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1.	Bhardwaj, Anshuman, et al. (författare) A review on remotely sensed land surface temperature anomaly as an earthquake precursor 2017 Ingår i: International Journal of Applied Earth Observation and Geoinformation. - : Elsevier. - 1569-8432 .- 1872-826X. ; 63, s. 158-166 Tidskriftsartikel (refereegranskat)abstract The low predictability of earthquakes and the high uncertainty associated with their forecasts make earthquakes one of the worst natural calamities, capable of causing instant loss of life and property. Here, we discuss the studies reporting the observed anomalies in the satellite-derived Land Surface Temperature (LST) before an earthquake. We compile the conclusions of these studies and evaluate the use of remotely sensed LST anomalies as precursors of earthquakes. The arrival times and the amplitudes of the anomalies vary widely, thus making it difficult to consider them as universal markers to issue earthquake warnings. Based on the randomness in the observations of these precursors, we support employing a global-scale monitoring system to detect statistically robust anomalous geophysical signals prior to earthquakes before considering them as definite precursors.
2.	Bhardwaj, Anshuman, et al. (författare) LiDAR remote sensing of the cryosphere : Present applications and future prospects 2016 Ingår i: Remote Sensing of Environment. - : Elsevier BV. - 0034-4257 .- 1879-0704. ; 177, s. 125-143 Tidskriftsartikel (refereegranskat)abstract The cryosphere consists of frozen water and includes lakes/rivers/sea ice, glaciers, ice caps/sheets, snow cover, and permafrost. Because highly reflective snow and ice are the main components of the cryosphere, it plays an important role in the global energy balance. Thus, any qualitative or quantitative change in the physical properties and extents of the cryosphere affects global air circulation, ocean and air temperatures, sea level, and ocean current patterns. Due to the hardships involved in collecting ground control points and field data for high alpine glaciers or vast polar ice sheets, several researchers are currently using remote sensing. Satellites provide an effective space-borne platform for remotely sensing frozen areas at the global and regional scales. However, satellite remote sensing has several constraints, such as limited spatial and temporal resolutions and expensive data acquisition. Therefore, aerial and terrestrial remote sensing platforms and sensors are needed to cover temporal and spatial gaps for comprehensive cryospheric research. Light Detection and Ranging (LiDAR) antennas form a group of active remote sensors that can easily be deployed on all three platforms, i.e., satellite, aerial, and terrestrial. The generation of elevation data for glacial and snow-covered terrain from photogrammetry requires high contrast amongst various reflective surfaces (ice, snow, firn, and slush). Conventional passive optical remote sensors do not provide the necessary accuracy, especially due to the unavailability of reliable ground control points. However, active LiDAR sensors can fill this research gap and provide high-resolution and accurate Digital Elevation Models (DEMs). Due to the obvious advantages of LiDAR over conventional passive remote sensors, the number of LiDAR-based cryospheric studies has increased in recent years. In this review, we highlight studies that have utilised LiDAR sensors for the cryospheric research of various features, such as snow cover, polar ice sheets and their atmospheres, alpine glaciers, and permafrost. Because this technology shows immense promise for applications in future cryospheric research, we also emphasise the prospects of utilising LiDAR sensors. In this paper, a large compilation of relevant references is presented to allow readers to explore particular topics of interest.
3.	Bhardwaj, Anshuman, et al. (författare) MODIS-based estimates of strong snow surface temperature anomaly related to high altitude earthquakes of 2015 2017 Ingår i: Remote Sensing of Environment. - : Elsevier. - 0034-4257 .- 1879-0704. ; 188, s. 1-8 Tidskriftsartikel (refereegranskat)abstract The high levels of uncertainty associated with earthquake prediction render earthquakes some of the worst natural calamities. Here, we present our observations of MODerate resolution Imaging Spectroradiometer (MODIS)-derived Land Surface Temperature (LST) anomaly for earthquakes in the largest tectonically active Himalayan and Andean mountain belts. We report the appearance of fairly detectable pre-earthquake Snow Surface Temperature (SST) anomalies. We use 16 years (2000–2015) of MODIS LST time-series data to robustly conclude our findings for three of the most destructive earthquakes that occurred in 2015 in the high mountains of Nepal, Chile, and Afghanistan. We propose the physical basis behind higher sensitivity of snow towards geothermal emissions. Although the preliminary appearance of SST anomalies and their amplitudes vary, we propose employing a global-scale monitoring system for detecting and studying such spatio-temporal geophysical signals. With the advent of improved remote sensors, we anticipate that such efforts can be another step towards improved earthquake predictions.
4.	Ali, Sheikh Nawaz, et al. (författare) Indian Himalayan capacity and adaptation programme : capacity-building in Himalayan glaciology 2014 Ingår i: Current Science. - 0011-3891. ; 106:3, s. 346- Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
5.	Arora, Aman, et al. (författare) Optimization of state-of-the-art fuzzy-metaheuristic ANFIS-based machine learning models for flood susceptibility prediction mapping in the Middle Ganga Plain, India 2021 Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 750 Tidskriftsartikel (refereegranskat)abstract This study is an attempt to quantitatively test and compare novel advanced-machine learning algorithms in terms of their performance in achieving the goal of predicting flood susceptible areas in a low altitudinal range, sub-tropical floodplain environmental setting, like that prevailing in the Middle Ganga Plain (MGP), India. This part of the Ganga floodplain region, which under the influence of undergoing active tectonic regime related subsidence, is the hotbed of annual flood disaster. This makes the region one of the best natural laboratories to test the flood susceptibility models for establishing a universalization of such models in low relief highly flood prone areas. Based on highly sophisticated flood inventory archived for this region, and 12 flood conditioning factors viz. annual rainfall, soil type, stream density, distance from stream, distance from road, Topographic Wetness Index (TWI), altitude, slope aspect, slope, curvature, land use/land cover, and geomorphology, an advanced novel hybrid model Adaptive Neuro Fuzzy Inference System (ANFIS), and three metaheuristic models-based ensembles with ANFIS namely ANFIS-GA (Genetic Algorithm), ANFIS-DE (Differential Evolution), and ANFIS-PSO (Particle Swarm Optimization), have been applied for zonation of the flood susceptible areas. The flood inventory dataset, prepared by collected flood samples, were apportioned into 70:30 classes to prepare training and validation datasets. One independent validation method, the Area-Under Receiver Operating Characteristic (AUROC) Curve, and other 11 cut-off-dependent model evaluation metrices have helped to conclude that the ANIFS-GA has outperformed other three models with highest success rate AUC = 0.922 and prediction rate AUC = 0.924. The accuracy was also found to be highest for ANFIS-GA during training (0.886) & validation (0.883). Better performance of ANIFS-GA than the individual models as well as some ensemble models suggests and warrants further study in this topoclimatic environment using other classes of susceptibility models. This will further help establishing a benchmark model with capability of highest accuracy and sensitivity performance in the similar topographic and climatic setting taking assumption of the quality of input parameters as constant.
6.	Bhardwaj, Anshuman, et al. (författare) A lake detection algorithm (LDA) using Landsat 8 data : A comparative approach in glacial environment 2015 Ingår i: International Journal of Applied Earth Observation and Geoinformation. - : Elsevier BV. - 1569-8432 .- 1872-826X. ; 38, s. 150-163 Tidskriftsartikel (refereegranskat)abstract Glacial lakes show a wide range of turbidity. Owing to this, the normalized difference water indices (NDWIs) as proposed by many researchers, do not give appropriate results in case of glacial lakes. In addition, the sub-pixel proportion of water and use of different optical band combinations are also reported to produce varying results. In the wake of the changing climate and increasing GLOFs (glacial lake outburst floods), there is a need to utilize wide optical and thermal capabilities of Landsat 8 data for the automated detection of glacial lakes. In the present study, the optical and thermal bandwidths of Landsat 8 data were explored along with the terrain slope parameter derived from Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model Version2 (ASTER GDEM V2), for detecting and mapping glacial lakes. The validation of the algorithm was performed using manually digitized and subsequently field corrected lake boundaries. The pre-existing NDWIs were also evaluated to determine the supremacy and the stability of the proposed algorithm for glacial lake detection. Two new parameters, LDI (lake detection index) and LF (lake fraction) were proposed to comment on the performances of the indices. The lake detection algorithm (LDA) performed best in case of both, mixed lake pixels and pure lake pixels with no false detections (LDI = 0.98) and very less areal underestimation (LF= 0.73). The coefficient of determination (R-2) between areal extents of lake pixels, extracted using the LDA and the actual lake area, was very high (0.99). With understanding of the terrain conditions and slight threshold adjustments, this work can be replicated for any mountainous region of the world.
7.	Bhardwaj, Anshuman, et al. (författare) Analysing Geospatial Techniques for Land Degradation Studies in Hindu Kush-Himalaya 2019 Ingår i: Environmental Change in the Himalayan Region. - Cham : Springer Nature. - 9783030033613 - 9783030033620 ; , s. 117-135 Bokkapitel (refereegranskat)abstract Degraded land is predominantly considered as an unusable natural resource for sustaining livelihood practices such as agriculture, forestry and tourism. Land degradation poses far more grave threats in mountains where exploitable land is limited. A sustainable existence in mountainous area depends on the conservation practices adopted and a judicious utilisation of land and water resources. Due to the vastness of the Hindu Kush-Himalaya (HKH), trans-boundary issues and difficult terrain and weather conditions, geospatial techniques utilizing remote sensing and Geographical Information System (GIS) play an important role in assessing the degree of land degradation. The main focus of this chapter is on analyzing the usability and effectiveness of the geospatial approaches and methods needed to study wide-scale land degradation in the HKH mountains. This Chapter further assesses the various aspects of land degradation in mountains and highlights the markers to study land degradation. It tries to analyze the degree of anthropogenic interference on land resources in the human-dominated Himalayan region. It provides an overview of significant studies that have dealt with the assessment of land degradation in the HKH using remote sensing and GIS methodologies. The Chapter offers suggestions that future studies using geospatial techniques in resource monitoring and assessment should take heed of. Additionally, it proposes conservation and livelihood strategies for sustainable development in these high mountains.
8.	Bhardwaj, Anshuman, et al. (författare) Applicability of Landsat 8 data for characterizing glacier facies and supraglacial debris 2015 Ingår i: International Journal of Applied Earth Observation and Geoinformation. - : Elsevier BV. - 1569-8432 .- 1872-826X. ; 38, s. 51-64 Tidskriftsartikel (refereegranskat)abstract present work evaluates the applicability of operational land imager (OLI) and thermal infrared sensor (TIRS) on-board Landsat 8 satellite. We demonstrate an algorithm for automated mapping of glacier facies and supraglacial debris using data collected in blue, near infrared (NIR), short wave infrared (SWIR) and thermal infrared (TIR) bands. The reflectance properties invisible and NIR regions of OLI for various glacier facies are in contrast with those in SWIR region. Based on the premise that different surface types (snow, ice and debris) of a glacier should show distinct thermal regimes, the 'at-satellite brightness temperature' obtained using TIRS was used as a base layer for developing the algorithm. This base layer was enhanced and modified using contrasting reflectance properties of OLI bands. In addition to fades and debris cover characterization, another interesting outcome of this algorithm was extraction of crevasses on the glacier surface which were distinctly visible in output and classified images. The validity of this algorithm was checked using field data along a transect of the glacier acquired during the satellite pass over the study area. With slight scene-dependent threshold adjustments, this work can be replicated for mapping glacier facies and supraglacial debris in any alpine valley glacier
9.	Bhardwaj, Anshuman, et al. (författare) Are Slope Streaks Indicative of Global‐Scale Aqueous Processes on Contemporary Mars? 2019 Ingår i: Reviews of geophysics. - : American Geophysical Union (AGU). - 8755-1209 .- 1944-9208. ; 57:1, s. 48-77 Tidskriftsartikel (refereegranskat)abstract Slope streaks are prevalent and intriguing dark albedo surface features on contemporary Mars. Slope streaks are readily observed in the equatorial and subequatorial dusty regolith regions with low thermal inertia. They gradually fade over decadal timescales. The proposed mechanisms for their formation vary widely based on several physicochemical and geomorphological explanations. The scientific community is divided in proposing both dry and wet mechanisms for the formation of slope streaks. Here we perform a systematic evaluation of the literature for these wet and dry mechanisms. We discuss the probable constraints on the various proposed mechanisms and provide perspectives on the plausible process driving global‐scale slope streak formation on contemporary Mars. Although per our understanding, a thorough consideration of the global distribution of slope streaks, their morphology and topography, flow characteristics, physicochemical and atmospheric coincidences, and terrestrial analogies weighs more in favor of several wet mechanisms, we acknowledge that such wet mechanisms cannot explain all the reported morphological and terrain variations of slope streaks. Thus, we suggest that explanations considering both dry and wet processes can more holistically describe all the observed morphological variations among slope streaks. We further acknowledge the constraints on the resolutions of remote sensing data and on our understanding of the Martian mineralogy, climate, and atmosphere and recommend continuous investigations in this direction using future remote sensing acquisitions and simulations. In this regard, finding more wet and dry terrestrial analogs for Martian slope streaks and studying them at high spatiotemporal resolutions can greatly improve our understanding.
10.	Bhardwaj, Anshuman, et al. (författare) Automated detection and temporal monitoring of crevasses using remote sensing and their implications for glacier dynamics 2016 Ingår i: Annals of Glaciology. - 0260-3055 .- 1727-5644. ; 57:71, s. 81-91 Tidskriftsartikel (refereegranskat)abstract Detailed studies on temporal changes of crevasses and their linkage with glacier dynamics are scarce in the Himalayan context. Observations of temporally changing surficial crevasse patterns and their orientations are suggestive of the processes that determine seasonal glacier flow characteristics. In the present study, on a Himalayan valley glacier, changing crevasse patterns and orientations were detected and mapped on Landsat 8 images in an automated procedure using the ratio of Thermal Infrared Sensor (TIRS) band 10 to Optical Land Imager (OLI) shortwave infrared (SWIR) band 6. The ratio was capable of mapping even crevasses falling under mountain shadows. Differential GPS observations suggested an average error of 3.65% and root-mean-square error of 6.32m in crevasse lengths. A year-round observation of these crevasses, coupled with field-based surface velocity measurements, provided some interesting interpretations of seasonal glacier dynamics.
11.	Bhardwaj, Anshuman, et al. (författare) Demarcation of potential avalanche sites using remote sensing and ground observations : A case study of Gangotri glacier 2014 Ingår i: Geocarto International. - : Informa UK Limited. - 1010-6049 .- 1752-0762. ; 29:5, s. 520-535 Tidskriftsartikel (refereegranskat)abstract This study demonstrates the effectiveness of remote sensing and analytical hierarchy process for avalanche hazard mapping. The layers incorporated in this study were of slope, aspect, profile curvature, ground cover and elevation. The accuracy of output was determined using the registered avalanche sites based on ground observations and field-based modelling techniques. 93.35% of avalanche-affected areas came under maximum and moderate hazard zones, thus proving the effectiveness of this technique for Gangotri glacier basin. A parallel study was done to observe the change in the results, if any, by using high-resolution DEM and Cartosat-1 imagery. Similar methodology was adopted and the outcome was having significant improvement over the previous result as 98.8% of the preregistered avalanche area falling within maximum and moderate hazard zones
12.	Bhardwaj, Anshuman, et al. (författare) Developing a statistical dengue risk prediction model for the state of delhi based on various environmental variables 2012 Ingår i: International Journal of Geoinformatics. - 1686-6576. ; 8:3, s. 45-52 Tidskriftsartikel (refereegranskat)abstract This work investigates dengue affected localities of Delhi using static and dynamic environmental factors and their possible spatial relationships. The static variables include soil drainage, built-up area and vegetation. The dynamic variables represent seasonal precipitation and temperature data for past hundred years. Significance test (t-test) provided deterministic evidence of variable importance to model. Weighted sum and quantile classification helped to create a final risk map. The model indicated non-uniform distribution of risk across the state and showed elevated risk in urban built-up areas mainly alongside the river Yamuna. Three years (2007, 2008 and 2009) data for confirmed dengue cases for affected localities were obtained from Municipal Corporation of Delhi (MCD) for validation. 57.98% of the reported cases were observed under high risk category as modeled in this study. Modeling results indicate that environmental factors like Precipitation, temperature, soil drainage, built-up area and vegetation govern mosquito breeding and are correlated with human dengue risk The approach verified that dengue risk can be modeled at the state level and can be modified for risk predictions of other vector-borne diseases in varied ecological regions
13.	Bhardwaj, Anshuman, et al. (författare) Discovery of recurring slope lineae candidates in Mawrth Vallis, Mars 2019 Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 9 Tidskriftsartikel (refereegranskat)abstract Several interpretations of recurring slope lineae (RSL) have related RSL to the potential presence of transient liquid water on Mars. Such probable signs of liquid water have implications for Mars exploration in terms of rover safety, planetary protection during rover operations, and the current habitability of the planet. Mawrth Vallis has always been a prime target to be considered for Mars rover missions due to its rich mineralogy. Most recently, Mawrth Vallis was one of the two final candidates selected by the European Space Agency as a landing site for the ExoMars 2020 mission. Therefore, all surface features and landforms in Mawrth Vallis that may be of special interest in terms of scientific goals, rover safety, and operations must be scrutinised to better assess it for future Mars missions. Here, we report on the initial detection of RSL candidates in two craters of Mawrth Vallis. The new sightings were made outside of established RSL regions and further prompt the inclusion of a new geographical region within the RSL candidate group. Our inferences on the RSL candidates are based on several morphological and geophysical evidences and analogies: (i) the dimensions of the RSL candidates are consistent with confirmed mid-latitude RSL; (ii) albedo and thermal inertia values are comparable to those of other mid-latitude RSL sites; and (iii) features are found in a summer season image and on the steep and warmest slopes. These results denote the plausible presence of transient liquid brines close to the previously proposed landing ellipse of the ExoMars rover, rendering this site particularly relevant to the search of life. Further investigations of Mawrth Vallis carried out at higher spatial and temporal resolutions are needed to identify more of such features at local scales to maximize the scientific return from the future Mars rovers, to prevent probable biological contamination during rover operations, to evade damage to rover components as brines can be highly corrosive, and to quantify the ability of the regolith at mid-latitudes to capture atmospheric water which is relevant for in-situ-resource utilization.
14.	Bhardwaj, Anshuman, et al. (författare) Distribution and Morphologies of Transverse Aeolian Ridges in ExoMars 2020 Rover Landing Site 2019 Ingår i: Remote Sensing. - : MDPI. - 2072-4292. ; 11:8 Tidskriftsartikel (refereegranskat)abstract Aeolian processes are believed to play a major role in the landscape evolution of Mars. Investigations on Martian aeolian landforms such as ripples, transverse aeolian ridges (TARs), and dunes, and aeolian sediment flux measurements are important to enhance our understanding of past and present wind regimes, the ongoing dust cycle, landscape evolution, and geochemistry. These aeolian bedforms are often comprised of loose sand and sharply undulating topography and thus pose a threat to mobility and maneuvers of Mars rovers. Here we present a first-hand account of the distribution, morphologies, and morphometrics of TARs in Oxia Planum, the recently selected ExoMars 2020 Rover landing site. The gridded mapping was performed for contiguous stretches of TARs within all the landing ellipses using 57 sub-meter high resolution imaging science experiment (HiRISE) scenes. We also provide the morphological descriptions for all types of TARs present within the landing ellipses. We use HiRISE digital terrain models (DTMs) along with the images to derive morphometric information for TARs in Oxia Planum. In general, the average areal TAR coverage was found to be 5.4% (±4.9% standard deviation), increasing from west to east within the landing ellipses. We report the average TAR morphometrics in the form of crest–ridge width (131.1 ± 106.2 m), down-wind TAR length (17.6 ± 10.1 m), wavelength (37.3 ± 11.6 m), plan view aspect ratio (7.1 ± 2.3), inter-bedform spacing (2.1 ± 1.1), slope (10.6° ± 6.1°), predominant orientations (NE-SW and E-W), and height (1.2 ± 0.8 m). While simple TARs are predominant, we report other TAR morphologies such as forked TAR, wavy TAR with associated smaller secondary ripples, barchan-like TAR, networked TAR, and mini-TARs from the region. Our results can help in planning the rover traverses in terms of both safe passage and scientific returns favoring aeolian research, particularly improving our understanding of TARs.
15.	Bhardwaj, Anshuman, et al. (författare) Identification and Mapping of Glacier-Like Forms (GLFs) Near Martian Subpolar Latitudes 2016 Konferensbidrag (refereegranskat)
16.	Bhardwaj, Anshuman, et al. (författare) Mapping debris-covered glaciers and identifying factors affecting the accuracy 2014 Ingår i: Cold Regions Science and Technology. - : Elsevier BV. - 0165-232X .- 1872-7441. ; 106-107, s. 161-174 Tidskriftsartikel (refereegranskat)abstract Supraglacial debris significantly hampers the mapping of glaciers using remote sensing data. A semi-automated approach for the mapping of debris-covered glacier was applied, which combined the inputs from thermal and optical remote sensing data and the Digital Elevation Model (DEM) derived morphometric parameters. A thermal mask that delineates the supraglacial debris extent was generated by the thresholding of surface temperature layer obtained from Landsat TM/ETM. + thermal band satellite data. The extent of clean glacier ice was identified by band ratioing and thresholding of TM/ETM. + 4 and TM/ETM. + 5 bands. Morphometric parameters like slope, plan curvature and profile curvature were rearranged in similar surface groups using the technique of cluster analysis. All these masks were vectorized and final classification maps were generated using geographic information system (GIS) overlay operations. The areal extent of semi-automated outlines of Hamtah and Patsio Glaciers derived from cluster analysis varied from manually derived outline using pan-sharpened Landsat ETM. + September 2000 image by -. 1.3% and -. 1.6%, respectively. Year 2011 classification map for Patsio Glacier was compared with the field observations and a high correlation and overall accuracy (~. 91%) were observed. The same classification methodology was adopted for images of years 2000 and 1989 for Patsio Glacier to observe the effects of varying snow cover patterns on adopted methodology. Also the methodology was adopted and verified for Hamtah Glacier, with different geometry and terrain conditions as compared to Patsio Glacier. Although the spatial resolution limitation of ASTER GDEM and Landsat TM/ETM. + thermal band limits the automated mapping of small debris-covered glaciers, the outcomes are still favorable enough to apply such methodologies for mapping different types of debris-covered glaciers in the future
17.	Bhardwaj, Anshuman, et al. (författare) Martian slope streaks as plausible indicators of transient water activity 2017 Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7:1 Tidskriftsartikel (refereegranskat)abstract Slope streaks have been frequently observed in the equatorial, low thermal inertia and dusty regions of Mars. The reason behind their formation remains unclear with proposed hypotheses for both dry and wet mechanisms. Here, we report an up-to-date distribution and morphometric investigation of Martian slope streaks. We find: (i) a remarkable coexistence of the slope streak distribution with the regions on Mars with high abundances of water-equivalent hydrogen, chlorine, and iron; (ii) favourable thermodynamic conditions for transient deliquescence and brine development in the slope streak regions; (iii) a significant concurrence of slope streak distribution with the regions of enhanced atmospheric water vapour concentration, thus suggestive of a present-day regolith-atmosphere water cycle; and (iv) terrain preferences and flow patterns supporting a wet mechanism for slope streaks. These results suggest a strong local regolith-atmosphere water coupling in the slope streak regions that leads to the formation of these fluidised features. Our conclusions can have profound astrobiological, habitability, environmental, and planetary protection implications
18.	Bhardwaj, Anshuman, et al. (författare) Remote sensing of alpine glaciers in visible and infrared wavelengths: a survey of advances and prospects 2016 Ingår i: Geocarto International. - : Informa UK Limited. - 1010-6049 .- 1752-0762. ; 31:5, s. 557-574 Tidskriftsartikel (refereegranskat)
19.	Bhardwaj, Anshuman, et al. (författare) Revisiting enigmatic Martian slope streaks 2019 Ingår i: Earth Space and Science News - Editors Vox. - : American Geophysical Union (AGU). ; 100 Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
20.	Bhardwaj, Anshuman, et al. (författare) Rock glaciers as proxies for identifying terrestrial and analogous Martian permafrost 2016 Ingår i: XI. International Conference On Permafrost. - Potsdam : Bibliothek Wissenschaftspark Albert Einstein. ; , s. 535-537 Konferensbidrag (refereegranskat)
21.	Bhardwaj, Anshuman, et al. (författare) The challenges and possibilities of earthquake predictions using non-seismic precursors 2021 Ingår i: The European Physical Journal Special Topics. - : Springer. - 1951-6355 .- 1951-6401. ; 230:1, s. 367-380 Forskningsöversikt (refereegranskat)abstract The catastrophic magnitude of life and monetary losses associated with earthquakes deserve serious attention and mitigation measures. However, in addition to the pre-earthquake and post-earthquake alleviation actions, the scientific community indeed needs to reconsider the possibilities of earthquake predictions using non-seismic precursors. A significant number of studies in the recent decades have reported several possible earthquake precursors such as anomalies in electric field, magnetic field, gas/aerosol emissions, ionospheric signals, ground water level, land surface temperature, surface deformations, animal behaviour, thermal infrared signals, atmospheric gravity waves, and lightning. Such substantial number of scientific articles and reported anomalous signals cannot be overlooked without a thoughtful appraisal. Here, we provide an opinion on the way forward for earthquake prediction in terms of challenges and possibilities while using non-seismic precursors. A general point of concern is the widely varying arrival times and the amplitudes of the anomalies, putting a question mark on their universal applicability as earthquake markers. However, a unifying concept which does not only define the physical basis of either all or most of these anomalies but which also streamlines their characterisation procedure must be the focus of future earthquake precursory research. Advancements in developing the adaptable instrumentation for in-situ observations of the claimed non-seismic precursors must be the next step and the satellite observations should not be taken as a replacement for field-based research. We support the need to standardise the precursor detection techniques and to employ a global-scale monitoring system for making any possible earthquake predictions reliable.
22.	Bhardwaj, Anshuman, et al. (författare) UAV Imaging of a Martian Brine Analogue Environment in a Fluvio-Aeolian Setting 2019 Ingår i: Remote Sensing. - : MDPI. - 2072-4292. ; 11:18 Tidskriftsartikel (refereegranskat)abstract Understanding extraterrestrial environments and landforms through remote sensing and terrestrial analogy has gained momentum in recent years due to advances in remote sensing platforms, sensors, and computing efficiency. The seasonal brines of the largest salt plateau on Earth in Salar de Uyuni (Bolivian Altiplano) have been inadequately studied for their localized hydrodynamics and the regolith volume transport across the freshwater-brine mixing zones. These brines have recently been projected as a new analogue site for the proposed Martian brines, such as recurring slope lineae (RSL) and slope streaks. The Martian brines have been postulated to be the result of ongoing deliquescence-based salt-hydrology processes on contemporary Mars, similar to the studied Salar de Uyuni brines. As part of a field-site campaign during the cold and dry season in the latter half of August 2017, we deployed an unmanned aerial vehicle (UAV) at two sites of the Salar de Uyuni to perform detailed terrain mapping and geomorphometry. We generated high-resolution (2 cm/pixel) photogrammetric digital elevation models (DEMs) for observing and quantifying short-term terrain changes within the brines and their surroundings. The achieved co-registration for the temporal DEMs was considerably high, from which precise inferences regarding the terrain dynamics were derived. The observed average rate of bottom surface elevation change for brines was ~1.02 mm/day, with localized signs of erosion and deposition. Additionally, we observed short-term changes in the adjacent geomorphology and salt cracks. We conclude that the transferred regolith volume via such brines can be extremely low, well within the resolution limits of the remote sensors that are currently orbiting Mars, thereby making it difficult to resolve the topographic relief and terrain perturbations that are produced by such flows on Mars. Thus, the absence of observable erosion and deposition features within or around most of the proposed Martian RSL and slope streaks cannot be used to dismiss the possibility of fluidized flow within these features
23.	Bhardwaj, Anshuman, et al. (författare) UAVs as remote sensing platform in glaciology : Present applications and future prospects 2016 Ingår i: Remote Sensing of Environment. - : Elsevier BV. - 0034-4257 .- 1879-0704. ; 175, s. 196-204 Tidskriftsartikel (refereegranskat)abstract Satellite remote sensing is an effective way to monitor vast extents of global glaciers and snowfields. However, satellite remote sensing is limited by spatial and temporal resolutions and the high costs involved in data acquisition. Unmanned aerial vehicle (UAV)-based glaciological studies are gaining pace in recent years due to their advantages over conventional remote sensing platforms. UAVs are easy to deploy, with the option of alternating the sensors working in visible, infrared, and microwave wavelengths. The high spatial resolution remote sensing data obtained from these UAV-borne sensors are a significant improvement over the data obtained by traditional remote sensing. The cost involved in data acquisition is minimal and researchers can acquire imagery according to their schedule and convenience. We discuss significant glaciological studies involving UAV as remote sensing platforms. This is the first review work, exclusively dedicated to highlight UAV as a remote sensing platform in glaciology. We examine polar and alpine applications of UAV and their future prospects in separate sections and present an extensive reference list for the readers, so that they can delve into their topic of interest. Because the technology is still widely unexplored for snow and glaciers, we put a special emphasis on discussing the future prospects of utilising UAVs for glaciological research.
24.	Cockell, Charles S., et al. (författare) Subsurface scientific exploration of extraterrestrial environments (MINAR 5) : analogue science, technology and education in the Boulby Mine, UK 2019 Ingår i: International Journal of Astrobiology. - : Cambridges Institutes Press. - 1473-5504 .- 1475-3006. ; 18:2, s. 157-182 Tidskriftsartikel (refereegranskat)abstract The deep subsurface of other planetary bodies is of special interest for robotic and human exploration. The subsurface provides access to planetary interior processes, thus yielding insights into planetary formation and evolution. On Mars, the subsurface might harbour the most habitable conditions. In the context of human exploration, the subsurface can provide refugia for habitation from extreme surface conditions. We describe the fifth Mine Analogue Research (MINAR 5) programme at 1 km depth in the Boulby Mine, UK in collaboration with Spaceward Bound NASA and the Kalam Centre, India, to test instruments and methods for the robotic and human exploration of deep environments on the Moon and Mars. The geological context in Permian evaporites provides an analogue to evaporitic materials on other planetary bodies such as Mars. A wide range of sample acquisition instruments (NASA drills, Small Planetary Impulse Tool (SPLIT) robotic hammer, universal sampling bags), analytical instruments (Raman spectroscopy, Close-Up Imager, Minion DNA sequencing technology, methane stable isotope analysis, biomolecule and metabolic life detection instruments) and environmental monitoring equipment (passive air particle sampler, particle detectors and environmental monitoring equipment) was deployed in an integrated campaign. Investigations included studying the geochemical signatures of chloride and sulphate evaporitic minerals, testing methods for life detection and planetary protection around human-tended operations, and investigations on the radiation environment of the deep subsurface. The MINAR analogue activity occurs in an active mine, showing how the development of space exploration technology can be used to contribute to addressing immediate Earth-based challenges. During the campaign, in collaboration with European Space Agency (ESA), MINAR was used for astronaut familiarization with future exploration tools and techniques. The campaign was used to develop primary and secondary school and primary to secondary transition curriculum materials on-site during the campaign which was focused on a classroom extra vehicular activity simulation.
25.	Gaffey, Clare, et al. (författare) Applications of Unmanned Aerial Vehicles in Cryosphere : Latest Advances and Prospects 2020 Ingår i: Remote Sensing. - : MDPI. - 2072-4292. ; 12:6 Tidskriftsartikel (refereegranskat)abstract Owing to usual logistic hardships related to field-based cryospheric research, remote sensing has played a significant role in understanding the frozen components of the Earth system. Conventional spaceborne or airborne remote sensing platforms have their own merits and limitations. Unmanned aerial vehicles (UAVs) have emerged as a viable and inexpensive option for studying the cryospheric components at unprecedented spatiotemporal resolutions. UAVs are adaptable to various cryospheric research needs in terms of providing flexibility with data acquisition windows, revisits, data/sensor types (multispectral, hyperspectral, microwave, thermal/night imaging, Light Detection and Ranging (LiDAR), and photogrammetric stereos), viewing angles, flying altitudes, and overlap dimensions. Thus, UAVs have the potential to act as a bridging remote sensing platform between spatially discrete in situ observations and spatially continuous but coarser and costlier spaceborne or conventional airborne remote sensing. In recent years, a number of studies using UAVs for cryospheric research have been published. However, a holistic review discussing the methodological advancements, hardware and software improvements, results, and future prospects of such cryospheric studies is completely missing. In the present scenario of rapidly changing global and regional climate, studying cryospheric changes using UAVs is bound to gain further momentum and future studies will benefit from a balanced review on this topic. Our review covers the most recent applications of UAVs within glaciology, snow, permafrost, and polar research to support the continued development of high-resolution investigations of cryosphere. We also analyze the UAV and sensor hardware, and data acquisition and processing software in terms of popularity for cryospheric applications and revisit the existing UAV flying regulations in cold regions of the world. The recent usage of UAVs outlined in 103 case studies provide expertise that future investigators should base decisions on.
26.	Kumar, Rajesh, et al. (författare) Development of a Glacio-hydrological Model for Discharge and Mass Balance Reconstruction 2016 Ingår i: Water resources management. - : Springer Science and Business Media LLC. - 0920-4741 .- 1573-1650. ; 30:10, s. 3475-3492 Tidskriftsartikel (refereegranskat)abstract The reconstruction of glacio-hydrological records for the data deficient Himalayan catchments is needed in order to study the past and future water availability. The study provides outcomes of a glacio-hydrological model based on the degree-day approach. The model simulates the discharge and mass balance for glacierised Shaune Garang catchment. The degree-day factors for different land covers, used in the model, were estimated using daily stake measurements on Shaune Garang glacier and they were found to be varying between 2.6 ± 0.4 and 9.3 ± 0.3 mm °C−1day−1. The model is validated using observed discharge during ablation season of 2014 with coefficient of determination (R2) 0.90 and root mean square error (RMSE) 1.05 m3 sec−1. The model is used to simulate discharge from 1985 to 2008 and mass balance from 2001 to 2008. The model results show significant contribution of seasonal snow and ice melt in total discharge of the catchment, especially during summer. We observe the maximum discharge in July having maximum contribution from snow and ice melt. The annual melt season discharge shows following a decreasing trend in the simulation period. The reconstructed mass balance shows mass loss of 0.89 m we per year between 2001 and 2008 with slight mass gain during 2000/01 and 2004/05 hydrological years.
27.	Kumar, Rajesh, et al. (författare) Dynamics of suspended sediment load with respect to summer discharge and temperatures in Shaune Garang glacierized catchment, Western Himalaya 2018 Ingår i: Acta Geophysica. - : Springer. - 1895-6572 .- 1895-7455. ; 66:5, s. 1109-1120 Tidskriftsartikel (refereegranskat)abstract The observed and predicted rise in temperature will have deleterious impact on melting of snow and ice and form of precipitation which is already evident in Indian Himalayan Region. The temperature-dependent entities like discharge and sediment load will also vary with the observed and predicted rise posing environmental, social and economic threat in the region. There is little known about sediment load transport in relation to temperature and discharge in glacierized catchments in Himalaya mainly due to the scarcity of ground-based observation. The present study is an attempt to understand the suspended sediment load and transportation in relation to variation in discharge and temperature in the Shaune Garang catchment. The result shows strong dependence of sediment concentration primarily on discharge (R2 = 0.84) and then on temperature (R2 = 0.79). The catchments with similar geological and climate setting were observed to have comparatively close weathering rate. The sediment load was found to be higher in the catchments in eastern and central part of Indian Himalayan Region in comparison with western part due to dominance of Indian Summer Monsoon leading to high discharge. The annual physical weathering rate in Shaune Garang catchment was found to be 411 t km−2 year−1 which has increased from 327 t km−2 year−1 in around three decades due to rise in temperature causing increase in discharge and proportion of debris-covered glacierized area.
28.	Kumar, Ramesh, et al. (författare) Hydro-geochemical analysis of meltwater draining from Bilare Banga glacier, Western Himalaya 2019 Ingår i: Acta Geophysica. - : Springer. - 1895-6572 .- 1895-7455. ; 67:2, s. 651-660 Tidskriftsartikel (refereegranskat)abstract The changing climate is affecting the melting process of glacier ice and snow in Himalaya and may influence the hydro-geochemistry of the glacial meltwater. This paper represents the ionic composition of discharge from Bilare Banga glacier by carrying out hydro-geochemical analysis of water samples of melting season of 2017. The pH and EC were measured on-site in field, and others parameters were examined in the laboratory. The abundance of the ions observed in meltwater has been arranged in decreasing order for cations as Ca2+ > Mg2+ > Na+ > K+ and for anions as HCO3− > SO42− > Cl− > NO3−, respectively. Analysis suggests that the meltwater is mostly dominated by Ca2+ and HCO3−. It has been observed that the ionic concentration HCO3− is dominant and Cl− is the least in the catchment. Piper plot analysis suggests that the chemical composition of the glacier discharge not only has natural origin but also has some anthropogenic input. Hydro-geochemical heterogeneity reflected the carbonate-dominated features (Ca2+–HCO3−) in the catchment. The carbonate weathering was found as the regulatory factor to control the chemistry of the glacial meltwater due to the high enrichment ratio of (Ca2+ + Mg2+) against TZ+ and (Na+ + K+). In statistical approach, PCA analysis suggests that geogenic weathering dynamics in the catchment is associated with carbonate-dominant lithology.
29.	Kumar, Rajesh, et al. (författare) Hydro-geochemical characteristics of glacial meltwater from Naradu Glacier catchment, Western Himalaya 2019 Ingår i: Environmental Earth Sciences. - : Springer. - 1866-6280 .- 1866-6299. ; 78:24 Tidskriftsartikel (refereegranskat)abstract The pattern of changing hydro-geochemical characteristics of water in Himalayan rivers is primarily controlled by sediment load from natural sources in higher altitudes and anthropogenic sources such as the burning of fossil fuels for domestic use, vehicular emissions, and wind transported industrial pollutants in the downstream region. The assessment of water quality is critical for the comparison of natural and anthropogenic sources in the downstream areas due to the dependence of the population on the glacial meltwater for freshwater supply. In the present study, we investigate the physical and ionic characteristics of glacial meltwater from Naradu Glacier catchment concerning the dominant weathering process. The freshwater samples were collected during the ablation period of 2016 and 2017 from specified locations. The physical parameters (pH, electrical conductivity, and temperature) were measured in the field while the analyses for concentrations of major cations (Ca2+, Mg2+, K+, Na+) and major anions (Cl−, SO42−, HCO3−, NO3−) were done in the laboratory. The anions (HCO3− > SO42− > Cl− > NO3−) and cations (Ca2+ > Mg2+ > Na+ > K+) concentrations were observed to have similar trends for both of the ablation period. The statistical analysis shows the predominance of geological weathering processes in the catchment as the controlling factor for the variation in concentration of different ionic species. The catchment was found to be rich in rocks with carbonate mineral making the Ca2+ and HCO3− the most dominant ions in the glacial meltwater.
30.	Martin-Torres, Javier, et al. (författare) Brine-Induced Tribocorrosion Accelerates Wear on Stainless Steel: Implications for Mars Exploration 2021 Ingår i: Advances in Astronomy. - : Hindawi Publishing Corporation. - 1687-7969 .- 1687-7977. ; 2021 Tidskriftsartikel (refereegranskat)abstract Tribocorrosion is a degradation phenomenon of material surfaces subjected to the combined action of mechanical loading and corrosion attack caused by the environment. Although corrosive chemical species such as materials like chloride atoms, chlorides, and perchlorates have been detected on the Martian surface, there is a lack of studies of its impact on materials for landed spacecraft and structures that will support surface operations on Mars. Here, we present a series of experiments on the stainless-steel material of the ExoMars 2020 Rosalind Franklin rover wheels. We show how tribocorrosion induced by brines accelerates wear on the materials of the wheels. Our results do not compromise the nominal ExoMars mission but have implications for future long-term surface operations in support of future human exploration or extended robotic missions on Mars.
31.	Mathanlal, Thasshwin (författare) Development of robotic instruments and techniques for space and astrobiological exploration and research 2020 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Astrobiology is the study of life in the universe. The search for life beyond the Earth requires an understanding of the signatures of life, and of the nature of the environments that support it. Space exploration is a crucial factor to achieve these goals. The PhD thesis focusses on developing novel techniques for astrobiological and Earth exploration. It includes instrument prototyping, validation and calibration of a flight-ready space in-strument.This thesis explains the development of four instruments namely 1) KORE – a robotic exploration rover designed for subsurface analogue planetary explorations; 2) InXSpace3D – a 3D mapping payload for biogeomorphological analysis based on a com-mercial RGB-D camera and an open-source algorithm; 3) S3ME2 – a self-sustainable environmental monitoring station capable of withstanding harsh environments on Earth; and 4) PACKMAN – a space weather monitoring instrument. The instruments are devoted to: 1) the spatial exploration and characterization (KORE and InXSpace3D) of a potentially habitable environment and 2) the monitorization of the rapidly vary-ing environmental variables that may affect life (S3ME2 and PACKMAN), its evolution and preservation. The instruments are developed according to the Technology Readiness Level (TRL) Ladder and a cost and time effective methodology which maximizes the use of Commercial Off-The-Shelf (COTS) components and Open source software.The thesis also discusses the bioburden sterilization and control procedure of some of the sensors on the flight-ready space Instrument HABIT (HabitAbility: Brines, Irradi-ation and Temperature), that will be part of the ExoMars 2022 mission. Again, a COTS and an open source software-based approach has been used in these higher TRL level procedures. This demonstrates the fact that such an engineering approach can benefit the scientific community by developing instruments with a minimal investment of time and resources without compromising the scientific quality of the instrument. The thesis concludes with the adaptation of the research methodology to adapt space technologies that are applicable in space for human support systems to address an emerging problem on Earth: ATMO-Vent, a low-cost COTS-based ventilator that produces an adapted breathable atmosphere for COVID-19 patients.During the PhD thesis, the author has published five peer-reviewed journal papers, two peer-reviewed conference abstracts and two co-authored peer-reviewed journal pa-pers. The first authored papers and conference abstracts have been appended to the Part-II of the thesis.
32.	Mathanlal, Thasshwin, et al. (författare) Self-Sustainable Monitoring Station for Extreme Environments (S3ME2): Design and validation 2019 Ingår i: 2018 Second International Conference on Green Computing and Internet of Things (ICGCIoT). - : IEEE. - 9781538656570 ; , s. 240-245 Konferensbidrag (refereegranskat)abstract We describe the development of a robust, self-sustainable, versatile environmental monitoring station, the S3ME2, with a multitude of sensors capable of operating in extreme environments (from cold arid sub-arctic regions to hot deserts and high-altitude mountain terrains), providing realtime quality data of critical climate and geophysical parameters for a wide field of research such as pressure, surface and subsurface temperature and humidity, magnetic field and seismic activity. The dedicated communication modem utilizes IoT technology and can deliver this data from remote regions. The S3ME2 has been designed as a low-cost instrument to facilitate the production of multiple units. During the pilot phase, it has demonstrated continuous operability for up to 6 months, including survival during extremely cold, snowy, and low insolation, and low wind periods in the Sub-Arctic region. With its robust design, S3ME2 exploits the use of renewable sources of energy such as solar and wind power to power the system. The S3ME2 has also been designed from a modular point of view with commercial off the shelf components (COTS) and open source hardware, considering long term operability of the station. The sensor modules can be easily added, replaced, or upgraded such that a stable functioning of the system is guaranteed.
33.	Mathanlal, Thasshwin, et al. (författare) Subsurface robotic exploration for geomorphology, astrobiology and mining during MINAR6 campaign, Boulby Mine, UK : part I (Rover development) 2020 Ingår i: International Journal of Astrobiology. - : Cambridge University Press. - 1473-5504 .- 1475-3006. ; 19:2, s. 110-125 Tidskriftsartikel (refereegranskat)abstract Autonomous exploration requires the use of movable platforms that carry a payload of instruments with a certain level of autonomy and communication with the operators. This is particularly challenging in subsurface environments, which may be more dangerous for human access and where communication with the surface is limited. Subsurface robotic exploration, which has been to date very limited, is interesting not only for science but also for cost-effective industrial exploitation of resources and safety assessments in mines. Furthermore, it has a direct application to exploration of extra-terrestrial subsurface environments of astrobiological and geological significance such as caves, lava tubes, impact or volcanic craters and subglacial conduits, for deriving in-situ mineralogical resources and establishing preliminary settlements. However, the technological solutions are generally tailor-made and are therefore considered as costly, fragile and environment-specific, further hindering their extensive and effective applications. To demonstrate the advantages of rover exploration for a broad-community, we have developed KORE (KOmpact Rover for Exploration); a low-cost, re-usable, rover multi-purpose platform. The rover platform has been developed as a technological demonstration for extra-terrestrial subsurface exploration and terrestrial mining operations pertaining to geomorphological mapping, environmental monitoring, gas leak detections and search and rescue operations in case of an accident. The present paper, the first part of a series of two, focuses on describing the development of a robust rover platform to perform dedicated geomorphological, astrobiological and mining tasks. KORE was further tested in the Mine Analogue Research 6 (MINAR6) campaign during September 2018 in the Boulby mine (UK), the second deepest potash mine in Europe at a subsurface depth of 1.1 km, the results of which will be presented in the second paper of this series. KORE is a large, semi-autonomous rover weighing 160 kg with L × W × H dimensions 1.2 m × 0.8 m × 1 m and a payload carrying capacity of 100 kg using 800 W traction power that can power to a maximum speed of 8.4 km h−1. The rover can be easily dismantled in three parts facilitating its transportation to any chosen site of exploration. Presently, the main scientific payloads on KORE are: (1) a three-dimensional mapping camera, (2) a methane detection system, (3) an environmental station capable of monitoring temperature, relative humidity, pressure and gases such as NO2, SO2, H2S, formaldehyde, CO, CO2, O3, O2, volatile organic compounds and particulates and (4) a robotic arm. Moreover, the design of the rover allows for integration of more sensors as per the scientific requirements in future expeditions. At the MINAR6 campaign, the technical readiness of KORE was demonstrated during 6 days of scientific research in the mine, with a total of 22 h of operation.
34.	Mathanlal, Thasshwin, et al. (författare) Subsurface robotic exploration for geomorphology, astrobiology and mining during MINAR6 campaign, Boulby Mine, UK : part II (Results and Discussion) 2021 Ingår i: International Journal of Astrobiology. - : Cambridge University Press. - 1473-5504 .- 1475-3006. ; 20:1, s. 93-108 Tidskriftsartikel (refereegranskat)abstract Geomorphological studies of the hidden and protected subsurface environments are crucial to obtain a greater insight into the evolution of planetary landforms, hydrology, climate, geology and mineralogy. From an astrobiological point of view subsurface environments are of interest for their potential habitability as they are local environments that are partially or fully shielded from the high levels of space and solar radiation. Furthermore, in the case of Mars, there is an increasing interest in searching for the presence of past or extant life in its subsurface. These applications make it mandatory to investigate equipment and instrumentation that allow for the study of subsurface geomorphology, as well as organic chemical biomarkers, such as biomolecules, carbon, nitrogen and sulphur isotopes, and other biologically significant minerals and gases. Mines on Earth can be used as analogues to investigate the geomorphology of Martian subsurface environments and perform astrobiology studies. With that goal, we have developed a low-cost, robust, remotely operable subsurface rover called KORE (KOmpact Rover for Exploration). This work illustrates the studies of a terrestrial analogue for the exploration of Mars using KORE during the Mine Analogue Research 6 (MINAR 6) campaign with the low-cost 3D mapping technology InXSpace 3D (In situ 3D mapping tool eXploration of space 3D). InXSpace 3D utilizes an RGB-D camera that captures depth information in addition to the RGB data of an image, operating based on the structured light principle capable of providing depth information in mm scale resolution at sub 3 m mapping range. InXSpace 3D is used to capture point clouds of natural and artificial features, thereby obtaining information about geologically relevant structures and also to incorporate them in earth mining safety. We tested two of the dense simultaneous localization and mapping (SLAM) algorithms: Kintinuous and Real-Time Appearance-Based Mapping (RTAB-Map) to check the performance of InXSpace 3D in a dark mine environment. Also, the air accumulation of volatiles such as methane and formaldehyde due to thermogenic and mining process was measured with the environmental station payload on the rover platform, which caters to both astrobiological significance and mine safety. The main conclusions of this work are: (1) a comparison made between the RTAB-Map algorithm and Kintinuous algorithm showed the superiority of Kintinuous algorithm in providing better 3D reconstruction; although RTAB-Map algorithm captured more points than the Kintinuous algorithm in the dark mine environment; (2) a comparison of point cloud images captured with and without lighting conditions had a negligible effect on the surface density of the point clouds; (3) close-range imaging of the polygonal features occurring on the halite walls using InXSpace 3D provided mm-scale resolution to enable further characterization; (4) heuristic algorithms to quickly post-process the 3D point cloud data provided encouraging results for preliminary analyses; (5) we successfully demonstrated the application of KORE to mine safety; and (6) the multi-sensors platform on KORE successfully monitored the accumulated volatiles in the mine atmosphere during its operation. The findings obtained during this KORE campaign could be incorporated in designing and planning future subsurface rover explorations to potential planetary bodies such as Mars with synergistic applications to subsurface environments in mines on Earth.
35.	Sam, Lydia, et al. (författare) Climate and Remotely Sensed Markers of Glacier Changes in the Himalaya 2019 Ingår i: Environmental Change in the Himalayan Region. - Cham : Springer. - 9783030033620 - 9783030033613 ; , s. 65-88 Bokkapitel (refereegranskat)abstract The study of past and future climatic variations in the Hindu Kush–Himalayan (HKH) region is a well-documented topic of scientific research. Recent studies have highlighted the significantly higher rates of warming in the HKH region compared to the global average. The HKH region has the largest reserves of glacial ice outside the poles. These glaciers are predominantly known to be sensitive indicators of changing regional and global climate. The large geographical extent, high elevation and perennial inclemency in weather conditions project remote sensing as the only viable option to study glacial characteristics periodically on a regional scale. The present chapter starts with a review of significant studies to assess the extent of climate change in the HKH. Climate-sensitive glacial markers which can be studied using remote sensing are identified. The chapter focuses on the key markers such as changes in glacier extents, glacier facies and supraglacial debris, and mass balance and thickness. The chapter examines these markers separately with respect to changing climate through recent remote sensing-based studies. It provides an overview of recent studies which deal with regional scale glaciological monitoring and assessment. The conclusive section of the chapter suggests the future role of remote sensing applications in studying these markers of climate change. The chapter uses recent studies to highlight key aspects that should be kept in perspective while undertaking remotely sensed glacial assessments.
36.	Sam, Lydia, et al. (författare) Heterogeneity in topographic control on velocities of Western Himalayan glaciers 2018 Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 8:1 Tidskriftsartikel (refereegranskat)abstract Studies of the seasonal and annual patterns of glacier velocities improve our understanding of the ice volume, topography, responses to climate change, and surge events of glaciers. Such studies are especially relevant and equally rare for the Himalayan glaciers, which supply many rivers that sustain some of the most heavily populated mountainous regions in the world. In particular, the control of the hypsometric distribution of geomorphometric parameters, such as slope, aspect, and curvature, on the dynamics of Himalayan glaciers have never been studied so far, at the river basin scale. Here, we present the degree to which topographic and hypsometric parameters affect the seasonal and annual average flow velocities of 112 glaciers in the Baspa River basin in the Western Indian Himalaya by analysing Global Land Ice Velocity Extraction from Landsat 8 (GoLIVE) datasets for the years 2013–2017. We observe, (i) significant heterogeneity in topographic controls on the velocities of these glaciers, (ii) elevation and the seasons play important roles in regulating the degree to which morphometric parameters (slope, aspect, and curvature) affect these velocities, (iii) a possible polythermal regime promoting both sliding and deformational forms of motion in a majority of these glaciers, and (iv) a detailed analysis of complex topographic controls within various elevation zones using a novel hypso-morphometric approach. These findings can help us to better model the dynamics of Himalayan glaciers and their responses to the future climatic scenarios. The inferences also suggest the need to incorporate dynamic topography in glacio-hydrological models in the wake of constant glacial evolutions.
37.	Sam, Lydia, et al. (författare) Remote sensing flow velocity of debris-covered glaciers using Landsat 8 data 2016 Ingår i: Progress in physical geography. - : SAGE Publications. - 0309-1333 .- 1477-0296. ; 40:2, s. 305-321 Tidskriftsartikel (refereegranskat)abstract Changes in ice velocity of a glacier regulate its mass balance and dynamics. The estimation of glacier flow velocity is therefore an important aspect of temporal glacier monitoring. The utilisation of conventional ground-based techniques for detecting glacier surface flow velocity in the rugged and alpine Himalayan terrain is extremely difficult. Remote sensing-based techniques can provide such observations on a regular basis for a large geographical area. Obtaining freely available high quality remote sensing data for the Himalayan regions is challenging. In the present work, we adopted a differential band composite approach, for the first time, in order to estimate glacier surface velocity for non-debris and supraglacial debris covered areas of a glacier, separately. We employed various bandwidths of the Landsat 8 data for velocity estimation using the COSI-Corr (co-registration of optically sensed images and correlation) tool. We performed the accuracy assessment with respect to field measurements for two glaciers in the Indian Himalaya. The panchromatic band worked best for non-debris parts of the glaciers while band 6 (SWIR – short wave infrared) performed best in case of debris cover. We correlated six temporal Landsat 8 scenes in order to ensure the performance of the proposed algorithm on monthly as well as yearly timescales. We identified sources of error and generated a final velocity map along with the flow lines. Over- and underestimates of the yearly glacier velocity were found to be more in the case of slow moving areas with annual displacements less than 5 m. Landsat 8 has great capabilities for such velocity estimation work for a large geographic extent because of its global coverage, improved spectral and radiometric resolutions, free availability and considerable revisit time.
38.	Sam, Lydia, et al. (författare) Small Lava Caves as Possible Exploratory Targets on Mars : Analogies Drawn from UAV Imaging of an Icelandic Lava Field 2020 Ingår i: Remote Sensing. - : MDPI. - 2072-4292. ; 12:12 Tidskriftsartikel (refereegranskat)abstract Volcanic-aeolian interactions and processes have played a vital role in landscape evolution on Mars. Martian lava fields and associated caves have extensive geomorphological, astrobiological, and in-situ resource utilization (ISRU) implications for future Mars missions which might be focused on subsurface exploration. Although several possible cave “skylights” of tens to >100 m diameter have been spotted in lava fields of Mars, there is a possibility of prevalence of meter-scale features which are an order of magnitude smaller and difficult to identify but could have vital significance from the scientific and future exploration perspectives. The Icelandic volcanic-aeolian environment and fissure volcanoes can serve as analogs to study lava flow-related small caves such as surface tubes, inflationary caves, liftup caves, and conduits. In the present work, we have tried to explore the usability of unmanned aerial vehicle (UAV)-derived images for characterizing a solidified lava flow and designing a sequential methodology to identify small caves in the lava flow. In the mapped area of ~0.33 km2, we were able to identify 81 small cave openings, five lava flow morphologies, and five small cave types using 2 cm/pixel high-resolution images. The results display the usefulness of UAV imaging for such analogous research, and also highlight the possibility of the widespread presence of similar small cave openings in Martian lava fields. Such small openings can facilitate optimal air circulation within the caves while sheltering the insides from physical weathering and harmful radiations. Using the available best resolution remote sensing images, we extend the analogy through the contextual and geomorphological analysis of several possible pit craters in the Tharsis region of Mars, in a region of extremely vesicular and fragile lava crust with pahoehoe-type morphology. We report two possible pit craters in this region, with diameters as small as ~20 m. The possibility that such small cave openings can lead to vast subterranean hollow spaces on Mars cannot be ruled out considering its low gravity.
39.	Sam, Lydia, et al. (författare) Use of Geospatial Tools to Prioritize Zones of Hydro-Energy Potential in Glaciated Himalayan Terrain 2016 Ingår i: Journal of the Indian Society of Remote Sensing. - : Springer Science and Business Media LLC. - 0255-660X .- 0974-3006. ; 44:3, s. 409-420 Tidskriftsartikel (refereegranskat)abstract Sustainable development of the Himalayan region is directly linked to optimal utilization of available renewable resources. There is a need to first select the zones suitable for hydropower sites, and then to focus on them only; as purely field-based surveying of rugged mountainous regions for hydropower generation requires too much of time and effort. We used geospatial tools to identify suitable sites for hydropower generation. A Geographic Information System (GIS)-based tool called Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) was used for computing annual runoff volume using watershed-wise topography and biophysical variables. The zones suitable for hydropower generation were then identified based on calculated hydropower energy using derived runoff volumes and hydraulic head. The model accuracy was checked using well established efficiency criteria: coefficient of determination (R2 = 0.98), RMSE-observations standard deviation ratio (RSR), Percent bias (PBIAS) and Nash–Sutcliffe efficiency (NSE). For all these parameters, the model was found to be performing satisfactorily.
40.	Shekhar, Mayank, et al. (författare) Himalayan glaciers experienced significant mass loss during later phases of little ice age 2017 Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7 Tidskriftsartikel (refereegranskat)abstract To date, there is a gap in the data about the state and mass balance of glaciers in the climate-sensitive subtropical regions during the Little Ice Age (LIA). Here, based on an unprecedented tree-ring sampling coverage, we present the longest reconstructed mass balance record for the Western Himalayan glaciers, dating to 1615. Our results confirm that the later phase of LIA was substantially briefer and weaker in the Himalaya than in the Arctic and subarctic regions. Furthermore, analysis of the time-series of the mass-balance against other time-series shows clear evidence of the existence of (i) a significant glacial decay and a significantly weaker magnitude of glaciation during the latter half of the LIA; (ii) a weak regional mass balance dependence on either the El Niño-Southern Oscillation (ENSO) or the Total Solar Irradiance (TSI) taken in isolation, but a considerable combined influence of both of them during the LIA; and (iii) in addition to anthropogenic climate change, the strong effect from the increased yearly concurrence of extremely high TSI with El Niño over the past five decades, resulting in severe glacial mass loss. The generated mass balance time-series can serve as a source of reliable reconstructed data to the scientific community.
41.	Singh, Mritunjay Kumar, et al. (författare) Effect of sensor modelling methods on computation of 3-D coordinates from Cartosat-1 stereo data 2016 Ingår i: Geocarto International. - : Informa UK Limited. - 1010-6049 .- 1752-0762. ; 31:5, s. 506-526 Tidskriftsartikel (refereegranskat)
42.	Singh, Mritunjay Kumar, et al. (författare) High resolution DEM generation for complex snow covered Indian Himalayan Region using ADS80 aerial push-broom camera : a first time attemp7 2015 Ingår i: Arabian Journal of Geosciences. - : Springer Science and Business Media LLC. - 1866-7511 .- 1866-7538. ; 8:3, s. 1-12 Tidskriftsartikel (refereegranskat)abstract Updated and Accurate Digital Elevation Model (DEM) of snow covered and glaciated mountainous area is essential for many applications such as avalanche hazard and numerical modelling of mass movements or mapping of terrain changes. The best high resolution terrain product available for Himalayan region is the DEM, with a spatial resolution of 10 m, generated using Cartosat-1 stereo ortho-kit data. Even this spatial resolution is insufficient for many applications like avalanche hazard mapping or forecasting in complex mountainous terrain. This study reports the process of high spatial resolution (1 m) DEM generation for Manali and nearby areas using digital aerial photogrammetric survey data of 40 cm Ground Sampling Distance (GSD), captured through airborne ADS80 push-broom camera for the first time in Indian Himalayas. This DEM was also evaluated with Differential Global Positioning System (DGPS) points for accuracy assessment. The ADS80 DEM gave Root Mean Square Error (RMSE) of ∼<1 m and Linear Error, at 90 % confidence interval (LE 90) of 1.36 m in comparison with the DGPS points.
43.	Singh, Mritunjay Kumar, et al. (författare) Scenario-Based Validation of Moderate Resolution DEMs Freely Available for Complex Himalayan Terrain 2016 Ingår i: Pure and Applied Geophysics. - : Springer Science and Business Media LLC. - 0033-4553 .- 1420-9136. ; 173:2, s. 463-485 Tidskriftsartikel (refereegranskat)
44.	Singh, Shaktiman, et al. (författare) Changing climate and glacio-hydrology: a case study of Shaune Garang basin, Himachal Pradesh 2018 Ingår i: International Journal of Hydrology Science and Technology. - : InderScience Publishers. - 2042-7808 .- 2042-7816. ; 8:3, s. 258-272 Tidskriftsartikel (refereegranskat)abstract The rise in temperature is already evident in Himalaya with rate of increase varying seasonally and spatially. Changes in precipitation are also evident with no clear trend. Several studies in different parts of Himalayas suggest that the glaciers are retreating in general with few exceptions as response to changes in temperature and precipitation. The stream flow in river basins in Indian Himalayan region (IHR) is already showing changes in studies undertaken in the last few decades. Use of glacio-hydrological models gives opportunity to estimate stream flow in glaciated river basins and understand the changes. The present study deals with estimation of discharge in Shaune Garang Basin, Himachal Pradesh using a glacio-hydrological model based on degree day factors. The model was used to estimate long term average of melt season discharge (1985-2007) in the basin. The modelled discharge shows good correlation with measured discharge for simulation period except for first year of comparison.
45.	Singh, Shaktiman, et al. (författare) Changing climate and glacio-hydrology in Indian Himalayan Region : a review 2016 Ingår i: Wiley Interdisciplinary Reviews. - : Wiley. - 1757-7780 .- 1757-7799. ; 7:3, s. 393-410 Tidskriftsartikel (refereegranskat)abstract This study presents a comprehensive review of the published literature on the evidences of a changing climate in the Indian Himalayan Region (IHR) and its impacts on the glacio-hydrology of the region. The IHR serves as an important source of fresh water for the densely populated areas downstream. It is evident from the available studies that temperature is significantly increasing in all parts of the IHR, whereas precipitation is not indicative of any particular spatiotemporal trend. Glacio-hydrological proxies for changing climate, such as, terminus and areal changes of the glaciers, glacier mass balance, and streamflow in downstream areas, highlight changes more evidently in recent decades. On an average, studies have predicted an increase in temperature and precipitation in the region, along with increase in streamflow of major rivers. Such trends are already apparent in some sub-basins of the western IHR. The region is particularly vulnerable to changing climate as it is highly dependent on snow and glacier melt run-off to meet its freshwater demands. We present a systematic review of key papers dealing with changing temperature, precipitation, glaciers, and streamflow in the IHR. We discuss these interdisciplinary themes in relation to each other, in order to establish the present and future impacts of climatic, glaciological, and hydrological changes in the region.
46.	Singh, Shaktiman, et al. (författare) Quantifying the Congruence between Air and Land Surface Temperatures for Various Climatic and Elevation Zones of Western Himalaya 2019 Ingår i: Remote Sensing. - : MDPI. - 2072-4292. ; 11:24 Tidskriftsartikel (refereegranskat)abstract The surface and near-surface air temperature observations are primary data for glacio-hydro-climatological studies. The in situ air temperature (Ta) observations require intense logistic and financial investments, making it sparse and fragmented particularly in remote and extreme environments. The temperatures in Himalaya are controlled by a complex system driven by topography, seasons, and cryosphere which further makes it difficult to record or predict its spatial heterogeneity. In this regard, finding a way to fill the observational spatiotemporal gaps in data becomes more crucial. Here, we show the comparison of Ta recorded at 11 high altitude stations in Western Himalaya with their respective land surface temperatures (Ts) recorded by Moderate Resolution Imagining Spectroradiometer (MODIS) Aqua and Terra satellites in cloud-free conditions. We found remarkable seasonal and spatial trends in the Ta vs. Ts relationship: (i) Ts are strongly correlated with Ta (R2 = 0.77, root mean square difference (RMSD) = 5.9 °C, n = 11,101 at daily scale and R2 = 0.80, RMSD = 5.7 °C, n = 3552 at 8-day scale); (ii) in general, the RMSD is lower for the winter months in comparison to summer months for all the stations, (iii) the RMSD is directly proportional to the elevations; (iv) the RMSD is inversely proportional to the annual precipitation. Our results demonstrate the statistically strong and previously unreported Ta vs. Ts relationship and spatial and seasonal variations in its intensity at daily resolution for the Western Himalaya. We anticipate that our results will provide the scientists in Himalaya or similar data-deficient extreme environments with an option to use freely available remotely observed Ts products in their models to fill-up the spatiotemporal data gaps related to in situ monitoring at daily resolution. Substituting Ta by Ts as input in various geophysical models can even improve the model accuracy as using spatially continuous satellite derived Ts in place of discrete in situ Ta extrapolated to different elevations using a constant lapse rate can provide more realistic estimates.
47.	Snehmani, Snehmani, et al. (författare) Modelling the hypsometric seasonal snow cover using meteorological parameters 2015 Ingår i: Journal of Spatial Science. - : Informa UK Limited. - 1449-8596 .- 1836-5655. ; 60:1, s. 51-64 Tidskriftsartikel (refereegranskat)abstract This study established a decadal correlation between meteorological observations (temperature and snowfall) and satellite-derived seasonal snow cover for a glacier catchment. The study area was classified into 10 elevation zones. The time period for considering climatic variables was from the start of the significant fresh snowfall of the new season to the date of satellite image acquisition. The snowfall inputs from the five meteorological stations at different altitudes were interpolated for the entire catchment using a discretised thin-plate spline technique. A local temperature lapse rate for this specific time period was calculated. It was applied throughout the catchment for interpolating the temperature, which was further used to refine the interpolated snowfall. Such a hypsometric approach along with third-order polynomial curve fitting (R2=0.998) finally gave an equation for estimating percent snow-covered area for different elevation zones with a good accuracy and very low average RMSE (Root Mean Square Error) of 3.16 percent.
48.	Snehmani, Snehmani, et al. (författare) Monitoring the status of Siachen glacier using multi temporal remote sensing approach 2014 Ingår i: Geostatistical and geospatial approaches for the characterization of natural resources in the environment : challenges, processes and strategies. - New Delhi : Capital Publishing Company. - 9789381891254 ; , s. 513-515 Konferensbidrag (refereegranskat)abstract The temporal monitoringof any glacier is important for observing the effects of changing climate. This study reports the decadal changes in Siachen glacier. Analysis was carried out on decadal basis by processing and analyzing Landsat images from 1978 to 2013. Images were coregistered within Root Mean Square Error (RMSE) limit of 0.5 pixel. An object based classification approach was adopted to perform temporal semi-automated areal change detection. The glacier inventory of 1978 showed around 74976 ha of glacier area which further decreased by around 1302 ha in 2013 with a shift of 1.5 km in the snout position.
49.	Snehmani, Snehmani, et al. (författare) Remote sensing of mountain snow using active microwave sensors : a review 2015 Ingår i: Geocarto International. - : Informa UK Limited. - 1010-6049 .- 1752-0762. ; 30:1, s. 1-27 Tidskriftsartikel (refereegranskat)abstract This work provides an overview of various methods for estimating snow cover and properties in high mountains using remote sensing techniques involving microwaves. Satellite-based remote sensing with its characteristics such as synoptic view, repetitive coverage and uniformity over large areas has great potential for identifying the temporal snow cover. Many sensors have been used in the past with various algorithms and accuracies for this purpose. These methods have been improving with the use of Synthetic Aperture Radar sensors, working in different microwave frequencies, polarisation and acquisition modes. The limitations, advantages and drawbacks are illustrated while error sources and strategies on how to ease their impacts are also reviewed. An extensive list of references, with an emphasis on studies since 1990s, allows the reader to delve into specific topics
50.	Snehmani, Snehmani, et al. (författare) Study of temporal changes in snout position and wet snow line for Gangotri glacier using remote sensing, ground observations and meteorological data 2013 Ingår i: International Journal of Geoinformatics. - 1686-6576. ; 9:1, s. 49-60 Tidskriftsartikel (refereegranskat)abstract The temporal changes (1891-2010) in snout position of Gangotri glacier were monitored using Landsat images, ground observations and SoI (Survey of India) toposheets. Temporal changes (2001-09) in wet snow line (wsl) altitude were also observed using LISS-III images and high resolution (6 m pixel size) DEM generated using Cartosat stereopair. These observations were correlated and justified with available snow meteorological data. OCGM (Oerlemans Coarse Grained Model) was run in parallel using meteorological inputs to support the obtained glacier retreat using Landsat data during 2001-10. The retreats observed were 73 m and 54 m respectively using Landsat data and OCGM. The difference was less than 20 m (less than a pixel of Landsat image) thus supporting the usefulness of remote sensing observations for monitoring of rough and hard to access terrain. The wsl altitude showed an overall ascending trend during melting season (May to September). Some atypical fluctuations in this trend were observed for different years which could be explained using available meteorological records

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