Meandering valley of Karjan-Terav rivers in district broach,Gujarat

Karjan river is an important tributary of Narmada in Gujarat. Along with one of its own tributaries, called Terav it has carved a “meandering valley” across the block faulted rldge and valley Deccan Trap topography, south of Narmada. Karjan originates at Bardipada, which is much nearer to Tapti river than Narmada and in the initial stretches its channel is consequent to faults and fractures. However, before emerging on to the alluvial plain in north it has a sinuous valley. With confines of this valley the present stream channel wanders back and forth and has incised deep into various Deccan Trap flows. The geometry of such meanders shows that this is an symmetric meandering valley. The valley as such is an antecedent one in which the present stream channel is ur.derfit and ingrown. Natural fluvial processes, accelerated by dynamic rejuvenation of the area and wetter climatic phases during Pleistocene and Holocene seem to have carved this meandering valley and integrated the drainage.     

Evaluation of geology and structure of eastern Harda-Barwah basin,Madhya Pradesh using remote sensing techniques with field checks in crucial sections

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.     

On the benefits of using a high-resolution mesoscale model to improve wind field for the study of upwelling off the Indian coasts

Abstract

Upwelling favourable winds along the Indian coasts were studied using a high-resolution (9 km grid) atmospheric mesoscale model (MM5) reanalysis from 1 to 5 June 2006, off the west coast of India and from 5 to 10 December 2005, off the east coast of India. Model winds are verified with satellite winds at two areas. Model wind hind-casts from the above periods reveal narrow bands (about 10×50 km) of strong winds to the coast and adjacent to the major coastal promontories. These bands, which are sub-grid scale in operational models, were capable of generating local upwelling greater than 10 m/s. Both the mean and spatial components of the model alongshore wind increase by a factor of 3 to 4 from the south to the north along the west coast, and by a factor of 2 to 3 from the north to the south along the east coast of India. Wind field increases will drive enhanced ocean upwelling along the west coast of India, and the new hypothesis suggests that the variations in local wind may contribute to the coastal upwelling in this region.     

Geomorphic Signatures of Active Tectonic in Drainage Basins in the Southern Bolkar Mountain,Turkey

Bolkar Mountain forms the northeast extent of the Central Taurus Mountains, which are located north of the eastern Mediterranean Sea and consist of 3000 m or higher summits. The study area southern part of Bolkar Mt, has been investigated for geomorphic signatures of active tectonics using Geographical information system (GIS). The lower valley floor-to-width to height and elongation ratios, higher convexity, stream length-gradient (SL) indices, hypsometric integral and convex nature of the hypsometric curves and topographic asymmetry show that relative tectonic activity is greater in the eastern sector affected by Ecemiş fault. Spatial variations of tectonic activity along rivers studied point to a general trend of decreasing activity towards the west as well as tectonic activity again increase in the west. Westward migration of basin and range extension is consistent with the place of uplift in the southern Bolkar Mt. Topography of the southern sector is the result of Late Miocene-Early Pliocene extension related uplift. Drainage systems in the upper part of the central and western sectors are under the lithological control and karstic denudation; whereas the development of the drainage systems in the middle and outlet parts of all sectors depend on sea level changes and Late Quaternary tectonism. The development of drainage systems of the eastern sector depends mostly on fault tectonism and climatic changes in the Late Quaternary.     

Utilization of high-resolution EGM2008 gravity data for geological exploration over the Singhbhum-Orissa Craton,India

High-resolution EIGEN6C4 and EGM2008 Bouguer gravity data of 2190 degree spherical harmonic over the Singhbhum-Orissa Craton, India, have been generated from the International Centre for Global Earth Models. The Bouguer gravity anomaly difference maps of (i) in situ and EIGEN6C4, (ii) in situ and EGM2008 and iii) EIGEN6C4 and EGM2008 of the study area are compared. It reveals that EIGEN6C4 has lesser systematic error than EGM2008. However, from different profile plots of Bouguer gravity, east–west horizontal derivative and north–south horizontal derivative anomalies of the in situ, EIGEN6C4 and EGM2008, it is observed that most of the signatures of lithounits and geological structural elements are delineated very well by EGM2008 and match 94–98% with those of EIGEN6C4. Further, the Bouguer gravity, east–west horizontal derivative and north–south horizontal derivative anomalies of EGM2008 data over the study area have been used effectively for identifying various lithounits and geological structural elements.     

Remote sensing and GIS application in change detection of the Barak River channel,N.E. India

Rivers flowing through the alluvium invariably have very low gradient forcing the river to flow slowly in a meandering and zigzag path. Nature and intensity of meandering is governed by the geological and tectonic conditions of the river basin. Barak River in tectonically active south Assam (Northeast India) exhibits intense meandering and shifting of the river course. Topographic data of two different years and satellite images of 4 different years covering a section of the Barak River have been investigated to verify the nature of changes undergone by the river through times. This study reveals active northward shift of the river and a prominent neck-cut off in the initial part of the study area. Northward shift of the river also occurred in the area west of Silchar. But, in the western part the river has shifted both towards north and south. Oscillatory shifting in the river channel has also been noticed. The river has shown a overall northward shift which is probably due to uplift of the southern part of the Barak River valley.     

Perspect and assessment of groundwater resources using remote sensing techniques in and around Choral river basin,Indore and Khargone districts,M.P.

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.     

中国大陆主要块体现今变形状态的反演研究

本文利用中国大陆的GPS运动速度场,研究了其中的7个亚板块和14个构造块体的变形状态,并做了动力学解释。研究中,构造了一种运动-变形模型来提取观测数据中的变形信息。结果表明:南北构造带东西两侧应变状态表现出显著的差异,西部各亚板块或块体的主应变量值从约4.5×10-8.a-1到约1.3×10-8.a-1,东部则从约3.0×10-.8a-1到约0.4×10-.8a-1,表明东西两部应变量值有较大的落差,并且主压应变方向从西部的北北东向逐步转到东部北东东向。南北构造带表现为其不同段落的各块体的变形趋势和量级都有显著不同。川滇块体是东部与西部的结合部位,变形量较大,主压应变为3.4×10-8.a-1,反映了印度板块向北的推挤在川滇块体造成了较大变形。中国北部地区向东西两个方向运动,塔里木块体、准噶尔块体、天山块体向西,柴达木-祁连山块体、阿拉善块体向东。这种推挤力和太平洋板块阻碍、遏制作用,造成了华北块体、鄂尔多斯块体以拉张为主的应变和逆时针旋转。     

A method for groundwater prospect zonation in data poor areas using remote sensing and GIS: a case study in Kalikavu Panchayath of Malappuram district,Kerala, India

Abstract

The present study was an attempt to delineate potential groundwater zones in Kalikavu Panchayat of Malappuram district, Kerala, India. The geo-spatial database on geomorphology, landuse, geology, slope and drainage network was generated in a geographic information system (GIS) environment from satellite data, Survey of India topographic sheets and field observations. To understand the movement and occurrence of groundwater, the geology, geomorphology, structural set-up and recharging conditions have to be well understood. In the present study, the potential recharge areas are delineated in terms of geology, geomorphology, land use, slope, drainage pattern, etc. Various thematic data generated were integrated using a heuristic method in the GIS domain to generate maps showing potential groundwater zones. The composite output map scores were reclassified into different zones using a decision rule. The final output map shows different zones of groundwater prospect, viz., very good (15.57% of the area), good (43.74%), moderate (28.38%) and poor (12.31%). Geomorphic units such as valley plains, valley fills and alluvial terraces were identified as good to excellent prospect zones, while the gently sloping lateritic uplands were identified as good to moderate zones. Steeply sloping hilly terrains underlain by hard rocks were identified as poor groundwater prospect zones.     

Landsat imagery analysis and field studies in the Kullu and Chauhar valleys,Himachal Pradesh,India

The rough terrain between the Gogar Dhar (Mandi-Brot rise) and the Kullu-Larji valley is geologically unexplored. This paper brings out for the first time the geology and regional tectonic set-up of the area on the basis of LANDSAT imagery interpretation and field checks. Image analysis of about 3700 sq. km area and field observations along selected sections of the area reveal that the area mainly comprises mica-chlorite schists, quartzites and phyllites i.e. low to medium grade Chail metamorophics with acid and basic intrusions within them. Structually the rocks are arranged in the form of a NNW-SSE trending faulted synclinorium, the axis of which passes through Daggi Dhar. The western flank of the synclinorium is more strongly folded. Granitoids and basics show concordent relations with the country rocks. Two belts of granitoids are found occupying the cores of the folds on both the limbs of the synclinorium. Along the Uhl river (in the Chauhar valley) and the Kullu valley passes the Chail thrust separating the Chail metamorphics from the rocks of the outer carbonate belt and the traps of the Mandi unit, and the inner carbonate belt of the Larji window zone respectively. The area is dissected into blocks by cross cutting, deep-seated major faults of three generations. The fold and fault systems have prominent control over the geomorphology including the drainage patterns and landforms of the area. The present area is a typical case of inverted relief, anticlinal valleys and synclinal hills being the main geomorphic features developed due to structural control. The change in the course of the Beas River between Mandi and Pandoh is a typical case of structural control on the present drainage system.     

Morphotectonics of the Area Around Renukoot,District Sonbhadra,U.P. Using Remote Sensing and GIS Techniques

A part of Precambrian rocks of central India around Renukoot, district Sonbhadra, U.P., exhibits noteworthy differences in morphometric characteristics such as drainage density, mean stream length, bifurcation ratio and stream frequency across Son Narmada South Fault of the Son Narmada Lineament Zone. The Remote Sensing and GIS based present study explains the tectonic evolution of the terrain by dividing the area into two morphotectonic units namely Dudhi Morphotectonic Unit (DMU) and Mahakoshal Morphotectonic Unit (MMU) with the help of a proposed model. The study reveals that the landform features of the rocks of DMU and MMU of the study area are strongly controlled by underlying lithology and structures. The study also reveals different tectonic histories for the units until the last or the fourth phase of deformation dominated by shearing movement.     

Remote sensing for geology,geomorphology and lineament study of Vindhyan basin,north of Shivpuri,Madhya Pradesh

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.     

基于GIS/AHP集成的浙江省洪涝灾害风险评估

将GIS技术引入洪涝灾害风险评估,可以弥补传统方法评估结果空间化显示不足的缺点。本文针对浙江省洪涝灾害的发生特点,从危险性和易损性两方面选择了浙江省洪涝灾害的影响因素,包括降雨量、地形、河网密度、人口密度和耕地百分比等因子。运用GIS空间分析技术对各因子进行空间化,结合层次分析法（AHP）确定各影响因素的权重,进行浙江省洪涝灾害风险评估和制图,并基于SuperMap iObjects平台设计与开发了浙江省洪涝灾害风险评估系统。研究结果表明：浙江省发生洪涝灾害的风险普遍偏高,高风险区域位于浙北和浙东南的沿海地带,较高风险区域位于浙东、浙南和浙北地区及金衢盆地中间地区,中等风险区位于浙南的西面、浙北及浙西地区。本文分析结果可为浙江省洪涝灾害预防和管理提供决策依据。     

中国西部地壳现今变形特征及其机制探讨

以中国大陆及周边10年来近400个GPS测站的复测资料为基础，获取并绘制了现今地壳水平运动与变形图像，结果表明：青藏块体内西半部南北向只存在微弱的缩短变化（5mm/a左右），东半部南北向则没有缩短的迹象，南北缩短的区域主要位于青藏块体南缘的喜马拉雅条带（约15mm/a），北缘中部的柴达木西区（约15mm/a）和青藏块体北面的天山块体及周围地区（约15mm/a）；青藏块体大约有10mm/a的东西拉张，但不均匀，自西向东经历了由弱到强再有所减弱的过程，整个西部地区东边缘的东向运动表现为南强北弱的左旋特征；川滇菱形块体不是逃逸块体而是变形块体；青藏块体东缘及附近地区是东向运动的消减区带，面应变结果显示，青藏块体周边以面收缩为主，内部则以面膨胀为主；其以北的地区以面收缩为主（但压中有张），面应变的量级为10^-8/a。这样的变形结果，若只靠来处于印度板块的北向挤压是无法解释的。由此并结合最新的地球物理研究成果可推断或证实，地壳下部来自南向的物质涌入是控制青藏块体乃至中国大陆形变的另一大动力源，甚至可能是主导动力源；或者具有深、浅立体活动的某种协同性。     

Geology of the area around Badami,Bijapur District,Karnataka state—A study based on interpretation of remotely sensed data

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.     

THE PLACE OF MOUNT EVEREST IN HISTORY

Abstract

The Himalaya are known as the highest mountains of the earth; but they have another title to fame not generally recognized in that they have been the home of civilized man for a longer period than any other mountain range. When the monoliths of Stonehenge were being raised in England and when the Pyramids were being built in Egypt, the glaciers of the Himalaya were being explored. The geographical names which are entered upon modern maps of the Central Himalaya are very ancient memorials of civilization. The existence of a mountain nomenclature, Aryan in the west and centre, Mongolian in the east, has given rise to linguistic problems not less difficult than the topographical problems of the snows. In 1927 the volumes of the Linguistic Survey of India were published; they had been written by Sir George Grierson, an officer of the Indian Civil Service, and they dealt with 723 different languages and dialects. In the Himalaya there are now in use among the peoples seventy different languages, all of which (with one aboriginal exception) belong either to the Aryan or Mongolian family. Languages are historical monuments, and from them Sir George Grierson has been able to decipher the outlines of history.     

Groundwater potential in the hard rock terrain of western ghats: A case study from Kottayam district,Kerala using resourcesat (IRS-P6) data and GIS techniques

The present study was aimed to identify and delineate the groundwater potential areas in parts of Western Ghats, Kottayam, covering the upper catchment of Meenachil river. The study area is composed rocks of Archaean age and Charnockite dominated over others. The information on lithology, geomorphology, lineaments, slope and land use/land cover was generated using the Resourcesat (IRS P6 LISS III) data and Survey of India (Sol) toposheets of scale 1:50,000 (surveyed in 1969) and integrated them with raster based Geographical Information System (GIS) to identify the groundwater potential of the study area. Thus, a GIS-based model which takes account of local condition/variations has been developed specifically for mapping groundwater potential. On the basis of hydrogeomorphology, three categories of groundwater potential zones namely good, moderate and poor were identified, and delineated. The high potential zones correspond to the fracture valleys, valley fills, pediments and denudational slope, which coincide with the low slope and high lineaments density areas. The low zone mainly comprise structural hills and escarpments and these act as run-off zones. The derived panchayath-wise groundwater potentiality information could be used for effective identification of suitable locations for extraction of potable water for rural populations.     

Volcano-tectonic scenario of Vulsini volcanoes (Central Italy) from LANDSAT-MSS images and digital elevation data

Through the analysis of LANDSAT-MSS images and Digital Elevation Model (DEM) from the Vulsini Volcanic District (VVD), Central Italy, 62 lineaments have been detected. All data sets have been converted into thematic maps showing the correspondence of the lineaments with geological limits, geophysical anomalies trends, mineral hot water locations, eruptive fractures and volcanic centres. Lastly, some lineaments have been correlated with basement tectonics and magma composition.     

喜马拉雅主逆冲断层闭锁程度与滑动亏损特征研究

基于融合的GPS速度场结果,使用DEFNODE负位错反演程序估算了喜马拉雅主逆冲断层（the main Himalayan thrust,MHT）的闭锁程度和滑动亏损空间分布,并结合剖面结果分析了断层远、近场的运动特征。结果表明,MHT的闭锁深度基本达到18~24 km,断层面闭锁宽度达到102~136 km,两次历史大地震破裂区域之间的未破裂段落和未发生大地震的段落闭锁深度更深,闭锁断层面更宽,2015年尼泊尔Mw7.8大地震就发生在两次大地震破裂区域之间的段落;MHT总滑动亏损速率和垂直断层挤压滑动亏损速率自东向西逐渐减小,平行断层右旋滑动亏损速率则基本上自东向西逐渐增加;MHT 3条剖面拟合结果也反映出其存在很强的闭锁。根据估算的此次Mw7.8地震的复发周期230年和最近500多年发生的大地震分布,认为MHT整条段落尤其是尼泊尔西部与印度接壤处和可能还没有破裂的不丹地区依然有发生8级大地震的危险。     

Microcomputer aided lineament analysis of Son-Mahanadi Valley coal basins,Central India from Landsat data

In the overall tectonic set up of various coal basins of the Peninsular India, the Son-Mahanadi Valley coal basins of Central India have a unique disposition. The coal measures sediments of Peninsular India are developed along well defined E-W and NW-SE trending linear narrow belts. The Son-Mahanadi Valley basins represent the tract where NW-SE trending Mahanadi Valley basins seemingly merge with the major east-west trending Damodar-Koel-Son-Satpura alignment. Landsat data of Son-Mahanadi Valley basins in the four spectral bands (0.5 to 1.1 Micrometers) were used to pick up the lineaments which are possibly of geologic origin. Detailed analysis of lineaments were carried out with the help of three softwares. Diglin (to produce rose diagram) and PLLIN (to plot digitized lineaments to produce a map on any scale) by a Hewlett Packard 45 series microcomputer equipped with graphics screen, plotter, digitiser and floppy disc unit. Detailed analysis revealed a pronounced direction roughly, N 70°E which is present in the northern half of the area while N 40°W direction is present alongwith N 70°E in the southern half. These trends correspond to the NW-SE trending Mahanadi Valley and to the E-W trending Damodar-Son Satpura belt. The above clearly brings out the striking parallelism between the lineament trends in the basement and the overlying coal bearing Gondwana Sediments. This parallelism is suggestive of a genetic relationship between the two.