Pollution-free rivers give indication of a healthy ecosystem. The stretch of Tawi river particula... more Pollution-free rivers give indication of a healthy ecosystem. The stretch of Tawi river particularly in the Jammu city is experiencing pollution load and the quality is degraded. The present study highlights the impact of COVID-19 lockdown on the water quality of Tawi river in Jammu, J&K Union Territory. Water quality data based upon the real-time water monitoring for four locations (Below Tawi Bridge, Bhagwati Nagar, Belicharana and Surajpur) have been obtained from the web link of Jammu and Kashmir Pollution Control Board. The important parameters used in the present study include pH, alkalinity, hardness, conductivity, BOD and COD. The river was designated fit for bathing in all the monitoring locations except Bhagwati Nagar which recorded a BOD value [5 mg/L because of domestic sewage and municipal waste dumping. The overall water quality in the river during lockdown was good and falls in Class B with pH (7.0-8.5), alkalinity (23.25-185.0 mg/L), hardness (84.25-177.5 mg/ L), conductivity (117-268 ms/cm). The improved water quality obtained during lockdown is never long-lasting as evident from the BOD and COD values observed during Unlock 1.0 due to accelerated anthropogenic activities in response to overcoming the economic loss, bringing the river water quality back to the degraded state. The statistical analysis known as cluster analysis has also been performed to evaluate the homogeneity of various monitoring sites based on the physicochemical variables. The need of the hour is to address the gaps of rejuvenation strategies and work over them for effective river resiliency and for sustainable river basin management. Keywords Tawi river basin Á Lockdown Á Jammu city Á Water quality Á COVID-19 pandemic Energ. Ecol. Environ.
The Himalayan mountain system to the north of the Indian land mass with arcuate strike of NW-SE f... more The Himalayan mountain system to the north of the Indian land mass with arcuate strike of NW-SE for about 2400 km holds one of the largest concentration of glaciers outside the polar regions in its high-altitude regions. Perennial snow and ice-melt from these frozen reservoirs is used in catchments and alluvial plains of the three major Himalayan river systems, i.e. the Indus, Ganga and Brahmaputra for irrigation, hydropower generation, production of bio-resources and fulfilling the domestic water demand. Also, variations in the extent of these glaciers are understood to be a sensitive indicator of climatic variations of the earth system and might have implications on the availability of water resources in the river systems. Therefore, mapping and monitoring of these freshwater resources is required for the planning of water resources and understanding the impact of climatic variations. Thus a study has been carried out to find the change in the extent of Himalayan glaciers during t...
Water, Cryosphere, and Climate Change in the Himalayas, 2021
Multispectral satellite imageries analyzed that the Himalayan region reflected the fast retreat o... more Multispectral satellite imageries analyzed that the Himalayan region reflected the fast retreat of most of the glaciers. This further showed that especially the moraine-dammed proglacial lakes are also increasing. Those lakes are a major threat to property and life to downstream locations. Numerous research carried out in the Himalayan region under the changing climate and glacier status has indicated an alarming rise in the number and sizes of the glacial lakes that may be potentially disastrous when converts into the glacial lake outburst flood (GLOF). This study focusses on the glacial lakes mapping at the different time frame in the basins of Chenab, Ravi, Satluj and Beas of Himachal Himalaya using LISS III. The remotely sensed imageries on the GIS platform helped in preparing the moraine dammed glacial lake inventory and assessing the potentiality of becoming the GLOF in these basins. This is of prime importance for preparedness against disasters due to GLOFs. This requires a c...
Agriculture and Hydrology Applications of Remote Sensing, 2006
The Himalayas possess one of the largest resources of snow and ice, which act as a huge freshwate... more The Himalayas possess one of the largest resources of snow and ice, which act as a huge freshwater reservoir. Monitoring the glaciers is important to assess the overall reservoir health. In this investigation, glacial retreat was estimated for 466 glaciers in Chenab, Parbati and Baspa basins from 1962. Expeditions to Chhota Shigri, Patsio and Samudra Tapu glaciers in Chenab basin, Parbati glacier in Parbati basin and Shaune Garang glacier in Baspa basin were organized to identify and map the glacial terminus. The investigation has shown an overall reduction in glacier area from 2077 sq. km in 1962 to 1628 sq. km at present, an overall deglaciation of 21%. However, the number of glaciers has increased due to fragmentation. Mean area of glacial extent has reduced from 1.4 to 0.32 sq. km between the 1962 and 2001. In addition, the number of glaciers with higher areal extent has reduced and lower areal extent has increased during the period. Small glaciarates and ice fields have shown extensive deglaciation. For example, 127 glaciarates and ice fields less than 1 sq. km have shown retreat of 38% from 1962, possibly due to small response time. This indicates that a combination of glacial fragmentation, higher retreat of small glaciers and climate change are influencing the sustainability of Himalayan glaciers.
Remote sensing satellite data have been used to recognize structures having tectonic significance... more Remote sensing satellite data have been used to recognize structures having tectonic significance. Based on satellite data, lineament map of Nurpur and its adjoining area of Kangra district, Himachal Pradesh, India, has been generated. LR-115 plastic track detectors have been used for the measurement of soil gas radon at 71 different locations of the study area. The results indicate zones of tectonically induced soil gas radon and the lineament density, which are co-relatable with the regional geology of the area.
Soil-gas activity in the vicinity of neotectonic fault zones within the Dharamsala area in the re... more Soil-gas activity in the vicinity of neotectonic fault zones within the Dharamsala area in the region of the NW Himalayas, India, has been investigated by determining enhanced concentration values of radon and helium in the soil, using an ionization chamber and an ASM 100 HDS (Alcatel), respectively. A geological map of the area was used for site selection and to locate the predicted courses of faults. Elevated levels of radon and helium in the soil gas were found along a profile of a major fault (MBT-2). Radon shows variation not only due to the tectonic structures but also due to change in lithology. Helium and radon anomalies together show that apart from conspicuous thrust MBT-2, the area under study is cut across by the N-S transverse faults/lineaments.
The present research is aimed at accessing the relationship between variation in the soil gases r... more The present research is aimed at accessing the relationship between variation in the soil gases radon (222 Rn) and helium (4 He) and recently developed fissures and other neotectonic features in Nurpur and Nadha areas of the NW Himalayas, India. Two soil-gas surveys were conducted on/near known faults to reconfirm their position using soil gas technique and to check their present activity. During these surveys, soil-gas samples were collected along traverses crossing the observed structures. The data analysis reveals that the concentrations of radon and helium along the Dehar lineament and the longitudinal profile (Profile D) are very high compared to any other thrust/lineament of the Nurpur area. The Nadha area shows high values of radon and helium concentrations along/near the Himalayan Frontal Fault (HFF) as compared to the adjoining areas. This indicates the presence of some buried fault/fault zone running parallel to the HFF, not exposed to the surface and not delineated by satellite data but is geochemically active and might be tectonically active too. Hence, soil helium and radon gas patterns have been combined with morphological and geological observations to supply useful constraints for deformation of tectonic environments.
The continuous soil gas radon monitoring is carried out at Palampur and the daily monitoring of r... more The continuous soil gas radon monitoring is carried out at Palampur and the daily monitoring of radon concentration in water is carried out at Dharamshala region of Kangra valley of North West Himalayas, India, a seismic zone V, to study the correlation of radon anomalies in relation to seismic activities. In this study, radon monitoring in soil was carried out by using barasol probe manufactured by Algade France, whereas the radon content in water was recorded using RAD 7 radon monitoring system of Durridge Company USA. The effect of meteorological parameters viz. temperature, pressure, wind velocity, rainfall, and humidity on radon emission has been studied. The seasonal average value and standard deviation of radon in soil and water is calculated to find the radon anomaly to minimize the effect of meteorological parameters on radon emission. The radon anomalies observed in the region have been correlated with the seismic events of MZ2 reported by Wadia Institute of Himalayas Geology Dehradoon and Indian Meteorological Department, New Delhi in NW Himalayas within 250 km distance from the monitoring stations.
Himalayas is a byproduct of the continent-to-continent collision due to the convergent movement o... more Himalayas is a byproduct of the continent-to-continent collision due to the convergent movement of the Indian plate towards Eurasian plate. Dharamsala area of NW Himalayas falls on the southern slope of the Dhauladhar range. The area is seismically active and falls in the High Seismic Zone V of the Seismic Map of India. Diverse lithology within a short span of distance makes the study area tectonically significant. A geochemical soil-gas survey has been conducted in the Dharamsala region. Transverse profiles have been taken across the Main Boundary Thrust 2 (MBT2) and some lineaments in Dharamsala and surrounding areas. To carry out the present investigation soil-gas samples were collected in sample bags at depth of about 0.7-1.0 m by using hollow steel probe. The collected soil-gas sample bags are analyzed for radon and helium. The radon concentration varies from 37 to 754 kBq/m3 and that of helium varies from 5.24 to 5.46 ppm. Anomalous values are found on MBT-2 and other tectonic features present in the area. The data analysis clearly reveals anomalous values of subsurface gases along the fault and lineaments.
Geomorphometric studies of Gaj watershed of Beas river basin, District- Kangra, Himachal Pradesh ... more Geomorphometric studies of Gaj watershed of Beas river basin, District- Kangra, Himachal Pradesh reveal accelerating land degradation due to sensitive and fragile geology of the area. The area under study falls in the Frontal Himalayan Zone which is characterized by higher values of erosional intensity that is related to the lithology, geomorphology and tectonic character of the area. In the present paper, an attempt has been made to understand evolution of landforms and degradational processes operating in the study area using morphometric analysis. Keywords : Geomorphometry, Watershed, Tectonic setting, Relief, Stream Order, Erosion intensity, Drainage density
The continuous soil gas radon and daily monitoring of radon concentration in water is carried out... more The continuous soil gas radon and daily monitoring of radon concentration in water is carried out at Amritsar (Punjab, India), a well known seismic zone to study the correlation of radon anomalies in relation to seismic activities in the study area. In this study, radon monitoring in soil was carried out by using barasol probe (BMC2) manufactured by Algade France whereas the radon content in water was recorded using RAD7 radon monitoring system of Durridge Company USA. The radon anomalies observed in the region have been correlated with the seismic events of M ≥ 2 recorded in NW Himalayas by Wadia Institute of Himalayas Geology Dehradun and Indian Meteorological Department, New Delhi. The effect of meteorological parameters; temperature, pressure, wind velocity and rainfall on radon emission has been studied. The correlation coefficient between radon and meteorological parameters has been calculated. Correlation coefficients (R) between radon anomaly (A), epicentral distance (D), ea...
Terrestrial, Atmospheric and Oceanic Sciences, 2010
Continuous monitoring of soil gas radon at Sarol and the daily monitoring of radon concentration ... more Continuous monitoring of soil gas radon at Sarol and the daily monitoring of radon concentration in water at Banikhet is carried out in Chamba valley of North West Himalayas, India "a well known seismic zone" to study the correlation of radon anomalies in relation to seismic activities of the region. Radon monitoring in soil gas was carried out by using Barasol probe manufactured by Algade France and the radon content in water was recorded using RAD7 radon monitoring system of Durridge Company, USA. The effect of meteorological parameters viz. temperature and pressure on soil gas radon emission has been studied. Correlation coefficient has been calculated between radon in soil gas, soil temperature and soil pressure. The radon anomalies observed in the region have been correlated with the seismic events in the magnitude range 2.2 to 5.0 recorded by Wadia Institute of Himalayan Geology Dehradun in NW Himalayan. Empirical equations between earthquake magnitude, epicentral distance and precursor time were examined, and respective constants were determined.
Journal of the Indian Society of Remote Sensing, 2010
Peri-glacial studies of the Samudra Tapu glacier reveal three stages of well preserved moraines w... more Peri-glacial studies of the Samudra Tapu glacier reveal three stages of well preserved moraines which are also marked by fluvial overprinting. The signatures of fluvial outwashes over the otherwise morainal deposits have been utilized in estimating the extent of palaeo-lake in the valley of Samudra Tapu glacier of the Chandra basin. Distance and thickness of snout of the glacier and its morainal deposits is estimated by the Laser Range Finder. With the change in the position of the snout there is a change in the extent and orientation of the lake. Recent expedition to the glacier confirms this process to be continuing. The study is important in reconstructing formation of the lake with respect to snout position of the glacier. Based on ground truth, fast melting of the snout is confirmed from year 2004 onwards, with the development of fresh end/terminal moraine. The study reveals that the snout region of the Samudra Tapu glacier is thinning and retreating at an alarming rate and is enlarging the lake extent. The development of fresh terminal moraine has the potential to impound the fast melting glacial waters which in turn can pose serious threat to the downstream regions of the Chandra valley.
Figure 1 Map showing the location of monitoring stations in NW Himalayas, India, where MCT denote... more Figure 1 Map showing the location of monitoring stations in NW Himalayas, India, where MCT denotes main central thrust, and MBT denotes main boundary thrust.
ABSTRACT Landslides are common in Himalaya due to high relief, weak, tectonised& highly w... more ABSTRACT Landslides are common in Himalaya due to high relief, weak, tectonised& highly weathered rocks, glacial debris and man-made activities like road construction and step cultivation. The triggering of landslides are caused mainly due to prolonged or high intensity rainfall. Losses caused due to landslide are over 200 deaths and Rs. 550 crore annually in Himalaya. It is therefore a necessity to assess Landslide Risk. Remote sensing and GIS is an effective tool for the assessment of landslide susceptibility at regional scale. The area for current research study is Chamoli- Joshimath region. Satellite data, toposheets, digital elevation model data, field observations and satellite based rainfall data are used as input data in this study. Various thematic layers, i.e., lithology, fault, lineament, geomorphology, drainage, slope angle, slope aspect, landuse /land cover, soil texture, and soil depth are generated by manual remote sensing based interpretations. Subsequently these thematic layers are integrated based on predefined rankings and weightages calculated using map algebra in GIS environment for generation of Landslide Susceptibility maps.The results show that this approach for the susceptibility evaluation is fairly accurate and precise after field validation.Landslide susceptibility map that gives spatial probability of landslides in conjunction with empirical rainfall thresholds can be used to warn the residents and local authorities about the hazard early on. In future, we plan to use the generated landslide susceptibility maps for risk perceptions studies in the area of interest.
Pollution-free rivers give indication of a healthy ecosystem. The stretch of Tawi river particula... more Pollution-free rivers give indication of a healthy ecosystem. The stretch of Tawi river particularly in the Jammu city is experiencing pollution load and the quality is degraded. The present study highlights the impact of COVID-19 lockdown on the water quality of Tawi river in Jammu, J&K Union Territory. Water quality data based upon the real-time water monitoring for four locations (Below Tawi Bridge, Bhagwati Nagar, Belicharana and Surajpur) have been obtained from the web link of Jammu and Kashmir Pollution Control Board. The important parameters used in the present study include pH, alkalinity, hardness, conductivity, BOD and COD. The river was designated fit for bathing in all the monitoring locations except Bhagwati Nagar which recorded a BOD value [5 mg/L because of domestic sewage and municipal waste dumping. The overall water quality in the river during lockdown was good and falls in Class B with pH (7.0-8.5), alkalinity (23.25-185.0 mg/L), hardness (84.25-177.5 mg/ L), conductivity (117-268 ms/cm). The improved water quality obtained during lockdown is never long-lasting as evident from the BOD and COD values observed during Unlock 1.0 due to accelerated anthropogenic activities in response to overcoming the economic loss, bringing the river water quality back to the degraded state. The statistical analysis known as cluster analysis has also been performed to evaluate the homogeneity of various monitoring sites based on the physicochemical variables. The need of the hour is to address the gaps of rejuvenation strategies and work over them for effective river resiliency and for sustainable river basin management. Keywords Tawi river basin Á Lockdown Á Jammu city Á Water quality Á COVID-19 pandemic Energ. Ecol. Environ.
The Himalayan mountain system to the north of the Indian land mass with arcuate strike of NW-SE f... more The Himalayan mountain system to the north of the Indian land mass with arcuate strike of NW-SE for about 2400 km holds one of the largest concentration of glaciers outside the polar regions in its high-altitude regions. Perennial snow and ice-melt from these frozen reservoirs is used in catchments and alluvial plains of the three major Himalayan river systems, i.e. the Indus, Ganga and Brahmaputra for irrigation, hydropower generation, production of bio-resources and fulfilling the domestic water demand. Also, variations in the extent of these glaciers are understood to be a sensitive indicator of climatic variations of the earth system and might have implications on the availability of water resources in the river systems. Therefore, mapping and monitoring of these freshwater resources is required for the planning of water resources and understanding the impact of climatic variations. Thus a study has been carried out to find the change in the extent of Himalayan glaciers during t...
Water, Cryosphere, and Climate Change in the Himalayas, 2021
Multispectral satellite imageries analyzed that the Himalayan region reflected the fast retreat o... more Multispectral satellite imageries analyzed that the Himalayan region reflected the fast retreat of most of the glaciers. This further showed that especially the moraine-dammed proglacial lakes are also increasing. Those lakes are a major threat to property and life to downstream locations. Numerous research carried out in the Himalayan region under the changing climate and glacier status has indicated an alarming rise in the number and sizes of the glacial lakes that may be potentially disastrous when converts into the glacial lake outburst flood (GLOF). This study focusses on the glacial lakes mapping at the different time frame in the basins of Chenab, Ravi, Satluj and Beas of Himachal Himalaya using LISS III. The remotely sensed imageries on the GIS platform helped in preparing the moraine dammed glacial lake inventory and assessing the potentiality of becoming the GLOF in these basins. This is of prime importance for preparedness against disasters due to GLOFs. This requires a c...
Agriculture and Hydrology Applications of Remote Sensing, 2006
The Himalayas possess one of the largest resources of snow and ice, which act as a huge freshwate... more The Himalayas possess one of the largest resources of snow and ice, which act as a huge freshwater reservoir. Monitoring the glaciers is important to assess the overall reservoir health. In this investigation, glacial retreat was estimated for 466 glaciers in Chenab, Parbati and Baspa basins from 1962. Expeditions to Chhota Shigri, Patsio and Samudra Tapu glaciers in Chenab basin, Parbati glacier in Parbati basin and Shaune Garang glacier in Baspa basin were organized to identify and map the glacial terminus. The investigation has shown an overall reduction in glacier area from 2077 sq. km in 1962 to 1628 sq. km at present, an overall deglaciation of 21%. However, the number of glaciers has increased due to fragmentation. Mean area of glacial extent has reduced from 1.4 to 0.32 sq. km between the 1962 and 2001. In addition, the number of glaciers with higher areal extent has reduced and lower areal extent has increased during the period. Small glaciarates and ice fields have shown extensive deglaciation. For example, 127 glaciarates and ice fields less than 1 sq. km have shown retreat of 38% from 1962, possibly due to small response time. This indicates that a combination of glacial fragmentation, higher retreat of small glaciers and climate change are influencing the sustainability of Himalayan glaciers.
Remote sensing satellite data have been used to recognize structures having tectonic significance... more Remote sensing satellite data have been used to recognize structures having tectonic significance. Based on satellite data, lineament map of Nurpur and its adjoining area of Kangra district, Himachal Pradesh, India, has been generated. LR-115 plastic track detectors have been used for the measurement of soil gas radon at 71 different locations of the study area. The results indicate zones of tectonically induced soil gas radon and the lineament density, which are co-relatable with the regional geology of the area.
Soil-gas activity in the vicinity of neotectonic fault zones within the Dharamsala area in the re... more Soil-gas activity in the vicinity of neotectonic fault zones within the Dharamsala area in the region of the NW Himalayas, India, has been investigated by determining enhanced concentration values of radon and helium in the soil, using an ionization chamber and an ASM 100 HDS (Alcatel), respectively. A geological map of the area was used for site selection and to locate the predicted courses of faults. Elevated levels of radon and helium in the soil gas were found along a profile of a major fault (MBT-2). Radon shows variation not only due to the tectonic structures but also due to change in lithology. Helium and radon anomalies together show that apart from conspicuous thrust MBT-2, the area under study is cut across by the N-S transverse faults/lineaments.
The present research is aimed at accessing the relationship between variation in the soil gases r... more The present research is aimed at accessing the relationship between variation in the soil gases radon (222 Rn) and helium (4 He) and recently developed fissures and other neotectonic features in Nurpur and Nadha areas of the NW Himalayas, India. Two soil-gas surveys were conducted on/near known faults to reconfirm their position using soil gas technique and to check their present activity. During these surveys, soil-gas samples were collected along traverses crossing the observed structures. The data analysis reveals that the concentrations of radon and helium along the Dehar lineament and the longitudinal profile (Profile D) are very high compared to any other thrust/lineament of the Nurpur area. The Nadha area shows high values of radon and helium concentrations along/near the Himalayan Frontal Fault (HFF) as compared to the adjoining areas. This indicates the presence of some buried fault/fault zone running parallel to the HFF, not exposed to the surface and not delineated by satellite data but is geochemically active and might be tectonically active too. Hence, soil helium and radon gas patterns have been combined with morphological and geological observations to supply useful constraints for deformation of tectonic environments.
The continuous soil gas radon monitoring is carried out at Palampur and the daily monitoring of r... more The continuous soil gas radon monitoring is carried out at Palampur and the daily monitoring of radon concentration in water is carried out at Dharamshala region of Kangra valley of North West Himalayas, India, a seismic zone V, to study the correlation of radon anomalies in relation to seismic activities. In this study, radon monitoring in soil was carried out by using barasol probe manufactured by Algade France, whereas the radon content in water was recorded using RAD 7 radon monitoring system of Durridge Company USA. The effect of meteorological parameters viz. temperature, pressure, wind velocity, rainfall, and humidity on radon emission has been studied. The seasonal average value and standard deviation of radon in soil and water is calculated to find the radon anomaly to minimize the effect of meteorological parameters on radon emission. The radon anomalies observed in the region have been correlated with the seismic events of MZ2 reported by Wadia Institute of Himalayas Geology Dehradoon and Indian Meteorological Department, New Delhi in NW Himalayas within 250 km distance from the monitoring stations.
Himalayas is a byproduct of the continent-to-continent collision due to the convergent movement o... more Himalayas is a byproduct of the continent-to-continent collision due to the convergent movement of the Indian plate towards Eurasian plate. Dharamsala area of NW Himalayas falls on the southern slope of the Dhauladhar range. The area is seismically active and falls in the High Seismic Zone V of the Seismic Map of India. Diverse lithology within a short span of distance makes the study area tectonically significant. A geochemical soil-gas survey has been conducted in the Dharamsala region. Transverse profiles have been taken across the Main Boundary Thrust 2 (MBT2) and some lineaments in Dharamsala and surrounding areas. To carry out the present investigation soil-gas samples were collected in sample bags at depth of about 0.7-1.0 m by using hollow steel probe. The collected soil-gas sample bags are analyzed for radon and helium. The radon concentration varies from 37 to 754 kBq/m3 and that of helium varies from 5.24 to 5.46 ppm. Anomalous values are found on MBT-2 and other tectonic features present in the area. The data analysis clearly reveals anomalous values of subsurface gases along the fault and lineaments.
Geomorphometric studies of Gaj watershed of Beas river basin, District- Kangra, Himachal Pradesh ... more Geomorphometric studies of Gaj watershed of Beas river basin, District- Kangra, Himachal Pradesh reveal accelerating land degradation due to sensitive and fragile geology of the area. The area under study falls in the Frontal Himalayan Zone which is characterized by higher values of erosional intensity that is related to the lithology, geomorphology and tectonic character of the area. In the present paper, an attempt has been made to understand evolution of landforms and degradational processes operating in the study area using morphometric analysis. Keywords : Geomorphometry, Watershed, Tectonic setting, Relief, Stream Order, Erosion intensity, Drainage density
The continuous soil gas radon and daily monitoring of radon concentration in water is carried out... more The continuous soil gas radon and daily monitoring of radon concentration in water is carried out at Amritsar (Punjab, India), a well known seismic zone to study the correlation of radon anomalies in relation to seismic activities in the study area. In this study, radon monitoring in soil was carried out by using barasol probe (BMC2) manufactured by Algade France whereas the radon content in water was recorded using RAD7 radon monitoring system of Durridge Company USA. The radon anomalies observed in the region have been correlated with the seismic events of M ≥ 2 recorded in NW Himalayas by Wadia Institute of Himalayas Geology Dehradun and Indian Meteorological Department, New Delhi. The effect of meteorological parameters; temperature, pressure, wind velocity and rainfall on radon emission has been studied. The correlation coefficient between radon and meteorological parameters has been calculated. Correlation coefficients (R) between radon anomaly (A), epicentral distance (D), ea...
Terrestrial, Atmospheric and Oceanic Sciences, 2010
Continuous monitoring of soil gas radon at Sarol and the daily monitoring of radon concentration ... more Continuous monitoring of soil gas radon at Sarol and the daily monitoring of radon concentration in water at Banikhet is carried out in Chamba valley of North West Himalayas, India "a well known seismic zone" to study the correlation of radon anomalies in relation to seismic activities of the region. Radon monitoring in soil gas was carried out by using Barasol probe manufactured by Algade France and the radon content in water was recorded using RAD7 radon monitoring system of Durridge Company, USA. The effect of meteorological parameters viz. temperature and pressure on soil gas radon emission has been studied. Correlation coefficient has been calculated between radon in soil gas, soil temperature and soil pressure. The radon anomalies observed in the region have been correlated with the seismic events in the magnitude range 2.2 to 5.0 recorded by Wadia Institute of Himalayan Geology Dehradun in NW Himalayan. Empirical equations between earthquake magnitude, epicentral distance and precursor time were examined, and respective constants were determined.
Journal of the Indian Society of Remote Sensing, 2010
Peri-glacial studies of the Samudra Tapu glacier reveal three stages of well preserved moraines w... more Peri-glacial studies of the Samudra Tapu glacier reveal three stages of well preserved moraines which are also marked by fluvial overprinting. The signatures of fluvial outwashes over the otherwise morainal deposits have been utilized in estimating the extent of palaeo-lake in the valley of Samudra Tapu glacier of the Chandra basin. Distance and thickness of snout of the glacier and its morainal deposits is estimated by the Laser Range Finder. With the change in the position of the snout there is a change in the extent and orientation of the lake. Recent expedition to the glacier confirms this process to be continuing. The study is important in reconstructing formation of the lake with respect to snout position of the glacier. Based on ground truth, fast melting of the snout is confirmed from year 2004 onwards, with the development of fresh end/terminal moraine. The study reveals that the snout region of the Samudra Tapu glacier is thinning and retreating at an alarming rate and is enlarging the lake extent. The development of fresh terminal moraine has the potential to impound the fast melting glacial waters which in turn can pose serious threat to the downstream regions of the Chandra valley.
Figure 1 Map showing the location of monitoring stations in NW Himalayas, India, where MCT denote... more Figure 1 Map showing the location of monitoring stations in NW Himalayas, India, where MCT denotes main central thrust, and MBT denotes main boundary thrust.
ABSTRACT Landslides are common in Himalaya due to high relief, weak, tectonised& highly w... more ABSTRACT Landslides are common in Himalaya due to high relief, weak, tectonised& highly weathered rocks, glacial debris and man-made activities like road construction and step cultivation. The triggering of landslides are caused mainly due to prolonged or high intensity rainfall. Losses caused due to landslide are over 200 deaths and Rs. 550 crore annually in Himalaya. It is therefore a necessity to assess Landslide Risk. Remote sensing and GIS is an effective tool for the assessment of landslide susceptibility at regional scale. The area for current research study is Chamoli- Joshimath region. Satellite data, toposheets, digital elevation model data, field observations and satellite based rainfall data are used as input data in this study. Various thematic layers, i.e., lithology, fault, lineament, geomorphology, drainage, slope angle, slope aspect, landuse /land cover, soil texture, and soil depth are generated by manual remote sensing based interpretations. Subsequently these thematic layers are integrated based on predefined rankings and weightages calculated using map algebra in GIS environment for generation of Landslide Susceptibility maps.The results show that this approach for the susceptibility evaluation is fairly accurate and precise after field validation.Landslide susceptibility map that gives spatial probability of landslides in conjunction with empirical rainfall thresholds can be used to warn the residents and local authorities about the hazard early on. In future, we plan to use the generated landslide susceptibility maps for risk perceptions studies in the area of interest.
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