Uttam Goswami | DIBRUGARH UNIVERSITY (original) (raw)

Papers by Uttam Goswami

Journal of the Geological Society of India, Jun 26, 2023

IOP conference series, Jun 1, 2022

Subansiri River is the largest tributary of the Brahmaputra River running through the Indian stat... more Subansiri River is the largest tributary of the Brahmaputra River running through the Indian states of Assam and Arunachal Pradesh, and Tibet, the Autonomous Region of China. The Subansiri River is 442 km long with a drainage basin of 32,640 km2 and it contributes approximately 7.92% of the Brahmaputra’s total flow. Sequential Channel shifting has been witnessed as the most important characteristic of the Subansiri River of Assam. The detailed study on channel migration of the present course of the Subansiri River through the upper floodplain of Brahmaputra valley indicates that the area is under active erosion for a long time. Therefore, an attempt has been made to understand the relationship between the rate of channel migration and successive land use/land cover changes in its surrounding floodplain area. The Support Vector Machine (SVM) and the Artificial Neural Network (ANN) algorithms are applied on Landsat images of the years 1973, 1988, 2001, and 2017 for generating land use/land cover maps through supervised classification technique. The overall accuracy of the land use/land cover classification ranges between 81% (for the year 1988) and 84% (for the year 2017). The land use/land cover maps show an increase in the built-up area and a decrease in the agricultural area. The change has been observed vis-a-vis channel migration indicating that the migration directly affects the floodplain habitats which in turn affects the land use, Findings of this study highlight geomorphological instabilities of the study area and the vulnerability of the habitations residing near the Subansiri river.

Journal of The Indian Society of Remote Sensing, Mar 1, 2007

The Burhi Dlhing river flows m a meandering course for about 220 km through alluvial plains of As... more The Burhi Dlhing river flows m a meandering course for about 220 km through alluvial plains of Assam inclnding a short rocky and hilly tract in between. Sequential changes in the position ofbanklines of the river due to consistent bank erosion have been studied from Survey of India topographic maps of 1934 and i 972, 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 cutoff 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 gamed due to sediment deposition are estimated separately. The total area eroded in both banks during 1934-1972 was more (26.796 km 2) as compared to sediment deposition (19.273 km2), whereas total sediment deposition was more (34.61 km z) during 1972-2001 as compared to erosion (23 152 km 2) Erosion was again more m 2001-2004 (7.568 km 2) as compared to sednnent deposition (2 493 kin2). During the entire period (1934-2004) of study the overall erosion oll the both banks was 31.169 km z and overall sediment deposition was 30.101 km 2. 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.

International Journal of Advanced Remote Sensing and GIS, Nov 11, 2017

Groundwater prospect evaluation in the interfluves of the Rivers Brahmaputra and Kolong, Assam ha... more Groundwater prospect evaluation in the interfluves of the Rivers Brahmaputra and Kolong, Assam has been studied by considering the geomorphology, lithology, drainage pattern and drainage density, slope and land use/land cover (LU/LC) of the area. The major geomorphic, lithologic and land use/land cover units of the area have been identified and delineated from satellite imageries. Slope map and drainage map of the study area were generated from the SOI toposheets as well as from the satellite imageries. The drainage density map was generated from drainage network of the interfluves using GIS. To demarcate the different groundwater prospect zones of the study area, all the thematic layers are integrated by raster index overlay technique in GIS. Weights are assigned to different thematic layers and ranks are assigned to different categories/classes of the thematic layers for the overlay analysis in GIS. The resultant map was classified into groundwater prospect zones as very good, good, moderate and poor. The groundwater prospect zone map indicates that the most part of the area is having well to very good groundwater prospect zones.

International journal of Geomatics and Geosciences, 2013

Remote Sensing is an efficient tool for change detection of land cover/forest cover/urban mapping... more Remote Sensing is an efficient tool for change detection of land cover/forest cover/urban mapping incorporating satellite imagery. It not only provides us with the extents but also indicates some cultural, political and ecological impacts due to which the changes have occurred or land cover is tempered. The images indicate such changes in the urban areas of Assam. From these images the severity and extent of deforestation is an eye-opener. In Assam along the Brahmaputra and the riverine tracts of its tributaries, several cities are selected where the extent and severity of deforestation is high. These cities belong to the districts of Tinsukia, Dibrugarh, Sivasagar, Jorhat, Golaghat, Nagaon, and Kamrup all along the river. The urban sprawl area is studied taking 1974 and 2009 Landsat imageries using ArcGIS online explorer. It has been found that vast changes occurred due to migration of the people to cities in search of jobs and cultural advantages, and this has resulted in the formation of huge urban areas and surrounding periurban environs. But its effects are impacting the quality of life in every region of Assam, in the large cities and small towns. The present trend is to rapidly develop farms, agricultural land and forests into housing developments or strip malls. And the rate of development is accelerating. As a result, people suffer from increased traffic congestion, longer commutes, increased dependence on fossil fuels, crowded schools, worsened air and water pollution, threatened surface and ground water supplies, lost open space and wetlands, increased flooding, destroyed wildlife habitat, higher taxes, and dying city centres. Moreover, sprawl is creating a hidden debt of unfunded infrastructure and services, social dysfunction, urban decay and environmental degradation.

Indian journal of applied research, Oct 1, 2011

Journal of Nepal Geological Society, Dec 1, 2002

Plate tectonic history of northeast Indian subcontinent can be viewed as a window to the evolutio... more Plate tectonic history of northeast Indian subcontinent can be viewed as a window to the evolution of Southeast Asia. One such important tectonic feature is the northern most part of Indo-Burmese Ranges where this research work has been carried out. Here we propose an evolutionary model that shows northward moving 'horse-tail' feature of the Hukawng Block from the Burma basin, pushed this region towards the rigid Mishmi Block and Upper Assam shelf, that caused the hyperoblique pattern of the ranges. It is the juxtaposition of the three continental blocks: India-Asia-Burma, where there are tectonic and geomorphic influences in the Block from both the Himalayan and Indo-Burmese orogeny. Stress distribution among north-easterly moving Indian plate and comparatively stiff Eurasian and Burma plates, within the India specific reference frame, is resulting in further changes. The study area mainly falls under Changlang district of Arunachal Pradesh, India; and the regional study has been done in the quadrangle from 26° to 28°N in latitudes and 95° to 97°E in longitudes. Morphotectonic study, lineament analysis, fault system characterisation, focal plane mechanism along with dynamic topography, seismic tomography and gravity anomaly have been incorporated in the field evidences. Morphotectonic study for Noa-Dihing River basin has resulted in a value of 56.59 for Asymmetric Factor, which shows similar asymmetry result like in the Chi (χ) analysis. This SW-ward tilted basin is moderately asymmetrical with Transverse Topographic Symmetric Factor value of 0.42. This indicates that the major river basin along with other subbasins are under the influence of active oblique rotational component. The regional lineaments are showing mean orientations of N11°E-S11°W, N70°W-S70°E and EW whereas some local trends of minor lineaments, in some places have mean orientations of N40°W-S40°E, N82°WS82°E and N42°E-S42°W. In Mishmi block the major regional trends are N35°W-S35°E and N40°E-S40°W comprising of probable cross-faults. In Hukawng Block, the lineament orientation changes from N50°W-S50°E in the west to N30°W-S30°E, N-S and N15°E-S15°W in the central valley region (north of Jade mines) and then to N50°E-S50°W in the eastern side. Major fault systems are mostly thrust, with some showing very low angle slip component, along with some oblique slip faults (e.g. Noa-Dihing River). The dynamic topography and seismic tomographic studies indicate presence of a high seismic velocity zone beneath Mishmi block indicating the crystalline rock materials. The block is still actively exhuming. Moreover, Changlang and Hukawng blocks have undergone uplift and then phases of subsidence during the last 20Ma. This indicates that the Low Velocity materials that are present underneath were subjected to some crustal deformations. This tectonic process has also resulted in gravity anomalies. The role of massive and rigid Mishmi block, comprising older crystalline rocks and, later forming Burma basins formed the oblique rotation of the Changlang block which is observed from all stated methods. Hukawng Block, which is controlled by the motion of Sagaing Fault, have influenced the Changlang Block by its varied strike-slip stress components. Moreover, Indo-Burmese Ranges also has an influence on this block and vice-versa.

Indian journal of applied research, Oct 1, 2011

Geomorphology, Dec 1, 1999

The sequential changes in the position of banklines as a result of bank erosion, as well as vario... more The sequential changes in the position of banklines as a result of bank erosion, as well as various changes in the channel have been studied in the Subansiri river in Assam, India. The study was carried out from available topographic maps of 1920, 1970 and satellite imagery of 1990. The types of changes taking place in the Subansiri river channel as observed from Ž. the above-mentioned maps and imagery are grouped into four categories: 1 alteration of the direction of flow due to neck Ž. Ž. Ž. cutoff , 2 widening of a channel in response to bar development, 3 development and subsequent abandonment of Ž. anabranches, and 4 progressive shifting of meander bends. The river channel has become substantially wider during the period of 1970-1990. There has also been a progressive increase in the number and area of mid-channel bars with a corresponding decrease in the number and area of point bars during 1920-1990. These periodic and progressive changes are responsible for a change in channel pattern of the river. A study made on nature and amount of change in the banklines of Ž. the Subansiri river by dividing the channel 84 km in 1970 into 10 equal segments reveals that the types of change are varied, and in some cases chaotic in nature. Study of the bankline shift of the Subansiri determined separately for the periods 1920-1970, 1970-1990 and 1920-1990 at 20 evenly spaced transverse sections reveals that there has been a substantial westward shift of both the banklines, up to a maximum of 6 km, in the three upstream sections during 1920-1970. However, shifting of banklines in both directions and the unequal amount of shifting in the same direction have caused a marked increase in channel width during 1970-1990. It is found that due to bankline migration, the total amount of area eroded along the entire course under study during 1920-1970 and 1970-1990 are 107.90 and 57.50 km 2 , respectively. The overall sinuosity which was 1.51 in 1920 has decreased to 1.30 in 1970, while the corresponding braiding intensity has increased from 0.79 to 1.32. The river channel seems to make a remarkable change from a meandering pattern in 1920 towards a braided pattern by 1990 as seen from gradual increase in overall braiding intensity.

Journal of Earth System Science, Feb 5, 2021

Abstract Many springs occur in and around Pasighat. Eight major springs of the area were consider... more Abstract Many springs occur in and around Pasighat. Eight major springs of the area were considered for the study. These springs are Dimple type, Fault dam type, and a combination of Fault dam and Border type. The highest discharge is 263.23 L/sec and the lowest is 1.91 L/sec. The aquifers are terrace deposits that comprise of unsorted boulders, cobbles and pebbles in sandy matrix and the springs occur at the base of different terrace levels. Due to the scarcity of dug wells or deep tube wells, subsurface investigations were done using vertical electric sounding (VES). VES data generated at six locations show H-type situation. The aquifers are at shallow depth, unconfined, and have good hydrogeological prospects. At the T 2 terrace, volume of water stored is 42,14,512.5 m 3 and the combined discharge of springs is 38,257.92 m 3 /day. These springs are recharged by precipitation and influent streams. Springs of the study area are aligned along the Himalayan Frontal Thrust (HFT) and its splays, and they have a major role in the evolution of these springs. The springs were formed due to topographic breaks and less permeable collapsed debris. Local people use spring water for the household, irrigation, laundry, and fisheries. Research highlights (i) Springs present along the base of the terraces have the highest discharge of 263.23 L/sec. (ii) These springs are genetically related to HFT. (iii) Terrace aquifers are suitable for groundwater development and groundwater flows from influent streams and foothill regions towards Siang River. (iv) Spring water is used by local people for household, irrigation, laundry, and fisheries and proper management of these springs will ensure good supply of water in future.

Journal of the Geological Society of India

IOP Conference Series: Earth and Environmental Science

Subansiri River is the largest tributary of the Brahmaputra River running through the Indian stat... more Subansiri River is the largest tributary of the Brahmaputra River running through the Indian states of Assam and Arunachal Pradesh, and Tibet, the Autonomous Region of China. The Subansiri River is 442 km long with a drainage basin of 32,640 km2 and it contributes approximately 7.92% of the Brahmaputra’s total flow. Sequential Channel shifting has been witnessed as the most important characteristic of the Subansiri River of Assam. The detailed study on channel migration of the present course of the Subansiri River through the upper floodplain of Brahmaputra valley indicates that the area is under active erosion for a long time. Therefore, an attempt has been made to understand the relationship between the rate of channel migration and successive land use/land cover changes in its surrounding floodplain area. The Support Vector Machine (SVM) and the Artificial Neural Network (ANN) algorithms are applied on Landsat images of the years 1973, 1988, 2001, and 2017 for generating land use...

change detection study of some of the urban areas of Assam, India

International Journal of Advanced Remote Sensing and GIS, 2017

Groundwater prospect evaluation in the interfluves of the Rivers Brahmaputra and Kolong, Assam ha... more Groundwater prospect evaluation in the interfluves of the Rivers Brahmaputra and Kolong, Assam has been studied by considering the geomorphology, lithology, drainage pattern and drainage density, slope and land use/land cover (LU/LC) of the area. The major geomorphic, lithologic and land use/land cover units of the area have been identified and delineated from satellite imageries. Slope map and drainage map of the study area were generated from the SOI toposheets as well as from the satellite imageries. The drainage density map was generated from drainage network of the interfluves using GIS. To demarcate the different groundwater prospect zones of the study area, all the thematic layers are integrated by raster index overlay technique in GIS. Weights are assigned to different thematic layers and ranks are assigned to different categories/classes of the thematic layers for the overlay analysis in GIS. The resultant map was classified into groundwater prospect zones as very good, goo...

Remote Sensing is an efficient tool for change detection of land cover/forest cover/urban mapping... more Remote Sensing is an efficient tool for change detection of land cover/forest cover/urban mapping incorporating satellite imagery. It not only provides us with the extents but also indicates some cultural, political and ecological impacts due to which the changes have occurred or land cover is tempered. The images indicate such changes in the urban areas of Assam. From these images the severity and extent of deforestation is an eye-opener. In Assam along the Brahmaputra and the riverine tracts of its tributaries, several cities are selected where the extent and severity of deforestation is high. These cities belong to the districts of Tinsukia, Dibrugarh, Sivasagar, Jorhat, Golaghat, Nagaon, and Kamrup all along the river. The urban sprawl area is studied taking 1974 and 2009 Landsat imageries using ArcGIS online explorer. It has been found that vast changes occurred due to migration of the people to cities in search of jobs and cultural advantages, and this has resulted in the form...

Journal of Earth System Science, 2021

Many springs occur in and around Pasighat. Eight major springs of the area were considered for th... more Many springs occur in and around Pasighat. Eight major springs of the area were considered for the study. These springs are Dimple type, Fault dam type, and a combination of Fault dam and Border type. The highest discharge is 263.23 L/sec and the lowest is 1.91 L/sec. The aquifers are terrace deposits that comprise of unsorted boulders, cobbles and pebbles in sandy matrix and the springs occur at the base of different terrace levels. Due to the scarcity of dug wells or deep tube wells, subsurface investigations were done using vertical electric sounding (VES). VES data generated at six locations show H-type situation. The aquifers are at shallow depth, unconfined, and have good hydrogeological prospects. At the T 2 terrace, volume of water stored is 42,14,512.5 m 3 and the combined discharge of springs is 38,257.92 m 3 /day. These springs are recharged by precipitation and influent streams. Springs of the study area are aligned along the Himalayan Frontal Thrust (HFT) and its splays...

Paripex Indian Journal of Research, Mar 1, 2012

Journal of the Geological Society of India, Jun 26, 2023

IOP conference series, Jun 1, 2022

Subansiri River is the largest tributary of the Brahmaputra River running through the Indian stat... more Subansiri River is the largest tributary of the Brahmaputra River running through the Indian states of Assam and Arunachal Pradesh, and Tibet, the Autonomous Region of China. The Subansiri River is 442 km long with a drainage basin of 32,640 km2 and it contributes approximately 7.92% of the Brahmaputra’s total flow. Sequential Channel shifting has been witnessed as the most important characteristic of the Subansiri River of Assam. The detailed study on channel migration of the present course of the Subansiri River through the upper floodplain of Brahmaputra valley indicates that the area is under active erosion for a long time. Therefore, an attempt has been made to understand the relationship between the rate of channel migration and successive land use/land cover changes in its surrounding floodplain area. The Support Vector Machine (SVM) and the Artificial Neural Network (ANN) algorithms are applied on Landsat images of the years 1973, 1988, 2001, and 2017 for generating land use/land cover maps through supervised classification technique. The overall accuracy of the land use/land cover classification ranges between 81% (for the year 1988) and 84% (for the year 2017). The land use/land cover maps show an increase in the built-up area and a decrease in the agricultural area. The change has been observed vis-a-vis channel migration indicating that the migration directly affects the floodplain habitats which in turn affects the land use, Findings of this study highlight geomorphological instabilities of the study area and the vulnerability of the habitations residing near the Subansiri river.

Journal of The Indian Society of Remote Sensing, Mar 1, 2007

The Burhi Dlhing river flows m a meandering course for about 220 km through alluvial plains of As... more The Burhi Dlhing river flows m a meandering course for about 220 km through alluvial plains of Assam inclnding a short rocky and hilly tract in between. Sequential changes in the position ofbanklines of the river due to consistent bank erosion have been studied from Survey of India topographic maps of 1934 and i 972, 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 cutoff 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 gamed due to sediment deposition are estimated separately. The total area eroded in both banks during 1934-1972 was more (26.796 km 2) as compared to sediment deposition (19.273 km2), whereas total sediment deposition was more (34.61 km z) during 1972-2001 as compared to erosion (23 152 km 2) Erosion was again more m 2001-2004 (7.568 km 2) as compared to sednnent deposition (2 493 kin2). During the entire period (1934-2004) of study the overall erosion oll the both banks was 31.169 km z and overall sediment deposition was 30.101 km 2. 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.

International Journal of Advanced Remote Sensing and GIS, Nov 11, 2017

Groundwater prospect evaluation in the interfluves of the Rivers Brahmaputra and Kolong, Assam ha... more Groundwater prospect evaluation in the interfluves of the Rivers Brahmaputra and Kolong, Assam has been studied by considering the geomorphology, lithology, drainage pattern and drainage density, slope and land use/land cover (LU/LC) of the area. The major geomorphic, lithologic and land use/land cover units of the area have been identified and delineated from satellite imageries. Slope map and drainage map of the study area were generated from the SOI toposheets as well as from the satellite imageries. The drainage density map was generated from drainage network of the interfluves using GIS. To demarcate the different groundwater prospect zones of the study area, all the thematic layers are integrated by raster index overlay technique in GIS. Weights are assigned to different thematic layers and ranks are assigned to different categories/classes of the thematic layers for the overlay analysis in GIS. The resultant map was classified into groundwater prospect zones as very good, good, moderate and poor. The groundwater prospect zone map indicates that the most part of the area is having well to very good groundwater prospect zones.

International journal of Geomatics and Geosciences, 2013

Remote Sensing is an efficient tool for change detection of land cover/forest cover/urban mapping... more Remote Sensing is an efficient tool for change detection of land cover/forest cover/urban mapping incorporating satellite imagery. It not only provides us with the extents but also indicates some cultural, political and ecological impacts due to which the changes have occurred or land cover is tempered. The images indicate such changes in the urban areas of Assam. From these images the severity and extent of deforestation is an eye-opener. In Assam along the Brahmaputra and the riverine tracts of its tributaries, several cities are selected where the extent and severity of deforestation is high. These cities belong to the districts of Tinsukia, Dibrugarh, Sivasagar, Jorhat, Golaghat, Nagaon, and Kamrup all along the river. The urban sprawl area is studied taking 1974 and 2009 Landsat imageries using ArcGIS online explorer. It has been found that vast changes occurred due to migration of the people to cities in search of jobs and cultural advantages, and this has resulted in the formation of huge urban areas and surrounding periurban environs. But its effects are impacting the quality of life in every region of Assam, in the large cities and small towns. The present trend is to rapidly develop farms, agricultural land and forests into housing developments or strip malls. And the rate of development is accelerating. As a result, people suffer from increased traffic congestion, longer commutes, increased dependence on fossil fuels, crowded schools, worsened air and water pollution, threatened surface and ground water supplies, lost open space and wetlands, increased flooding, destroyed wildlife habitat, higher taxes, and dying city centres. Moreover, sprawl is creating a hidden debt of unfunded infrastructure and services, social dysfunction, urban decay and environmental degradation.

Indian journal of applied research, Oct 1, 2011

Journal of Nepal Geological Society, Dec 1, 2002

Plate tectonic history of northeast Indian subcontinent can be viewed as a window to the evolutio... more Plate tectonic history of northeast Indian subcontinent can be viewed as a window to the evolution of Southeast Asia. One such important tectonic feature is the northern most part of Indo-Burmese Ranges where this research work has been carried out. Here we propose an evolutionary model that shows northward moving 'horse-tail' feature of the Hukawng Block from the Burma basin, pushed this region towards the rigid Mishmi Block and Upper Assam shelf, that caused the hyperoblique pattern of the ranges. It is the juxtaposition of the three continental blocks: India-Asia-Burma, where there are tectonic and geomorphic influences in the Block from both the Himalayan and Indo-Burmese orogeny. Stress distribution among north-easterly moving Indian plate and comparatively stiff Eurasian and Burma plates, within the India specific reference frame, is resulting in further changes. The study area mainly falls under Changlang district of Arunachal Pradesh, India; and the regional study has been done in the quadrangle from 26° to 28°N in latitudes and 95° to 97°E in longitudes. Morphotectonic study, lineament analysis, fault system characterisation, focal plane mechanism along with dynamic topography, seismic tomography and gravity anomaly have been incorporated in the field evidences. Morphotectonic study for Noa-Dihing River basin has resulted in a value of 56.59 for Asymmetric Factor, which shows similar asymmetry result like in the Chi (χ) analysis. This SW-ward tilted basin is moderately asymmetrical with Transverse Topographic Symmetric Factor value of 0.42. This indicates that the major river basin along with other subbasins are under the influence of active oblique rotational component. The regional lineaments are showing mean orientations of N11°E-S11°W, N70°W-S70°E and EW whereas some local trends of minor lineaments, in some places have mean orientations of N40°W-S40°E, N82°WS82°E and N42°E-S42°W. In Mishmi block the major regional trends are N35°W-S35°E and N40°E-S40°W comprising of probable cross-faults. In Hukawng Block, the lineament orientation changes from N50°W-S50°E in the west to N30°W-S30°E, N-S and N15°E-S15°W in the central valley region (north of Jade mines) and then to N50°E-S50°W in the eastern side. Major fault systems are mostly thrust, with some showing very low angle slip component, along with some oblique slip faults (e.g. Noa-Dihing River). The dynamic topography and seismic tomographic studies indicate presence of a high seismic velocity zone beneath Mishmi block indicating the crystalline rock materials. The block is still actively exhuming. Moreover, Changlang and Hukawng blocks have undergone uplift and then phases of subsidence during the last 20Ma. This indicates that the Low Velocity materials that are present underneath were subjected to some crustal deformations. This tectonic process has also resulted in gravity anomalies. The role of massive and rigid Mishmi block, comprising older crystalline rocks and, later forming Burma basins formed the oblique rotation of the Changlang block which is observed from all stated methods. Hukawng Block, which is controlled by the motion of Sagaing Fault, have influenced the Changlang Block by its varied strike-slip stress components. Moreover, Indo-Burmese Ranges also has an influence on this block and vice-versa.

Indian journal of applied research, Oct 1, 2011

Geomorphology, Dec 1, 1999

The sequential changes in the position of banklines as a result of bank erosion, as well as vario... more The sequential changes in the position of banklines as a result of bank erosion, as well as various changes in the channel have been studied in the Subansiri river in Assam, India. The study was carried out from available topographic maps of 1920, 1970 and satellite imagery of 1990. The types of changes taking place in the Subansiri river channel as observed from Ž. the above-mentioned maps and imagery are grouped into four categories: 1 alteration of the direction of flow due to neck Ž. Ž. Ž. cutoff , 2 widening of a channel in response to bar development, 3 development and subsequent abandonment of Ž. anabranches, and 4 progressive shifting of meander bends. The river channel has become substantially wider during the period of 1970-1990. There has also been a progressive increase in the number and area of mid-channel bars with a corresponding decrease in the number and area of point bars during 1920-1990. These periodic and progressive changes are responsible for a change in channel pattern of the river. A study made on nature and amount of change in the banklines of Ž. the Subansiri river by dividing the channel 84 km in 1970 into 10 equal segments reveals that the types of change are varied, and in some cases chaotic in nature. Study of the bankline shift of the Subansiri determined separately for the periods 1920-1970, 1970-1990 and 1920-1990 at 20 evenly spaced transverse sections reveals that there has been a substantial westward shift of both the banklines, up to a maximum of 6 km, in the three upstream sections during 1920-1970. However, shifting of banklines in both directions and the unequal amount of shifting in the same direction have caused a marked increase in channel width during 1970-1990. It is found that due to bankline migration, the total amount of area eroded along the entire course under study during 1920-1970 and 1970-1990 are 107.90 and 57.50 km 2 , respectively. The overall sinuosity which was 1.51 in 1920 has decreased to 1.30 in 1970, while the corresponding braiding intensity has increased from 0.79 to 1.32. The river channel seems to make a remarkable change from a meandering pattern in 1920 towards a braided pattern by 1990 as seen from gradual increase in overall braiding intensity.

Journal of Earth System Science, Feb 5, 2021

Abstract Many springs occur in and around Pasighat. Eight major springs of the area were consider... more Abstract Many springs occur in and around Pasighat. Eight major springs of the area were considered for the study. These springs are Dimple type, Fault dam type, and a combination of Fault dam and Border type. The highest discharge is 263.23 L/sec and the lowest is 1.91 L/sec. The aquifers are terrace deposits that comprise of unsorted boulders, cobbles and pebbles in sandy matrix and the springs occur at the base of different terrace levels. Due to the scarcity of dug wells or deep tube wells, subsurface investigations were done using vertical electric sounding (VES). VES data generated at six locations show H-type situation. The aquifers are at shallow depth, unconfined, and have good hydrogeological prospects. At the T 2 terrace, volume of water stored is 42,14,512.5 m 3 and the combined discharge of springs is 38,257.92 m 3 /day. These springs are recharged by precipitation and influent streams. Springs of the study area are aligned along the Himalayan Frontal Thrust (HFT) and its splays, and they have a major role in the evolution of these springs. The springs were formed due to topographic breaks and less permeable collapsed debris. Local people use spring water for the household, irrigation, laundry, and fisheries. Research highlights (i) Springs present along the base of the terraces have the highest discharge of 263.23 L/sec. (ii) These springs are genetically related to HFT. (iii) Terrace aquifers are suitable for groundwater development and groundwater flows from influent streams and foothill regions towards Siang River. (iv) Spring water is used by local people for household, irrigation, laundry, and fisheries and proper management of these springs will ensure good supply of water in future.

Journal of the Geological Society of India

IOP Conference Series: Earth and Environmental Science

Subansiri River is the largest tributary of the Brahmaputra River running through the Indian stat... more Subansiri River is the largest tributary of the Brahmaputra River running through the Indian states of Assam and Arunachal Pradesh, and Tibet, the Autonomous Region of China. The Subansiri River is 442 km long with a drainage basin of 32,640 km2 and it contributes approximately 7.92% of the Brahmaputra’s total flow. Sequential Channel shifting has been witnessed as the most important characteristic of the Subansiri River of Assam. The detailed study on channel migration of the present course of the Subansiri River through the upper floodplain of Brahmaputra valley indicates that the area is under active erosion for a long time. Therefore, an attempt has been made to understand the relationship between the rate of channel migration and successive land use/land cover changes in its surrounding floodplain area. The Support Vector Machine (SVM) and the Artificial Neural Network (ANN) algorithms are applied on Landsat images of the years 1973, 1988, 2001, and 2017 for generating land use...

change detection study of some of the urban areas of Assam, India

International Journal of Advanced Remote Sensing and GIS, 2017

Groundwater prospect evaluation in the interfluves of the Rivers Brahmaputra and Kolong, Assam ha... more Groundwater prospect evaluation in the interfluves of the Rivers Brahmaputra and Kolong, Assam has been studied by considering the geomorphology, lithology, drainage pattern and drainage density, slope and land use/land cover (LU/LC) of the area. The major geomorphic, lithologic and land use/land cover units of the area have been identified and delineated from satellite imageries. Slope map and drainage map of the study area were generated from the SOI toposheets as well as from the satellite imageries. The drainage density map was generated from drainage network of the interfluves using GIS. To demarcate the different groundwater prospect zones of the study area, all the thematic layers are integrated by raster index overlay technique in GIS. Weights are assigned to different thematic layers and ranks are assigned to different categories/classes of the thematic layers for the overlay analysis in GIS. The resultant map was classified into groundwater prospect zones as very good, goo...

Remote Sensing is an efficient tool for change detection of land cover/forest cover/urban mapping... more Remote Sensing is an efficient tool for change detection of land cover/forest cover/urban mapping incorporating satellite imagery. It not only provides us with the extents but also indicates some cultural, political and ecological impacts due to which the changes have occurred or land cover is tempered. The images indicate such changes in the urban areas of Assam. From these images the severity and extent of deforestation is an eye-opener. In Assam along the Brahmaputra and the riverine tracts of its tributaries, several cities are selected where the extent and severity of deforestation is high. These cities belong to the districts of Tinsukia, Dibrugarh, Sivasagar, Jorhat, Golaghat, Nagaon, and Kamrup all along the river. The urban sprawl area is studied taking 1974 and 2009 Landsat imageries using ArcGIS online explorer. It has been found that vast changes occurred due to migration of the people to cities in search of jobs and cultural advantages, and this has resulted in the form...

Journal of Earth System Science, 2021

Many springs occur in and around Pasighat. Eight major springs of the area were considered for th... more Many springs occur in and around Pasighat. Eight major springs of the area were considered for the study. These springs are Dimple type, Fault dam type, and a combination of Fault dam and Border type. The highest discharge is 263.23 L/sec and the lowest is 1.91 L/sec. The aquifers are terrace deposits that comprise of unsorted boulders, cobbles and pebbles in sandy matrix and the springs occur at the base of different terrace levels. Due to the scarcity of dug wells or deep tube wells, subsurface investigations were done using vertical electric sounding (VES). VES data generated at six locations show H-type situation. The aquifers are at shallow depth, unconfined, and have good hydrogeological prospects. At the T 2 terrace, volume of water stored is 42,14,512.5 m 3 and the combined discharge of springs is 38,257.92 m 3 /day. These springs are recharged by precipitation and influent streams. Springs of the study area are aligned along the Himalayan Frontal Thrust (HFT) and its splays...

Paripex Indian Journal of Research, Mar 1, 2012