Browsing by Author "Chand, Pritam"

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Analyzing shoreline dynamicity and the associated socioecological risk along the Southern Odisha Coast of India using remote sensing-based and statistical approaches
(Taylor and Francis Ltd., 2021-02-06T00:00:00) Mishra, Manoranjan; Acharyya, Tamoghna; Chand, Pritam; Santos, Celso Augusto Guimar�es; Kar, Dipika; Das, Prabhu Prasad; Pattnaik, Namita; Silva, Richarde Marques da; Nascimento, Thiago Victor Medeiros do
The coastal zone is an extremely volatile environment and is constantly changing. We assessed short- and long-term shoreline changes in the Ganjam district of Odisha on the eastern coast of India from 1990 to 2019 using Landsat satellite imagery and the Digital Shoreline Analysis System (DSAS) tool in a geographic information system. In addition, we have also projected the likely future coastline position for the 2030�2040 period and the possible impact on the socioecology of the shoreline. In this study, we used the endpoint rate (EPR) analysis, weighted linear regression (WLR) analysis, and trigonometric functions to analyze the shoreline from 1990 to 2019 and also forecasted for year 2030 and 2040. The shoreline of the Ganjam coastal zone is one of the most biologically productive ecosystems in the world, and it is well-known due to the breeding and mass nesting grounds of olive ridley turtles and the economically connected ports, famous beaches, and cyclone-prone areas. During the study period (1990�2019), the average erosion and accretion rates in the Ganjam shoreline were ?2.58 m/year and 11.63 m/year, respectively. The rate of shoreline erosion increased during years of cyclone landfall, which was revealed during the short-term shoreline analysis of the periods from 1995 to 2000 (1999 super cyclone) and 2015 to 2019 (2019 category�IV cyclone Fani). The short- to long-term analyses of the shoreline assisted in identifying erosion (Ramyapatna, Podampetta) and accretion (southern part of Gopalpur port, spits along the Bahuda and Rushikulya Rivers) hotspots within the Ganjam coastal zone. The identified erosion hotspots could submerge a significant number of coastal villages that serve as breeding and mass nesting grounds for olive ridley turtles. The dominant erosion along the Ganjam coastline are likely to enhance socioecological risk and further threaten coastal communities in the future. The output of the undertaken research will benefit coastal planners, policymakers, and conservationists by helping them to formulate the most suitable action plan for coastal zone management with consideration of all stakeholders. � 2021 Informa UK Limited, trading as Taylor & Francis Group.
Assessment of Existing Himalayan Glacier Inventories for Glacier Studies: A Case Study from the Ravi Basin of North-Western Himalaya (India)
(Springer International Publishing, 2023-03-10T00:00:00) Ahmed, Ishtiaq; Sharma, Vikram; Kumar, Rinku; Lal, Devi; Bhandari, Rajan; Chand, Pritam
Outside of the polar regions, the Hindukush-Karakoram-Himalaya (HKH) has the highest cluster of snow cover and glaciers, which offer various ecosystem services, including water, to the billions of people who live across this region. A glacier inventory is a vital prerequisite for researching a wide range of diverse phenomena, processes, and effects of such glacier changes across these regions. In recent years, several glacier inventories are available for the HKH region, namely, the Geological Survey of India (GSI) Glacier Inventory, the Space Application Center (SAC) Glacier Inventory, the International Centre for Integrated Mountain Development (ICIMOD) Glacier Inventory, Randolph Glacier Inventory (RGI), and Glacier Area Mapping for Discharge from the Asian Mountains (GAMDAM) Glacier Inventory (GGI). Prior to being used for any glacier investigations, it�s critical to evaluate the quality and consistency of these inventory datasets. Thus, the current study provides a detailed quality assessment of all these available glacier inventories by comparing them with the detailed Ravi basin glacier inventory (RBGI). The comprehensive RBGI was created using the Landsat Enhanced Thematic Mapper (ETM+) images (2002) with a supplement of medium- to high-resolution imagery and field validations. The RBGI consists of 285 glaciers in 2002 with a mapped area of 164.5 � 7.5 km2. There are 71 glaciers out of the total glaciers that have debris-covered parts, which occupy 36.1 � 2.1 km2 (~22% of the whole area covered by glaciers). Large variations were found in the glacial area (ranging from 202 to 112.7 km2) and a total number of glaciers (ranging from 299 to 192) mapped within the Ravi basin among these available glacier inventories. With few spatial differences in the total number of the glacier, their extent, and median elevation, it was found that the recently updated GGI inventory, which is incorporated into the revised version of RGI V6 for the Himalayan region, is most comparable to our RBGI inventory. Likely causes of the significant difference among these inventories include standard glacier definition (minimum area of glacier mapping and headwall definition), misinterpretation of the seasonal snow cover, demarcation of debris-covered areas, and consequences of excluding glacier sections in the shaded regions. � The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2023.
Characteristics of surge-type tributary glaciers, Karakoram
(Elsevier B.V., 2022-02-10T00:00:00) Bhambri, Rakesh; Hewitt, Kenneth; Haritashya, Umesh K.; Chand, Pritam; Kumar, Amit; Verma, Akshaya; Tiwari, Sameer Kumar; Rai, Santosh Kumar
The Karakoram has a large concentration of surge-type glaciers, including 69 tributary glaciers, compared to 152 surge-type main or trunk glaciers. The paper addresses the interactions between tributary and trunk glaciers using digital elevation models (DEMs), surface displacement, field and archival reports. In particular, it explores the behavior and impacts of 13 tributary glacier surges on three trunk glaciers, namely the Hispar, Braldu and Panmah. Observations include five surge tributaries of Panmah, five of Braldu, and three of Hispar. We observed ASTER DEMs can help in some cases to detect surge signature where automated surface displacement does not detect the surge. We also observed substantial differences in surge dimensions, timing and histories of the main trunk glacier and their tributaries. East Braldu III tributary surged between 2000 and 2003, whereas East Braldu IV surged from 2003 to 2006, but in these periods, no other tributary shows surge signature. Between 2013 and 2016, Braldu trunk Glacier surged along with four tributaries out of five except West Braldu I. Volumes and geometry of ice transferred from tributary to trunk glaciers are unique to each case, but the surging ice melted rapidly in about 2 to 4 years for some cases such as Little Skamri and Drenmang. The tributary ice modified all studied trunk glacier dynamics, morphology, distribution of debris and hypsography. The ice transferred from tributaries such as Little Skamri and Drenmang blocked the flow of trunk Nobande Sobonde Glacier from 2004 to 2006. Such ice transfer by surge tributaries to the main trunk glacier is referred here as surge-modified ice. It introduces indirect and post-surge effects and complicates or delay in tracking glacier responses to climate change. Also, mass balance in surge-type and surge-modified glaciers differ from systematic direct responses to climate in non-surge-type glaciers. Therefore, more research and monitoring are required to address the distinct responses of such glaciers and individual tributaries to better understand the heterogeneity of surging glaciers in Karakoram. � 2022 Elsevier B.V.
Climate Change Adaptation, Risk Management and Sustainable Practices in the Himalaya
(Springer International Publishing, 2023-03-10T00:00:00) Sharma, Sanjeev; Kuniyal, Jagdish Chandra; Chand, Pritam; Singh, Pardeep
This volume analyzes ecological and socio-economic risks due to climate change in the Himalayan mountain ecosystems, communities, and proposes adaptation strategies and sustainability practices. In order to better understand the potential actions required to improve natural resource conservation and the development of mountain people's livelihoods. The authors discuss the current status of local knowledge system on various environmental aspects of conservation and sustainable use of mountain resources in the Himalaya. The book addresses the institutional capacities, gaps, and priority areas of capacity building to strengthen policies and governance in regard to climate change, landuse management, biodiversity conservation, and sustainable management in the Himalayan region. The aim of this book is to enhance coordination building among policymakers, planners, mountain communities to foster collaboration between different stakeholders by understanding local perceptions of climate change as well as variability issues, and establishing adaptation strategies to cope with these impacts. The chapters incorporate theoretical and applied aspects, and may serve as baseline information for the sustainability of mountain ecosystems through the contribution of multidisciplinary and interdisciplinary expertise from the Himalayan region. The book will be useful for students, teachers, and researchers working in different areas pertaining to mountain ecosystems, as well as policymakers and planners working on issues related to the sustainability of the mountain ecosystem. � The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2023.
Contextualizing the lake ecosystem syndromes and research development activities in Chilika Lake (Odisha coast, India): a bibliometric overview (1970�2021)
(Springer Science and Business Media B.V., 2023-05-25T00:00:00) Acharyya, Tamoghna; Sudarsan, Desul; Mishra, Manoranjan; Santos, Celso Augusto Guimar�es; Chand, Pritam; da Silva, Richarde Marques; Pradhan, Subhasis
Chilika Lagoon is traditionally known as a productive study site for various areas of knowledge. It is also well-known for its successful ecological restoration in 2000, following ecological degradation due to siltation and proliferation of weeds in the 1980s and 1990s. Since then, Chilika Lagoon has been facing various coastal syndromes that are likely to worsen due to climate change and increasing anthropogenic pressure on its waters and catchment area. This study analyzed bibliometric data from the Scopus database over the past five decades (1970?2021) to understand the ever-evolving publication pattern and research domains in Chilika Lagoon. A total of 457 records were selected for the analyzed period, with contributions from 944 authors, primarily in peer-reviewed journal articles (86%). Although the number of publications and citations is increasing, as expected, there is minimal international collaboration. An interesting pattern was found in�publication and research themes, correlating with the evolving history of lagoon management and governance. The establishment of the Wetland Research and Training Centre led to a surge in research publications from 2002 onwards. However, a mismatch appears to exist�between the research scope and publication records, as evidenced by the mere 11 seagrass-related records in Scopus, even though Chilika Lagoon hosts the second-largest seagrass patch in India. Simultaneously, there is a lack of research addressing the real-world challenges faced by the local people who depend on Chilika Lagoon for their livelihoods. Graphical abstract: [Figure not available: see fulltext.]. � 2023, The Author(s), under exclusive licence to Springer Nature B.V.
Decadal terminus position changes and ice thickness measurement of Menthosa Glacier in Lahaul region of North-Western Himalaya
(Taylor and Francis Ltd., 2021-06-05T00:00:00) Prakash, Satya; Sharma, Milap Chand; Sreekesh, S.; Chand, Pritam; Pandey, Vijendra Kumar; Latief, Syed Umer; Deswal, Sanjay; Manna, Ishita; Das, Suresh; Mandal, Sandip Tanu; Bahuguna, I.M.
Glacier ice-thickness measurement and distribution is one of the essential variables to assess present status of glacier-water equivalent and its volumetric reserve as well as to model the future glacier dynamics under the climate changing scenario. Yet, substantial gaps in ice thickness information exist for the Himalayan glaciers. The present study provides a long-term assessment (1965�2016) of recessional and area change patterns, as well as the detailed field-based (2016�2017) Ground Penetrating Radar(GPR), derived ice-thickness measurement of the Menthosa Glacier, Lahaul Himalaya. Additionally, the study examines whether the modelled ice thickness from remote sensing data is consistent with the field-based GPR measurement and how can it be improved. The extensive field surveys coupled with the multi-temporal high (Corona KH-4A) to medium resolution (Landsat Enhanced Thematic Mapper+ (ETM+)/Operational Land Imager (OLI), Sentinel 2A-Multispectral Instrument (MSI)) remote sensing data and cross-sectional GPR surveyed profile measurements have been used to examine past half a century (1965�2016) glacier fluctuation and the recent ice-thickness estimations, respectively. The results show that the Menthosa Glacier receded by 301.5 � 19.2 m during the past half a century (1965�2016) with an average annual retreat of 5.9 � 0.4 m a?1, whereas glacier lost 0.09 km2 ice in the frontal section. Field measurement over the past one decade (2006�2017) also conforms to a continuous recessional pattern and substantial glacier degeneration particularly the extensive surface lowering and significant appearance of ice-cliffs in the ablation and lateral zones over this period. The GPR measurements (2017) show the minimum glacier ice thickness of 24 meters at 4691 m a.s.l. (in the lower part of ablation area) and maximum glacier ice thickness of 55 meters measured at 4758 m a.s.l. (in the upper left-side tributary part of ablation area). Moreover, the modelled ice thickness derived from remotely sensed data is having Root Mean Square Error (RMSE) between 38 to 72 � 10 m as compared with GPR measured ice thickness. � 2021 Informa UK Limited, trading as Taylor & Francis Group.
Deciphering the impact of anthropogenic coastal infrastructure on shoreline dynamicity along Gopalpur coast of Odisha (India): An integrated assessment with geospatial and field-based approaches
(Elsevier B.V., 2022-10-22T00:00:00) Mishra, Manoranjan; Kar, Prabin K.; Chand, Pritam; Mohanty, Pratap K.; Acharyya, Tamoghna; Santos, Celso Augusto Guimar�es; Gon�alves, Rodrigo Mikosz; Silva, Richarde Marques da; Bhattacharyya, Debdeep; Beja, Santosh Kumar; Behera, Balaji
Odisha's coastline supports various development activities that are critical to the state and national economy, such as oil and gas, ports and harbors, power plants, fishing, tourism, and mining that continues to not only detriment the coastal ecology but also affect the overall shoreline morphodynamics. The morphological changes are complicated processes involving both natural and human-induced drivers, but it is critical to understand how recent development activities further impact beach morphodynamics and shoreline dynamicity. The study analyzes the overall shoreline morphodynamics in response to the recent development of port and other related infrastructure for annual and decadal scale using two-dimensional (2-D) shoreline changes along with detailed 3-D beach profile volumetric changes for different studied zones along the Gopalpur coast. The results reveal that nearly all studied zones of the Gopalpur shoreline, Zone-4 (EPR = ?05.64 m a?1 and LRR = ?04.25 m a?1), Zone-3 (EPR = ?04.51 m a?1 and LRR = ?07.01 m a?1) and Zone-1 (EPR = ?2.85 m a?1 and LRR = ?01.46 m a?1), experienced erosion between 2010 and 2020 except Zone-2 (EPR = 24.31 m a?1 and LRR = 25.96 m a?1), which showed overall sign of deposition. The interannual shoreline analysis depicted that Zone-1 (tourist beach area) remained almost stable, Zone-2 (south of the breakwater of Gopalpur Port) showed accretion trends, Zone-4 (north side of the port) dominantly showed an erosion pattern, whereas Zone-3 (port area) showed a high level of uncertainty in the context of erosional or deposition trends. Calculated volumetric loss along the surveyed 3-D beach profiles supports these 2-D changes for all the studied zones. The results showed substantial changes in coastal morphodynamics in different studied zones of the Gopalpur region and severe erosion along its northern segment of the constructed coastal infrastructure. These findings can potentially promote effective coastal zone management and prevent further deterioration along the Gopalpur coast in future. � 2022 Elsevier B.V.
Evolution of Supraglacial Lakes from 1990 to 2020 in the Himalaya�Karakoram Region Using Cloud-Based Google Earth Engine Platform
(Springer, 2023-10-27T00:00:00) Sahu, Rakesh; Ramsankaran, Raaj; Bhambri, Rakesh; Verma, Prateek; Chand, Pritam
Evolution of glacial lakes in the Himalayan and Karakoram (H�K) mountain ranges is an important indicator of glacier changes in response to climatic warming. The study utilized multi-temporal Landsat 4, 5, 7, and 8 images accessible in the cloud-based Google Earth Engine platform to analyse the spatiotemporal variations of the supraglacial lake (SGL) in the H�K regions from 1990 to 2020 at a decadal interval. It is observed that 61% (4.79�km2) of the SGL area increased from 1990 to 2020, while 223 new lakes formed in a similar time period. The most significant increase in the area of SGLs (30.15%; 2.93�km2) was observed between 2010 and 2020, while the slowest growth was observed between 1990 and 2000 (1.13%; 0.09�km2). The results indicate heterogeneity in SGL area changes in different regions. The region of Central Himalaya (CH) experienced the highest increase of 160% (3.8�km2) in the�SGL area from 1990 to 2020 with most of the rise in the�SGL area was observed in the Everest region, while a decrease of 9.4% (0.12�km2) was observed in the Eastern Himalaya (EH) region. During the study period, some SGLs converted into proglacial lakes in the EH region, which may be responsible for reducing the SGL area. The rise of SGL in the CH region can be attributed to higher mass loss, decreased glacier surface velocity, and increased rainfall in the�CH region. We also identified 15 glaciers that have SGLs near the terminus of the glaciers. If the same trend continues, these SGLs may soon be converted into proglacial lakes. The current inventory of SGL at a decadal scale shall be useful as baseline data for other hydro-glaciological models. � 2023, Indian Society of Remote Sensing.
Frontal Changes of Gangotri Glacier, Garhwal Himalaya, between 1935 and 2022
(Springer, 2023-02-07T00:00:00) Bhambri, Rakesh; Sain, Kalachand; Chand, Pritam; Srivastava, Deepak; Tiwari, Sameer K.; Yadav, Jairam Singh
Gangotri Glacier is one of the most thoroughly investigated glaciers in the Indian Himalaya in terms of terminus monitoring. This study aims to update the frontal retreat of Gangotri Glacier between 1935 and 2022 using a large scale Geological Survey of India map, remote sensing images, and repeated photography. Gangotri Glacier�s retreat rate varied significantly during the study period. This glacier receded by 1727 � 51m (19.8 � 0.2 m a?1) between 1935 and 2022. The retreat of Gangotri Glacier decreased from 2001 to 2006 (7.0 � 4.0 m a?1) compared to the previous observation (1980�2001; 21.0 � 1.2 m a?1) but increased about three times between 2006 and 2017 (21.9 � 1.9 m a?1). Furthermore, from 2017 to 2022, the frontal retreat accelerated by about 1.5 times (33.8 � 6.7 m a?1) compared to the period between 2006 and 2017. The findings of the present study are consistent with ground based survey conducted by the Geological Survey of India. � 2023, Geological Society of India, Bengaluru, India.
Heterogeneity in glacier thinning and slowdown of ice movement in the Garhwal Himalaya, India
(Elsevier B.V., 2023-03-05T00:00:00) Bhambri, Rakesh; Schmidt, Susanne; Chand, Pritam; N�sser, Marcus; Haritashya, Umesh; Sain, Kalachand; Tiwari, Sameer K.; Yadav, Jairam Singh
Limited ground-based surveys and extensive remote sensing analyses have confirmed glacier thinning in the Garhwal Himalaya. More detailed studies on specific glaciers and the drivers of reported changes are essential to comprehend small-scale differences in the effects of climatic warming on Himalayan glaciers. We computed elevation changes and surface flow distribution for 205 (?0.1 km2) glaciers in the Alaknanda, Bhagirathi, and Mandakini basins, all located in the Garhwal Himalaya, India. This study also investigates a detailed integrated analysis of elevation changes and surface flow velocities for 23 glaciers with varying characteristics to understand the impact of ice thickness loss on overall glacier dynamics. We observed significant heterogeneity in glacier thinning and surface flow velocity patterns using temporal DEMs and optical satellite images with ground-based verification. The average thinning rate was found to be 0.07 � 0.09 m a-1 from 2000 to 2015, and it increased to 0.31 � 0.19 m a-1 from 2015 to 2020, with pronounced differences between individual glaciers. Between 2000 and 2015, Gangotri Glacier thinned nearly twice as much as the neighbouring Chorabari and Companion glaciers, which have thicker supraglacial debris that protects the beneath ice from melting. The transitional zone between debris-covered and clean ice glaciers showed substantial flow during the observation period. However, the lower reaches of their debris-covered terminus areas are almost stagnant. These glaciers experienced a significant slowdown (~25 %) between 1993�1994 and 2020�2021, and only the Gangotri Glacier was active even in its terminus region during most observational periods. The decreasing surface gradient reduces the driving stress and causes slow-down surface flow velocities and an increase in stagnant ice. Surface lowering of these glaciers may have substantial long-term impacts on downstream communities and lowland populations, including more frequent cryospheric hazards, which may threaten future water and livelihood security. � 2023 Elsevier B.V.
Hydrological Characteristics of 7th February 2021 Rishi Ganga Flood: Implication towards Understanding Flood Hazards in Higher Himalaya
(Springer, 2021-08-07T00:00:00) Rana, Naresh; Sundriyal, Yaspal; Sharma, Shubhra; Khan, Firoz; Kaushik, Sameeksha; Chand, Pritam; Bagri, Dhirendra Singh; Sati, Saraswati Prakash; Juyal, Navin
A flash flood that originated from Raunthi Gad-a tributary of the Rishi Ganga river, in Garhwal Himalaya, caused unprecedented loss to lives and damaged two hydropower projects on 7th Februray 2021. In order to asses the flood magnitude, the flow parameters of the flood were calculated using the super-elevation of the flood marks preserved in the flood affected valleys. The textural characteristics of the flood deposits in the upper reaches of the valleys indicate dominance of debris flows. The peak discharge upstream of the confluence of Rishi Ganga and Dhauli Ganga was around 1.1�105 m3/s, which was four order of magnitiude higher than the normal peak discharge (? 3 m3/s). The flow achieved a velocity of 30�3 m/s. An exponential reduction in the flow velocity (from ?37 to 2 m/s) with distance is observed. For which the river gradient and increase in sediment load is implied flow that along its entrained way downstream between Raini and Tapovan. Considering the sensitivity of paraglacial zones to climate change, the paper calls for detailed studies pertaining to the response of paraglacial zones to extreme weather events. Importantly, it is necessary to have more hydrological data covering multiple valleys for predictive model simulation of the nature and magnitude of such disasters in future. � 2021, GEOL. SOC. INDIA.
Mapping main risk areas of lightning fatalities between 2000 and 2020 over Odisha state (India): A diagnostic approach to reduce lightning fatalities using statistical and spatiotemporal analyses
(Elsevier Ltd, 2022-07-04T00:00:00) Mishra, Manoranjan; Acharyya, Tamoghna; Santos, Celso Augusto Guimar�es; Silva, Richarde Marques da; Chand, Pritam; Bhattacharyya, Debdeep; Srivastava, Sanjay; Singh, Omvir
This study analyzes the spatiotemporal variation of lightning flashes and lightning strike deaths from 2001 to 2020 among all 30 districts of Odisha State, India. Lightning flash data for the study area were acquired from Lightning Imaging Sensor (LIS) installed aboard the Tropical Rainfall Measuring Mission (TRMM) for the 2001�2014 period and from International Space Station for the 2017�2020 period. Deaths by lightning flashes were acquired from the annual report of natural calamities for the 2001�2020 period from the Revenue and Disaster Management Department, Government of Odisha. In this study, the spatial pattern of lightning flashes based on LIS data and resultant deaths were assessed using spatiotemporal statistical analysis, including the interpolation method and Sen's slope estimator. The geospatial heat maps of lightning strikes and deaths highlight the spatiotemporal heterogeneity of lightning strikes and induced deaths in Odisha State. Furthermore, statistical analyses demonstrate an apparent increase in lightning strikes in the state as a whole, with particular attention to the Mayurbhanj, Sundargarh, and Keonjhar districts, which had the highest incidence of lightning. Odisha State was hit by more than 10,000 lightning strikes every year between 2000 and 2020, excluding 2001, 2017, and 2018. The results show a moderate correlation (R = 0.61) between lightning strikes and lightning deaths in Odisha State during the analyzed period, which further needs to be investigated with respect to the seasonality of lightning, the locational vulnerability, and temporal risk. � 2022 Elsevier Ltd
Perceptions and adaptation behavior of farmers to climate change in the upper Brahmaputra Valley, India
(Springer Science and Business Media B.V., 2021-03-08T00:00:00) Baruah, Ujjal Deka; Saikia, Anup; Robeson, Scott M.; Mili, Nitashree; Chand, Pritam
To better understand how farmers perceive and adapt to climate change, climate trends and a survey of farmer attitudes and behavior in the upper Brahmaputra valley zone (UBVZ) of India were analyzed. Rainfall and temperature trends were estimated in combination with the results from a detailed questionnaire of 384 farmers across 20 villages in rainfed areas of the UBVZ. From 1971 to 2007, the annual mean temperature in the UBVZ increased by 0.15��C/decade while summer rainfall decreased markedly. Logistic regression was used for modeling the perceptions and adaptation behavior of farmers. Farmers perceptions of climate change tended to closely match those estimated from the climate data, but farmers with better access to water resources, credit, and those with higher family income, higher production, and larger farm sizes had more options to adapt and were more likely to adopt techniques to cope with climate change and variability. Factors such as age, education level, and family size of respondents were less likely to impact farmers� decisions to adapt to climate change. � 2021, The Author(s), under exclusive licence to Springer Nature B.V.
Quantitative assessment of present and the future potential threat of coastal erosion along the Odisha coast using geospatial tools and statistical techniques
(Elsevier B.V., 2023-02-28T00:00:00) Mishra, Manoranjan; Chand, Pritam; Beja, Santosh Kumar; Santos, Celso Augusto Guimar�es; Silva, Richarde Marques da; Ahmed, Ishtiaq; Kamal, Abu Hena Mustafa
The eastern coast of India is one of the regions where most of the population resides in urban areas in the low-elevation coastal zone, making it vulnerable to frequent extreme weather events. The objectives of this study are to assess the short- to long-term shoreline changes of the Odisha coast, to understand how anthropogenic influences, and particularly extreme natural events, affect these changes, and to predict shoreline changes for 2050. This study utilized multi-temporal/spectral/spatial resolution satellite images and a digital shoreline analysis (DSAS) tool to appraise the short- (at five/six-year intervals) and long-term (1990�2019) shoreline dynamics along the coastal part of Odisha over the past three decades (1990�2019). The long-term shoreline analysis shows that the mean shoreline change is about 0.67 m/year and highlights that 52.47 % (227.4 km), 34.70 % (150.4 km), and 12.83 % (55.6 km) of the total Odisha coastline exhibit erosion, accretion, and stability, respectively. During the short-term analysis, the 2000�2005 period had the highest percentage of erosion (64.27 %), followed by the 2005�2010 period with an erosional trend of 59.06 %. The 1995�2000 period showed an accretion trend, whereas, during the last period, i.e., 2015�2019, the percentage of transects depicting erosion and accretion was almost similar. In 2050, 55.85 % of the transects are expected to show accretion, while 44.15 % would show erosion or a constant trend. The study identified the hotspots of coastal erosion along delineated study zones by synthesizing data from previous studies as well. The regional analysis of shoreline change along the Odisha coast would not only provide coastal managers with critical information on shoreline dynamics but also draw attention to vulnerable areas linked to shoreline dynamicity along the coast. � 2023 Elsevier B.V.
Reassessing the Karakoram Through Historical Archives
(Springer International Publishing, 2022-11-11T00:00:00) Bhambri, Rakesh; Chand, Pritam; N�sser, Marcus; Kawishwar, Prashant; Kumar, Amit; Gupta, Anil K.; Verma, Akshaya; Tiwari, Sameer K.
The Karakoram region is an integral part of the Hindu Kush�Karakoram�Himalaya (HKH) mountain system and forms the great divide between the drainage of the Indus and Tarim basins. This region has a substantial geographical, historical, economical, cultural, and geopolitical importance owing to its location, rugged topography, distinct climate regime, and the presence of numerous glaciers. It acts as a water tower where its unique assemblage paved the way for developing ancient trade routes facilitating cultural exchange between Central Asia and the Indian subcontinent. It has attracted a large number of expeditions and scientific studies for more than 200 years, bringing significant advances in geographical knowledge. However, the spatial extent of the Karakoram in many studies particularly during the 2010s exhibits a large inconsistency. We, therefore, complied ?100 maps and vast literature to present the evolution of the geographical term �the Karakoram� and its spatial extent based on historical archives. We also provide a digital outline of the Karakoram region using GIS tools based on descriptive enumerations of the Royal Geographical Society (RGS) and the Survey of India (SoI) which we hope will provide new insight for a wide range of scientific disciplines, including geography, glaciology, geology, history, and cartography. � The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.
Reconstruction of post-little ice age glacier recession in the Lahaul Himalaya, north-west India
(Taylor and Francis Ltd., 2022-12-13T00:00:00) Deswal, Sanjay; Sharma, Milap Chand; Saini, Rakesh; Chand, Pritam; Prakash, Satya; Kumar, Pawan; Barr, Iestyn David; Latief, Syed Umer; Dalal, Padma; Bahuguna, I.M.
Understanding past glaciation and deglaciation is vital for assessing present-day glacier dynamics and response to climate change. We focus on reconstructing past glacier fluctuations in Lahaul, north-west India, a region located between arid Ladakh and the humid the Pir-Panjal range. We focus specifically on six glaciers in the Miyar and Thirot catchments of varying size, aspect and debris cover. To reconstruct past terminus fluctuations of these glaciers, we used repeat terrestrial photography and historical archives as data sets and mapped the terminus positions and latero-terminal moraines in the field along with glacier terminus mapping from high to medium resolution satellite images (e.g. Corona, Hexagon, Landsat and LISS IV). Results show that since the little ice age, all the studied glaciers have experienced terminus retreat and area loss, with average values of 1.46 and 0.9 km2, respectively. Precipitation data show a statistically significant decreasing trend during the last century with an increasing trend in annual average maximum (T max) and minimum (T min) temperature. This warming trend is more statistically significant for T min. Although total ice loss at the six studied glaciers is considerable (5.48 km2), this varies both spatially (i.e. from glacier to glacier) and temporally. We attribute this variability to topographic controls such as glacier hypsometry and another non-climatic factor, i.e. varying degree of debris cover. � 2022 Swedish Society for Anthropology and Geography.
Response of long- to short-term tidal inlet morphodynamics on the ecological ramification of Chilika lake, the tropical Ramsar wetland in India
(Elsevier B.V., 2021-10-06T00:00:00) Mishra, Manoranjan; Acharyya, Tamoghna; Chand, Pritam; Santos, Celso Augusto Guimar�es; Silva, Richarde Marques da; Santos, Carlos Antonio Costa dos; Pradhan, Subhasis; Kar, Dipika
The long- to short-term morphodynamic response in low-lying coastal wetlands raises serious concerns worldwide about the loss of their biodiversity and ecological ramifications due to change in tidal amplitude and cyclonic events. One such place worth studying is Chilika lake, India, a prominent Ramsar site, the largest brackish water lagoon in Asia, and the second-largest coastal lagoon in the world. It experiences frequent cyclone landfalls and strong littoral drift that tends to open/close the tidal inlet. The goal of this study was to analyze the response of slow onset events such as long- (1952�2020) to short-term (~annual scale from 1989 to 2020) tidal inlet movement, shoreline change (1990�2020 with almost every five-year interval), spit morphodynamics (~annual scale from 1989 to 2020) on ecological ramification in Chilika lake as well as the implications of sudden onset event such as cyclonic landfall. In this study, we used the Digital Shoreline Change Analysis System (DSAS) to compute the statistics of shoreline change rate by calculating end point rate (EPR) values for short-term shoreline change (1990, 1995, 2000, 2005, 2011, 2016, and 2020) and weighted linear regression (WLR) for long-term shoreline change (1990�2020). The results show that Chilika lake experienced both erosion and accretion processes with a remarkably high erosion rate of 19.87 m year?1 and accretion of 16.91 m year?1 during a long-term scale (1990�2020). The average erosion and accretion rates were 2.25 m year?1 and 4.67 m year?1, respectively, during the past three decades (1990�2020). The short-term analysis suggests that the highest mean erosion of 4.37 m year?1 occurred during 2005�2011, mainly due to cyclonic storms, reduction in sediment discharge, and lunar eclipse, which induced tide with very high amplitude in August 2008. Overall, the annual scale analysis of tidal inlet shows a shifting trend towards the northward side even after the artificial opening of an inlet in 2000. It can be ascribed mainly to the prevalent direction of longshore drift along this coast. This study observed that the landfall of cyclones significantly affects the spit morphodynamics and opening of the tidal inlet, which defines the inflow of the seawater into the lagoon and further substantial impacts on the ecological ramification. The current study's methodology can be extended to comprehend the response of long- to short-term changes of the tidal inlet, shoreline, and spit morphodynamics on the ecological ramification of coastal lagoons worldwide along with impacts of sudden-onset events caused by cyclonic landfall. � 2021 Elsevier B.V.
The retreat of mountain glaciers since the little ice age: A spatially explicit database
(MDPI, 2021-10-11T00:00:00) Marta, Silvio; Azzoni, Roberto Sergio; Fugazza, Davide; Tielidze, Levan; Chand, Pritam; Sieron, Katrin; Almond, Peter; Ambrosini, Roberto; Anthelme, Fabien; Alviz Gazit�a, Pablo; Bhambri, Rakesh; Bonin, Aur�lie; Caccianiga, Marco; Cauvy-Frauni�, Sophie; Lievano, Jorge Luis Ceballos; Clague, John; Rapre, Justiniano Alejo Cochach�n; Dangles, Olivier; Deline, Philip; Eger, Andre; Encarnaci�n, Rolando Cruz; Erokhin, Sergey; Franzetti, Andrea; Gielly, Ludovic; Gili, Fabrizio; Gobbi, Mauro; Guerrieri, Alessia; H�gvar, Sigmund; Khedim, Norine; Kinyanjui, Rahab; Messager, Erwan; Morales-Mart�nez, Marco Aurelio; Peyre, Gwendolyn; Pittino, Francesca; Poulenard, Jerome; Seppi, Roberto; Sharma, Milap Chand; Urseitova, Nurai; Weissling, Blake; Yang, Yan; Zaginaev, Vitalii; Zimmer, Ana�s; Diolaiuti, Guglielmina Adele; Rabatel, Antoine; Ficetola, Gentile Francesco
Most of the world�s mountain glaciers have been retreating for more than a century in response to climate change. Glacier retreat is evident on all continents, and the rate of retreat has accelerated during recent decades. Accurate, spatially explicit information on the position of glacier margins over time is useful for analyzing patterns of glacier retreat and measuring reductions in glacier surface area. This information is also essential for evaluating how mountain ecosystems are evolving due to climate warming and the attendant glacier retreat. Here, we present a non-comprehensive spatially explicit dataset showing multiple positions of glacier fronts since the Little Ice Age (LIA) maxima, including many data from the pre-satellite era. The dataset is based on multiple historical archival records including topographical maps; repeated photographs, paintings, and aerial or satellite images with a supplement of geochronology; and own field data. We provide ESRI shapefiles showing 728 past positions of 94 glacier fronts from all continents, except Antarctica, covering the period between the Little Ice Age maxima and the present. On average, the time series span the past 190 years. From 2 to 46 past positions per glacier are depicted (on average: 7.8). � 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Spatio-temporal characterization of tropospheric ozone and its precursor pollutants NO2 and HCHO over South Asia
(Elsevier B.V., 2021-10-25T00:00:00) Baruah, Ujjal Deka; Robeson, Scott M.; Saikia, Anup; Mili, Nitashree; Sung, Kang; Chand, Pritam
In recent decades, South Asia has experienced declining air quality, with much of the attention being focused on extremely high levels of particulate matter. Here, we analyze tropospheric ozone (O3), formaldehyde (HCHO), and nitrogen dioxide (NO2) to assess other measures of air quality across South Asia from 2008 to 2018. The IASI-Forli retrieved tropospheric ozone data was validated with ozonesonde, reanalysis (ERA5), satellite (TES), and model simulation products (GEOS-Chem and TOMCAT/SLIMCAT). Space-based observations of these three trace gases were used to conduct a spatio temporal analysis over South Asia using trend analysis (Theil-Sen and linear regression), change-point detection (Pettitt's test), and hotspot identification (Getis-Ord Gi*). We used the formaldehyde-nitrogen dioxide ratio (FNR) to identify NOx limited, VOC limited, and transitional regimes in South Asia. Counter to previous studies, a statistically significant decrease of HCHO (?0.0041 DU yr?1) and O3 (?0.064 DU yr?1) was detected for South Asia; however, NO2 is increasing the 0.001 DU yr?1 over South Asia during 2008�18. The Indo-Gangetic Plains emerged as being critically affected by the three trace gases. Certain parts of southern and south-eastern India are gradually emerging as NO2 and HCHO hotpots. No significant O3 hotspots were discernible, though coldspots existed along the Himalaya belt of India, Nepal, and Bhutan and mountainous tracts of Pakistan. FNR indicates the reduction of NOx in NOx-limited regime of the Indo-Gangetic Plains reduced the formation of tropospheric O3 over South Asia. � 2021 Elsevier B.V.