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Glacial lakes dynamics has a concomitant impact over glacial retreat, mass change and glacial lake outburst floods (GLOFs) events. Recent warming led increase in glacial retreat at High-Mountain Asia (HMA) which has accelerated the formation of moraine-dammed glacial lakes; however, their relative potential for catastrophic events i.e., GLOF, are still a matter of detailed research. In the present study, the changes are assessed at the terminus position, glacier area and associated proglacial lake of Gepang Gath Glacier (GGGL), Chandra basin, western Himalaya, India, using multi-years satellite dataset of Landsat series (TM, ETM+ and OLI, 1989–2017). The results of glacial volume estimations using volume-area scaling method suggests ∼0.28 km3 of ice volume loss between 1989 and 2017. The glacier has retreated ∼846 m with an average rate of 30 m a−1 and lost ∼0.73 ± 0.05 km2 frontal area from 1989 to 2017. However, the glacier has not shown uniform retreat rate. Between 1989 and 2000 glacier retreat about ∼14 m a−1 and the rate was increased gradually to ∼38 m a−1 (2000–2009) and ∼50 m a−1 (2015–2017). The calculated proglacial lake area has expanded ∼44 % and estimated equilibrium line altitude (ELA) rise was 54 ± 12 m, during the study period. The study explains that the continuous expansion of proglacial lake and ice loss can be dangerous to downstream region. It is concluded by underlining the importance of glacier-lake relationships to predict the glacial lake behavior and understand the probability of lake catastrophic events i.e., GLOF and associated hazards.

The size-dependent chemical maturity of sediment cycling in a high-altitude glacial/periglacial environment was studied by examining the sediments of the Chorabari Glacier, Mandakini Valley, centra...

The glaciers are considered as iconic indicators of climate change, and receding at differential rates worldwide. Variable retreat rates of glacier termini and inadequate supporting field data (e.g. mass balance, ice thickness, velocity, etc.) of the glaciers makes it difficult to access the impact of climate change. Here, we examined eight glaciers in the upper Rishi Ganga catchment, Nanda Devi region, Central Himalaya, India, to assess their spatial and temporal variability towards the climate change. The temporal coverage of analysis spans from twentieth to early twenty-first centuries (ranges 1980 to 2017). The study was designed by comparing the estimates of different temporal satellite images of the Hexagon KH-9 (1980) with Landsat 5 TM (1989), Landsat 7 ETM+ (1999), Landsat 8 OLI/TRIS (2017) and ASTER DEM (2011) with local and regional meteorological conditions of the study area. The upper Rishi Ganga catchment covers an area of ~690 km2, having a glaciated area of ~243 km2 (~35% of the total area) during 1980. Our study reveals that the glaciers of the valley lost ~26 km2 (10%) of the glaciated area between 1980 and 2017. The total glacierized area in 2017 is ~217 km2, which is ~26% of the total area. However, during the same periods (1980–2017) the Equilibrium Line Altitude (ELA) of the glaciers fluctuated between 5200 and 5700 m asl. The present study suggests that the glaciers in the region have responded to deprived precipitation conditions since 1980, overlapping our understanding of glacier retreat due to temperature increase, in the context of the global warming scenario.

Srivastava and Jovane (2020) have made several comments on our assessment of proxy data and challenged the outcome of Shukla et al. (2020) based mainly on interpretation of environmental magnetic parameters. We respond to their criticisms and re-evaluate our paper, remove ambiguities and validate our conclusions through additional proxies (grain-size and geochemistry). We welcome their comments and do not entirely rule out their interpretation for magnetic mineralogy. We highlight the importance of proxy validation for high-energy environments like Chorabari lake. However, single proxy data correlation is likely to produce biased results with no relevant meaning. The objective of our study was to understand complexities in the glacial-climate system by reconstructing late-Holocene climate variations using the glacial lake sediment records from the Mandakini River Basin, Central Himalaya, India. We presented the complexities in Shukla et al. (2020), and this was also highlighted by Srivastava and Jovane (2020). In response, we provide additional justification of proxy response and substantiate our results with present-day estimates from the Chorabari glacier valley. We disagree with the thesis put forward by Srivastava and Jovane (2020) in their conclusion as they overemphasize the interpretation of a single proxy. We maintain that the investigation of present-day glacial settings is an important precursor of paleoclimatic data interpretation and that this supports our conclusions. We will try to incorporate the important suggestions of Srivastava and Jovne (2020) relating to the interpretation of magnetic data in future work.

We studied a periglacial lake situated in the monsoon-dominated Central Himalaya where an interplay of monsoonal precipitation and glacial fluctuations during the late Holocene is well preserved. A major catastrophe occurred on 16–17 June 2013, with heavy rains causing rupturing of the moraine-dammed Chorabari Lake located in the Mandakini basin, Central Himalaya, and exposed 8-m-thick section of the lacustrine strata. We reconstructed the late-Holocene climatic variability in the region using multi-parametric approach including magnetic, mineralogical and chemical (XRF) properties of sediments, paired with grain size and optically simulated luminescence (OSL) dating. The OSL chronology suggests that the lake was formed by a lateral moraine during the deglaciation phase of Chorabari Glacier between 4.2 and 3.9 ka and thereafter the lake deposited about 8-m-thick sediment sequence in the past 2.3 ka. The climatic reconstruction of the lake broadly represents the late-Holocene glacial chronology of the Central Himalaya coupled with many short-term climatic perturbations recorded at a peri-glacial lake setting. The major climatic phases inferred from the study suggests (1) a cold period between 260 BCE and 270 CE, (2) warmer conditions between 900 and 1260 CE for glacial recession and (3) glacial conditions between ~1370 and 1720 CE when the glacier gained volume probably during the ‘Little Ice Age’ (LIA). We suggest a high glacial sensitivity to climatic variability in the monsoon-dominated region of the Himalaya.

Satellite-based real-time monitoring is needed for Himalayan glacial catchments

Warming-induced expansion in vegetation coverage and activity can accelerate the montane hydrological regimes. However, the climate impacts on ecohydrology of forested valleys of the Himalaya are uncertain. In this study, utilizing results of about three centuries of cellulose isotope chronologies (δ 13C and δ 18O) of dominant tree species, geo-chronological proxies, bio-geophysical dataset and simulations including satellite observations, we show an activation in the ecophysiological processes including evapotranspiration (ET) since the 1950s. Observation suggests rapid greening, while isotopic records indicate enhanced assimilation and transpiration in deciduous species vis-à-vis conifers post 1950s. Given strong vegetation-precipitation feedback and superimposed on the increasing trends of conducive atmospheric factors affecting valley-scale convective processes, intensification in forest ET is manifesting in a progressive enhancement in extreme rainfall events (EREs) since the last few decades. Results suggest that representation of ecophysiological processes and dynamics of seasonal moisture loading in observational and modelling framework is critical for understanding EREs under climate change.

The astronomical theory of Milankovitch supports the waxing and waning of ice sheets and polar glaciers by orbital forcing, excluding the fact that small changes in solar radiation flux are difficult to reconcile with the amplitude of glacial cycles. The numerical model explaining the 100 kyr problem has now revealed that the phase locking mechanism of orbital forcing has started to modulate the climatic transitions since ∼1.2 Myr back and remained locked till present climatic state (Rial et al., 2013). However, the true evidence to confirm it is not present. The present study is an attempt to comprehend the concept of synchronization of summer insolation modulation and internal climate forcing, responsible for glacial/interglacial termination present in and around the Himalaya-Tibet and worldwide. We present geographical evidences of glaciations from the Himalayan-Tibet region pointing out that responses (i.e. 18–24 kyr and 60–70 kyr BP glaciation events) are similar to the progression in climatic data and glaciations cycles for the last 100 kyr. The compelling evidence presents a possible explanation towards synchronized modulation of 100 kyr orbital cycles with 41 kyr obliquity cycles, coincidently resulting in unprecedentedly large glaciation around the last glacial cycle (60–70 kyr BP) and the Last Glacial Maxima (18–24 kys BP). By considering the influence of internal and external factors on glacier mechanism, we underline the most probable cause of 41 kyr cycle (obliquity) as the foremost driver of glaciations in the Himalaya and Tibet on longer timescales. We provide several lines of evidence to establish the possible connection of glaciation events and orbital cycles with the help of geographical and geological records consistent with the fact that resonance might be faded through time but the effect of frequency modulation still persists in the system.

This paper presents new insights into the global carbon cycle related to CO2 consumption from chemical denudation in heavily glacierised Himalayan catchments. Data from previous studies of solute concentrations from glacierised catchments were reprocessed to determine the regional scale of CO2 consumption and solute hydrolysis. The results show that ~90% of the SO42− is derived from crustal sulphide oxidation and ~10% from aerosols and sea salts. However, HCO3− flux calculation estimates contribution from sulphide oxidation to carbonate dissolution (SO-CD) (~21%), similar to the contributions from silicate dissolution and simple hydrolysis (~21 and ~20%, respectively). Furthermore, the atmospheric CO2 consumption estimations suggests 10.6 × 104 mole km−2 a−1 (19%) through silicate weathering, 15.7 × 104 mole km−2 a−1 (28%) through simple hydrolysis, 9.6 × 104 mole km−2 a−1 (17%) through SO-CD reaction and 5.9 × 104 mole km−2 a−1 (11%) through carbonate carbonation reaction. Our solute provenance calculations clearly indicate that HCO3− production and CO2 consumption via silicate weathering reactions is balanced by the simple hydrolysis and coupled SO-CD process. This shows a counter mechanism operating in subglacial environments of the Himalaya as a source of CO2 to runoff rather than a sink.

Himalayan glaciers are invariably covered by supra-glacial debris. Of these glaciers, the Chhota Shigri Glacier (CSG) in the western Himalaya has minimal debris cover (3.4%), yet has a comparable melt rate to other Himalayan glaciers. Utilizing osmium isotopic composition, and major and trace element geochemistry of cryoconite, a dark colored aggregate of mineral and organic materials on the surface of the ablation zone of the CSG, we show that the surface of CSG is essentially free of anthropogenically emitted particles, contrary to many previous findings. Given this and the overall lack of debris, we conclude that the high melt rate of CSG is primarily related to the increase of the Earth's near-surface temperature linked directly to global warming. Therefore, the future meltwater supply for glacial-fed rivers originating from Lahaul and Spiti region would be most vulnerable for >50 million population living downstream and requires immediate attention.

The world's large rivers have been intensely studied to better understand the impact of climate change and direct human interventions on river water quality and quantity Of particular importance is the extent to which industrial, domestic, and agricultural discharges are modifying the dissolved inorganic constituents (major elements, trace elements, nutrients, and heavy metals) of large river systems vis-a-vis water quality The COVID-19 pandemic lockdown provides a rare opportunity to quantify the impact of restricted anthropogenic activities on the water chemistry resilience of large rivers By analyzing the daily geochemical record of the Ganga River, we demonstrate that reduced industrial discharge during 51 days of mandated nationwide lockdown decreased the dissolved heavy metal concentrations by a minimum of 50% In contrast, nitrate and phosphate inputs predominantly derived from agricultural runoff and domestic sewage maintained a chemical status quo as these sources were not impacted by the nationwide confinement or their residence time was longer than the characteristic time of the perturbation We demonstrate the high resilience of dissolved heavy metals and conclude that industrial wastewater minimization programs will substantially improve heavy metal pollution of the Ganga River in a short time span of a few months © 2020 American Chemical Society All rights reserved

The western Himalaya glaciers seasonally melt, in part, controlled by the presence of ice surface impurities in the form of dust, organic, and inorganic particles. The hitherto knowledge that dark-colored impurities on the ice surface are a mechanistic driver of heat absorption and thus enhancing ice mass wasting makes understanding the concentrations, origin, and pathways of emission residues on the glacier surface a global concern to conserve the Himalayan ice mass that provides water to more than one billion people. Yet, the source, origin, and pathways of metal impurities on the ice surface of Himalayan glaciers remain poorly constrained. Here, we present major and trace element geochemistry, rhenium-osmium (Re-Os) isotopes composition of cryoconite – a dark-colored aggregate of mineral and organic materials – on the ablation zone of the Chhota Shigri Glacier (CSG) considered as a benchmark glacier for process understanding in the western Himalaya. We find that the cryoconite possesses elemental ratios and crustal enrichment factor that reveal a predominant crustal source. Further, the 187Os/188Os composition in cryoconite varies from non-radiogenic (0.36) to radiogenic (1.31) compositions. Using a three-component isotope mixing model we show that the Os in cryoconite is dominantly derived from local rocks with negligible input from anthropogenic Os sources. Given that the CSG has limited debris cover (~ 3.4 %) and the near absence of anthropogenically derived particles; our results suggests that dark-colored surficial deposits of anthropogenic dust particles are not one of the significant drivers of glacier melting in the western Himalaya, as observed elsewhere.

The study presents the Late Quaternary glaciation history of monsoon-dominated Dokriani Glacier valley, Dingad basin, central Himalaya, India. The basin is tested for the mechanism of landforms preservation in high relief and abundant precipitation regimes of the Higher Himalaya. Field geomorphology and remote sensing data, supported by Optical Stimulated Luminescence (OSL) dating enabled identification of five major glacial events of decreasing magnitude. The oldest glacial stage, Dokriani Glacial Stage I (DGS-I), extended down to ∼8 km (2883 m asl) from present-day snout (3965 m asl) followed by other four glaciations events viz. DGS-II, DGS-III, DGS-IV and DGS-V terminating at ∼3211, 3445, 3648 and ∼3733 m asl respectively. The DGS-I glaciation (∼25–∼22 ka BP) occurred during early Marine Isotope Stage (MIS) −2, characterized as Last Glacial Maximum (LGM) extension of the valley. Similarly, DGS-II stage (∼14–∼11 ka BP) represents the global cool and dry Older Dryas and Younger Dryas event glaciation. The DGS-III glaciation (∼8 ka BP) coincides with early Holocene 8.2 ka cooling event, the DGS-IV glaciations (∼4–3.7 ka BP) corresponds to 4.2 ka cool and drier event, DGS-V (∼2.7–∼1 ka BP) represents the cool and moist late Holocene glacial advancement of the valley. This study suggests that the Dokriani Glacier valley responded to the global lowering of temperature and variable precipitation conditions. This study also highlights the close correlation between the monsoon-dominated valley glaciations and Northern Hemisphere cooling events influenced by North Atlantic climate.

Exceptional early high monsoon rains between 15 and 17 June 2013 combined with discharge from snowmelt water caused widespread floods in every major river of the Garhwal Himalaya. This catastrophic event triggered widespread landslides and devastation in the region, affecting the movement of the people that led to stranding of pilgrims in various pilgrimage routes. This event caused many casualties and irreparable damage to the infrastructures and property in the Garhwal Himalaya. A large volume of debris was deposited in Kedarnath town (3.9 × 10 6 m 3 ), and a huge amount of debris was removed from Rambara and surrounding areas (2.6 × 10 8 m 3 ). The study also found that villages like Lambaghar, Bhyundar (Alaknanda River Valley), and Rambara (Mandakini River Valley) were completely washed away, leaving no trace of earlier settlement. Govindghat and Pulna villages in the Alaknanda River Valley were also badly damaged. Approximately 0.3 × 10 6 and 0.72 × 10 6 m 3 of debris was deposited, respectively. Similarly in the Mandakini Valley, Kedarnath and Sonprayag towns were also badly damaged and ~ 3.9 × 10 6 and ~ 1.4 × 10 6 m 3 of debris was deposited in the area, respectively. Simultaneously, the moraine-dammed Chorabari Lake breached releasing ~ 6.1 × 10 5 m 3 of water with an average rate of ~ 1429 m 3 /s (discharge of lake). The towns of Pandukeshwar in the Alaknanda Valley and Gaurikund in the Mandakini Valley were partially damaged. However, no evidence of such magnitude of destruction was reported from the Yamuna River Valley during the same period. This catastrophic event changed the landscape in many parts of Uttarakhand, making the whole region more fragile and vulnerable. A disaster of such magnitude was perhaps not witnessed by the region for at least the last 100 years.

Atmospheric pollutant transport and deposition at the Himalaya affects the climate, cryosphere, and monsoon patterns and impose an adverse impact over the Himalayan ecosystem. At present, the data on trace elements (TEs) concentrations and dynamics over the high-altitude Himalayan region are scarce and has received less attention. Therefore, in the present study, we investigated the TEs concentration and depositional pattern at Dokriani Glacier, central Himalaya to understand their levels, dynamics, and potential effects. A total of 39 samples were collected from two snowpit stratigraphies, deposited during non-monsoon period and monsoonal precipitation between 4530 to 4630 m a.s.l. altitude in the year 2017. The results of analyzed trace metals (Al, Cr, Mn, Fe, Sr, Co, Ni, Cu, Zn, Cd, As, and Pb) showed high enrichment values for Zn, Cr, Co, Ni and Mn compared to other parts of the Himalayan region, suggesting the influence of anthropogenic emissions (e.g., fossil fuel, metal production, and industrial processes) from urbanized areas of South Asia. Our results also revealed the possible health effects related to the enrichment of Zn and Cd, which may be responsible for skin-related diseases in Uttarakhand region. We attribute increasing anthropogenic activities in the environment to have a significant impact on the ecosystem health of the central Himalayan region. This study provides the baseline information on TEs concentration and sources in the Himalayas, which needs wide dissemination to scientific community as well as policymakers. Therefore, systematic observations, management, and preparing action plan to overcome the health effects from TEs pollution are urgently needed over the remote, pristine Himalayan region.

The study of geomorphological system not only gives information about environmental processes operating there but also relate them whith global environmental system. The geomorphological analysis of Dokriani glacier, Garhwal Himalaya shows five phases of glacial advancement and retreat in the form of well preserved lateral and terminal moraines. The observed retreat rate of glacier in last two decades is about 17.2 m/yr which represents its negative mass balance followed by change in snout position, area and surface height. The farthest glacier expansion of the valley represented as terminal moraine is situated at 8.3 km from present day snout. Whereas, the other sucsessive glacial stages has followed the similar fashion of glacial advancement due to climatic sensitiveness.

Sediments released from high altitude glaciers exhibit varying evacuation patterns and transport characteristics owing to the presence of thick debris cover over the glacier. Despite the recent needs for integrated hydrometeorological studies in the Himalaya, little is known about the impacts of suspended sediment on hydropower generation, reservoir sedimentation, and abrasion of turbine components. Present study involves analysis of particle size distribution of suspended sediments to understand sediment evacuation patterns and transport characteristics in variable energy conditions during the ablation season. Peak suspended sediments were evacuated during extreme rainfall events. The estimated seasonal modern sediment erosion rate varies from 0.6 to 2.3 mm y− 1 for the study period (2009–2012). The analysis shows dominance of medium silt-sized to fine sand-sized particles having sediment size of 0.0156–0.25 mm corresponding to 70–80% without any significant seasonal variation. These transported sediments show that they are poorly sorted, coarser in nature with a nearly symmetrical to coarse skewed texture and kurtosis analysis suggesting mesokurtic distribution of sediments. The particle size fraction ranges between 4.65 and 5.23 ϕ, which is dominantly medium to coarse silty in texture. Results indicate that suspended sediments are evacuated in highly variable energy conditions through subglacial transport pathways because of increase in availability of meltwater with the progressive ablation season. Bulk geochemical characterization has been carried out to differentiate the source of suspended sediments and intensity of weathering. Chemical Index of Alterations (CIA) values of sediment flux range from 54.68 to 55.18 compared to the Upper Continental Crust (UCC) ~ 50, indicating moderate intensity of weathering. Mean seasonal (2009–2012) elemental fluxes and their contribution to the suspended sediment flux reflect that Si and Al are responsible for about 85% of the total detrital elemental flux. Trace elements show high concentrations of radioactive elements like U, Th, Pb, and Rb that suggest their high anomalous presence in the catchment lithology. An overall study indicates that the hydroclimatic conditions over the debris-covered glacier play a dominant controlling factor in erosion, transportation, and evacuation of suspended sediments during the ablation season.

Transport of Dissolved Inorganic Carbon (DIC) by glacier fed Himalayan streams links the atmospheric carbon dioxide (CO2) concentrations, glacial weathering, and the global carbon cycle. However, the importance of weathering-derived DIC fluxes through glacial streams of the Himalaya with concomitant short- and long-term variability in carbon cycle has rarely been examined. This study provides new constraints on the present day CO2 drawdown by chemical weathering and glacial streams DIC fluxes in the Himalaya. Consequently, we reassessed meltwater ionic composition of five glacierized basins in the central and the western Himalaya between the ablation seasons of 1989 to 2017. We demonstrate that the drawdown of CO2 through silicate weathering is ~2.9 × 105 mol km−2 yr−1 (~17%) for Na bearing minerals, ~3.8 × 105 mol km−2 yr−1 (~22%) for K bearing minerals, and 0.5 × 105 mol km−2 yr−1 (~3%) for Ca bearing minerals. Similarly, CO2 drawdown through carbonate weathering accounts for ~9 × 105 mol km−2 yr−1 (~58%) for Ca and Mg associated minerals (Ca-Mg carbonate). The contribution of DIC flux from the Himalayan glacierized basins to the ocean suggests a total ~0.02 Gg C km−2 yr−1 (1 Gg = 109 g), of which, ~0.009 Gg C km−2 yr−1 is released through silicate weathering (Na, K, and Ca bearing minerals) and ~0.011 Gg C km−2 yr−1 through carbonate (Ca-Mg bearing minerals) weathering. We observed that the present day atmospheric CO2 drawdown and its associated DIC fluxes in retreating Himalayan glacierized basins is dominantly controlled by carbonate weathering. Our findings indicate the importance of carbonate weathering from glacial terrains in carbon sink studies for global carbon models in elucidating climate change effects.

Global climate change has a huge impact on our environment. The shrinking of the glaciers has affected not only the rivers and lakes but also the animals and birds. According to IPCC reports, climatic change is adversely affecting the glaciers and the trend will increase with the passage of time. The green house gases added by human activities are increasing the global temperature. Some glaciers are receding by 20 meters per year while few smaller ones have vanished or have come on the verge of extinction. The most of the rivers of South Asia like Ganga, Yamuna, Sindhu, Brahmaputra, etc. are fed by glaciers. In the absence of glaciers, these rivers will become seasonal rivers. This will affect lives of millions of people residing in their respective valleys/ plains, and have to face drought and flood frequently. In this research, the physical parameter of water has been studied in relation to the climate change, and their effects of glacier have been summed up. Over the past few decades, melting and retreat of the glaciers of the Himalayas have emerged as a major problem. In many Himalayan states, various types of efforts and research are being done to preserve the glaciers, to overcome the water crisis and climate change problem in future.

The climatic changes occurring in Himalayan areas are varied as the structures, lithology, geomorphology and evolutionary history of Himalaya. The water resources of India are dependant upon meltwater discharge which is presently the livelihood for 0.8 billion downstream peoples and significantly impacts them by its increased frequency and magnitude of extreme events. Changes in atmospheric parameters like temperature and precipitation play an important role in changing/ modifying the availability of water resources. Present study intends to highlight the changes in patterns of long-term climatic fluctuations by reanalysing the 100 years of IMD (water portal) data of atmospheric variables like temperature and precipitation with the support of extreme events that occurred in the recent past. The trends in precipitation and temperature data show the spatially variable response for Himalaya in last 100 years with decreasing pattern in all stations of Himalaya except north-west Himalaya; the weakening of Indian summer monsoon precipitation patterns also provide an evident to this fact. An attempt is done in this direction to assess and minimise the losses caused by the hazards and also use this baseline data of water resource management strategies to eradicate the threat of water availability for the billions of people.

The uncertainty in assessing the numerous atmospheric pollutants transported via wind from arid and semi-arid regions is affecting the glacial ecosystem. In our study area due to the complexity of the system, a prominent seasonal difference noticed among major ions (Ca2+, Mg2+, SO42−, and NO3−). There is a need for understanding the ions cycling as a whole and the directionality of the feedback loops in the system. Therefore, we provide an appraisal of our current hypothesis for seasonal difference in major ion concentration from snow samples for two corresponding years (2013 and 2015) at Dokriani Glacier. A systematic study of chemical compositions in the shallow snow pit from Dokriani Glacier was undertaken for the pre-monsoon season to understand the cycling of major ions from atmosphere to solute acquisition process. The intimating connections of ions cycling in snow and its temporal behavior was observed and analyzed through various statistical tests. Among major ions, the SO42− has the highest concentration among anions on an average considered as 14.21% in 2013 and 29.46% in 2015. On the other side Ca2+ is the dominant cation contributing 28.22% in 2013 and 15.3% in 2015 on average. The average ratio of Na+/Cl− was higher in 2013 whereas lower in 2015. The backward trajectory analysis suggests the possible sources of the ions transported from Central Asia through the Western Disturbance (WD) as a prominent source of winter precipitation mainly in the Central Himalaya. Ionic concentration of Ca2+ in cations was highly dominated while in anion SO42− played the major role. Factor analysis and correlation matrix suggested that, the precipitation chemistry is mostly influenced by anthropogenic, crustal, and sea salt sources over the studied region. The elemental cycling through ocean, atmosphere and biosphere opens up new ways to understand the geochemical processes operating at the glacierized catchments of the Himalaya. Moreover, increasing the field-based studies in the coming decades would also have the certain advantage in overcoming the conceptual and computational geochemical modelling difficulties.

Warfarin is a commonly prescribed oral anticoagulant used for prophylaxis and treatment of deep vein thrombosis, myocardial infarction, heart valve replacement, pulmonary embolisms, and other thromboembolic disorders. Because overdosing of warfarin is fatal to patients and only a few studies are available on the Indian population, the present study was undertaken to develop genotyping assays for the monitoring of patients undergoing warfarin therapy specific to the Indian population. Warfarin dosing is correlated with polymorphisms in VKORC1 (vitamin K epoxide reductase complex 1) and CYP2C9 (cytochrome P450 family 2, subfamily C, polypeptide 9) genes. Hence, this study was undertaken to assess the impact of these genetic variations (SNPs) in VKORC1 and CYP2C9 genes of Indian patients on warfarin therapy. In the present study, genomic DNA samples from 136 individuals (patients on stabilized warfarin therapy) were analyzed through polymerase chain reaction (PCR) and DNA sequencing. Furthermore, the observed SNPs were correlated with the dosage pattern in order to understand the genotype–phenotype correlation significance. Additionally, an amplification refractory mutation system PCR-based genotyping assay was developed for the VKORC1 –1639G>A allele, as a rapid and cost-effective detection tool. The analysis of samples from warfarin-sensitive patients showed that 84.78% of participants had mutant alleles in either the CYP2C9 or the VKORC1 gene. A novel mutation with an insertion of G at 3725 position (Ins-G –1586 with respect to the start codon) in the promoter region of the VKORC1 gene—along with the VKORC1 –1639G>A allele—was observed in four patients, all of whom were on a higher dosage of warfarin (>7 mg/d). Our results clearly indicate that there is a variation in the dosage pattern associated with the VKORC1 –1639G>A genotype in the presence of this novel promoter insertion, further suggesting the need for large-scale studies to be conducted on Indian populations for the validation of warfarin sensitivity tests.

On 16 and 17 June 2013, high-intensity rainfall (>400 mm) in different parts of the state of Uttarakhand caused devastating flash floods and triggered widespread landslides incurring heavy losses to the infrastructure, agricultural fields, human and animal lives, roads and widespread destruction of natural resources. Such a magnitude of disaster was perhaps not witnessed by the region at least over the last 100 years. Thus, this disaster can be considered as an extreme climatic event of the century. The extent and intensity of the tragedy can easily be visualised by the fact that all the famous shrines of the Uttarakhand state, located in high mountainous, snow-bound areas such as Badrinath (3133 m asl on Alaknanda River), Kedarnath (3584 m asl on Mandakini River), Gangotri (3140 m asl on Bhagirathi River), Yamunotri (3291 m asl on Yamuna River) and Hemkund Sahib (4433 m asl on Alaknanda River), were badly affected by this extreme fury of the nature.