏成藏模式也各不相同,以斜坡中带的隐蔽油藏类型发育最为齐全,是寻找规模储量的主要靶区。 相似文献
17.
Juraj Holec Martin Bednarik Marián Šabo Jozef Minár Isik Yilmaz Marián Marschalko 《Natural Hazards》2013,69(1):1081-1107
This study presented herein compares the bivariate and multivariate landslide susceptibility mapping methods and presents the landslide susceptibility map of the territory of Western Carpathians in small scale. This study also describes pioneer work for the territory of Western Carpathians, overreaching state borders, using verified sophisticated statistical methods. In the susceptibility mapping, digital elevation model was first constructed using a GIS software, and parameter maps affecting the slope stability such as geology, seismicity, precipitation, topographical elevation, slope angle, slope aspect and land cover were considered. In the last stage of the analyses, landslide susceptibility maps were produced using bivariate and multivariate analyses, and they were then compared by means of their validations. The validation of the bivariate analysis data was performed using the results of bivariate analysis for landslide areas of Slovakia containing five classes of susceptibility in scale 1:500,000. The validation area is the area of Western Carpathians within Slovakia. Eighty-two per cent of area does not differ in more than one class. The validation of the multivariate analysis data was performed using the results from the Kysuce region in the northern part of Slovakia in scale 1:10,000. The raster calculator was used to express the difference between each pair of pixels within these two layers. Seventy-seven per cent of the pixels do not differ in more than 25 %, 94 % of the pixels do not differ in more than 50 %. The maximal possible difference is 100 % (one pixel with value 0 and other with value 1, or vice versa). Receiver operating characteristic analysis was also performed, the area under curve value for bivariate model was calculated to be 0.735, while it was 0.823 for multivariate. The results of the validation can be considered as satisfactory. 相似文献
18.
In this study, the land surface in an arid mountainous area in southwestern Iran, Jooyom, was segmented by self-organizing maps, using an unsupervised method. The classification was performed using a digital elevation model with 10-m resolution and window size of 17?×?17. Twenty-two morphometric layers were calculated using elevation derivatives with first, second, and third orders. The morphometric layers then were ranked and the optimum numbers of parameters and classes were selected with an optimum index factor and Davies–Bouldin index methods. It was found that the most effective parameters in classification of the area were differential curvature, slope insolation, rotor, aspect, cross-sectional curvature, total ring curvature, extreme curvature, vertical curvature, and unsphericity. The study area was segmented into six classes of negative contact, pitty-thalweg valley, gently eastward and westward sloping transversely concave and convex plains, sloping or slopy pass, and peaky ridges. The average parameters of each class confirmed their gravity, debris, and wash behavior of the surface slopes. The relative coverage percent of each formation in each class showed that the Asmari formation with highest coverage of classes 5 and 6 and Mole member marl limestone with the highest coverage of class 1 have the smallest maturity and highest maturity between formations, respectively. The maturities of each formation based on coverage percentages of different classes agreed with their corresponding hypsometric integral indexes. Furthermore, the distribution of classes in watersheds on mountain flanks confirmed the existence of tectonic tilting in this area. 相似文献
19.
The influence of slope aspect on the distribution of landslides was studied in the Milia and Roglio basins in Tuscany, Italy. For each basin, the new Tuscany region landslide inventory that was initiated in 2010 was used. The landslides were split into separate datasets based on their prevailing movement typology. To assess the results that were obtained from the different slope aspect values, maps of the lithology, slope angle, distances to streams, and distances to tectonic lineaments were included in the bivariate statistical analysis as comparison terms. For each basin, all of the geo-environmental factor maps were compared with the different landslide typologies with GIS software. Pearson's Chi2 (χ2) coefficient was used to test the degree of spatial association between each predictor variable and landslide type. In addition, Cramer's V test was used to quantify the strength of the degree of association. Next, a conditional analysis was applied to all of the possible combinations that occurred between the slope aspect and other landslide-predisposing factors. Overall, the slope aspect significantly affected the distribution of superficial landslide types, but apparently not that of other landslide types. 相似文献
20.
重庆市喀斯特槽谷地区农村居民点分布与地貌形态要素关系研究 总被引：1，自引：0，他引：1
选取喀斯特槽谷地区——重庆市石柱土家族自治县鱼池镇团结村农村居民点为研究对象,借助ArcGIS空间分析和地统计法,综合应用地貌-面积频度分布指数和信息熵分析了不同海拔、坡度、坡向、地形起伏度、地表粗糙度、剖面曲率和平面曲率7个地貌形态要素间农村居民点的分布特征。结果表明:①农村居民点分布的优势地形位分别为高程956.2~1000m,坡度5°~15°,坡向SW、W、NW和E,地形起伏度0~1m,地表粗糙度1.0~1.1,剖面曲率和平面曲率0°~5°的低地形位上;②在槽谷谷底,农村居民点信息熵的最大值为1.15,最小值为0.02,说明农村居民点在低地形位上分布的有序性较高。 相似文献