共查询到20条相似文献,搜索用时 250 毫秒
1.
J. K. Pati V. P. Malviya K. Prakash 《Journal of the Indian Society of Remote Sensing》2006,34(1):47-56
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
2.
Change of river channel and bank erosion of the burhi dihing river (assam), assessed using remote sensing data and gis 总被引:1,自引:0,他引:1
The Burhi Dining river flows in a meandering course for about 220 km through alluvial plains of Assam including a short rocky
and hilly tract in between. Sequential changes in the position of banklines of the river due to consistent bank erosion have
been studied from Survey of India topographic maps of 1934 and 1972, and digital satellite data of 2001 and 2004 using GIS.
Two broad kinds of changes have been observed, e.g. alteration of direction of flow due to neck cut-off and progressive gradual
change of the meander bends that accounts for translational, lateral, rotational, extensional and other types of movement
of the meander bends. Study of bankline shift due to the bank erosion has been carried out for the periods 1934–1972, 1972–2001,
2001–2004 and 1934–2004 at 13 segments spaced at 5′ longitude interval (average 15 km) as the river course trends nearly east
to west. The amounts of the bank area lost due to erosion and gained due to sediment deposition are estimated separately.
The total area eroded in both banks during 1934–1972 was more (26.796 km2) as compared to sediment deposition (19.273 km2), whereas total sediment deposition was more (34.61 km2) during 1972-2001 as compared to erosion (23.152 km2). Erosion was again more in 2001–2004 (7.568 km2) as compared to sediment deposition (2.493 km2). During the entire period (1934–2004) of study the overall erosion on the both banks was 31.169 km2 and overall sediment deposition was 30.101 km2. The highest annual rates of bank erosion as well as bank building of the river are 21055.47 m2/km in 2001–2004 and 9665.81 m2/km in 1972-2001, respectively. Similarly the highest average annual rates of erosion as well as sediment deposition in both
banks are observed during 2001–2004 and 1972–2001, respectively. The hard rocks of the hilly tract situated in between result
in development of entrenched meandering and this tract has suffered minimum bank erosion. 相似文献
3.
S. Srinivasa Vittala S. Govindaiah H. Honne Gowda 《Journal of the Indian Society of Remote Sensing》2005,33(4):483-493
The study area is one of the watersheds of North Pennar basin, covering an area of 570 km2 in Pavagada taluk of Tumkur district. The watershed has been subdivided into nine sub-watersheds namely Dalavayihalli, Maddalenahalli,
Talamaradahalli, Puluvalli tank, Nagalamadike, Gowdatimmanahalli, Naliganahalli, Devadabetta and Byadanur. These nine sub-watersheds
have been evaluated to delineate groundwater potential zones based on the characteristics of geomorphic units together with
slope, geology, lineaments, borewell data using Remote Sensing and Geographic Information System (GIS) techniques. Slope varies
from nearly level (0–1%) to very steep (>35%). The different geomorphic units in each sub-watershed consist of denudational
hills, residual hills, inselbergs, pediment inselberg complex, pediments, shallow weathered pediplains, moderately weathered
pediplains and valley fills. The lineament map for each sub-watershed has been prepared and the trends were analysed with
rose diagrams. The analysis of borewell locations and their yield data in association with lineaments at subwatersheds level
reveals that the lineaments are acting as a pathway for groundwater movement. The integrated map comprising groundwater potential
zones prepared by “Union” function using GIS indicate that valley fills and moderately weathered pediplains are very good
to good, shallow weathered pediplains are good to moderate, pediment inselberg complex and pediments are moderate to poor
and denudational hills, residual hills and inselbergs are poor to very poor groundwater prospect zones. 相似文献
4.
SS Rana 《Journal of the Indian Society of Remote Sensing》1998,26(1-2):35-44
The significance of neotectonic lineaments for groundwater prospecting was studied for the area around Bhinmal — a semi-arid part of Thar desert. The application of Directional Filtering procedures on IRS LISS I Band 4 digital image of the study area revealed NE-SW, NW-SE and E-W trending lineaments which are very subtle and in two cases, even unnoticed otherwise. The use of exploratory borehole lithologs and field evidences indicated that the identified lineaments are long rectilinear buried and partly exposed channels and the intersection zones are characterised by thick lenses of coarse sand and gravel. These buried channels and zones of coarse sediments thus represent potential sites for the accumulation of freshwater during rain. The present work has highlighted the suitability of Directional Filtering procedures for lineament mapping and buried channel studies in a desertic terrain. 相似文献
5.
S. Anbazhagan N. K. Sainaba S. Arivazhagan 《Journal of the Indian Society of Remote Sensing》2012,40(1):145-153
In the present study, The Landsat 7 ETM satellite data was collected for the Sittampundi anorthosites complex and digital
image analysis was carried out. The anorthositic rocks available at Sittampundi complex is considered as an equivalent of
lunar highland rocks. Hence, a remote sensing study comprises of image analysis and spectral profile analysis was carried
out. The satellite data was digitally processed and generated various outputs like band combinations, color composites, stretched
outputs, and PCA. The suitable processed outputs were identified for delineating the anorthosite complex. The diagnostic absorption
features of reflectance spectra are the sensitive indicators of mineralogy and chemical composition of rocks, which are interest
to the planetary scientists. The spectral profile of Landsat ETM plotted for pure and mixed anorthosite pixels and compared
with the field and lab reflectance spectra. The percentages of image spectra vary from 30% to 60% for Sittampundi anorthosite.
The spectral bands 2, 4 and 6 have low reflectance and bands 3 and 5 have high reflectance. The spectral range of bands 2,3,4,5
and 6 are 525 nm–605 nm, 630 nm–690 nm, 750 nm–900 nm, 1550 nm–1750 nm and 10400 nm–12500 nm respectively. The field spectral
curve has weak absorptions at 650 nm and 1000 nm due to the iron transition absorption and low ca- pyroxene respectively available
in the anorthosite, matching with the image spectra. However, hyperspectal image with narrow bandwidth could be more useful
in selecting the suitable spectrum for remotely mapping the anorthosite region, as equivalent test site for lunar highland
region. 相似文献
6.
In the present study analysis of Landsat MSS, TM and SPOT imagery and digital analysis of IRS LISS-1 data of Doon Valley was carried out. Various geomorphic features were identified and classified, morphostratigraphy of the area has been established. Main geomorphic units of the area are Mussoorie Hill Range (Denudational), Siwalik Hills (Structural), Remnant Hills (Residual). Siwalik Piedmont. Doon Piedmont, River Terraces and Flood Plain. Three large fan lobes are identified on Doon Piedmont deposits, viz., Western fan lobe, Central fan lobe and Eastern fan lobe. Average slope of these three fan lobes are 2°21′, 2°3′, and 1°24′ for the western, central and eastern fan lobes respectively. Western and central fan lobes have been affected by neotectonic activity which is reflected in transverse profiles. 相似文献
7.
D. Arabelos 《Journal of Geodesy》1985,59(2):109-123
The evaluation of deflections of the vertical for the area of Greece is attempted using a combination of topographic and astrogeodetic
data. Tests carried out in the area bounded by 35°≤ϕ≤42°, 19°≤λ≤27° indicate that an accuracy of ±3″.3 can be obtained in
this area for the meridian and prime vertical deflection components when high resolution topographic data in the immediate
vicinity of computation points are used, combined with high degree spherical harmonic expansions of the geopotential and isostatic
reduction potential. This accuracy is about 25% better than the corresponding topographic-Moho deflection components which
are evaluated using topographic and Moho data up to 120 km around each station, without any combination with the spherical
harmonic expansion of the geopotential or isostatic reduction potential. The accuracy in both cases is increased to about
2″.6 when the astrogeodetic data available in the area mentioned above are used for the prediction of remaining values. Furthermore
the estimation of datum-shift parameters is attempted using least squares collocation. 相似文献
8.
Shubhada Badhe 《Journal of the Indian Society of Remote Sensing》1981,9(2):13-19
Detailed Landsat imagery interpretation was carried out in Dhansiri Valley, Lower Assam, employing the standard visual interpretation techniques. Optico-electronic analysis using 1215 Video Image Processer was also carried out. Edge enhancement of the imagery using photographic methods was found to sharpen lineaments to a great extent. As many as fifteen localities have been identified as “anomalies” reflecting possible subsurface structures. The delineation is based on different factors including tone, texture, drainage etc. Prominent structural trends delineated are in NE-SW and ENE-WSW directions. The NE-SW trending Borholla-Mikir hills fault zone divided the valley into two distinct structural units, the relatively shallower northern sector dominated by the ENE-WSW trending faults and the southern sector comprising the Dhansiri-Diyung flood plains dominated by tne NE-SW trending faults. 相似文献
9.
A study was undertaken to evaluate the potential of RADARSAT SAR data (Standard-7 and Wide-2 beam positions) for delineating
the geomophological units in Itanagar Capital Complex of Arunachal Pradesh, India. Principal Component Analysis (PCA) has
been applied to Standard-7 and Wide-2 data with incidence angle 45° – 49° and 31 ° – 39° respectively. The resulting components
yield imagery that highlights the Geomorphological units. The area of investigation has been classified into five geomophological
units’ viz., High relief structural hills, low relief structural hills, low relief rugged hills, piedmont and intermontane
valley. The surface roughness can be observed by studying the difference of the responses from different incidence angles.
Wide-2 beam position was found to be more useful for identifying features in flat terrain, and Standard-7 beam position data
for features of high relief. 相似文献
10.
M. P. Kale G. Talukdar R. K. Panigrahy S. Singh 《Journal of the Indian Society of Remote Sensing》2010,38(3):401-413
Fragmentation leads to the loss of connectivity among forested landscapes, which is important for biological conservation
and biodiversity maintenance. Fragmentation analysis carried out on 20 years time interval in northern-Western Ghats revealed
that, losses under moderate and high fragmented forests have decreased from 1985–87 to 2005; however, it is not enough to
compensate the loss of intact forests (not fragmented). The area of dense forests in intact forests has decreased from 1985–87
to 2005, this essentially means the loss of quality habitat in the area. While investigating connectivity between fragmented
patches by taking different topographical and ecological parameters into the consideration, it was observed that potential
connectivity exists between protected areas present in northern and southern areas. 相似文献
11.
C. Jeganathan V. K. Dadhwal Kiran Gupta P. L. N. Raju 《Journal of the Indian Society of Remote Sensing》2009,37(4):539-549
The study compared forest cover maps derived using coarse resolution vegetation continuous fields (MODIS VCF; 500m resolution)
with the maps derived from medium resolution (24m; IRS LISS-III) data. The comparison of VCF, per cent tree cover product,
for the years 2000 to 2004 with LISS III forest density class maps of 2001 and 2003 was carried out for two sites representing
hilly (Uttarakhand) and undulating terrains (Madhya Pradesh). Slicing VCF to corresponding forest crown cover, i.e., 0–10%,
10–40%, 40–70% and >70% produced considerable difference in forest area estimates when compared to original LISS III derived
crown cover area. The corresponding value range in VCF for 0–10% of actual forest cover were 0–31% and 0–25% in 2 sites respectively,
and the respective limit was consistent at 1–20% when VCF range were sliced with respect to upscaled LISS III at 500m resolution.
Similarly, all other class limits were also found through iterative process. These limits were similar, within a site, across
five years. Spatial Kappa match between these two data indicated higher match in 40–70% class, and also in undulating site.
When compared at same resolution, similar forest area cover estimated with weighted area upscaling gave closest match. The
study is useful in knowing the usability and limits of VCF product, and utility of spatial Kappa. 相似文献
12.
A comparison and analysis of airborne gravimetry results from two strapdown inertial/DGPS systems 总被引:2,自引:0,他引:2
In September 1996 the University of Calgary tested a combination of strapdown inertial navigation systems and differential
global positioning system (DGPS) receivers for their suitability to determine gravity at aircraft flying altitudes. The purpose
of this test was to investigate the long-term accuracy and repeatability of the system, as well as its potential for geoid
and vertical gradient of gravity determination. The test took place during a 3-day period in the Canadian Rocky Mountains
over a single 100 × 100 km area which was flown with 10-km line spacing. Two flights were done at 4350 m in E–W and N–S profile
directions, respectively, and one at 7300 m with E–W profiles. Two strapdown inertial systems, the Honeywell LASEREF III and
the Litton-101 Flagship, were flown side by side. Comparison of the system estimates with an upward-continued reference showed
root-mean-square (RMS) agreement at the level of 3.5 mGal for 90- and 120-s filter lengths. The LASEREF III, however, performed
significantly better than the Litton 101 for shorter filtering periods of 30 and 60 s. A comparison between the two systems
results in an RMS agreement of 2.8 and 2.3 mGal for the 90- and 120-s filters. The better agreement between the two systems
is mainly due to the fact that the upward-continued reference has not been filtered identically to the system gravity disturbance
estimates. Additional low-frequency differences seem to point to an error in the upward-continued reference. Finally, an analysis
of crossover points between flight days for the LASEREF III shows a standard deviation of 1.6 mGal, which is near the noise
level of the INS and GPS data. Further improvements to the system are possible, and some ideas for future work are briefly
presented.
Received: 17 March 1998 / Accepted: 1 February 1999 相似文献
13.
Sandip R. Oza R. K. K. Singh N. K. Vyas Abhijit Sarkar 《Journal of the Indian Society of Remote Sensing》2010,38(4):611-616
Long term variations in Sea ice distribution strongly influence the atmosphere and ocean in the polar regions. In the recent
period significant variations in sea ice cover have been observed in both the hemispheres. In the past, studies have been
carried out that report the trends either at the Arctic/Antarctic level or at sector level. However, only a few studies have
concentrated on the investigation of trends at grid level using scatterometer data. The present study focuses on the investigations
of the sea ice trend at 1 × 1 degree grid level over the period 2000–2007 using QuickSCAT 0.2-degree resolution Scatterometer
data. It was observed that in the Arctic overall monthly trend is negative in all the sectors, with the Arctic level decline
of 3.26% per year. In the Antarctic, region-wise different trends have been observed. Negative trend is observed in the Amundsen-
Bellingshausen Seas and also in the Indian Ocean sector near the continental Ice shelves. It was highlighted that significant
trends exists within the pockets of marginal seas. 相似文献
14.
P. H. V. Vasudeva Rao E. Amminedu R. V. Rama Rao 《Journal of the Indian Society of Remote Sensing》2000,28(4):281-291
Spectral reflectance characteristics of jojoba (Simmondsia chinensis (Link) Schneid.), a dioecious member of Buxaceae have been studied, especially under salinity stress. Reflectance is minimum at bands 1 and 2 (450–520 nm and 520–590 run) of visible range and maximum at bands 3 and 4 (620–680 nm and 770–860 nm) of near infrared range. At all wavelength intervals, male plants have greater reflectance than females. Reflectance in near infrared range (band 4) decreases with increasing age and leaf area index (LAI). A reverse trend occurs at band 3. Absorptance increases in visible as well as Infrared ranges with increasing salinity from control to 10 PSU of sea water concentration. 相似文献
15.
S. Anbazhagan T. K. Biswal T. Roy K. N. Kusuma 《Journal of the Indian Society of Remote Sensing》2006,34(4):331-341
The geology of northwestern part of Indian peninsula is considered to be important due to complete preservation of rocks from Archaean to Upper Proterozoic. Further, these rocks have served as ideal host of varieties of economic minerals. The present work is an attempt to study the structurally deformed granulitic terrain in parts of Gujarat and Rajasthan in light of remote sensing. The study area falls under Sirohi, Banas Kantha and Sabar Kantha districts of Rajasthan and Gujarat. Remote sensing technique is utilized for the understanding of structural geology and deciphering the shear pattern. The methods adopted in this study include generation of False Color Composite (FCC) of satellite data, interpretation of lineaments from FCC and study the drainage pattern, structural basin delineation, profiling, and field mapping. It is observed that the area has undergone extensive deformation. There are two major sets of lineaments interpreted in the granulitic terrain such as WNW-ESE and NE-SW directions. Majority of the WNW-ESE lineaments are brittle in nature and N-S, NE-SW trending lineaments are ductile in nature. Overall the study area bifurcated into seven structural basins comprises of basic granulites, calc granulites and pelitic granulites. 相似文献
16.
U. P. Shahi Suman Kumar N. P. Singh A. K. Chaubey Yogesh Kumar 《Journal of the Indian Society of Remote Sensing》2007,35(1):53-65
The potential usefulness of spectral properties and vegetation indices in varietal discrimination of potato genotypes was
studied in the field experiment. Spectral measurements were recorded in different bands in blue (450–520 nm), green (520–590
nm), red (620–680 nm) and infrared (770–860 nm) of the electromagnetic spectrum at different stages during crop growth period.
A ground based hand held multiband radiometer (Model/041) was used for the purpose. The mean per cent green reflectance value
among different genotypes was lowest in genotype MS/86-89, while it was observed highest in genotype JX-216. Significant difference
among these genotypes was found at all growth stages except 6 week after planting. Consequent to variation in spectral reflectance
the vegetation indices like, NDVI, RVI, TVI and DVI showed significant difference among genotypes at all growth stages except
at 8th week after planting. The vegetation indices are good indicators of crop growth and condition. Similarly, fresh weight, dry
weight, and leaf area index were also highest in MS/86-89, followed by KUFRI Bahar and KUFRI Sutlej while in case of leaf
area index it was followed by Kufri Sutlej and Kufri Bahar. JX-23 was highest in chlorophyll content and tuber yield followed
by MS/86-89 and JW-160, while lowest chlorophyll content was seen in MS/89-1095 and poorest tuber yield in MS/89-60. Most
of the genotypes exhibited considerable variation in their spectral response and vegetation indices thereby indicating the
possibility of their discrimination through remote sensing technique. 相似文献
17.
Hema Raghavan V. G. Phansalkar V. V. Peshwa A. G. Dessai 《Journal of the Indian Society of Remote Sensing》1983,11(1):63-70
Photogeological studies of the area shows the presence of four major lithological groups as : 1. Precambrian basement made up of granitic gneisses and Charnockites, 2. The Utatur Group of rocks, 3. The Trichinopoly Group of rocks and 4. The Ariyalur Group of rocks. Some prominant lineaments roughly trending in NE-SW direction are seen. These lineaments represent the traces of the reactivated faults in the basemeht. The photogeological studies were supplemented by morphometric analyses. It is seen that the drainage in lower order basins is controlled by structure, i.e. by the strike of the rocks and faults in the basement. The higher order streams apparently follow the direction of regional gradient. 相似文献
18.
Over the last four decades exploitation of natural resources to meet increasing societal demands for land based products has
caused significant changes in land use and land cover not only in nature’s best gifted regions but also environmentally sensitive
arid regions. Through digital interpretation of IRS LISS-III data of 2004 supported with field survey, the present land use
map of Jhunjhunun district of arid Rajasthan has been prepared. Agriculture is the dominant land use constituting 84% (including
38% irrigated cropland) area. The land use changes over time and space are worked out by comparing with Landsat 2 MSS data
of 1975 and Land use/land cover map of 1988–89. These changes are correlated by analyzing historical land use and cropping
pattern data from 1957–58 to 2004–05. The region witnessed record increase in irrigated area but sharply depleted ground water
and rendered hectares of irrigated double cropland into dry land agriculture. Strategies and technologies are suggested for
sustainable use and management of different category of land. 相似文献
19.
R. H. Rapp 《Journal of Geodesy》1997,71(5):282-289
This paper suggests that potential coefficient models of the Earth's gravitational potential be used to calculate height
anomalies which are then reduced to geoid undulations where such quantities are needed for orthometric height determination
and vertical datum definition through a potential coefficient realization of the geoid. The process of the conversion of the
height anomaly into a geoid undulation is represented by a height anomaly gradient term and the usual N–ζ term that is dependent on elevation and the Bouguer anomaly. Using a degree 360 expansion of 30′ elevations and the OSU91A
potential coefficient model, a degree 360 representation of the correction terms was computed. The magnitude of N–ζ reached –3.4 m in the Himalaya Mountains with smaller, but still significant, magnitudes in other mountainous regions.
Received: 6 May 1996; Accepted: 30 October 1996 相似文献
20.
Arun K. Thakur Gajendra Singh Sarnam Singh G. S. Rawat 《Journal of the Indian Society of Remote Sensing》2011,39(1):127-134
The study reports the impact of migratory livestock in the buffer area of Kedarnath Wildlife Sanctuary. The cumulative impacts
of livestock grazing, fuel wood extraction and other anthropogenic pressures on forest cover in and around camping sites have
been analyzed using satellite data and field observations. Multi-date satellite data were used to map the forest cover around
16 seasonal livestock camps. An annual loss of about 7.25 ha of forest covers during 1976–1990, 13.57 ha during 1990–1999
and 11.46 ha during 1999–2005 are recorded. A loss of 108.53 ha of forestland has been estimated during 1976–1990, about 122.16 ha
during 1990–1999 and 68.78 ha during 1999–2005. It is also observed that many of the isolated camping sites are now connected
due to loss of vegetation. Phytosociological analysis indicates that the number of seedlings and saplings in three species
of Quercus (Q. leucotrichophora, Q. floribunda and Q. semecarpifolia) as compared to mature tress is very less around cattle camping sites. The ratio of number of sapling with seedling and trees
indicates that the status of sapling is nil to very poor, an indication of loss of saplings due to either trampling or grazing. 相似文献