Browsing by Author "Kumar, Pankaj"

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Ag-S Type Quantum Dots versus Superatom Nanocatalyst: A Single Sulfur Atom Modulated Decarboxylative Radical Cascade Reaction
(American Chemical Society, 2023-04-06T00:00:00) Meena, Sangeeta; Dastider, Saptarshi G.; Nishad, Chandra Shekhar; Jangid, Dilip Kumar; Kumar, Pankaj; Khirid, Samreet; Bose, Shubhankar Kumar; Mondal, Krishnakanta; Banerjee, Biplab; Dhayal, Rajendra S.
The preparation of high-nuclearity silver nanoclusters in quantitative yield remains exclusive and their potential applications in the catalysis of organic reactions are still undeveloped. Here, we have synthesized a quantum dot (QD)-based catalyst, [Ag62S13(SBut)32](PF6)4 (denoted as Ag62S12-S) in excellent yield that enables the direct synthesis of pharmaceutically precious 3,4-dihydroquinolinone in 92% via a decarboxylative radical cascade reaction of cinnamamide with ?-oxocarboxylic acid under mild reaction conditions. In comparison, a superatom [Ag62S12(SBut)32](PF6)2 (denoted as Ag62S12) with identical surface anatomy and size, but without a central S2- atom in the core, gives an improved yield (95%) in a short time and exhibits higher reactivity. Multiple characterization techniques (single-crystal X-ray diffraction, nuclear magnetic resonance (1H and 31P), electrospray ionization mass spectrometry, energy dispersive X-ray spectroscopy, Brunauer-Emmett-Teller (BET), Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis) confirm the formation of Ag62S12-S. The BET results expose the total active surface area in supporting a single e- transfer reaction mechanism. Density functional theory reveals that leaving the central S atom of Ag62S12-S leads to higher charge transfer from Ag62S12 to the reactant, accelerates the decarboxylation process, and correlates the catalytic properties with the structure of the nanocatalyst. � 2023 American Chemical Society.
Assessing the Effects of Drought on Rice Yields in the Mekong Delta
(MDPI, 2023-01-04T00:00:00) Lavane, Kim; Kumar, Pankaj; Meraj, Gowhar; Han, Tran Gia; Ngan, Luong Hong Boi; Lien, Bui Thi Bich; Van Ty, Tran; Thanh, Nguyen Truong; Downes, Nigel K.; Nam, Nguyen Dinh Giang; Minh, Huynh Vuong Thu; Singh, Suraj Kumar; Kanga, Shruti
In contrast to other natural disasters, droughts may develop gradually and last for extended periods of time. The World Meteorological Organization advises using the Standardized Precipitation Index (SPI) for the early identification of drought and understanding of its characteristics over various geographical areas. In this study, we use long-term rainfall data from 14 rain gauge stations in the Vietnamese Mekong Delta (1979�2020) to examine correlations with changes in rice yields. Results indicate that in the winter�spring rice cropping season in both 2016 and 2017, yields declined, corresponding with high humidity levels. Excessive rainfall during these years may have contributed to waterlogging, which in turn adversely affected yields. The results highlight that not only drought, but also humidity has the potential to adversely affect rice yield. � 2023 by the authors.
Assessing the Impact of the 2004 Indian Ocean Tsunami on South Andaman�s Coastal Shoreline: A Geospatial Analysis of Erosion and Accretion Patterns
(MDPI, 2023-05-28T00:00:00) Singh, Saurabh; Singh, Suraj Kumar; Prajapat, Deepak Kumar; Pandey, Vikas; Kanga, Shruti; Kumar, Pankaj; Meraj, Gowhar
The 2004 Indian Ocean earthquake and tsunami significantly impacted the coastal shoreline of the Andaman and Nicobar Islands, causing widespread destruction of infrastructure and ecological damage. This study aims to analyze the short- and long-term shoreline changes in South Andaman, focusing on 2004�2005 (pre- and post-tsunami) and 1990�2023 (to assess periodic changes). Using remote sensing techniques and geospatial tools such as the Digital Shoreline Analysis System (DSAS), shoreline change rates were calculated in four zones, revealing the extent of the tsunami�s impact. During the pre- and post-tsunami periods, the maximum coastal erosion rate was ?410.55 m/year, while the maximum accretion was 359.07 m/year in zone A, the island�s east side. For the 1990�2023 period, the most significant coastal shoreline erosion rate was also recorded in zone A, which was recorded at ?2.3 m/year. After analyzing the result, it can be seen that the tsunami severely affected the island�s east side. To validate the coastal shoreline measurements, the root mean square error (RMSE) of Landsat-7 and Google Earth was 18.53 m, enabling comparisons of the accuracy of different models on the same dataset. The results demonstrate the extensive impact of the 2004 Indian Ocean Tsunami on South Andaman�s coastal shoreline and the value of analyzing shoreline changes to understand the short- and long-term consequences of such events on coastal ecosystems. This information can inform conservation efforts, management strategies, and disaster response plans to mitigate future damage and allocate resources more efficiently. By better understanding the impact of tsunamis on coastal shorelines, emergency responders, government agencies, and conservationists can develop more effective strategies to protect these fragile ecosystems and the communities that rely on them. � 2023 by the authors.
Assessing the impacts of current and future changes of the planforms of river Brahmaputra on its land use-land cover
(Elsevier B.V., 2023-02-02T00:00:00) Debnath, Jatan; Sahariah, Dhrubajyoti; Lahon, Durlov; Nath, Nityaranjan; Chand, Kesar; Meraj, Gowhar; Kumar, Pankaj; Kumar Singh, Suraj; Kanga, Shruti; Farooq, Majid
River bankline migration is a frequent phenomenon in the river of the floodplain region. Nowadays, channel dynamics-related changes in land use and land cover (LULC) are becoming a risk to the life and property of people living in the vicinity of rivers. A comprehensive evaluation of the causes and consequences of such changes is essential for better policy and decision-making for disaster risk reduction and management. The present study assesses the changes in the Brahmaputra River planform using the GIS-based Digital Shoreline Analysis System (DSAS) and relates it with the changing LULC of the floodplain evaluated using the CA-Markov model. In this study, the future channel of the Brahmaputra River and its flood plain's future LULC were forecasted to pinpoint the erosion-vulnerable zone. Forty-eight years (1973�2021) of remotely sensed data were applied to estimate the rate of bankline migration. It was observed that the river's erosion-accretion rate was higher in early times than in more recent ones. The left and right banks� average shifting rates between 1973 and 1988 were ?55.44 m/y and ?56.79 m/y, respectively, while they were ?17.25 m/y and ?48.49 m/y from 2011 to 2021. The left bank of the river Brahmaputra had more erosion than the right, which indicates that the river is shifting in the leftward direction (Southward). In this river course, zone A (Lower course) and zone B (Middle course) were more adversely affected than zone C (Upper course). According to the predicted result, the left bank is more susceptible to bank erosion than the right bank (where the average rate of erosion and deposition was ?72.23 m/y and 79.50 m/y, respectively). The left bank's average rate of erosion was ?111.22 m/y. The research assesses the LULC study in conjunction with river channel dynamics in vulnerable areas where nearby infrastructure and settlements were at risk due to channel migration. The degree of accuracy was verified using the actual bankline and predicted bankline, as well as the actual LULC map and anticipated LULC map. In more than 90% of cases, the bankline's position and shape generally remain the same as the actual bankline. The overall, and kappa accuracy of all the LULC maps was more than 85%, which was suitable for the forecast. Moreover, chi-square (x2) result values for classified classes denoted the accuracy and acceptability of the CA-Markov model for predicting the LULC map. The results of this work aim to understand better the efficient hazard management strategy for the Brahmaputra River for hazard managers of the region using an automated prediction approach. � 2023 China University of Geosciences (Beijing) and Peking University
Career challenges for young independent researchers in India
(Indian Academy of Sciences, 2022-04-15T00:00:00) Agashe, Deepa; Maheshwary, Sugandha; Pattanaik, Jitendra Kumar; Prakash, Jai; Bhatt, Pragya; Arya, S.S.; Chatterjee, Sriparna; Kumar, Pankaj; Singh, Paramdeep; Abbas, Nazia; Sharma, Chandra Shekhar; Chaudhuri, Chirasree Roy; Devi, Pooja
The scientific enterprise in India has grown dramatically in the past few decades, with research emerging as a viable and important career option for students of science. The country thus has a large population of young scientists in the early stages of establishing their independent research careers. While this demographic is arguably the most important group that will determine the future of scientific research in India, their status and concerns are poorly understood. The Indian National Young Academy of Sciences conducted a national survey to better understand and present the challenges faced by them. Through a structured questionnaire, we sought the views of research-ers below 45 years of age. Here, we summarize the responses from 854 participants across multiple early career stages. We highlight key challenges faced by these scientists in establishing an inde-pendent research career, and suggest steps to address them. � 2022,Current Science.All Rights Reserved
Cellular Automata-Based Artificial Neural Network Model for Assessing Past, Present, and Future Land Use/Land Cover Dynamics
(MDPI, 2022-11-08T00:00:00) Sajan, Bhartendu; Mishra, Varun Narayan; Kanga, Shruti; Meraj, Gowhar; Singh, Suraj Kumar; Kumar, Pankaj
Land use and land cover change (LULCC) is among the most apparent natural landscape processes impacted by anthropogenic activities, particularly in fast-growing regions. In India, at present, due to the impacts of anthropogenic climate change, supplemented by the fast pace of developmental activities, the areas providing the highest agricultural yields are facing the threat of either extinction or change in land use. This study assesses the LULCC in the fastest-changing landscape region of the Indian state of Bihar, District Muzaffarpur. This district is known for its litchi cultivation, which, over the last few years, has been observed to be increasing in acreage at the behest of a decrease in natural vegetation. In this study, we aim to assess the past, present and future changes in LULC of the Muzaffarpur district using support vector classification and CA-ANN (cellular automata-artificial neural network) algorithms. For assessing the present and past LULC of the study area, we used Landsat Satellite data for 1990, 2000, 2010, and 2020. It was observed that between 1990 and 2020, the area under vegetation, wetlands, water body, and fallow land decreased by 44.28%, 34.82%, 25.56%, and 5.63%, respectively. At the same time, the area under built-up, litchi plantation, and cropland increased by 1451.30%, 181.91%, and 5.66%, respectively. Extensive ground truthing was carried out to assess the accuracy of the LULC for 2020, whereas historical google earth images were used for 1990, 2000, and 2010, through the use of overall accuracy and kappa coefficient indices. The kappa coefficients for the final LULC for the years 1990, 2000, 2010, and 2020 were 0.79, 0.75, 0.87, and 0.85, respectively. For forecasting the future LULC, first, the LULC of 1990 and 2010 were used to predict the landscape for 2020 using the CA-ANN model. After calibrating and validating the CA-ANN outputs, LULC for 2030 and 2050 were generated. The generated future LULC scenarios were validated using kappa index statistics by comparing the forecast outcomes with the original LULC data for 2020. It was observed that in both 2030 and 2050, built-up and vegetation would be the major transitioning LULC. In 2030 and 2050, built-up will increase by 13.15% and 108.69%, respectively, compared to its area in 2020; whereas vegetation is expected to decrease by 14.30% in 2030 and 32.84% in 2050 compared to its area in 2020. Overall, this study depicted a decline in the natural landscape and a sudden increase in the built-up and cash-crop area. If such trends continue, the future scenario of LULC will also demonstrate the same pattern. This study will help formulate better land use management policy in the study area, and the overall state of Bihar, which is considered to be the poorest state of India and the most vulnerable to natural calamities. It also demonstrates the ability of the CA-ANN model to forecast future events and comprehend spatiotemporal LULC dynamics. � 2022 by the authors.
Clay minerals as paleo-climate proxy in Quaternary Dun sediments, NW Himalaya, India
(Springer Science and Business Media Deutschland GmbH, 2023-10-17T00:00:00) Amrutha, K.; Ahmad, Samad; Kumar, Pankaj; Pattanaik, Jitendra Kumar
Purpose: Clay mineral assemblages are widely used for deciphering paleoclimatic information, where diagenetic and detrital clays provide different signatures. The type and amount of clay present in the alluvial fan sediments account for the prevailing climate, topography, transport dynamics, diagenesis, and lithology of the catchment area. Clay mineral analysis of sediments collected from the younger lobe of Kiratpur Fan, Pinjaur dun, NW Himalaya, will help to understand the late-Quaternary climatic perturbations during marine isotope stage (MIS)-3 and to evaluate the suitability of clay minerals as paleoclimatic proxy. Materials and methods: Samples were collected from three sites along the Kiratpur Nadi near Paploha village, Haryana, where exposed sections had a total height of ~ 28�m. In this study, 31 samples from these sediment sections were collected and after initial processing, clay minerals were separated and oriented slides were prepared. These samples were analysed using X-ray diffractometer (XRD) with/without glycolation and heating treatments. One aliquot of dried clay from selected samples were used for FTIR to complement the XRD analysis. For FTIR analysis, about 1�mg of clay samples was mixed with ~ 10�mg of KBr and press pellets were prepared. Results and discussion: The clay fraction of these sediments constitute illite (~ 52 � 0.8%), kaolinite (~ 13 � 1.6%), and chlorite-montmorillonite interstratified clay (~ 35 � 1.5%). Shale and mudstone distributed in the catchment area might be the source of these clay minerals. Illite chemistry index of ~ 0.37 � 0.14, kaolinite/illite ratio (0.21�0.29), illite crystallinity (IC) (0.23 � 0.04), and kaolinite percentage suggest the dominance of physical weathering in the catchment area. These sediments are generated during a cold and dry period, and deposited during an aggradational phase associated with warm and wet phase within MIS-3 (40�30 Ka). Further, it was found that illite is the dominant clay throughout the Himalayas, Ganga plain, and Bay of Bengal (BoB) sediments, irrespective of their distance from the source. Hence, associating illite to younger and less-transported sediment does not work in this setting. Conclusion: Though the proxies based on clay percentage is very useful, only limited data is available. There is a significant difference in the value of IC in the Himalayan front and BoB sediments may be due to the modifications during the transportation of sediments. Overall, when sediments are transported for a longer distance, correlating clay mineral percentage with the maturity of sediment is not apparent. � 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Decoding Chambal River Shoreline Transformations: A Comprehensive Analysis Using Remote Sensing, GIS, and DSAS
(MDPI, 2023-05-08T00:00:00) Singh, Saurabh; Meraj, Gowhar; Kumar, Pankaj; Singh, Suraj Kumar; Kanga, Shruti; Johnson, Brian Alan; Prajapat, Deepak Kumar; Debnath, Jatan; Sahariah, Dhrubajyoti
Illegal sand mining has been identified as a significant cause of harm to riverbanks, as it leads to excessive removal of sand from rivers and negatively impacts river shorelines. This investigation aimed to identify instances of shoreline erosion and accretion at illegal sand mining sites along the Chambal River. These sites were selected based on a report submitted by the Director of the National Chambal Sanctuary (NCS) to the National Green Tribunal (NGT) of India. The digital shoreline analysis system (DSAS v5.1) was used during the elapsed period from 1990 to 2020. Three statistical parameters used in DSAS�the shoreline change envelope (SCE), endpoint rate (EPR), and net shoreline movement (NSM)�quantify the rates of shoreline changes in the form of erosion and accretion patterns. To carry out this study, Landsat imagery data (T.M., ETM+, and OLI) and Sentinel-2A/MSI from 1990 to 2020 were used to analyze river shoreline erosion and accretion. The normalized difference water index (NDWI) and modified normalized difference water index (MNDWI) were used to detect riverbanks in satellite images. The investigation results indicated that erosion was observed at all illegal mining sites, with the highest erosion rate of 1.26 m/year at the Sewarpali site. On the other hand, the highest accretion was identified at the Chandilpura site, with a rate of 0.63 m/year. We observed significant changes in river shorelines at illegal mining and unmined sites. Erosion and accretion at unmined sites are recorded at ?0.18 m/year and 0.19 m/year, respectively, which are minor compared to mining sites. This study�s findings on the effects of illegal sand mining on river shorelines will be helpful in the sustainable management and conservation of river ecosystems. These results can also help to develop and implement river sand mining policies that protect river ecosystems from the long-term effects of illegal sand mining. � 2023 by the authors.
Dithiophosphonate Anchored Heterometallic (Ag(I)/Fe(II)) Molecular Catalysts for Electrochemical Hydrogen Evolution Reaction
(American Chemical Society, 2022-08-12T00:00:00) Jangid, Dilip Kumar; Dastider, Saptarshi G.; Biswas, Rathindranath; Khirid, Samreet; Meena, Sangeeta; Kumar, Pankaj; Sahoo, Subash C.; Verma, Ved Prakash; Makde, Ravindra D.; Kumar, Ashwani; Jangir, Ravindra; Mondal, Krishnakanta; Haldar, Krishna Kanta; Dhayal, Rajendra S.
The dichalcogenide ligated molecules in catalysis to produce molecular hydrogen through electroreduction of water are rarely explored. Here, a series of heterometallic [Ag4(S2PFc(OR)4] [where Fc = Fe(?5-C5H4)(?5-C5H5), R = Me, 1; Et, 2; nPr, 3; isoAmyl, 4] clusters were synthesized and characterized by IR, absorption spectroscopy, NMR (1H, 31P), and electrospray ionization mass spectrometry. The molecular structures of 1, 2, and 3 clusters were established by single-crystal X-ray crystallographic analysis. The structural elucidation shows that each triangular face of a tetrahedral silver(I) core is capped by a ferrocenyl dithiophosphonate ligand in a trimetallic triconnective (?3 ?2, ?1) pattern. A comparative electrocatalytic hydrogen evolution reaction of 1-5 (R = iPr, 5) was studied in order to demonstrate the potential of these clusters in water splitting activity. The experimental results reveal that catalytic performance decreases with increases in the length of the carbon chain and branching within the alkoxy (-OR) group of these clusters. Catalytic durability was found effective even after 8 h of a chronoamperometric stability test along with 1500 cycles of linear sweep voltammetry performance, and only 15 mV overpotential was increased at 5 mA/cm2 current density for cluster 1. A catalytic mechanism was proposed by applying density functional theory (DFT) on clusters 1 and 2 as a representative. Here, a ?1 coordinated S-site between Ag4 core and ligand was found a reaction center. The experimental results are also in good accordance with the DFT analysis. � 2022 American Chemical Society.
Evolution of the Permo-Triassic Satpura Gondwana Basin, Madhya Pradesh, India: Insights from geochemical provenance and palaeoclimate of the siliciclastic sediments
(John Wiley and Sons Ltd, 2022-10-19T00:00:00) Singh, Yumlembam Priyananda; Kingson, Oinam; Sharma, Kongrailatpam Milankumar; Ghosh, Prosenjit; Patnaik, Rajeev; Tiwari, Raghavendra Prasad; Pattanaik, Jitendra Kumar; Kumar, Pankaj; Thomas, Harel; Singh, Ningthoujam Premjit; Singh, Nongmaithem Amardas
Geochemical study in the siliciclastic sediments of a basin provides an understanding of palaeoclimate, provenance and subsequently, it can be used to reconstruct the palaeo-tectonics and evolution of the basin. Sedimentation in the Gondwana basins, worldwide, generally provides a record of climatic fluctuations and evidences of the Permo-Triassic mass extinction. In spite of its global importance, our knowledge about the nature of sedimentation, basin development and conceptual regional tectonic model in the Satpura Basin, one of the Gondwana basins of India is limited. Major and trace element concentrations of the mudstones from the Denwa Formation along with the existing geochemical data of other formations are studied here for establishing a comprehensive idea about the palaeoclimate, tectonic settings, provenance and basin evolution. The composition of the sediments in the lowermost Talchir Formation revealed cold and dry climatic conditions at the sources, whereas the sources of the sediments for the overlying formations have experienced warm, humid and semiarid climates. The contributions of the mafic rock-derived sediments are relatively higher in the Talchir, Barakar and Motur formations compared to the overlying formations. Approximately 60% of the sediments in the overlying Bijori, Pachmarhi and Denwa formations were derived from the felsic volcanic rocks and granites of the Sausar Mobile Belt and Betul-Chindwara Mobile Belt (BCMB) with minor inputs from mafic volcanic rocks of the BCMB. Furthermore, the sediments of the Talchir Formation were derived from the BCMB when they became tectonically active, whereas the sediments in the younger formations have been derived from a passive tectonic setting. � 2022 John Wiley & Sons Ltd.
Geospatial modeling to assess the past and future land use-land cover changes in the Brahmaputra Valley, NE India, for sustainable land resource management
(Springer Science and Business Media Deutschland GmbH, 2022-11-24T00:00:00) Debnath, Jatan; Sahariah, Dhrubajyoti; Lahon, Durlov; Nath, Nityaranjan; Chand, Kesar; Meraj, Gowhar; Farooq, Majid; Kumar, Pankaj; Kanga, Shruti; Singh, Suraj Kumar
Satellite remote sensing and geographic information system (GIS) have revolutionalized the mapping, quantifying, and assessing the land surface processes, particularly analyzing the past and future land use-land cover (LULC) change patterns. Worldwide river basins have observed enormous changes in the land system dynamics as a result of anthropogenic factors such as population, urbanization, development, and agriculture. As is the scenario of various other river basins, the Brahmaputra basin, which falls in China, Bhutan, India, and Bangladesh, is also witnessing the same environmental issues. The present study has been conducted on the Brahmaputra Valley in Assam, India (a sub-basin of the larger Brahmaputra basin) and assessed its LULC changes using a maximum likelihood classification algorithm. The study also simulated the changing LULC pattern for the years 2030, 2040, and 2050 using the GIS-based cellular automata Markov model (CA-Markov) to understand the implications of the ongoing trends in the LULC change for future land system dynamics. The current rate of change of the LULC in the region was assessed using the 48�years of earth observation satellite data from 1973 to 2021. It was observed that from 1973 to 2021, the area under vegetation cover and water body decreased by 19.48 and 47.13%, respectively. In contrast, cultivated land, barren land, and built-up area increased by 7.60, 20.28, and 384.99%, respectively. It was found that the area covered by vegetation and water body has largely been transitioned to cultivated land and built-up classes. The research predicted that, by the end of 2050, the area covered by vegetation, cultivated land, and water would remain at 39.75, 32.31, and 4.91%, respectively, while the area covered by built-up areas will increase by up to 18.09%. Using the kappa index (ki) as an accuracy indicator of the simulated future LULCs, the predicted LULC of 2021 was validated against the observed LULC of 2021, and the very high ki observed validated the generated simulation LULC products. The research concludes that significant LULC changes are taking place in the study area with a decrease in vegetation cover and water body and an increase of area under built-up. Such trends will continue in the future and shall have disastrous environmental consequences unless necessary land resource management strategies are not implemented. The main factors responsible for the changing dynamics of LULC in the study area are urbanization, population growth, climate change, river bank erosion and sedimentation, and intensive agriculture. This study is aimed at providing the policy and decision-makers of the region with the necessary what-if scenarios for better decision-making. It shall also be useful in other countries of the Brahmaputra basin for transboundary integrated river basin management of the whole region. � 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Land Use and Land Cover Change Monitoring and Prediction of a UNESCO World Heritage Site: Kaziranga Eco-Sensitive Zone Using Cellular Automata-Markov Model
(MDPI, 2023-01-02T00:00:00) Nath, Nityaranjan; Sahariah, Dhrubajyoti; Meraj, Gowhar; Debnath, Jatan; Kumar, Pankaj; Lahon, Durlov; Chand, Kesar; Farooq, Majid; Chandan, Pankaj; Singh, Suraj Kumar; Kanga, Shruti
The Kaziranga Eco-Sensitive Zone is located on the edge of the Eastern Himalayan biodiversity hotspot region. In 1985, the Kaziranga National Park (KNP) was declared a World Heritage Site by UNESCO. Nowadays, anthropogenic interference has created a significant negative impact on this national park. As a result, the area under natural habitat is gradually decreasing. The current study attempted to analyze the land use land cover (LULC) change in the Kaziranga Eco-Sensitive Zone using remote sensing data with CA-Markov models. Satellite remote sensing and the geographic information system (GIS) are widely used for monitoring, mapping, and change detection of LULC change dynamics. The changing rate was assessed using thirty years (1990�2020) of Landsat data. The study analyses the significant change in LULC, with the decrease in the waterbody, grassland and agricultural land, and the increase of sand or dry river beds, forest, and built-up areas. Between 1990 and 2020, waterbody, grassland, and agricultural land decreased by 18.4, 9.96, and 64.88%, respectively, while sand or dry river beds, forest, and built-up areas increased by 103.72, 6.96, and 89.03%, respectively. The result shows that the area covered with waterbodies, grassland, and agricultural land is mostly converted into built-up areas and sand or dry river bed areas. According to this study, by 2050, waterbodies, sand or dry river beds, and forests will decrease by 3.67, 3.91, and 7.11%, respectively; while grassland and agriculture will increase by up to 16.67% and 0.37%, respectively. The built-up areas are expected to slightly decrease during this period (up to 2.4%). The outcome of this study is expected to be useful for the long-term management of the Kaziranga Eco-Sensitive Zone. � 2023 by the authors.
Lithostratigraphy, trace fossils and palaeoenvironment of Paleogene sequences in Parwanoo-Subathu sector of Himachal Himalaya, India
(Geological Society of India, 2018) Singh, Ram Jivan; Sharma, K. Milankumar; Kumar, Pankaj; Ghosh, T.
The Paleogene belt of the Outer Himalaya in the Shimla Hills is represented by the Paleocene to Lower Miocene ma-rine to ?uvial rocks of the Sirmur Group which is divisible into the Subathu, Dagshai and Kasauli formations in younging order in Parwanoo-Subathu area of the Himachal Pradesh, India. The shallow marine fossil bearing Subathu Formation overlies the various Proterozoic lithostratigraphic units like the Simla Group, Krol Group, Baliana Group, Shali Group/Deoban Group and others with an unconformable contact marked by a thin layer of oxidized and ferruginised laterite, indicating prevalence of warm tropical climate before deposition of these shallow transgressive marine rocks. The Subathu Formation grades upward into ?uvial deposits,compris-ing an alternate sequence of reddish-purple mudstone and ?ne to medium grained, reddish-brown sandstone of the Dagshai Formation along with multiple palaeosol horizons. The rocks of the Dagshai Formation are further gradationally overlain by the plant fossil bear-ing ?uvial sequence of medium to coarse grained, massive, multistory, greenish-grey micaceous sandstone and minor grey-orange mudstone of the Kasauli Formation. In response to southward leading deformation front of the Himalayan orogeny, due to collision tectonics of the Indian and Eurasian plates, the para-autochthonous Paleogene fold-thrust belt exposed between the northerly dipping Main Boundary Thrust (MBT)/Krol Thrust in north and the Main Boundary Fault (MBF) in the south shows repetition of some forma-tions of the Sirmur Group along Parwanoo-Darampur-Barog-Subathu section of the Himachal Himalaya. The abundance of vertical and cylindrical burrows of Skolithos linearis, S. annulatus, S. ingen, S. bulbus, Ophiomorpha esp., Thallasinoides paradoxides, etc. within the upper part of the Subathu Formation suggest lower intertidal to subtidal environment. This ichnofossil assemblage along with Skolithos-Thallasinoids-Ophiomorpha represent littoral zone, intertidal to subtidal environment of deposition
Predicting Future Land Use Utilizing Economic and Land Surface Parameters with ANN and Markov Chain Models
(Multidisciplinary Digital Publishing Institute (MDPI), 2023-09-18T00:00:00) Rani, Ankush; Gupta, Saurabh Kumar; Singh, Suraj Kumar; Meraj, Gowhar; Kumar, Pankaj; Kanga, Shruti; ?urin, Bojan; Dogan?i?, Dragana
The main aim of this study is to comprehensively analyze the dynamics of land use and land cover (LULC) changes in the Bathinda region of Punjab, India, encompassing historical, current, and future trends. To forecast future LULC, the Cellular Automaton�Markov Chain (CA) based on artificial neural network (ANN) concepts was used using cartographic variables such as environmental, economic, and cultural. For segmenting LULC, the study used a combination of ML models, such as support vector machine (SVM) and Maximum Likelihood Classifier (MLC). The study is empirical in nature, and it employs quantitative analyses to shed light on LULC variations through time. The result indicates that the barren land is expected to shrink from 55.2 km2 in 1990 to 5.6 km2 in 2050, signifying better land management or increasing human activity. Vegetative expanses, on the other hand, are expected to rise from 81.3 km2 in 1990 to 205.6 km2 in 2050, reflecting a balance between urbanization and ecological conservation. Agricultural fields are expected to increase from 2597.4 km2 in 1990 to 2859.6 km2 in 2020 before stabilizing at 2898.4 km2 in 2050. Water landscapes are expected to shrink from 13.4 km2 in 1990 to 5.6 km2 in 2050, providing possible issues for water resources. Wetland regions are expected to decrease, thus complicating irrigation and groundwater reservoir sustainability. These findings are confirmed by strong statistical indices, with this study�s high kappa coefficients of Kno (0.97), Kstandard (0.95), and Klocation (0.97) indicating a reasonable level of accuracy in CA prediction. From the result of the F1 score, a significant issue was found in MLC for segmenting vegetation, and the issue was resolved in SVM classification. The findings of this study can be used to inform land use policy and plans for sustainable development in the region and beyond. � 2023 by the authors.
Reconstruction of Quaternary climate in Svalbard: CRN as proxy
(Elsevier, 2021-08-27T00:00:00) Amrutha, K.; Kumar, Pankaj; Khare, Neloy; Pattanaik, Jitendra Kumar
Polar region experienced a large-scale melting of glaciers and sea ice retreat in the recent past. Drastic decrease of ice cover and its foreseen impact on ocean circulations, sea level, and ocean chemistry brought Arctic into the forefront of climate change studies. High-latitude glaciers withstand minor climatic change. However, recent trend of global climatic conditions started influencing polar ice sheet and glacier to an alarming state. Compared to lower latitudes, Arctic is significantly affected by minor changes in temperature and precipitation pattern, referred as �Arctic amplification.� Ice dynamics and impact of climate change on Antarctica ice sheet is different than the Arctic Circle as the surrounding environment and atmospheric circulations acting in these areas are diverse in nature. External forces like Milankovitch Cycles and solar irradiance; atmospheric forces like greenhouse gas concentrations, albedo, and cloud cover; and interaction among these forces are key factors responsible for prevailing climate and its changes in the Arctic Circle. Since few decades, Arctic Circle witnessed complex atmospheric, oceanic, and terrestrial changes. Location of Svalbard archipelago is very crucial in terms of the ocean circulation as it is lying between North Atlantic Ocean and Arctic Ocean. The climate here is largely governed by the North Atlantic Oscillation and thermohaline circulation. However, rise in annual average temperature of Arctic is linked to increase in CO2 concentration and decrease in SO4 gas in the atmosphere. Study suggests that role of SO4 concentration in the atmosphere is more important than the solar irradiation in the Arctic climate. Therefore it is essential to understand how climate has responded to external and atmospheric forces. Svalbard located in the North Atlantic sector of Arctic region has shown a high response to present climate changes due to multiple feedback mechanisms associated with oceanic, atmospheric, and cryosphere processes. � 2021 Elsevier Inc. All rights reserved.
Simulating Groundwater Potential Zones in Mountainous Indian Himalayas�A Case Study of Himachal Pradesh
(MDPI, 2023-03-13T00:00:00) Sud, Anshul; Kanga, Rahul; Singh, Suraj Kumar; Meraj, Gowhar; Kanga, Shruti; Kumar, Pankaj; Ramanathan, A.L.; Sudhanshu; Bhardwaj, Vinay
Groundwater resources are increasingly important as the main supply of fresh water for household, industrial, and agricultural activities. However, overuse and depletion of these resources can lead to water scarcity and resource deterioration. Therefore, assessing groundwater availability is essential for sustainable water management. This study aims to identify potential groundwater zones in the Bilaspur district of Himachal Pradesh using the Multi Influencing Factor (MIF) technique, a modern decision-making method widely used in various sectors. Geospatial models were integrated with the MIF technique to evaluate prospective groundwater areas. Grid layouts of all underground water influencing variables were given a predetermined score and weight in this decision-making strategy. The potential groundwater areas were then statistically assessed using graded data maps of slope, lithology, land-use, lineament, aspect, elevation, soil, drainage, geomorphology, and rainfall. These maps were converted into raster data using the raster converter tool in ArcGIS software, utilizing Survey of India toposheets, SRTM DEM data, and Resourcesat-2A satellite imageries. The prospective groundwater zones obtained were classified into five categories: nil�very low, covering 0.34% of the total area; very low�low (51.64%); low�moderate (4.92%); moderate�high (18%) and high�very high (25%). Scholars and policymakers can collaborate to develop systematic exploration plans for future developments and implement preservative and protective strategies by identifying groundwater recharge zones to reduce groundwater levels. This study provides valuable insights for long-term planning and management of water resources in the region. � 2023 by the authors.
Status of Air Pollution during COVID-19-Induced Lockdown in Delhi, India
(MDPI, 2022-12-13T00:00:00) Singh, Harikesh; Meraj, Gowhar; Singh, Sachchidanand; Shrivastava, Vaibhav; Sharma, Vishal; Farooq, Majid; Kanga, Shruti; Singh, Suraj Kumar; Kumar, Pankaj
To monitor the spread of the novel coronavirus (COVID-19), India, during the last week of March 2020, imposed national restrictions on the movement of its citizens (lockdown). Although India�s economy was shut down due to restrictions, the nation observed a sharp decline in particulate matter (PM) concentrations. In recent years, Delhi has experienced rapid economic growth, leading to pollution, especially in urban and industrial areas. In this paper, we explored the linkages between air quality and the nationwide lockdown of the city of Delhi using a geographic information system (GIS)-based approach. Data from 37 stations were monitored from 12 March, 2020 to 2 April, 2020 and it was found that the Air Quality Index for the city was almost reduced by 37% and 46% concerning PM2.5 and PM10, respectively. The study highlights that, in regular conditions, the atmosphere�s natural healing rate against anthropogenic activities is lower, as indicated by a higher AQI. However, during the lockdown, this sudden cessation of anthropogenic activities leads to a period in which the natural healing rate is greater than the induced disturbances, resulting in a lower AQI, and thus proving that this pandemic has given a small window for the environment to breathe and helped the districts of Delhi to recover from serious issues related to bad air quality. If such healing windows are incorporated into policy and decision-making, these can prove to be effective measures for controlling air pollution in heavily polluted regions of the World. � 2022 by the authors.
Uncovering the hydro-meteorological drivers responsible for forest fires utilizing geospatial techniques
(Springer, 2023-05-29T00:00:00) Gupta, Saurabh Kumar; Kanga, Shruti; Meraj, Gowhar; Kumar, Pankaj; Singh, Suraj Kumar
Forest fires have become a growing concern worldwide, with climate change exacerbating their frequency and intensity. In the Simlipal region of India, forest fires are relatively rare; however, in 2021, significant damage occurred in the buffer area�s forests. Understanding the driving factors behind these events is essential for developing effective management strategies. This study investigates the impact of hydro-meteorological conditions on forest fire causes in the Simlipal region by analyzing Terra climatic data and geo-statistics for the period of 1984 to 2021. Long-term trends were determined using non-parametric tests on the Google Earth Engine (GEE) cloud computing platform. Our findings reveal that the maximum burned area location has a decreasing trend in Land Surface Temperature (LST), with a small portion (<10%) showing an increasing trend (0.02 �C/year) near burned locations. Wind speed is decreasing at a rate of ?0.006 m/s/year. The sudden forest fires are caused by the combined effect of increasing LST and decreasing wind speed in some areas (<10% of the region). However, the major factor contributing to forest fires in the entire area is the rising trend of annual potential water deficit and actual evapotranspiration, as well as an increasing trend of minimum temperature. The soil moisture deficit during the summer season, especially between 2012 and 2021, contributed to forest fires in the burned area. The soil moisture deficit during the summer season, particularly from 2012 to 2021, played a significant role in the occurrence of forest fires in the affected area. The study emphasized the need for increased attention to this region in order to preserve biodiversity, which was assessed through an analysis of burned severity mapping in GEE (Google Earth Engine). These findings have important implications for future forest management strategies in the Simlipal region. Climate variability is likely to exacerbate the frequency and intensity of forest fires in the region, necessitating effective management strategies to mitigate their impact. Such strategies could involve improving fire prevention and control measures, such as creating fire breaks and increasing the availability of fire-fighting equipment, as well as enhancing forest monitoring systems to detect potential fires early. Additionally, efforts to address climate change, proper management of land use practices, and reduce greenhouse gas emissions could help to mitigate the future impacts of forest fires in the Simlipal region and elsewhere. � 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.
Unveiling Nature�s Resilience: Exploring Vegetation Dynamics during the COVID-19 Era in Jharkhand, India, with the Google Earth Engine
(Multidisciplinary Digital Publishing Institute (MDPI), 2023-09-08T00:00:00) Ahmad, Tauseef; Gupta, Saurabh Kumar; Singh, Suraj Kumar; Meraj, Gowhar; Kumar, Pankaj; Kanga, Shruti
The Severe Acute Respiratory Syndrome Coronavirus Disease 2019 (COVID-19) pandemic has presented unprecedented challenges to global health and economic stability. Intriguingly, the necessary lockdown measures, while disruptive to human society, inadvertently led to environmental rejuvenation, particularly noticeable in decreased air pollution and improved vegetation health. This study investigates the lockdown�s impact on vegetation health in Jharkhand, India, employing the Google Earth Engine for cloud-based data analysis. MODIS-NDVI data were analyzed using spatio-temporal NDVI analyses and time-series models. These analyses revealed a notable increase in maximum vegetation greenery of 19% from April 2019 to 2020, with subsequent increases of 13% and 3% observed in March and May of the same year, respectively. A longer-term analysis from 2000 to 2020 displayed an overall 16.7% rise in vegetation greenness. While the maximum value remained relatively constant, it demonstrated a slight increment during the dry season. The Landsat data Mann�Kendall trend test reinforced these findings, displaying a significant shift from a negative NDVI trend (1984�2019) to a positive 17.7% trend (1984�2021) in Jharkhand�s north-west region. The precipitation (using NASA power and Merra2 data) and NDVI correlation were also studied during the pre- and lockdown periods. Maximum precipitation (350�400 mm) was observed in June, while July typically experienced around 300 mm precipitation, covering nearly 85% of Jharkhand. Interestingly, August 2020 saw up to 550 mm precipitation, primarily in Jharkhand�s southern region, compared to 400 mm in the same month in 2019. Peak changes in NDVI value during this period ranged between 0.6�0.76 and 0.76�1, observed throughout the state. Although the decrease in air pollution led to improved vegetation health, these benefits began to diminish post-lockdown. This observation underscores the need for immediate attention and intervention from scientists and researchers. Understanding lockdown-induced environmental changes and their impact on vegetation health can facilitate the development of proactive environmental management strategies, paving the way towards a sustainable and resilient future. � 2023 by the authors.