喀斯特地貌景观特点及旅游形象塑造   总被引：6，自引：0，他引：6  

赖良杰  彭东 《中国岩溶》2003,22(4):318-323

在分析了喀斯特地貌旅游资源具有的景观特色、竞争特点和环境特点之后,提出喀斯特旅游地形象的塑造应以喀斯特地貌景观的特点为基础,通过对喀斯特旅游地的文脉辨析、形象调查和竞争性分析确定其形象定位,继而围绕其形象定位进行喀斯特旅游地的形象口号设计、视觉形象塑造、行为形象塑造和形象传播策略的选择,并提出在形象塑造过程中要正确处理好与自然景观的协调和喀斯特景观的可持续开发两个问题。   相似文献   

一次台风暴雨的多普勒速度图像分析   总被引：3，自引：0，他引：3  

帅方红  钟卓约  苏卫东  施碧霞 《热带气象学报》1997,13(4):357-364

利用国产第一部７１４ＳＤ多普勒天气雷达加密观测资料对发生在厦门及附近县，市的一次台风暴雨过程的多普勒速度图像进行分析，结果表明：这次暴雨过程由两场暴雨组成，低层切变线侵入高能区触发第一场暴雨，此时对流层存在三支气流，而第二场暴雨则主要由切变线上生成的边界层气旋和低空西南急流的脉动造成。虽然造成两场暴雨的中尺度系统以及流场特征有很大差异，但两场暴雨的发生有其内在联系。  相似文献   

Image analysis and circular statistics for shape-fabric analysis: applications to lithified ignimbrites     

Bruno Capaccioni  Laura Valentini  Marco B. L. Rocchi  Giovanni Nappi  Damiano Sarocchi 《Bulletin of Volcanology》1997,58(7):501-514

 Computer-assisted image analysis can be successfully used to derive quantitative textural data on pyroclastic rock samples. This method provides a large number of different measurements such as grain size, particle shape and 2D orientation of particle main axes (directional- or shape-fabric) automatically and in a relatively short time. Orientation data reduction requires specific statistical tests, mainly devoted to defining the kind of particle distribution pattern, the possible occurrence of preferred particle orientation, the confidence interval of the mean direction and the degree of randomness with respect to pre-assigned theoretical frequency distributions. Data obtained from image analysis of seven lithified ignimbrite samples from the Vulsini Volcanic District (Central Italy) are used to test different statistics and to provide insight about directional fabrics. First, the possible occurrence of a significant deviation from a theoretical circular uniform distribution was evaluated by using the Rayleigh and Tukey χ ² tests. Then, the Kuiper test was performed to evaluate whether or not the observation fits with a unimodal, Von Mises-like theoretical frequency distribution. Finally, the confidence interval of mean direction was calculated. With the exception of one sample (FPD10), which showed a well-developed bimodality, all the analysed samples display significant anisotropic and unimodal distributions. The minimum number of measurements necessary to obtain reasonable variabilities of the calculated statistics and mean directions was evaluated by repeating random collections of the measured particles at increments of 100 particles for each sample. Although the observed variabilities depend largely on the pattern of distribution and an absolute minimum number cannot be stated, approximately 1500–2000 measurements are required in order to get meaningful mean directions for the analysed samples. Received: 9 April 1996 / Accepted: 26 December 1996  相似文献   

奎赛公路段岩土体工程地质类型及不良地质现象解译标志   总被引：6，自引：1，他引：6  

陆关祥  周鼎武  腾志宏 《国土资源遥感》2001,12(3):21-24

通过彩色红外航空像片解译与野外实地调查,总结了奎赛公路段的各种岩土体工程地质类型及不良地质现象的解译标志。为我国西部气候干旱和环境恶劣地区的岩土体解译及不良地质现象信息提取提供了参考资料.  相似文献   

中等植被覆盖区金矿蚀变TM及JERS－1OPS遥感信息增强技术   总被引：3，自引：1，他引：3  

张满郎 《国土资源遥感》1996,7(4):51-56

本文分析了与金矿化相伴的蚀变矿物(铁氧化物、粘土矿物、碳酸盐矿物)的反射光谱吸收特征及金矿区上覆植被反射光谱对金矿化蚀变信息的干扰,同时介绍了利用植被指数法、比值-主成份变换法和植被掩模法对陆地卫星TM、JERS-1OPS等遥感图像进行处理,压抑植被反射光谱干扰信息和增强金矿化蚀变反射光谱信息的方法和效果。  相似文献   

Landslide susceptibility mapping of the slopes in the residual soils of the Mengen region (Turkey) by deterministic stability analyses and image processing techniques   总被引：23，自引：0，他引：23  

C. Gkceoglu  H. Aksoy 《Engineering Geology》1996,44(1-4):147-161

The aim of the present study is to prepare a landslide susceptibility map of a region of about 120 km², between Gökcesu and Pazarköy (around Mengen, NW Turkey) at approximately 10 km north of the North Anatolian Fault Zone, where frequent landslides occur. For this purpose, mechanisms of the landslides were studied by two-dimensional stability analyses together with field observations, and the parameters controlling the development of such slides were identified. Field observations indicated that the failures generally developed within the unconsolidated and/or semiconsolidated soil units in forms of rotational, successive shallow landslides within the weathered zone in Mengen, Cukurca and Sazlar formations. Although consisting of residual soils, Capak and Gökdag formations do not exhibit landslides as the natural slopes formed on these, do not exceed the critical slope angles. Statistical evaluations and distribution of the landslides on the topographical map showed that such parameters as cohesion, angle of internal friction, slope, relative height, orientation of slopes, proximity to drainage pattern, vegetation cover and proximity to major faults were the common features on the landslides. Digital images were obtained to represent all these parameters on gray scale on the SPOT image and on the digital elevation model (DEM) of the area using image processing techniques. Soil mechanics tests were carried out on 36 representative samples collected from different units, and parameters were determined for two-dimensional stability analyses basing on “sensitivity approach” and for the preparation of digital shear strength map. In order to determine the critical slope angle values for the residual soils, a series of sensitivity analyses were realized by using two-dimensional deterministic slope stability analyses techniques for varying values of cohesion, angle of internal friction and slope height along with varying saturation conditions. According to the results of the sensitivity analyses, the Mengen formation was found to be most susceptible unit to landslides, covering about 33.5% of the region studied in terms of surface area. The distribution of the critical slopes were determined by superimposing the critical slope values from sensitivity analyses on slope map of the study area. On the other hand, iso-cohesion and iso-friction maps were produced by locating the values of cohesion and internal friction angles in a geographic coordinate system such that they coincide with sample locations on the DEM and by further interpolation of the values concerned. The pixel values were evaluated in gray scale from 0 to 255, 0 representing the lowest pixel value and 255 representing the highest. Sensitivity analyses on cohesion and angle of internal friction to investigate the effects of these parameters only on stability, revealed that cohesion was effective at a rate of 70% by itself, while angle of internal friction alone controlled the stability by a rate of 30%. The iso-cohesion and iso-friction maps previously obtained were digitally combined in these rates and a “shear strength map” was prepared. The geographic setting of the study area is such that northern slopes usually receive dense precipitation. In relation to this fact, about 42% of the landslides are due north. Thus, a slope orientation map was prepared using the DEM, and slopes facing north were evaluated as being more susceptible to sliding. Proximity to the drainage pattern was another important factor in the evaluation, as streams could adversely affect the stability by either eroding the toe or saturating the slope, or both. When considered together, in conjunction with the field observations, faults and landslides showed a close association. In the area, about 88% of the landslides were detected within an area closer than 250 m to major faults, therefore, a main discontinuity map was produced using the SPOT image of the region, and “proximity to major faults” was evaluated as a parameter as most of the landslides developed in areas where the vegetation was rather sparse. A vegetation cover map was therefore obtained from the SPOT image, and the areas with denser vegetation were considered to be less susceptible to sliding with respect to the areas with less or no vegetation. Having prepared the maps accounting for the distribution of critical slopes, shear strength properties, relative height, slope angle, orientation of the slopes, vegetation cover, proximity to the drainage pattern, geographic corrections were carried on each of these, and a potential failure map was obtained for the residual soils by superimposing all these maps. Next, a classification was performed on the final map and five relative zones of susceptibility were defined. When compared with this map, all of the landslides identified in the field were found to be located in the most susceptible zone. The performance of the method used in processing the images appears to be quite high, the zones determined on the map being the zones of relative susceptibility.  相似文献   

多因素严重干扰区成矿围岩蚀变信息的计算机图像处理──以加拿大西北某地找金实践为例     

朱凯 《铀矿地质》1996,(5)

本文从分析ＴＭ各波段图像信息特征入手，在冰雪和植被等环境因素干扰严重的地区，试验应用了图像掩膜、波段比值、主成分分析等技术，成功地从ＴＭ图像中提取了与金成矿有关的蚀变围岩信息。在此基础上，进一步研究了蚀变与断裂构造和围岩类型的关系，确定了金矿找矿远景区。  相似文献   

图形图像处理方法图示航空物探数据的有效性研究   总被引：1，自引：0，他引：1  

熊盛青 《铀矿地质》1996,12(5):295-300

本文在介绍航空物探微机图形图像处理系统的基础上，通过不同地区实测航空物探资料的处理，对用图形图像处理技术处理和图示航空物探数据的有效性进行了探讨。总结出适用于地质填图、突出局部弱异常及与矿化有关的弱信息等不同地质任务的有效方法组合。分析了各种航空物探图示方法的特点，并就如何发挥图形图像处理技术在航空物探资料的解释处理中的作用提出了建议。认为图形图像处理技术是一种图示航空物探数据的有效方法，可以作为等值线图的补充和改进形式推广应用。  相似文献   

GIS辅助下的基于知识的遥感影像分类方法研究——以土地覆盖/土地利用类型为例   总被引：23，自引：1，他引：23  

术洪磊  毛赞猷 《测绘学报》1997,(4)

提高计算机遥感影像的分类精度，是遥感应用中研究的主要问题之一。作者以规则的形式表示遥感影像解译知识，使用ＴＭ影像数据和ＤＥＭ、坡度、土地利用图等地理辅助数据，从遥感影像处理／地理数据／专家知识一体化的角度出发，使用基于知识的方法进行了研究，改善了分类精度。实例研究证明了方法的正确性。  相似文献   

Non-linear filtering of compression blocking effects in reconstructed images     

V. Kazarian-Le Brun  A. Llebaria  T. Nguyen-Trong 《Experimental Astronomy》1997,7(1):35-50

The increasing use of data compression by space mission experiments poses the question of quality of the images obtained after the compression-decompression process. Indeed, working on an Image Compression Module (ICM), Using Discrete Cosine Transform (DCT), with 8*8 pixel-sized sub-images (each pixel being coded on eight bits), one can find blocking effects on their boundaries. Avril and Nguyen (1992, thereafter ANG 1992), have shown that One Neighbour Accounting Filters, used after image reconstruction without modifying the coding method , provide the best and fastest correction as far as linear filtering is concerned. We present here a non-linear method, also used after image reconstruction, but working on spatial frequencies. It allows us to segregate, in the Fourier space, the signal from the defect, and then to remove it through applying a filter adapted to the frequency spectrum of each spoiled image. Employing the reverse Fourier transform, we then retrieve the corrected image. The efficiency of this new method was tested by three different means:- when Fourier filtering is applied to a reference set of aerial photographs of the Earth, blocking effects are quite indistinguishable by human vision, even when zooming on the images, which was not the case with ONAF;- the improvement of the Root Mean Square (RMS) Error, calculated between the filtered and original images, is at least three times greater than the one obtained with ONAF;- the reconstruction of a three-dimensional view of a landscape, thanks to two stereoscopic images having undergone a compression-decompression process with an algorithm using DCT and a compression rate of about 10, is possible only after Fourier filtering has been applied.The quite good preliminary results of the application of Fourier filtering to the Clementine images of the Moon are also represented.  相似文献