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Application of digital elevation model and orthoimages derived from IRS-1C pan stereo data in monitoring variations in glacial dimensions 总被引：1，自引：0，他引：1
An attempt has been made to study variations in the glacier extent over a period of time using digital elevation model (DEM)
and orthoimages derived from IRS-1C PAN stereo pairs of 1997–98 and topographical map surveyed during 1962–63. DEM and orthoimages
have been generated using integrated software developed for processing of IRSIC/ID panchromatic stereo data using the softcopy
photogrammetric workstation. Case studies of two glaciers, i.e. the Janapa garang and Shaune garang glaciers of the Basapa
basin, a sub-basin of Satluj River in India, have been presented here. Generation of DEM has been followed by the estimation
of its accuracy. PAN images were interpreted for identification of the snout of the glaciers. The geographical locations of
the snouts on the images were compared with the location as mapped on the topographical map of the study area. To verify satellite
observations, field investigations were carried out at Shaune garang glacier area. The Janapa garang and the Shaune garang
are observed to have retreat of 596m and 923 m respectively. Reduction in the thickness of ice in the deglaciated part of
the Shaune garang glacier was estimated on the basis of change in the elevations of the glacial surface from 1963 to 1998. 相似文献
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Gunawat Anshuman Sharma Devesh Sharma Aditya Dubey Swatantra Kumar 《Natural Hazards》2022,111(2):2077-2096
Natural Hazards - Crop simulation models are essential tools to facilitate the evaluation and application of crop production practices under different climate scenarios. The present study analyzed... 相似文献
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The aim of this study is to understand the land use change and urban expansion of Jaipur City of Rajasthan (India). Landsat 5 TM and Landsat 8 OLI satellite data of 4 years, i.e., 1993, 2000, 2010, and 2015 are used for land use and land surface temperature (LST) analysis. ERDAS Imagine and ArcGIS software are used to conduct the analysis. Urban settlement increased from 13.5 to 57.3% in the study period. Open land is mainly changed to urban areas. Urban settlement is also expanded to peri-urban area of Jaipur City. Jaipur City expanded along three directions i.e., north, west, and south and less development is found in the east direction. Based on radial analysis, it is observed there is not much development within the periphery of 2 km (close to city center) but maximum growth is observed within the distance from 4 to 6 km radius of city center. Expansion intensity was observed highest in the period 2015–2010 from 6 km onwards and reached to a maximum value close to 17 km2/year. In LST analysis, there is less change in extreme temperature, but more areal increase in average temperature range (30–35 °C). Urbanization is the main driving process of land cover changes and consequently changes in LST. 相似文献
15.
D. G. Shah Anjali Bahuguna B. Deshmukh S. R. Nayak H. S. Singh B. H. Patel 《Journal of the Indian Society of Remote Sensing》2005,33(1):155-163
Mangroves of the Marine National Park constitute the second largest patch of mangroves in Gujarat, extending up to 11,000
ha, comprising six species of mangroves. Earlier studies carried out using remote sensing data pertained to baseline data
generation and mapping and monitoring the mangroves (density-wise) of the Park from 1975 to 1993. Using IRS IC/ID LISS III
data (1998–2001) supported by ground data, the distribution of different mangrove communities in the Park has been attempted.
Amongst various image-processing techniques, band ratioing followed by supervised classification gave the best result (classification
accuracy was 92%).Avicennia community is the most dominant community accounting for more than 70% of the area. TheRhizophora community occupies the inward margins of the creeks and theCeriops community is present in the interior regions. The ecotone between the marsh and mangrove communities has been identified
as the transitional mangroves (Avicennia alba, Sueada), representing the transition from the less saline mangrove to the highly saline marsh community. The zoning of the mangroves
has also helped in assessing the diversity of the region. Based on the richness of species, three areas, namely Bhains Bid,
North-east Dide Ka Bet and South-east Chhad Island have been identified as highly diverse (most suitable area for preservation). 相似文献
16.
Eco-Geomorphological zonation of The Bangaram Reef, Lakshadweep 总被引：1，自引：0，他引：1
Benidhar Deshmukh Anjali Bahuguna Shailesh Nayak V. K. Dhargalkar T. G. Jagtap 《Journal of the Indian Society of Remote Sensing》2005,33(1):99-106
Coral reefs, which are known for rich biological diversity and productivity, are being threatened throughout the world by various natural and anthropogenic activities. The present study concentrates on establishing methodology to zone the geo-morphological and ecological zones of the Bangaram reef (of atoll type), Lakshadweep islands, using remotely sensed data and adequately supported by field data. Classification system has been evolved to zone the reefs. Comparative studies have also been carried out using image processing techniques in order to establish the suitable technique for studying the Indian reefs. The IRS LISS III images representing three different tidal conditions of the period 1998-2000 were analyzed. The unsupervised classification of both the raw images as well as principal component images gave similar information. The classified product was subjected to contextual editing. Misclassification among various classes was found to increase with the increase in the depth of the water column present over the reef. The zones identified on the image are central deep lagoon, reef knolls (rising steeply from the central deep lagoon floor), reef edge, reef platform, coralline shelf, broad shallow sandy-bottomed lagoon, beach and two islets. The zonation has helped in getting information on the presence of live corals on the Bangaram reef. This kind of study is a valuable input in assessing the health of the reefs and its diversity. 相似文献
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Anil V Kulkarni S S Randhawa B P Rathore I M Bahuguna R K Sood 《Journal of the Indian Society of Remote Sensing》2002,30(4):221-228
Himalayan region has high concentrations of mountain glaciers. Large extent of this region is covered by seasonal snow during winter. Runoff generates from melting of these snow and glaciers is one of the important sources of water for the Himalayan Rivers. Glaciers and snowfields are distributed throughout the Himalayas and form a source of numerous streams. Due to steep slopes, all such streams have potential sites for hydropower generation. If this potential is fully utilized, it will help in generating power from environmentally friendly Run-of-River (RoR) hydropower stations. Considering these aspects, a stream flow simulation model was developed for small streams. This will help in estimation of average seasonal unrestricted hydropower potential of snow and glaciated streams for winter, summer, monsoon and autumn seasons. Information generated through remote sensing technique as glacier, permanent snow cover, seasonal snow cover, altitude of snow and glaciers were used in conjunction with daily maximum and minimum temperature, rainfall and discharge. The model was developed for Malana nala located in Parbati River basin near Kullu in Himachal Pradesh. It was validated at adjacent Tosh nala in the same basin. Seasonal runoff computed from the model is comparable with observed data for all seasons except Monsoon. Good results in autumn, winter and summer seasons demonstrates usefulness of runoff model to assess hydropower potential of snow and glaciated streams and therefore, the model was applied to ungauged Sorang Gad and Kirang Khad. In winter runoff was estimated as 1.8 and 1.69 cumecs for Kirang Khad and Sorang Gad, respectively. This is important, as viability of hydropower station depends upon winter stream runoff. These results suggest that the model is useful tool to assess initial estimate of hydropower potential for large number of snow and glaciated streams, for which no hydrological data is available. 相似文献
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Singh Shishir Kumar Radhakrishnan S. R. Jaswant Mishra Sumit Kumar Shukla Devesh Kumar Ranjan Ashish Sharma Chhemendra 《Journal of Atmospheric Chemistry》2022,79(2):117-139
A Raman lidar system was operated along with the Microtops sunphotometer measurements to carry out the study of the variation of the optical properties of aerosols over Palampur (32.11° N and 76.53° E), India from 17th April to 11th May 2019. The lidar system is furnished with Raman (N2) channel and depolarization channel allowing independent measurement of Lidar Ratio (LR) and linear depolarization ratio. The study reveals that the majority of the aerosols approximately were restricted within the planetary boundary layer (PBL) and very less loading was present in the free troposphere over the study location. The particle loading over the study period was found to be very less with aerosol backscatter coefficient (at 355 nm) ranging from ～0.13 Mm?1sr?1 to ～7.25 Mm?1sr?1 with mean value of 2.67?±?0.82 Mm?1sr?1 and it is well supplemented by the mean aerosol optical depth (AOD) of 0.37?±?0.13 obtained from Microtops Sunphotometer. The average lidar ratio values for 0-1 km altitude (L1) 72?±?13sr, for 1-2 km (L2) altitude 55?±?8sr, for 2-3 km (L3) 54?±?15sr were observed as suggesting dominance of the biomass burning aerosols and anthropogenic aerosols. The particle depolarization ratio (355 nm) values were found from approximately 4.8?±?2.7% to 11.5?±?1.9% with the mean value of 7?±?1.3% suggesting the presence of non-spherical particles. To trace the sources of the pollution, we derived the HYSPLIT trajectory which shows the majority of the movement was from local sources.
相似文献20.
C K Unnikrishnan John P George Abhishek Lodh Devesh Kumar Maurya Swapan Mallick E N Rajagopal Saji Mohandas 《Journal of Earth System Science》2016,125(5):935-944
Surface level soil moisture from two gridded datasets over India are evaluated in this study. The first one is the UK Met Office (UKMO) soil moisture analysis produced by a land data assimilation system based on Extended Kalman Filter method (EKF), which make use of satellite observation of Advanced Scatterometer (ASCAT) soil wetness index as well as the screen level meteorological observations. Second dataset is a satellite soil moisture product, produced by National Remote Sensing Centre (NRSC) using passive microwave Advanced Microwave Scanning Radiometer 2 measurements. In-situ observations of soil moisture from India Meteorological Department (IMD) are used for the validation of the gridded soil moisture products. The difference between these datasets over India is minimum in the non-monsoon months and over agricultural regions. It is seen that the NRSC data is slightly drier (0.05%) and UKMO soil moisture analysis is relatively wet during southwest monsoon season. Standard AMSR-2 satellite soil moisture product is used to compare the NRSC and UKMO products. The standard AMSR-2 and UKMO values are closer in monsoon season and AMSR-2 soil moisture is higher than UKMO in all seasons. NRSC and AMSR-2 showed a correlation of 0.83 (significant at 0.01 level). The probability distribution of IMD soil moisture observation peaks at 0.25 m3/m3, NRSC at 0.15 m3/m3, AMSR-2 at 0.25 m3/m3 and UKMO at 0.35 m3/m3 during June–September period. Validation results show UKMO analysis has better correlation with in-situ observations compared to the NRSC and AMSR-2 datasets. The seasonal variation in soil moisture is better represented in UKMO analysis. Underestimation of soil moisture during monsoon season over India in NRSC data suggests the necessity of incorporating the actual vegetation for a better soil moisture retrieval using passive microwave sensors. Both products have good agreement over bare soil, shrubs and grassland compared to needle leaf tree, broad leaf tree and urban land cover types. 相似文献