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Precipitation over the southern rim of the Indian Himalayan Region (IHR) mainly occurs due to two dominant synoptic weather systems: Indian winter (IWM: December, January, February) and summer monsoon (ISM: June, July, August, September). The genesis and evolution of these systems are extensively researched. Additionally, geographical location, season, orography controls the strengths of these systems along and across the southern rim of the IHR. However, plausible positioning of the frontal threshold limit of precipitation during IWM and ISM over the IHR remains an elusive scientific question. Thus, with the help of water samples collected in the upper Bhilangana River Basin (BRB in the central Himalayas), an attempt has been made to assess this frontal threshold limit of precipitation and is defined as “quasi monsoon front (QMF)" in the IHR. Results show depleted (enriched) stable water isotopic values at higher (lower) altitudes suggesting an elevation control. The intercepts of local meteoric water lines (LMWLs) of glacier ice/glacier melt (2.5), snow packs/snow melt (7.7), and stream water (10.3) reflect mixing of precipitation due to IWM and ISM. The d-excess values in water samples lie between the d-excess value of a typical IWM (~20‰) and ISM (~10‰), suggesting mixing of moisture from both Atlantic ocean – Mediterranean sea and Indian ocean-Bay of Bengal-Arabian sea. The tracer based hydrographic analysis indicates dominance of snow melt contributions to the regional hydrology. Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) model in the back trajectory mode estimates moisture sources of the IWM and ISM. Based on precipitation isotopic composition and associated moisture source regions, QMF oscillates in the northwest and southeast direction of the IHR depending on the strength and/or weakness of IWM and ISM. This work hypothesizes for upscale determination and description of the pulsatory extension of QMF in the central Himalayas (along BRB).

Conventional pH meters perform measurements using a two-electrode scheme that consists of a glass electrode (pH) and a reference electrode whose known electrochemical potential is insensitive to pH. This conventional scheme is, however, poorly adapted for remote sensing and in-situ monitoring due to technical difficulties related to making electrical contacts and the stability of the electrodes. By using the highly sensitive Raman response of metallic Single-Walled Carbon Nanotubes (SWCNTs), we devised a pH responsive optical probe comprised of SWCNTs in contact with a platinum redox couple, here referred to as Pt-SWCNTs. When placed in a buffer solution, the Pt-SWCNT probe shows a strong Raman shift of the G-band as a function of pH, which is ascribed to charge transfer doping of the SWCNT reference electrode. Referenced potential measurements are demonstrated along with the accurate monitoring of pH in solutions of different ionic strengths. Controlled experiments at constant ionic strength show precise pH measurements across the full range between 1 and 12 with a best accuracy of ±500 mpH units. This work demonstrates for the first time an optical pH sensing scheme that is analogous to a conventional pH sensor equipped with a built-in internal reference.

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 present study generates a glacial lake inventory of Arunachal Pradesh, Eastern Himalaya, India using Landsat 8 Operational Land Imager (OLI) images (2016-2018). The study reveals that there are in total 1532 (> 0.001 km2) glacial lakes, covering an area of 93.7 km2. Glacier erosion lakes are the most dominant type with 1268 glacial lakes (82.8%) and an area of 76.8 km2 (∼82%). About 50% of the lakes are located in the four districts of eastern Arunachal Pradesh, while ∼16% in the three districts of central and ∼33% in the four districts of western Arunachal Pradesh. The western Arunachal Pradesh has mixed patterns of glacial lakes types, whereas the erosion lakes dominate the eastern and central Arunachal Pradesh. The current inventory can serve as a baseline database for understanding glacial lake-related flood hazard studies in Arunachal Pradesh.

International audience; On 7 February 2021, a catastrophic mass flow descended the Ronti Gad, Rishiganga, and Dhauliganga valleys in Chamoli, Uttarakhand, India, causing widespread devastation and severely damaging two hydropower projects. More than 200 people were killed or are missing. Our analysis of satellite imagery, seismic records, numerical model results, and eyewitness videos reveals that~27 × 10 6 cubic meters of rock and glacier ice collapsed from the steep north face of Ronti Peak. The rock and ice avalanche rapidly transformed into an extraordinarily large and mobile debris flow that transported boulders greater than 20 meters in diameter and scoured the valley walls up to 220 meters above the valley floor. The intersection of the hazard cascade with downvalley infrastructure resulted in a disaster, which highlights key questions about adequate monitoring and sustainable development in the Himalaya as well as other remote, high-mountain environments.

Climate change and associated glacier recession have led to the formation of new glacial lakes and the expansion of existing ones across the Himalayas. Many pose a potential glacial lake outburst flood (GLOF) threat to downstream communities and infrastructure. In this paper, 4418 glacial lakes in the Indian Himalayan Region and 636 transboundary lakes are analyzed. We consider hazard, exposure, and integrated danger levels using robust geographic information system-based automated approaches. The hazard level of lakes was estimated based on the potential for avalanches to strike the lake, size of the lake and its upstream watershed, and distal slope of its dam. Exposure levels were calculated by intersecting cropland, roads, hydropower projects, and the human population with potential GLOF trajectories. Then, GLOF danger was determined as a function of hazard and exposure. The study demonstrates that Jammu and Kashmir (JK) is potentially the most threatened region in terms of total number of very high and high danger lakes (n = 556), followed by Arunachal Pradesh (AP) (n = 388) and Sikkim (SK) (n = 219). Sectorwise, JK faces the greatest GLOF threat to roads and population, whereas the threat to cropland and hydropower is greatest in AP and SK, respectively. Transboundary lakes primarily threaten AP and, to a lesser extent, Himachal Pradesh (HP). For Uttarakhand (UK), the impacts of potential future glacial lakes, expected to form during rapid ongoing glacier recession because of climate change, are explored. Finally, a comparison of current results with previous studies suggests that 13 lakes in SK, 5 in HP, 4 in JK, 2 in UK, and 1 in AP are of highest priority for local investigation and potential risk reduction measures. Current results are of vital importance to policymakers, disaster management authorities, and the scientific community.

Widespread retreat of glaciers has accelerated over recent decades in most mountain regions as a consequence of global warming, leading to rapid expansion of glacial lakes, bringing related risks.When water is suddenly released, Glacial Lake Outburst Floods (GLOFs) can devastate lives and livelihoods up to hundreds of kilometres downstream of their source. This threat is most apparent in High Mountain Asia (HMA), home to >200 million inhabitants, and where >150 GLOFs have been recorded from moraine dammed lakes alone. Here we reflect on our recent experience working across HMA to outline key learnings, challenges and perspectives in applying GLOF hazard and risk assessment at various scales, with an emphasis on how results have or can inform local response planning.The number of large-scale assessment studies has increased exponentially over recent years, often giving inconsistent results in terms of what are considered potentially dangerous lakes. This makes it difficult for authorities and funding agencies to identify where more detailed hazard mapping and risk management strategies should be targeted, especially in cases where the science may not be aligned with local understanding and experience. We therefore recommend a consensus approach, drawing across multiple studies, and including the knowledge of local authorities to arrive at a final listing of high priority lakes which may be subject to further monitoring, Early Warning Systems and other response strategies. In our stakeholder interactions, we have particularly emphasised that GLOFs from even relatively small lakes can lead to significant damages when combined with other hazardous processes, e.g., the case of 2013 Chorabari GLOF combining with monsoon flooding and landslides in Northern India, or the 2016 outburst from Gongbatongshaco, Chinese Himalaya, Tibet, where erosion and bulking was significantly enhanced as a consequence of the Gorkha earthquake occurring a year earlier.Looking to the future, several assessment studies have now combined modelling of glacier bed topography to identify where new lakes could emerge in the future, and even combined this information with changing exposure levels (e.g., planned hydropower development). However, there are challenges around communicating these uncertain future hazards and risks, and to what extent they should be considered in planning. In the transboundary Poiqu basin originating in Tibet, we have focussed on worst-case scenario modelling for such a future lake, demonstrating that flow depths and velocities would exceed the threat from current lakes, and the peak wave would reach the border with Nepal up to 20 minutes faster. Open questions remain around how triggering processes will evolve in the future. Most assessments currently focus on cascading process chains triggered by ice or rockfall, whereas under a wetter and warmer future climate, heavy rainfall and snowmelt as a direct or indirect trigger could become increasingly important. Further, major uncertainties arise from socio-economic developments and related changes in exposure and vulnerability, that could, in some regions, be the most significant drivers of future GLOF risk. Ultimately, forward-looking, GLOF hazard and risk assessment must ensure that response strategies remain robust in the face of ongoing environmental and societal change.

The present study aims to estimate the trends in daytime land surface temperature (LST) and its relationship with other parameters such as elevation and land use/land cover (LULC) over the Ganga River Basin (GRB) during 2001–2019. The study examined monthly daytime clear-sky LST, elevation, LULC, snow cover area (SCA), clear-sky days, and aerosols data of the GRB. Annual mean clear-sky daytime LST has been declining at the rate −0.017 °C year−1 over the basin during the study period. At seasonal scale, LST has been rising during monsoon (average rate of 0.026 °C year−1), whereas other seasons show a decline with the highest magnitude during winter season (−0.078, oC year−1). The study observed pronounced warming trends (0.003 to 0.07 °C year−1) in post-monsoon above the elevation of 3000 m amsl indicating elevation-dependent warming (EDW) in the basin. The vagary in LST over the basin may be attributed to the changes in LULC, increasing aerosols loading, and rising hazy days.

Debris-covered glaciers are a notable feature in the greater Himalaya, and their ongoing mass loss under changing climate will affect the water resources of over a billion people. The current knowledge of the mass balance of Himalayan glaciers is restricted by the paucity of in-situ measurements of glaciers in both space and time, as well as the resolution of satellite remote sensing imageries. Recently, the use of Unmanned Aerial System (UAS) imagery has shown the potential to bridge this gap by enabling very detailed monitoring of inaccessible glacial areas. UAS imagery-based monitoring of Himalayan glaciers has so far been limited to a single glacier in the entire Himalaya, providing a limited understanding of spatial variability in glacier mass balance and driving factors. In the first UAS based glacial mass change estimation in the trans-Himalaya, we conducted two Unmanned Aerial System (UAS) surveys (May and November 2019) over the debris-covered Annapurna III glacier in the Himalaya. We performed Structure-from-Motion (SfM) analysis and utilized differential GPS field observations to derive geometrically accurate point clouds, ortho-mosaics and digital surface models (DSMs). The glacial volumetric loss was estimated from DSM differencing, and the magnitude and spatial variability of glacier surface change was derived from 3-D differencing of point clouds. Results revealed a heterogeneous glacial melt pattern, with an average elevation loss of 0.89 m during the monitored time period. The majority of the glacial tongue exhibited surface lowering except the area above and around the glacial snout that surprisingly exhibited significant elevation gain. Both the highest magnitude of mass loss and the highest spatial variability in mass change was observed in areas with exposed ice-cliffs and supraglacial ponds. Glacial surface velocity derived from manual feature tracking showed velocity ranging from 0-4.1 m. A detailed evaluation of specific areas allowed an improved understanding of the complex interplay of factors leading to observed surface change. Our findings expand the extent of UAS based monitoring of debris-covered glaciers in the Himalaya and conclude that UAS derived 3D topographic products will become increasingly important for monitoring of thinning debris-covered glaciers.

Climate change has enormous impacts on the cryosphere In the Indian Himalayan Region (IHR) which have been increasingly documented over the past years. The effects of cryosphere change on people, ecosystems and economic sectors is less clear but bears important risks. Adaptation to changing conditions and risks is a priority for the region. Here we draw on experiences of Indo-Swiss collaborations in the field of climate change, cryosphere, risks and adaptation in the IHR. First, we provide a synthesis of the climate and cryosphere in the IHR, and related impacts on downstream communities and systems. Second, we analyze the associated risks from a conceptual and adaptation perspective. We then introduce concepts of co-production of knowledge as an approach to an inclusive and sustainable adaptation process which includes the development of future scenarios with a wide range of stakeholders. We visualize this approach using examples of the water resource sector.

Research on the Himalayan cryosphere has increasingly focused on climate change, considering aspects such as snow cover dynamics, precipitation and temperature trends. The Uttarakhand Himalaya is hydrologically very significant and a more comprehensive understanding of its response to climate change is needed. This paper analyses of elevation-dependent distribution and trends in snow-covered area (SCA), precipitation and temperature for the period 2000–2020 employing MODIS-Terra data, together with reanalysis (CHIRPS) and Landsat-8 data products within the Google Earth Engine (GEE) platform. The study reveals a significant increasing trend in annual, seasonal and monthly precipitation (except November) at different elevations, while SCA and temperatures exhibited more variable trends during the period. Digital elevation and spectral reflectance models reveal the effects of topography and surface attributes on snow cover. Statistical analyses reveal a significant relationship between precipitation and SCA (R2 = 0.78), while seasonal changes in temperature are apparent in an emerging pattern of warmer winters and a cooler pre-monsoon. SCA trends vary markedly between elevation zones in response to precipitation and temperature fluctuations. At higher altitudes, SCA decreased from 2000 to 2020 since, although precipitation increased slightly, marginally higher temperatures led to more snowmelt. Reduced snow cover and increased temperature are also associated with a decline in downstream fluvial during the period for which such data are available (2000 to 2005). The analysis of snow cover dynamics across different elevations improves our understanding of the overall hydrological conditions in the region and enable more reliable flood forecasting and management of water resources.

We analysed the recession of the Milam glacier in the Gori Ganga River valley, Uttarakhand Himalaya using historical plane-table survey maps, topographical maps, Corona image (1968), Landsat 5 TM (1990), Landsat 7 ETM+ (2001) and Sentinel 2 (2017) satellite data. We estimate that the Milam glacier has receded by 1565.4 ± 20.6 m (31.9 ± 0.4 m a-1) over the period 1968-2017, while lower recession rate (21.1 ± 1.7 m a-1) was observed between 2001 and 2017. The Milam glacier lost 2.27 ± 0.06 km2 of its area from 1968 to 2017 due to recession. Two tributary glaciers detached from the main trunk between 1990 and 2017, which indicates glacier thinning and melting. The glacier recession also resulted in deformation of moraine ridges on either sides in lower ablation zone of Milam glacier, which is caused due to the removal of basal ice support caused by glacier melting.

Two new ternary tetrazolate Eu(III) complexes with phosphine oxide co-ligands Eu(PTO)3 ·(P1/P2) [PTO = 5-(2-pyridyl-1-oxide)tetrazole, P1 = diphenylphosphorylamino-phenylphosphoryl-benzene, P2 = diphenylphosphorylpyridine)-bis-isobutyricphosphoryl] were synthesized and characterized using UV, fluorescence, IR and (1) H NMR spectroscopic techniques. The analytical data prove that the complexes are mononuclear in nature and the central Eu(III) ion is coordinated by three N and three O atoms of tetrazolate, and two O atoms of the corresponding bidentate phosphine oxide ligands. The ancillary ligand increased the photoluminescence efficiency of Eu(PTO)3 ·P1 (complex 3) by twofold compared with our previously reported Eu(PTO)3 complex (complex 1). Copyright © 2015 John Wiley & Sons, Ltd.

Carbon nanotubes are among the most promising platforms for biological applications such as cancer targeting, medical imaging and drug delivery. Herein we present a novel approach to modify single-walled carbon nanotubes (SWCNTs) into Raman nanoprobes capable of targeting biomarkers on cancer cells. The process involves cleaning and shortening in acids followed by encapsulation of specific organic dyes. Subsequently the as-synthesized Raman nanoprobes are then covalently attached with modified NH2-PEG-COOH to make a generic nanoprobe that is bio-compatible and highly dispersed in aqueous or buffer media. When covalently linked to specific antibodies anti-E-cadherin (monoclonal mouse anti-human) and CK19 (cytokeratin), such nanoprobes can be used to detect there bio-markers in the membrane of breast cancer cell lines. Here, we will first discuss a modified synthetic approach to densify the covalent pegylation used to link bio-molecules on the SWCNTs and show results with nanoprobes incubated with T47D antibody (ab) and MDA231 cell lines. The immunofluorescence and Raman imaging data shows that dyes@SWCNT/PEG/ab composites can specifically target cancer cells overexpressing high affinity receptors of the specific biomarkers linked to the probes. By densifying the covalently attached PEGs, the results show higher stability and improved selectivity of the Raman nanoprobes towards bio-molecules on cancer cells.

Single-Walled Carbon Nanotubes (SCWNTs) have attracted a lot of attention in biomedical fields. Their easily functionalised surface and ability to encapsulate different materials make them interesting not only for imaging, but also for other applications, such as drug delivery and cell targeting. This work concerns specifically the use of SWCNTs to fabricate Raman nanoprobes for bio-imaging. These nanoprobes are composed of dyes encapsulated inside the SWCNTs and the nanotubes are grafted with anti-bodies functionalized on the outer surface. First, we aim to optimize the encapsulation process so that the dye/SWCNTs nanohybrid gives a strong, uniform and reproductible signal that is easily detectable by Raman imaging. This is done by varying the parameters of the liquid-phase encapsulation process and crosschecking the results by Raman imaging. We also work to optimize the stability of the nanohybrid in biological media. This parameter is important to determine the best conditions for antibody attachment and cell/tissue interactions. Using different biological buffers, we study the dispersion of the assemblies with Dynamic Light Scattering (DLS) and their stability with Electrophoretic Light Scattering (ELS). The results of the analysis on the nanohybrids show an average hydrodynamic radius of 160 nm and a Zeta potential at -45 mV in aqueous media, proving that the stability of the short nanohybrids in water is favourable to the development of nanoprobes.

This paper analyses the spatio-temporal trends and variability in annual, seasonal, and monthly rainfall with corresponding rainy days in Bhilangana river basin, Uttarakhand Himalaya, based on stations and two gridded products. Station-based monthly rainfall and rainy days data were obtained from the India Meteorological Department (IMD) for the period from 1983 to 2008 and applied, along with two daily rainfall gridded products to establish temporal changes and spatial associations in the study area. Due to the lack of more recent ground station rainfall measurements for the basin, gridded data were then used to establish monthly rainfall spatio-temporal trends for the period 2009 to 2018. The study shows all surface observatories in the catchment experienced an annual decreasing trend in rainfall over the 1983 to 2008 period, averaging 15.75 mm per decade. Analysis of at the monthly and seasonal trend showed reduced rainfall for August and during monsoon season as a whole (10.13 and 11.38 mm per decade, respectively); maximum changes were observed in both monsoon and winter months. Gridded rainfall data were obtained from the Climate Hazard Infrared Group Precipitation Station (CHIRPS) and Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR). By combining the big data analytical potential of Google Earth Engine (GEE), we compare spatial patterns and temporal trends in observational and modelled precipitation and demonstrate that remote sensing products can reliably be used in inaccessible areas where observational data are scarce and/or temporally incomplete. CHIRPS reanalysis data indicate that there are in fact three significantly distinct annual rainfall periods in the basin, viz. phase 1: 1983 to 1997 (relatively high annual rainfall); phase 2: 1998 to 2008 (drought); phase 3: 2009 to 2018 (return to relatively high annual rainfall again). By comparison, PERSIANN-CDR data show reduced annual and winter precipitation, but no significant changes during the monsoon and pre-monsoon seasons from 1983 to 2008. The major conclusions of this study are that rainfall modelled using CHIRPS corresponds well with the observational record in confirming the decreased annual and seasonal rainfall, averaging 10.9 and 7.9 mm per decade respectively between 1983 and 2008, although there is a trend (albeit not statistically significant) to higher rainfall after the marked dry period between 1998 and 2008. Long-term variability in rainfall in the Bhilangana river basin has had critical impacts on the environment arising from water scarcity in this mountainous region.

This book discusses the science, causes, impacts and risk reduction strategies for climate change and disasters. It focuses on the use of traditional knowledge, new innovation and education to build a culture of safety and resilience at all levels in order to promote sustainable development goals in general and disaster risk reduction in particular. The global climate has changed substantially over the last century. There is strong evidence of global climate change in the form of increase in air and sea surface temperature, recession of glaciers, changes and shifting of climate regimes, increasing number of extreme events and sea levels changes. The increasing frequency of climate change induced disasters in particular is posing a threat to resilience, lives and livelihoods at global, regional and local levels. Major ecosystems of the world have experienced several climate induced disaster events in recent past. This book provides new insights into the occurrence and impacts of climatic extremes and strategies for disaster risk reduction. It includes studies on rainfall and temperature trends, floods and drought disasters, weather and climatic related disasters in mountains, changes in plant activities, risk assessment and responses in different ecosystems of the world. The book is particularly useful for environmental and disaster managers, researchers and graduate students, as well as policy makers.

Climate change has become an important factor for many environmental disasters in vulnerable communities and ecosystems. Poverty, poor education and health facilities and other aspects of human population in low and middle income countries have led to increased exposure and high levels of vulnerability and risk. Most of the deaths caused due to different disasters have occurred in developing countries. As a consequence, major efforts at the international level have been made to reduce the risks related to various disasters. The International Decade for Natural Disaster Reduction (1990–1999) was one of the important international initiatives followed by the International strategy for Disaster Reduction (1999), the Yokohama Strategy (1994), the Hyogo Framework for Action (2005), and most recently the Sendai Framework, the Paris Agreement, and the Sustainable Development Goals (all in 2015). Furthermore, the Intergovernmental Panel on Climate Change (IPCC) has played a fundamental role in assessing the state of knowledge in climate and impact science for almost 30 years. This introductory chapter summarizes the international initiatives in this field and thus prepares the ground for the following chapters which are introduced at the end of this chapter.

A new class of antenna chromophores so called 'tetrazolates' have not been explored much for lanthanide luminescencent complexes. However, we have already published several articles considering pyridineoxide tetrazolates as sensitizer with lanthanide ions. Although this class of antenna attracted much less attention because of its poor photoluminescence quantum yields (tris-pyridineoxide tetrazolate europium complex = 13% in solution) we tried and successfully achieved to improve the photoluminescence quantum yields for this particular antenna molecule by replacing coordinated water from the inner coordination sphere of europium ion by introducing phosphine oxides as additional chromophore. In the present article the two bis-phosphine oxides attach two molecules of tris-pyridineoxide tetrazolate europium(III) complex which leads to the improvement of the overall molar absorption coefficients as well as photo-physical properties of the complexes. We found more than two-fold increase (31% in solution) in photoluminescence quantum yield with one of the coordinated phosphine oxides comparing with that of tris-pyridineoxide tetrazolate europium(III) complex.

Glacial lakes and associated outburst floods (GLOFs) have increased in the Himalayan region due to climate change during the last century that has led to huge losses to society. Therefore, the present study was undertaken to map glacial lakes, their increasing extent, and associated damage potential in Nanda Devi Biosphere Reserve (NDBR), Indian Himalaya. The glacial lakes were mapped on Landsat TM (3 November, 2009 and 6 November 2010) and Landsat MSS satellite images (15 November 1976 and 26 October 1979) to assess their changing area. Potential GLOFs sites have been identified and studied for their damage potentials using site characteristics and past occurrence of GLOFs. A total of 35 lakes were mapped, of which 14 lakes are located at more than 4500 m. The size and damage potentials of lakes have increased. Some lakes grew so much that they merged to form a big lake. All of these are potential GLOFs and can cause severe damage to society.

The local hydrological, agricultural and economic activities heavily depend on micro-level rainfall. Therefore, this study examines trends and variability of rainfall in Uttarakhand state of western Himalaya, India. The season and station-wise results of this study differ from India level results. The annual rainfall declined in high altitudes. Similarly, the monsoon rains declined in high altitudes and increased in low altitudes, whereas winter rainfall show mixed trends. The variability of monsoon rainfall was lowest for all stations and seasons, while the winters show low variability. Inter-seasonal variability is recorded highest in plains and lowest in high altitudes.

New ternary Eu(III) 5-(2-pyridyl-1-oxide)tetrazolate complexes with phosphine oxide co-ligands have been synthesized and characterized by elemental analysis, and IR and 1H NMR spectroscopic techniques. The analytical data revealed that these complexes are mononuclear, and the central Eu(III) ion is coordinated by three oxygen and three nitrogen atoms of the tetrazolate and two oxygen atoms from the phosphine oxide ligands. The ancillary ligands increased remarkably the luminescence efficiency of the Eu(III) tetrazolate.

The new triphenylene 1,3-diketone (1-triphenylen-2-yl-3-trifluoroacetylacetone (TphTA)) and its europium complexes were synthesized. The preliminary data on photophysical properties of Eu(TphTA)3(H2O)(C2H5OH) (1), Eu(TphTA)3(TOPO)(H2O) (2), Eu(TphTA)3(TOPO)2 (3) and Eu(TphTA)2NO3(TOPO)2 (4) are reported. Addition of a tri-n-octylphosphine oxide (TOPO) co-ligand to the europium diketonate complex removes water molecules from the coordination sphere, that leads to a significant increase of the photoluminescence quantum yield. The behavior of complexes 3 and 4 in nematic liquid crystal was investigated.

Mountains are globally significant as ‘water towers’ of the Earth, as core areas of biodiversity and as source regions for important natural resources and ecosystem services. The ecological integrity of mountain environments is increasingly threatened by global environmental changes including climate change to which physical and ecological systems in mountains are highly vulnerable. Global warming rates have been higher in mountain regions compared to the global mean and have strongly affected the cryosphere, mountain biota and ecosystem processes.

Changing glacier snout positions, surface area, and mass balance are considered as important indicators of climate change. Climatic warming and cooling are reflected through shrinkage and expansion of glaciers, often without significant time lags. Glaciers are important sources of water supply for lowlands and thus have significant influence on ecosystem services, agriculture, and socioeconomic conditions. The economy of the Indo-Gangetic Plain is particularly vulnerable in this respect. Therefore, the present study assesses recent changes (2001–2013) of glaciers in central Himalayan region using remote sensing data. A total of 31 glaciers were mapped on Landsat ETM+ (2001) and OLI (2013) and compared to estimate the changes in snout positions. The study reveals that there are significant variations in glacier retreat. The retreat rate varies between 5.6 m−1 (Lawan Glacier) and about 35.6 m−1 (Pachu Glacier). A total of 6 glaciers retreated with less than 10 m−1, 16 between 10 and 20 m−1, 6 between 20 and 30 m−1, and 3 more than 30 m−1. An attempt has also been made to assess underlying driving forces of the varying retreat rate of glaciers. The elevation of snouts, the area, and the length of glaciers have implications on snout retreat rate. There are, however, some other important factors, e.g., accumulation area ratio, slope angles of accumulation and ablation, amount of rainfall and snowfall, temperature conditions, and debris cover, that have significant bearings on glacier retreat.

Tetrazole-2-pyridine-1-oxide was prepared from 2-cyanopyridine and sodium azide, followed by oxidation with m-chloroperbenzoic acid. This ligand forms neutral 1:3 complexes with Eu(III) and Tb(III) cations. The complexes are photoluminescent in solution, with photoluminescence quantum yields 13% and 31%, respectively.

Tourism industry has become an important part of Indian economy, and tourism development has been, however, concentrated to a few areas. Accumulation of tourism activities has reached the critical stage in most of the tourism centers, which pose serious threats to the natural environment. The Bhyundar Valley of Nanda Devi Biosphere Reserve (NDBR) in Uttarakhand State of the Indian Himalaya is a burning example of such problems. Land use/cover changes, deforestation and accumulation of garbage are some of the negative impacts of unregulated tourism in the valley. Unsustainable activities of tourists and villagers in the valley make such problems very severe. To deal with the ongoing problems and ensure community involvement in tourism management and environmental conservation, the Biosphere Reserve Authority introduced ecotourism in the form of Eco Development Committees (EDCs) in the Bhyundar Valley. Study reveals that many problems associated with tourism have been minimized to some extent with the help of EDCs but few are still prevailing in valley. However, the existing attempts to conserve the valley from the negative effects of tourism are inadequate and modifications are needed in the current initiatives.

Two new ternary tetrazolate Eu(III) complexes with phosphine oxide co-ligands Eu(PTO)3 ·(P1/P2) [PTO = 5-(2-pyridyl-1-oxide)tetrazole, P1 = diphenylphosphorylamino-phenylphosphoryl-benzene, P2 = diphenylphosphorylpyridine)-bis-isobutyricphosphoryl] were synthesized and characterized using UV, fluorescence, IR and (1) H NMR spectroscopic techniques. The analytical data prove that the complexes are mononuclear in nature and the central Eu(III) ion is coordinated by three N and three O atoms of tetrazolate, and two O atoms of the corresponding bidentate phosphine oxide ligands. The ancillary ligand increased the photoluminescence efficiency of Eu(PTO)3 ·P1 (complex 3) by twofold compared with our previously reported Eu(PTO)3 complex (complex 1). Copyright © 2015 John WileySons, Ltd.