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1.
Synoptivity and the exemplified fracture systems exhibited by the space borne imagery data has helped in solving many of the geological enigma in various parts of the world. The study conducted, using such remotly sensed data, in Jhalawar anticline, part of Proterozoic Cratonic Vindhyan Basin, Rajasthan, India, led to infer the history of tectonic evolution of peribasinal deformation which has been a matter of controversy for a century and more. In Landsat MSS data the Jhalawar region displays a panorama of lineaments and their analysis through azimuthal frequency diagrams, isofracture, lineament incidence and lineament intersection incidence density maps shows that the mean orientation of the lineaments fall in NW-SE and NE-SW and the shape of the various lineament density contours also show NE-SW and NW-SE orientations. In aerial photographs the area exhibits four sets of lineaments in NE-SW, NW-SE, N-S and E-W directions. Amongst these the former two sets are expressed as wide open master fracture systems with prolific vegetation fills along them and the latter two sets are characteristically observed as thin vegetation linears with frequent strike slip faulting along them. The further analysis of these fracture/lineament systems derived from multi-level remote sensing data shows that the Jhalawar anticline, which followed the pattern of flexural slip fold mechanism, was evolved by horizontally disposed σ1 (greatest principal stress) and 3σ (least principal stress) with the former oriented in NE-SW and the latter aligned in NW-SE directions with vertically disposed 2σ. The inference of such palaeostress environment of the Jhalawar region lead in the identification of a buried rigid basement high southwest of Jhalawar anticline, beneath the Deccan pile and loci of ground water, silica sand and probable igneous plug.  相似文献   

2.
Lineaments of Panchpatmali plateau and the adjoining areas in Koraput District, Orissa, lying on the East Coast of India, were analysed to elucidate their influence on the occurrence of’ laterite/bauxite duricrust of the area. A detailed lineament map and a map of the explored and expected deposits of laterite and bauxite of the areas have been prepared from satellite imagery after ‘Band Ratioing’ and ‘Maximum Likelihood Classification’ and ground truth study. Development of laterite/bauxite plateaus follows the regional lineament trend of NE - SW, probably due to the tectonic activities in the area. It has been observed that there are atleast two major planation surfaces - the older one shows complete development of laterite/bauxite duricrust, whereas the younger planation surfaces are devoid of any.  相似文献   

3.
Fortran 77 programs have been developed for summarisation of lineament pattern and fracture traces on MS-DOS based micro-computer system. Two menu driven programmes CLAFY and HIST perform the above task. CLAFY reads the X, Y co-ordinates of lineament and points from an input file and produces an output file containing azimuth frequency, total length and average length for 18 predefined azimuth classes at 10 degree interval. HIST reads the output generated by CLAFY and offers an option to generate histograms of azimuth frequency/total length/average length on a dot matric printer. CLAFY and HIST were tested using digitised lineament co-ordinates derived from lineament maps of parts of Central Kerala region, southwestern, India which were prepared based on Landsat imagery interpretation. The programmes afford repetitive manipulation of large quantities of lineament data without ignoring short and /or faint lineaments which have geologic significance.  相似文献   

4.
Groundwater being a valuable resource in today’s world needs proper evaluation and management for overall development within the region for its judicious use. The Baghmundi Block of Purulia district, West Bengal is within the hard rock terrain of Ayodhya hills and Matha Protected forest. The groundwater in this region is confined within the fracture zones and weathered residuum. Hydrogeomorphologically, the entire area is classified into following categories such as - i) Very shallow weathered pediment, ii) Moderately weathered pediment, iii) Valley fills, iv) Erosional gullies, v) Lateritic Upland and vi) Accumulation gullies. The hydrogeomorphic map of the area prepared by Department of Science and Technology, Govt. of West Bengal has been digitized for the present study. The lineament map has been prepared from the satellite imagery. The lineament map has also been digitized for the present study. From this the lineament density contour map has been prepared. An integrated remote sensing and Geographic Information System (GIS) based methodology has been used for the delineating Groundwater potential zones in the study area. Here the Geomorphology and Lineament density maps are overlaid following the Weighted Index Overlay Method, which delineates groundwater potential zones.  相似文献   

5.
本文介绍了遥感、物化探、地质等信息复合图像增强处理的基本技术方法.对多源地学信息复合处理图像新发现的色异常、线性和环形构造的分布、影像特征做了较详细的叙述;并探讨了该区的环形和线性构造对多金属矿的控矿作用,认为香花岭地区是环形和线形构造的复合控矿,在此基础上建立了香花岭矿田遥感影像模式:在环形构造内,发育北西向和北东向线性构造组合,交叉成“井”字型格式,控制金属矿的分布.根据已知矿床特征和相应影像特征的关系,提出细密线性影像和环、线交切影像两种找矿标志,指出上述标志在湘南花岗岩发育地区具有普遍找矿意义.文章最后根据多种信息综合分析,圈定了两个找矿有望地段,取得了良好的找矿效果.  相似文献   

6.
Remotely-sensed satellite data of Landsat 5 (TM) and IRS-1A (LISS II) covering parts of central portion of Chotanagapur plateau have been analysed visually to delineate some prominent lineaments in Ranchi district and its adjoining area. One of the most prominent lineament “Ranchi mega lineament? has been analysed in this paper. This lineament is a potential site for base metal mineralisation at some places, and it acts as good groundwater conduit in the region. No earlier attempt to map this entire structural unit as a separate entity is known. Geophysical bouguer gravity anomaly map, lithological and structural maps have some remarkable correlation with this lineament. In the present paper authors have tried to analyse the lineament with respect to its tectonic, mineralisation and groundwater prospects. Resistivity survey carried in close proximity of this lineament at selected sites, indicate that rocks are well fractured at depth. Available lithological and structural map support this lineament as a shear near Purulia (W.B.) and also having base-metal mineralisation potential in this area. Authors opine that existing gravity anomaly map may be further augmented in the light of present study.  相似文献   

7.
This article presents a GIS‐based methodology to integrate a measure of geographic attractiveness of localities in the process of allocating potential dwellings in the context of a large urban region. The methodology was developed for a study area in Brisbane‐South East Queensland (SEQ), known as the Sunbelt Region, a rapidly growing region and a popular tourist destination in Australia. In this article, we have used a multivariate technique to develop a set of parameterised linear equations to define underlying dimensions that drive residential location decision choices. Aesthetic and accessibility factors were identified in the factor analysis from data collected via a survey of Quality of Life. Spatial measures were based on a combination of network distance and kernel density estimation to calculate ‘aesthetic’ and ‘accessibility’ scenarios, which were then overlaid and multiplied by their subjective weights to create an ‘overall attractiveness scenario’. These development scenarios were integrated as a set of criteria to control the allocation of potential dwelling capacity over the next 25 years at a grid cell level.  相似文献   

8.
A set of techniques was developed for automatically detecting tectonic lineaments from multi-source remotely-sensed data at various scales. The techniques include adaptive shading of grid data to enhance linear features, a segment-tracing algorithm to extract line segments from the shaded grid data, grouping of the segments by concatenating short segments, and connecting them by proximity and co-linearity criteria to form a lineament that represents significant tectonic structure. B-spline smoothing was adopted for lineament representation. Finally, a technique for assessing the orientations and styles of faulting (normal, reverse, and strike-slip types) was developed for use in characterizing the extrapolated fracture planes. The applicability of the developed techniques was examined using 30 arc-second topography/bathymetry grids, 1-min gravity anomaly grids, and 2-min total field magnetic intensity grids covering Egypt and its surroundings. Lineaments derived from data types so diverse in composition and from various depths corresponded well with the referenced tectonic features over much of the region. Prominent trends and faulting styles of lineaments provided important clues as to the timing of their development as well as strong support for a structural inheritance model. Results demonstrated the effectiveness of the developed techniques combined with integration of remotely-sensed data in detecting regional fracture systems accurately and in characterizing geodynamics over a long timeframe.  相似文献   

9.
The eastern border of India with Burma represents a fairly young tectonic zone. The main rock types of the area belong to the Disang Group of Eocene to Upper Cretaceous age. The Ophiolites have concordant relationship with these rocks. The 200 km long belt of NNE -SSW trending Ophiolite suite of rocks in Manipur and Nagaland is of great academic importance as it has been postulated as probable plate boundary along which ophiolites have been emplaced. It holds immense economic importance too, being the carrier of elements of strategic mineral importance, such as nickel, chromium, platinum etc. Photo-interpretation has been successfully used in delineating the extensions of and location of the important NNE-SSW. lineament along which ophiolite has been emplaced. It has been possible to demarcate .the ophiolite bodies on the basis of their distinct photo-characters from that of sedimentaries. An attempt has also been made to decipher its structural and tectonic relationship with country rocks.  相似文献   

10.
The geological studies of the eastern parts of Harda-Barwah basin covering about 3000 sq. km area on 1∶50,000 scale have been carried out using satellite imagery of IRS (FCC), supplemented by Landsat TM/MSS scences and air photos. The present studies with the aid of satellite imagery and remote sensing techniques have brought out the regional stratigraphy and structure of the area and helped in deciphering the interrelationship of various rock groups in the Narmada lineament zone. The area comprises Archaean/Proterozoic gneisses, the Mahakoshal volcano sedimentary suite, the Harda granitoids, the Bijawar Group and the rocks of Vindhyan Supergroup, Deccan Trap and Quaternary sediments. The Archaean/Proterozoic rocks comprising gneisses and schist form basement. The Mahakoshal Group of rocks occur along the ENE-WSW to E-W trending Narmada lineament zone and comprise foliated quartzite, actinolite-chlorite-sericite phyllite and metabasics. The Harda granitoids showing intrusive relationship with earlier rocks, comprise coarse-grained crudely foliated grey to pink granites, fine to medium grained homogeneous granites and porphyritic granites. The Bijawar Group comprises quarzite, chert breccia and dolomite in the order of younging and shows unconformable relationship with the Mahakoshal and the Harda granitoids. The Bijawar rocks show doubly plunging major synformal structure and numerous sympathetic minor folds along ENE-WSW to E-W axis and cross folds along NW-SW axis. The Bijawar rocks are unconformably overlain by a sequence of sandstone and shales belonging to the Rewa Group of the Vindhyan Supergroup. The Deccan Trap lava flows represent the last igneous activity in the area. The Quaternary deposits comprising a cyclic sequence of sand, silt, clay and rock gravels of the Narmada river represent the youngest formation of the area.  相似文献   

11.
Kimberlite clan of rocks (KCR) comprising of mantle derived ultrabasic rocks such as Kimberlite and related Lamproites and Lamprophyres,are the primary source of diamond. Locating the KCR is first step in the diamond exploration, which is highly challenging in the field due to (i) very small spatial extent of KCR pipes (ii) high susceptibility of KCR to weathering and alteration on exposure to atmosphere, owing to their ultrabasic composition. Predictive statistical models using the geospatial data are often used to minimize the search and the present work attempts to apply the Frequency Ratio (FR) based predictive model in GIS to prepare KCR potential zone maps based on the relationship between the already explored KCR locations and the factors that favour their emplacement. Wajrakarur Kimberlite Field (WKF) in the Dharawar Craton of India, with more than 30 explored kimberlite pipes is selected as the study area. Geospatial technology has been used to generate thematic maps such as known KCR pipe locations, lineament density, lineament buffer zone, lineament intersection buffer zone, drainage anomaly buffer zone, geomorphology, and classified image showing distribution of mineral such as clay, iron oxide and calcrete, which are surface expression of KCR emplacement from various sources. Landsat 8 OLI satellite data, ASTER DEM were used in preparing the geomorphology, lineament map, and band ratio based mineral classified map. The thematic maps were converted to raster grid of 10 sq. m. FR values for each unit in each thematic map were obtained by correlating the spatial relationship between thematic map and the 25 locations of the 33 “known” KCR locations in WKF used for FR modelling. Cumulative FR value were obtained by carrying out overlay analysis of the thematic maps, which are classified into five classes by Natural Breaking method as (i)Very Low Favourable (VLF), (ii) Low Favourable (LF), (iii)Moderate favourable (MF), (iv)High Favourable (HF), and (v)Very High Favourable (VHF). The model was validated by ground verification at random sites and statistical method. During the ground visit, we observed KCR-like lithology’s at four new sites that have calcrete exposure at limited spatial extent and also some pieces of ultrabasic rocks similar to the explored sites. To ascertain their chemical composition of the samples were plotted in the MgO-K2O-Al2O3 ternary diagram. All the four samples fall in the Kimberlite/Lamproite field confirming them to be KCR. The FR predictive model was also validated statistically. Total 13 locations, including 8 site out of 33 known KCR locations, one newly discovered pipe by GSI and the four locations discovered during this study were used for the validation. Statistical validation shows that 84% of model accuracy is achieved. The study reveals that Lineament Intersection, and circular drainage anomaly in 3rd order streams, lineament density are significant themes in predicting KCR emplacement zones. The study demonstrates the utility of statistical based model such as FR model in predicting the location of KCR emplacement, even with statistically insignificant distribution of KCRs and can be applied elsewhere in the world to locate the KCRs. In the process, we report discovery of four new KCR pipes in the WKF.  相似文献   

12.
In the present study efforts have been made to evaluate ground water potential zones for ground water targeting using IRS-IC LISS-II1 geo-coded data on 1:50,000 scale. The drainage, geology, geomorpholgoy and lineament information has been generated and integrated to evaluate hydro-geomorphological characteristics of the Gairnukh watershed, Bhandara district, Maharashtra for delineation of ground water potential zones. The analysis reveals that the deep valley fills with thick alluvium have excellent, shallow valley tills and deeply weathered pediplains with thin alluvium have very good and moderately weathered pediplains in the geological formations of Tirodi Gneiss and Sausar Groups have god ground water potential and these units are highly favourable for ground water exploration and development. Shallow weathered pediments in geological formations of Tirodi Gnesis and Sausar Groups are marked under moderate ground water potential zone. Shallow weathered pediplains in geological formations of Tiridi Gneiss and Sausor Groups are grouped under limited ground water potential category, except along the fractures/lineaments. Structural hills in geological formations of Tirodi Gneiss and Sausar Groups have poor ground water prospects. Inselbergs and Linear ridges in geological formations of Tirodi Gneiss are grouped under very poor ground water prospects zone. The good inter-relationship was found among the geological units, geomorphological units, lineament density, hydro-geomorphological zones and ground water yield data.  相似文献   

13.
The study area around Choral river basin in the Narmada valley region, forms a part of Indore and Khargone districts of Madhya Pradesh. The geological, geomorphologic, lineament, hydrogeomorphic and groundwater potential zone maps of the study area have been prepared using IRS IC LISS III FCC imagery on 1:50,000 scale. Various litho-units, different land-forms, lineament fabric and hydro-geomorphic units have been worked out by visual interpretation methods and frequent field checks. The integrated hydro-geomorphological map of the study area reveals that the groundwater potential in denudation landforms such as buried pediplains, plateaus, denudational and residual hills is moderate-to-poor. On the other hand, the groundwater occurrence in structural landforms like structural hills, lineaments/faults and narrow gorges is likely to be good to moderate and the depositional landforms namely alluvial plains, valley-fills and meandering-channels favour the accumulation of sub-surface water and, therefore, may be considered as good recharge zones. From the point of view of groundwater occurrence, various hydro-geomorphic units have been classified as high, moderate and low potential zones.  相似文献   

14.
The study area comprises Bundelkhand Granite of Archaean age in the east, unconformably overlain by Upper Vindhyan sequence, ranging from Upper Kaimur Sandstone to Lower Bhander Sandstone Groups, in the west. Geomorphologically, the area has been divided into three geomorphic provinces viz. (1) Bundelkhand inselberg — pediplain, (2) Vindhyan structural plateau, consisting of two major sub-levels of Upper and Lower Bhander Sandstone Groups and two minor sub-levels of Upper and Lower Rewa Sandstone Groups, separated by escarpment and/or valleys, and (3) Chambal alluvial plain. Photo-interpretation and field studies indicate that there are three sets of lineament trends in the area out of which the NNW-SSE trend comes out very strongly on imagery and is correlatable with basement fracture trend of Bundelkhand massif. The synoptic view through imagery also gives the impression that the course of Chambal river towards north and west is controlled by a major lineament, possibly a regional fault trending NE-SW. The NNW-SSE lineament trend mentioned above then probably reflects tension release aspect of the faulting. The field check has brought out some very broad, gentle warps also with NNE-SSW trend in the area. The paper presents the salient observations on geological, structural and geomorphological studies for Shivpuri area based on remote-sensing techniques and their utility for such regional investigations.  相似文献   

15.
微烃渗漏遥感探测的机理主要是建立在烃类微渗漏异常地球化学表征和形成的基础上。本文主要依据Schum acher(1996)和Saunders等(1999)提出的烃类微渗漏异常地球化学原理和模型,以鄂尔多斯盆地伊盟隆起东部为研究区,以多光谱遥感和航空放射性遥感为探测手段,分别利用氧化铁指数(TM3/TM1)、亚铁指数(TM5/TM4)和黏土化指数(TM5/TM7)来识别Fe3 氧化物、Fe2 氧化物和有机质、黏土化和碳酸盐化的相对富集区,同时用矿物组合图像来增强显示上述信息。综合亚铁指数(TM5/TM4)分割图像、矿物组合图像、航放铀、钍、钾信息及钍归一化铀指数等信息,提取了研究区微烃渗漏地段。研究表明,研究区存在两条Fe2 氧化物和有机质相对富集区带。一条为与库布齐沙漠走向近于一致的北部近东西向带,它与石油部门发现和描述的油气渗漏区域基本一致。另一条为泊海子—准召—新庙不连续的北西向带,它的北界与泊海子—准召断裂展布基本一致。在垂直中部北西向微烃渗漏带的剖面上,清晰显示亚铁指数(Fe2 )、航放测量铀(U)、钍归一化铀(Ud)为正异常;氧化铁指数(Fe3 )、航放测量总道值(Tc)和钾(K)、钍归一化(Kd)为负异常的特点。研究认为地表还原带是由油气微渗漏形成的,推测受断裂、裂隙带控制的、主要由油气微渗漏形成的还原带对东胜铀矿带形成聚集起了重要作用。  相似文献   

16.
本文以福建省高盖山隧道区线性构造为研究对象,对其进行了分形特征研究。应用GIS和RS技术对该区的SPOT遥感影像进行线性构造信息的提取,利用线性构造分布图,使用盒计维数法计算该区线性构造的分维值。结果表明,高盖山隧道区线性构造具有分形特征,根据岩体工程质量标准,研究区应属"好"的级别,对于铁路隧道的建设较为有利。分形理论为线性构造的研究提供了定量化的技术手段,并可为相关工程地质评价提供一个量化的指标。  相似文献   

17.
The aim of this study is to derive environmental factors that are likely to influence malarial distribution from Nigeriasat-1 in a geographical information systems (GIS) environment and relate it to the empirical evidence of reported malarial cases in the hospitals using discriminant analysis (DA) to characterize, identify and map malarial risk zones. It is found that using a stepwise DA, Nigeriasat-1 and GIS it is possible to classify the accurately the low malarial risk zone (100%), medium and high risk zones (83.33%), with an overall accuracy of 88.9% being achieved for the study area. The results obtained were in agreement with the ground validation exercise that was carried out and the cross validation method of ‘‘leaving-one-out’ in DA function. These findings indicate that Nigeriasat-1 and GIS combined with statistical technique of DA can be utilized as a decision support tool for a precise identification of the areas warranting mitigation efforts.  相似文献   

18.
Obtaining spatial similarity degrees among the same objects on multi-scale maps is of importance in map generalization. This paper firstly defines the concepts of ‘map scale change’ and ‘spatial similarity degree’; then it proposes a model for calculating the spatial similarity degree between a river basin network at one scale and its generalized version at another scale. After this, it validates the new model and gets 16 points in the model validation process. The x-coordinate and y-coordinate of each point are map scale change and spatial similarity degree, respectively. Last, a formula for calculating spatial similarity degree taking map scale change as the only variable is obtained by the curve fitting method. The formula along with the model can be used to automate the algorithms for simplifying river basin networks.  相似文献   

19.
GIS支持下滑坡灾害空间预测方法研究   总被引:11,自引:0,他引:11  
滑坡预测在防灾减灾工作中具有重要意义,它包括空间、时间预测两个方面。基于统计模型进行区域评价与空间预测是滑坡灾害研究的重要方向,但是预测结果往往依赖样本数量和空间分布等。本文以马来西亚金马伦高原为研究区,选择高程、坡度、坡向、地表曲率、构造、土地覆盖、地貌类型、道路和排水系统作为评价因子,探讨运用地理信息系统(GIS)和遥感(RS)获取与管理滑坡灾害信息,以及热带雨林地区湿热环境下滑坡空间预测的方法。支持向量机(SVM)和逻辑(Logistic)回归模型分别应用于滑坡空间预测,结果显示平均预测精度分别为95.9%和86.2%,SVM法具有较高的描述精度,值得推荐;同时,基于SVM模型的滑坡空间预测受样本影响较小,预测结果相对比较稳定,这对于滑坡灾害区域评价与预测的快速实现具有实际意义。  相似文献   

20.
Automatic 3D extraction of building roofs from remotely sensed data is important for many applications including city modelling. This paper proposes a new method for automatic 3D roof extraction through an effective integration of LIDAR (Light Detection And Ranging) data and multispectral orthoimagery. Using the ground height from a DEM (Digital Elevation Model), the raw LIDAR points are separated into two groups. The first group contains the ground points that are exploited to constitute a ‘ground mask’. The second group contains the non-ground points which are segmented using an innovative image line guided segmentation technique to extract the roof planes. The image lines are extracted from the grey-scale version of the orthoimage and then classified into several classes such as ‘ground’, ‘tree’, ‘roof edge’ and ‘roof ridge’ using the ground mask and colour and texture information from the orthoimagery. During segmentation of the non-ground LIDAR points, the lines from the latter two classes are used as baselines to locate the nearby LIDAR points of the neighbouring planes. For each plane a robust seed region is thereby defined using the nearby non-ground LIDAR points of a baseline and this region is iteratively grown to extract the complete roof plane. Finally, a newly proposed rule-based procedure is applied to remove planes constructed on trees. Experimental results show that the proposed method can successfully remove vegetation and so offers high extraction rates.  相似文献   

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