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1.
Geological studies in the area around Badami, Bijapur District, Karnataka, were carried out with the help of Landsat imagery and aerial photographs. The study are forms a part Kaladgi Basin which is located on the northernmost fringes of the exposed Dharwar Craton. Archaen Peninsular Gneiss and intrusive Granodiorite/Granites (≈Clospet Granite) form the basement for the Middle to Late Proterozoic Kaladgi Super Group sediments which are, in turn, overlain in the north by the Upper Cretaceous to Lower Eocene Deccan flood basalt lavas. Geological mapping of the study area and inferences about the structural setup were primarily based on interpretation of the remotely sensed data. The combined interpretative study of Landsat imagery and aerial photographs was instrumental in mapping of the lithostratigraphic units exposed in the study area along with the structures associated with them.  相似文献   

2.
The paper gives the results of the investigations carried out, both in the laboratory as well as in the field, aided by aerial photointerpretation on the scale of 1:55,000. The are investigated is to the west of Gokak, town, Belgaum district, Karnataka state. The study helped in demarcating the areal limits of the major lithounits exposed within the area. However it was not possible to delineate all the numerous basic and acidic intrusive bodies, which are exposed in the area, intruding the Dharwarian metasediments. This interpretative exercise has also thrown significant light on the palaeotopography of the basement on which the Kaladgi sediments were deposited.  相似文献   

3.
North Maidan consist of seven districts of North Karnataka. It is named after its relatively low and subdued relief or landscape of monoto-nous plateau. Most of the area lies in the rain shadow of the Western Ghats. The land utilization map shows majority of the area during December and January months is under agriculture with fallow land as the second largest category Large areas of North Maidan are under grassland which look barren by the beginning of summer. A total of nine landuse categories were delineated wifh the help of Landsat data.  相似文献   

4.
Landslide hazards are a major natural disaster that affects most of the hilly regions around the world. In India, significant damages due to earthquake induced landslides have been reported in the Himalayan region and also in the Western Ghat region. Thus there is a requirement of a quantitative macro-level landslide hazard assessment within the Indian subcontinent in order to identify the regions with high hazard. In the present study, the seismic landslide hazard for the entire state of Karnataka, India was assessed using topographic slope map, derived from the Digital Elevation Model (DEM) data. The available ASTER DEM data, resampled to 50 m resolution, was used for deriving the slope map of the entire state. Considering linear source model, deterministic seismic hazard analysis was carried out to estimate peak horizontal acceleration (PHA) at bedrock, for each of the grid points having terrain angle 10° and above. The surface level PHA was estimated using nonlinear site amplification technique, considering B-type NEHRP site class. Based on the surface level PHA and slope angle, the seismic landslide hazard for each grid point was estimated in terms of the static factor of safety required to resist landslide, using Newmark’s analysis. The analysis was carried out at the district level and the landslide hazard map for all the districts in the Karnataka state was developed first. These were then merged together to obtain a quantitative seismic landslide hazard map of the entire state of Karnataka. Spatial variations in the landslide hazard for all districts as well as for the entire state Karnataka is presented in this paper. The present study shows that the Western Ghat region of the Karnataka state is found to have high landslide hazard where the static factor of safety required to resist landslide is very high.  相似文献   

5.
Abstract

Tectonic mapping and geologic evolution of a region were historically conducted on the basis of field observations. After the advent of remote sensing technology, tectonic mapping became much easier and structural mapping through imagery has gained credibility and suitability in regional mapping, tectonic evolution and modeling. In this regard, an attempt has been made to make use of the satellite technology to bring out the structural trends and the fracture/lineament pattern in Biligirirangan region of Northern Tamil Nadu through satellite remote sensing. The folded architecture in Biligirirangan region has evolved from structural trends. The subsurface structures of the region were derived through resistivity contours and resistivity images created by GIS software.

The surficial information derived from the satellite imagery and subsurface structures derived from the resistivity contours and images were integrated with field observations. This integration has given a clear tectonic picture of the Biligirirangan region and the tectonic structures were then analysed for tectonic forces, evolution and modeling.

The study determined that the Structural trends were mostly in a N‐S direction and the folds were of isoclinal type with alternating synclinal and anticlinal folds of an easterly dipping nature. These folds in conjunction with the lineaments have brought out the palaeostress pattern of the Biligirirangan region. The study further suggests that the regional compressive force trending in ENE‐WSW direction was responsible for the present configuration of folds. In addition, the study also focuses the efficacy of the satellite imagery in tectonic analysis and the resistivity contours and images for the subsurface structural analysis.  相似文献   

6.
Abstract

Photogeological techniques were used to analyze Landsat‐TM images of the Paraiba State, which resulted in the identification of the following structures: lineaments of regional extent, short en echelon lineaments, intricate ramification of the wrench system, and infrastructures among major lineaments and circular or ring structures. This lineament map was correlated to existing geological maps, to areas of known hydrothermal mineralization (Cu, Au, Mo, Ni, W and Ti), and the lineament map was verified in the field reconnaissance. Due to lack of systematic studies of the geology and natural resources of the region the mineral exploration is still in rudimentary stages. The objective of this research is to emphasize the detection and analysis of lineaments, their patterns, and geometry and their relations with the occurrence of mineral resources and its exploration in areas as yet explored. A large number of mineral‐bearing pegmatites of the region are controlled by major lineaments and associated minor lineaments. It is believed that the structures of interest in search for mineral deposits are warping part of the minor shear zones, the intersections of short and regional lineaments, and the circular features.  相似文献   

7.
The study of lineament pattern based on IRS-IA sub-scene (P24–R50) and Landsat (P143– R42) data combined with the drainage analysis and field observations, two prominent sets of lineament (NE-SW and NNW-SSE), besides less prominent E-W and N-S trending lineaments of tectonic origin have been observed in parts of Allahabad area. Pervasive and penetrative sub-vertical joint sets parallel to the macroscopic linear structures along with collapse structures possibly of neotectonic origin are also noted in the basement rock exposed to the SSW of Allahabad. The development of various meso- and macroscopic deformed structures, presence of collapse structure in the basement strata and the near orthogonal channel shift of axial rivers provide evidence of basement reactivation in parts of Allahabad area, Ganga plain in space and time.  相似文献   

8.
松辽盆地西部斜坡区烃渗漏蚀变信息遥感探测   总被引：2，自引：0，他引：2  
使用陆地卫星ETM+7图像对松辽盆地西部斜坡区进行稠油探测,图像增强方法有主成分分析、波段比值和假彩色合成等.主成分因子1,3,4,5-PC3(1,3,4,5主成分分析的第3主成分),1,3,5,7-PC3,2,3,5,7-PC3和3,4,5,7-PC4与波段比值3/1,4/3,7/5和(4/3)-(2/3)等用丁假彩色合成,在合成影像上圈定烃渗漏蚀变区域.结果表明烃渗漏蚀变区域与地质背景密切相关,与下伏油藏的分布大致相符.  相似文献   

9.
An anomaly detection method with a clustering based feature reduction is proposed in this paper to improve the performance of the Local RX detector. Because of high dimensionality of hyperspectral image and the low number of available samples in each local region around each testing pixel, the estimate of local covariance matrix is not possible. So, because of singularity problem, Local RX cannot use the local covariance matrix and misses the local structures of data to model the background clutter. To deal with this problem, a supervised clustering based feature reduction is introduced for extraction of background features with minimum overlap and redundant information. In the projected feature space with reduced dimensionality, the local structures of background pixels are estimated to efficiently model the background data. The experiments done on both synthetic and real hyperspectral images show the superior detection performance of the proposed method with a relatively high speed.  相似文献   

10.
本文应用我国第一代国土卫星摄影资料和地质、物探等资料, 结合美国陆地卫星图像对塔里 木盆地覆盖区进行了石油地质解译, 探讨了覆盖区影像异常形成机理, 提出了一些新的见解, 为 塔北雅克拉油气田的进一步勘探, 提供了新的思路和重要线索。并认为塔东南地区具有一定的含 油气远景。  相似文献   

11.
Land cover (LC) changes play a major role in global as well as at regional scale patterns of the climate and biogeochemistry of the Earth system. LC information presents critical insights in understanding of Earth surface phenomena, particularly useful when obtained synoptically from remote sensing data. However, for developing countries and those with large geographical extent, regular LC mapping is prohibitive with data from commercial sensors (high cost factor) of limited spatial coverage (low temporal resolution and band swath). In this context, free MODIS data with good spectro-temporal resolution meet the purpose. LC mapping from these data has continuously evolved with advances in classification algorithms. This paper presents a comparative study of two robust data mining techniques, the multilayer perceptron (MLP) and decision tree (DT) on different products of MODIS data corresponding to Kolar district, Karnataka, India. The MODIS classified images when compared at three different spatial scales (at district level, taluk level and pixel level) shows that MLP based classification on minimum noise fraction components on MODIS 36 bands provide the most accurate LC mapping with 86% accuracy, while DT on MODIS 36 bands principal components leads to less accurate classification (69%).  相似文献   

12.
Talakadu is a well known historic place situated on bank of the river Cauvery in Mysore district of Karnataka. The place is close to concave side of a prominent meander where large amount of sand has accumulated. It is believed that after construction of a reservoir upstream, sand was exposed to wind action burying the structures of Ganga dynasty and other later kingdoms. A number of buried sites have been identified by archaeological excavations conducted so far. Presently the area forms sand dunes with thick plantation cover. Analysis of RADAR data (fine beam RADARSAT and ENVISAT ASAR) led to identifying a hitherto unknown buried channel through the Old Talakadu town adjoining the excavated archaeological sites. The study suggests that RADAR penetration through the plantation canopy seems to have occurred as observed by comparing with corresponding optical data of LISS-IV. Below the canopy, sand and shrubs on top of the channel (topographically low area) are acting as smooth surface providing dark tone on radar imagery. During field validation GPS was extensively used to navigate through the forest canopy and locate the buried channel, excavated archaeological sites as well as other anomalous patterns. Synergistic application of optical (RESOURCESAT-1 LISS-IV and CARTOSAT-1 & 2) and radar (fine beam RADARSAT and ENVISAT ASAR) data led to identifying remote sensing based guides for archaeological exploration. Integration of known archaeological sites with the identified anomalous patterns was done in GIS environment. This study adds on to the knowledge base of the site and compliments already known information and suggested new areas for further archaeological exploration.  相似文献   

13.
Urban system is shaped by the interactions between different regions and regions planned by the government, then reshaped by human activities and residents’ needs. Understanding the changes of regional structure and dynamics of city function based on the residents’ movement demand are important to evaluate and adjust the planning and management of urban services and internal structures. This paper constructed a probabilistic factor model on the basis of probabilistic latent semantic analysis and tensor decomposition, for purpose of understanding the higher order interactive population mobility and its impact on urban structure changes. First, a four-dimensional tensor of time (T)?×?week (W)?×?origin (O)?×?destination (D) was constructed to identify the day-to-day activities in three time modes and weekly regularity of weekday/weekend pattern. Then we reclassified the urban regions based on the space clustering formed by the space factor matrix and core tensor. Finally, we further analysed the space–time interaction on different time scales to deduce the actual function and connection strength of each region. Our research shows that the application of individual-based spatial–temporal data in human mobility and space–time interaction study can help to analyse urban spatial structure and understand the actual regional function from a new perspective.  相似文献   

14.
An area of 2300 sq km s has been mapped around Bundi based on aerial photo-interpretation, with selected field checks at key areas. The oldest rocks exposed are Aravallis comprising a thick pile of argillaceous sediments with thin interbeds of quartzite. The Aravalli rocks have been subjected to two phases of folding and have undergone a low grade of metamorphism. The Vindhyan rocks which comprise arenaceons, argillaceous and calcareous sediments constitute the Kaimur, Rewa and Bhander groups. These rocks occur south of the Aravallis with a faulted contact (Great Boundary Fault) for the major part, and also with unconformable contact at places. The upliftment of the Aravallis on the northern side of the Great Boundary Fault might have created the Vindhyan Basin south of it. The movement appears to have been gradual, keeping pace with the Vindhyan sedimentation, and was possibly revived even after the Vindhyan sedimentation as evidenced by the presence of folding and faulting in Vindhyans in the vicinity of the boundary fault. Strike faulting parallel to the boundary fault is very conspicious resulting in the repetition of the Vindhyan strata in the area east of Bundi. The Vindhyans of Bundi area indicate deposition of sediments in shallow water coastal barrier and lagoonal set-up as evidenced by sedimentary features such as tabular current bedding, ripple marks, huge blankets of sandstone, alternation of shale and limestone etc. Geomorphologically the area may be divided into three units namely:-(a) Pediment on Aravallis, (b) Structural hills on Vindhyan, expressing generally as hogback and cuesta ridges and strike valleys, and (c) Piedmont and alluvial plains (Chambal valley). The photo characters of the different litho-units have been described.  相似文献   

15.
Visual interpretation of satellite images could help in the identification of present and past landforms. An attempt has been made to identify the palaeochannels of the Cauvery river in Karnataka state through visual interpretation of IRS-1C, LISS III False Colour Composites (FCC). In order to assess their inter-relationship with other hydrogeomorphic elements, various geomorphic units have been mapped. Major geomorphic units like alluvial plain, pediplain, valley fill. residual hill, ridges, meander scar, channel bars and water bodies have been demarcated. Considering the hydrogeomorphic setup of the palaeochannels. it is inferred that the disposition of palaeochannels of the area are controlled by the geology and structure and the prevailing geomorphic process.  相似文献   

16.
Geological studies of the area around Katta, in the southern part of the Ratnagiri District of Maharashtra, were carried out with the help of visual remote sensing techniques using LANDSAT imageries on 1:250,000 scale and aerial photographs on 1:60,000 scale. The major stratigraphic units represented in the area under study are the Archean Complex, Kaladgi Supergroup, Deccan Trap, Laterite and Alluvium. The Kaladgis unconformably overlie the Archean metasediments and also at places exhibit faulted contacts with the latter. The major part of the area is covered by a thick evergreen vegetation. The interpretation followed by field work and laboratory work revealed the following:
  1. The different lithologic units could be delineated on the aerial photographs.
  2. Different lineaments marked on the imagery were found to be due either to faults or fracture zones. Some of the older faults appear to have been rejuvenated after the formation of the laterites.
  3. Some of the lithologic horizons can be identified on the Landsat imagery by virtue of their spatial signatures.
These studies indicate that even in the area covered with thick vegetation, aerospace imagery in appropriate band and data scale can provide significant geological information.  相似文献   

17.
朱武  窦昊  殷那政  程意清  张双成  张勤 《测绘学报》2022,51(10):2083-2092
膨胀土边坡具有吸水剧烈膨胀、失水剧烈收缩及反复胀缩形变的特性,工程中与外界接触极易引发膨胀土滑坡。南水北调中线工程是一项缓解我国华北平原水资源短缺、优化水资源配置的国家重大战略工程。中线总干渠约有1/3段穿越膨胀土区域,增加了南水北调工程沿线边坡失稳的可能性,亟须开展膨胀土边坡形变监测和特征分析。基于此,本文收集了112景Sentinel-1A升轨SAR数据,采用时间序列InSAR技术获取了中线某渠道沿线2017年3月12日—2021年4月8日的时间序列形变,并基于奇异谱分析(SSA)对时间序列形变进行分解提取膨胀土边坡形变特征。研究结果表明:干渠挖方膨胀土边坡由于卸荷回弹作用表现为抬升形变,最大年抬升速率约为18 mm/a;填充膨胀土边坡由于土体固结作用表现为下沉形变,最大年下沉速率约为15 mm/a;膨胀土形变量大小与填挖深度正相关,挖方越深抬升形变越大,填充越高下沉形变越大;降雨和温度是影响干渠膨胀土边坡形变的主要外部因素,其造成的形变会时滞2~3个月。本文研究将为南水北调工程膨胀土边坡稳定性评估提供科学依据。  相似文献   

18.
ABSTRACT

Increasing attention has been paid to the deterioration of air quality in China during the past decade. This study presents the spatiotemporal variations of aerosol concentration across China during 2000–2016 using aerosol optical depth (AOD) from the atmospheric product of Moderate Resolution Imaging Spectroradiometer. Percentile thresholds are applied to define AOD days with different loadings. Temporally, aerosol concentration has increased since 2000 and reached the highest level in 2011; then it has declined from 2011 to 2016. Seasonally, aerosol concentration is the highest in summer and the lowest in winter. Spatially, North China and Sichuan Basin are featured by high aerosol concentration with increasing trends in North China and decreasing trends in Sichuan Basin. North, Southeast and Southwest China have been through increasing days with low AOD loading; however, Northeast China has experienced increasing days with high AOD loading. It is likely that air quality influenced by aerosols has notably improved over North China in spring and summer, over Southwest and Southeast China in autumn, but has degraded over Northeast China in autumn.  相似文献   

19.
The present study demonstrates the use of gridded bathymetry in the form of a Digital Elevation Model (DEM) in a geographic information system (GIS) in geomorphic characterization of the seafloor in the Western Indian offshore around Bombay High region and presents the salient findings. The variography of bathymetry and its derivatives and their spatial correlation provides a technique to measure the presence of seafloor features and provides an insight into the processes involved. The current study utilizes tools available within a GIS for processing of a DEM and its derivatives involving spatial techniques like spatial correlation and variography studies for geomorphic characterization. A broad regional analysis for the study area comprising the near shore coast to the deep waters is discussed, followed up by a detailed study limiting to the coastal region around Bombay High.  相似文献   

20.
Landsat images have been used in conjunction with topographical and geological information to prepare soil map of Mudhol taluk in Bijapur district, Karnataka state. The map has been compared with the reconnaisance map prepared by conventional method using 1:63,360 scale Survey of India toposheets. The study reveals that more accurate soil maps in terms of boundary delineation and composition of soil mapping units could be prepared by interpretation of Landsat images with adequate ground data. The method can thus be used in revising and improving many of the existing reconnaissance soil maps prepared by conventional method.  相似文献   

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