Indian Himalaya Research Articles

Spatially Explicit climate change vulnerability assessment of ecological systems along altitudinal gradients in the Indian Himalayan region

Spatial ecological vulnerability assessments are important for devising management plans for ecological systems to maintain the flow of ecosystem services, especially in the mountains. Himalayan mountains, being a fragile ecosystem, have considerable ecological value, however, information on ecological vulnerability is lacking. The present evaluation attempts to prioritize ecosensitive zones by assessing the altitudinal ecological vulnerability of Garhwal Himalaya, India by devising a framework using a mix of bio-physical parameters. Eight bio-physical parameters, viz., Land Use and Land Cover (LULC), slope, aspect, landscape fragmentation, temperature, precipitation, soil moisture, and Normalized Difference Vegetation Index (NDVI)) were identified and considered to assess vulnerability. Spatial Principal Component Analysis (SPCA) results in five Principal Components (PCs), which were integrated and weighted for the calculation of the Ecological Vulnerability Index (EVI). The analysis results differential vulnerability across the altitudes with above 2000m altitude showed severe vulnerability and classified as potential vulnerability (36.25 %), slight vulnerability (35.25 %), medium vulnerability (20.25 %), high vulnerability (8.25 %) and severe vulnerability (0.25 %). The vulnerable regions were prioritized based on their ecological vulnerability as per the classes viz., region of strict protection (24.70 %), region of focal protection (60.41%) and region of composite development (14.89 %). The study suggetsed priority conservation and management actions for addressing the vulnerable areas for sustainable development of the region. The study provides valuable insights of vulnerability and associated protection measures leading to devising the most suitable management strategies for the sustainability of the ecological systems.

Enrichment of arsenic in the Yarlung Tsangpo basin, Southern Tibetan Plateau: Provenance, process, and link with tectonic setting

Geogenic As enrichment is prevalent in freshwater systems worldwide, yet the connection between such enrichment and regional tectonics remains poorly understood, especially within orogenic environments like the Tibetan Plateau. To provide new insights into the sources and processes of arsenic, as well as its relationship with tectonics in the plateau basin, we selected the Yarlung Tsangpo basin, situated at the collision zone between the Indian (Himalaya block) and Eurasian plates (Lhasa block) as the study area. We analyzed and compared the chemical compositions of waters and sediments across various litho-tectonic domains. This also involved assessing arsenic concentrations in river waters, suspended particulate matter (SPM), sediments, geothermal waters, and rocks. The main findings are as follows: (a) High-arsenic geothermal waters and igneous rocks are common in the Lhasa block, and the discharge of these geothermal waters is the main source of dissolved As in river water, whereas erosion of igneous rocks contributes most of the As in sediments. (b) Metal oxides adsorb dissolved As, which leads to further As enrichment in the sediments. (c) The occurrence of high As concentrations in the southern Tibetan Plateau can be explained by a crustal cycling model. Arsenic likely originated in Neo-Tethys oceanic crustal rocks and was concentrated in the upper crust of the active continental margin (Lhasa block) during geological cycling at convergent plate boundaries. These studies highlight the role of tectonic settings on influencing arsenic enrichment in the plateau basin.

Evaluation of strength and mechanical properties of Disang sandstone from Tertiary formation in Indian Himalaya under complete and incomplete uniaxial cyclic loading conditions

Evaluation of strength and mechanical properties of Disang sandstone from Tertiary formation in Indian Himalaya under complete and incomplete uniaxial cyclic loading conditions

Elevation gradients alter vegetation attributes in mountain ecosystems of eastern Himalaya, India

The present study describes how vegetation (the tree layer) is shaped along the elevation gradients in the eastern part of the Indian Himalayan Region. Various vegetation attributes, distribution, population structure, and regeneration patterns of 75 tree species belonging to 31 families were studied. Tree species richness shows a low plateau (peaked between 1,300–1,500 m) with a linearly decreasing pattern above 1,500 m asl. Ericaceae was found as the dominant family, followed by Lauraceae and Rosaceae. The distributional pattern of species-to-genera ratio (S/G) did not follow any particular trends, while β-diversity increased along the elevation gradient. The Margalef index of species richness, the Menheink index of species richness, and the Fisher alpha were found to be highest at lower altitudes (1,000–1,500 m), while the Simpson index was highest at middle altitudes (2,600–3,000 m). Random distribution was shown by maximum tree species (47.3%), followed by a contagious distribution (42.9%), and regular distribution (10.8%). The regeneration of tree species was found to be good with a healthier number of seedlings (10.2%), fair (43.5%), poor (30.3%), while 16% were observed not regenerating. Acer laevigatum (1,500 m), Prunus nepalensis (3,300 m), Viburnum sympodiale (3,400 m) were among the new regenerating species at the respective altitudes. The population structure of tree species in terms of proportion of individuals in seedlings, saplings, and the adult class varied in all the elevation transects. Species with better regeneration on upper distribution limits have been recognized as probable for upward movement.

Comprehensive volatile composition of vegetative parts of Bunium persicum B. Fedtsch.: Spice of alpine Himalaya

In the present study, headspace gas chromatography coupled with mass spectrometry (HS–GC/MS) was applied to profile volatile components of Bunium persicum samples (rhizomes, roots, stems, leaves, flowers and unripe & ripe seeds), which were collected from two locations of Indian alpine Himalaya. Thirty-six different volatile metabolites were characterized in all samples, representing (77.9-96.9%) of the total oils. Extracted volatile oils (VOs) were dominated by monoterpenes (37.9-94.8%), oxygenated monoterpenes (0.1-28.8%) and sesquiterpenes (0.2-24.3%) hydrocarbons. γ-Terpinene (6.0-64.1%), α-terpinolene (1.1-43.7%), p-cymene (0.4-8.9%), o-cymene (1.4-14.8%), sabinene (0.1-12.3%), β-pinene (0.7-14.2%), β-myrcene (1.2-11.0%), limonene (1.3-9.3%), sylvestrene (3.1-7.7%), and cymen-7-al (6.9-10.9%) were key volatile components identified in different parts of B. persicum using HS–GC/MS. These findings revealed a very high quantitative variation of VOs composition among the samples. The multivariate statistical analysis also classified these variations within the plants and their parts at two locations. HS-GC/MS technique can be utilized for the quality assessment and discrimination analysis of B. persicum, especially its essential oil (BEO). Further, essential oils of both the seed samples showed significant antioxidant activity in DPPH and ABTS assay. The current methodology will help to monitor the varietal development and smart agriculture practices as quality perspectives.

Rarities pattern of vascular plants in the high-altitude forests of Indian western Himalaya: Conservation implications

The assessment of plant rarity patterns and mapping of endemic species is a challenging task, however, this kind of assessment having great conservation significance. In the present study, a classification system of rarity, considering biogeographical, ecological and abundance of species was developed along with assessing the vegetation composition. Following systematic random approach of vegetation sampling, three altitude transects were sampled within each 100 m interval in three possible aspects (North-West, North-East and South-West) in the high-altitude forested zone (2000–3300 m asl) of Kedarnath Wildlife Sanctuary (KWS). The study identified a total of 295 plant species (191 genera and 70 families) in the studied region. Considering different attributes of rarity, 8- rarity groups were used for identification of rare and endemic plants. Altogether, most of the species exhibited wide geographical distribution an attribute of commonness, and few of these have narrow distributions due to habitat specificity. The lower altitudinal zone exhibited the maximum floristic diversity (184 spp.; 62.4 %), and minimum in the higher zone (134 spp.; 45.4 %). Tree species richness decreases, and its endemic subset increased along the altitudinal gradient due to remoteness, habitat heterogeneity, isolation of the areas and other environmental factors. A sharp decline was observed in the tree species richness from lower (33 spp.; 84.6 %) to higher altitude (8 spp.; 20.51 %). The species to genera ratio in the entire altitudinal range was 1.2 for trees and 1.6 for shrubs and herbs. Rarity analysis of these native and endemic species has highlighted conservation priorities at local and regional scale.

Ecological and human health risk assessment of pharmaceutical compounds in the Sirsa River of Indian Himalayas

The Baddi-Barotiwala-Nalagarh (BBN) region of Indian Himalayas is one of the most important pharmaceutical industrial clusters in Asia. This study investigated the distribution, and ecological and human health risks of four most frequently used pharmaceuticals [ciprofloxacin (CIP), norfloxacin (NOR), cetirizine (CTZ) and citalopram oxalate (ECP)] when co-occurring with metal ions in the Sirsa river water of the BBN region. The concentration range of the selected pharmaceuticals was between ‘not detected’ to 50 μgL−1 with some exception for CIP (50–100 μgL-1) and CTZ (100–150 μgL-1) in locations directly receiving wastewater discharges. A significant correlation was found between the occurrences of NOR and Al (r2 = 0.65; p = 0.01), and CTZ and K (r2 = 0.50; p = 0.01) and Mg (r2 = 0.50; p = 0.01). A high-level ecological risk [risk quotient (RQ) > 1] was observed for algae from all the pharmaceuticals. A medium-level risk (RQ = 0.01–0.1) was observed for Daphnia from CIP, NOR and ECP, and a high-level risk from CTZ. A low-level risk was observed for fishes from CIP and NOR, whereas CTZ and ECP posed a high-level risk to fishes. The overall risk to ecological receptors was in the order: CTZ > CIP > ECP > NOR. Samples from the river locations receiving water from municipal drains or situated near landfill and pharmaceutical factories exhibited RQ > 1 for all pharmaceuticals. The average hazard quotient (HQ) values for the compounds followed the order: CTZ (0.18) > ECP (0.15) > NOR (0.001) > CIP (0.0003) for children (0–6 years); ECP (0.49) > CTZ (0.29) > NOR (0.005) > CIP (0.001) for children (7–17 years), and ECP (0.34) > CTZ (0.21) > NOR (0.007) > CIP (0.001) for adults (>17 years). The calculated risk values did not readily confirm the status of water as safe or unsafe because the values of predicted no-effect concentration (PNEC) would depend on various other environmental factors such as quality of the toxicity data, and species sensitivity and distribution, which warrants further research.

Carbon stocks and sequestration potential of community forests in Bhutan

Community Forestry (CF) is recognized globally as a forest management regime with the potential to address deforestation and forest degradation, provide forest goods and services to local communities and contribute to climate change mitigation. Around 4% of Bhutan's forests are currently under CF management and these forests provide essential goods and services for local communities. However, the potential of CF in Bhutan to contribute to climate change mitigation is not well understood and has not been researched.In this study, we estimated the carbon stock and carbon sequestration of community forests in Bhutan by using data from the 2015 National Forest Inventory (NFI). The total biomass carbon in community forests was 130.3 Mg ha−1 (107.3–153.2) and the soil organic carbon was 52.8 Mg ha−1 (30.4–75.1). Carbon sequestration was 0.7 Mg ha−1 yr⁻¹. Other attributes: basal area, stem density and tree height, were also determined to assess forest condition and the potential to increase carbon sequestration.The values for biomass carbon in Bhutan's community forests as well as the non-community forests (all other forests) were similar to those reported from Forest Resource Assessment and NFI for forests in Nepal and the Indian Himalayan states respectively. Disaggregation of data from 38 research studies across the Himalayan region indicated that biomass carbon in Bhutan's forests was significantly lower than that in well-stocked (non-degraded) forests in the Indian and Nepal Himalayas. It was also much lower than that in Bhutan's Forest Management Units, which were used as an indicator of the potential upper limit of biomass carbon in Bhutan's forest environment. Similarly, basal area, stem density and mean tree height were also lower in Bhutan's community forests than in well-stocked forests in other Himalayan countries.The Bhutan Government is currently exploring the potential to generate revenue from the sale of carbon sequestered in its forests. This study confirms that there is potential to increase carbon sequestration by improving management of existing forests. Currently, the 107,866 ha of community forests in Bhutan store about 19 million Mg of carbon. With improved management by Community Forest Management Groups, which have the institutional capacity to control local management outcomes, the carbon stock could likely be doubled (to 40 million Mg of carbon), thereby demonstrating the potential of Community Forestry to play an important role in climate change mitigation, while not jeopardizing the provision of day-to-day goods and services to local communities.

Carbon sequestration potential and economic benefits of agroforestry in Shiwalik region of Himalaya in India

Carbon sequestration potential and economic benefits of agroforestry in Shiwalik region of Himalaya in India

Sustainable solid waste management challenges in hill cities of developing Countries: Insights from eastern Himalayan smart cities of Sikkim, India

Rapid urbanization and the growing tourism industry in the Himalayan region have raised significant concerns about the sustainable handling and management of solid waste in the area. This concern is particularly pronounced in the unique and vulnerable ecosystem of cities nestled in the eastern Indian Himalayas, where geography, ecology, and socio-economic factors converge to create distinctive challenges. This study undertakes a thorough investigation of solid waste management practices and challenges in two smart cities nestled in the eastern Himalayan region of India, specifically Gangtok and Namchi. The primary objective was to unveil the complex challenges confronting these cities by conducting an in-depth exploration of waste management practices. This comprehensive investigation was achieved through the collection of samples, conducting surveys within each ward of the cities, and performing physicochemical characterization analyses. The study also proposes a solution-oriented approach leveraging life cycle analysis. Despite the Himalayan backdrop, waste generation varies significantly, with Gangtok producing substantially more waste (50 tons per day (TPD)) compared to Namchi (4.6 TPD). Both cities excel in waste collection, but Gangtok leads in proactive treatment, with 22% (11 TPD) undergoing composting and recycling. However, shared challenges at riverside disposal sites, including overfilled dumpsites and leachate contamination, pose potential environmental hazards amid the Himalayan allure. Organic waste predominates at 40.9% and 40.01% in both cities, indicating composting potential. Plastic closely at 22.25% (Namchi) and 22.65% (Gangtok) was way above the global (12 %) and national (8.4 %) average respectively, emphasizing the urgency of plastic waste reduction strategy. The 16.95% cardboard in Gangtok highlights potential commerce-related waste. The study also highlights the importance of comprehensive policies for informal sector well-being. The lifecycle assessment of Namchi and Gangtok reveals significant methane emissions (99%) from waste anaerobic decomposition potentially due to poor source segregation. Implementing a futuristic waste strategy reduces emissions by 38% in Namchi and 40% in Gangtok, through biogas utilization and renewable energy adoption. The findings advocate for citizen engagement, improved collection, targeted campaigns, and circular economy principles. To ensure sustainability and resilience in waste management within mountain regions, tailored strategies such as material recycling facilities, community engagement initiatives, and landfill diversion mandates should integrate ecological, socioeconomic, and logistical considerations, fostering awareness and participation among communities.

Assessment of exhalation rates of radon and thoron in soil from the Jaunsar-Bawar region of the Indian Himalayas

Assessment of exhalation rates of radon and thoron in soil from the Jaunsar-Bawar region of the Indian Himalayas

Tree spacings and nutrient sources effect on turmeric yield, quality, bio-economics and soil fertility in a poplar-based agroforestry system in Indian Himalayas

Tree spacings and nutrient sources effect on turmeric yield, quality, bio-economics and soil fertility in a poplar-based agroforestry system in Indian Himalayas

Exploring the role of quadcopter technology in enhancing healthcare access in remote Himalayan Regions: a case study of Almora, Uttarakhand.

Quadcopters are employed in diverse civil applications, ranging from monitoring airports and disaster management to serving as public address systems for announcing government directives, aiding in infrastructure monitoring for resilience, and facilitating real-time automobile detection, among others. Nevertheless, the utilization of quadcopters and hexacopters for delivering health assistance to remote and intriguing grounds has garnered comparatively less attention and research worldwide. This paper presents the basics of quadcopter machinery in delivering medications and highlights its benefits for concerned patients who previously struggled to access life-saving medications due to challenging road infrastructure. The efficiency of quadcopters in terms of various parameters for delivering crucial medical supplies is significantly pronounced, particularly in the Almora District of Uttarakhand State, where many villages do not have roads to various villages. A comprehensive analysis of the road infrastructure in the mountainous terrain of the Himalayas in India was conducted to understand the situation of individuals who are denied of access to life-saving medications because of the lack of nearby roads. The findings indicate that the widespread use of quad/hexacopters can offer a ray of optimism to people living in distant areas. The quadcopter can provide basic facilities of medicines by dropping them at their doorsteps in the remote places of Almora, not accessed by Uttarakhand, thereby providing hope of living to the people.

Microplastic pollution in high-altitude Nainital lake, Uttarakhand, India

Microplastics (MPs) contamination has been reported in all environmental compartments, but very limited information is available at higher-altitude lakes. Nainital Lake, located at a high altitude in the Indian Himalayas, has various ecosystem services and is the major source of water for Nainital town, but the MP abundance is still unknown. This study presents the first evidence of the abundance and distribution of MP in Nainital Lake. Surface water and sediment samples were analysed from 16 different sites in and around the catchment area of Nainital Lake. The MP were observed in all the samples, and their abundance in surface water was 8.6–56.0 particles L−1 in the lake and 2.4–88.0 particles L−1 in hotspot sites. In the surface sediment, MP abundance ranged from 0.4–10.6 particles g−1, while in the hotspot sediment, the mean abundance was 0.6 ± 0.5 particles g−1. Fibers were the dominant MP, while 0.02–1 mm were the predominant size of MP particles. The results of chemical characterization showed the presence of six polymers, among which high-density polyethylene was the most abundant. The Polymer Hazard Index assessment classified the identified polymers as low-to high-risk categories, with a higher abundance of low- (polypropylene) and medium- (polyethylene)-risk polymers. Tourist activities and run-off catchments can be considered the major sources of MP, which can affect the ecosystem. Minimal concentrations of MP were observed in the tube well and drinking water, which depicts the direct risks to humans and, thus, the need for remedial measures to prevent MP contamination in drinking water. This study improves the knowledge of MP contamination in the higher-altitude freshwater lake, which can be the major pathway for the transport of MP to the rivers, and also emphasizes the need for waste management in Nainital town.

Abating water storage and associated hydrological processes in Indian Himalayan river basins

Abating water storage and associated hydrological processes in Indian Himalayan river basins

Investigating the dynamic nature of landslide susceptibility in the Indian Himalayan region.

Landslide susceptibility zonation (LSZ) mapping is used to delineate areas prone to landslides and is critical for effective landslide hazard management. The existing methodologies for generating such maps tend to neglect the influence of dynamic environmental variables on landslide occurrences, which may lead to obsolete and erroneous estimates of landslide susceptibility (LS) for a concerned area. Although recent studies have started to report the effects of Land Use/ Land Cover (LULC) variation on LSZ mapping, variations in other dynamic variables like rainfall, soil moisture, and evapotranspiration apart from LULC may also influence slope stability in mountainous regions. The present study investigates the impact of variations in these four variables on the LS distribution, of a selected Indian Himalayan region between 2017 and 2021. Random Forest (RF) susceptibility models are utilized for evaluating the LS for the selected years and geospatial technologies are employed for LS change detection. The results indicate up to 19% variations in the spatial extent for some of the zones of the generated LSZ maps. The research findings of this study are crucial since they reveal the impact of dynamic behavior on LS, which has not been previously documented in the literature.

Relationship between the variations in glacier features classified on a large scale with climate variables: a case study of Gangotri Glacier.

Changes in glacier area, glacial lakes, debris cover, and geomorphological features such as debris fans have a significant impact on glacial dynamics. Therefore, precise and timely observation and tracking of glacier surface changes is a necessity. The availability of high spatial resolution remote sensing images has made it viable to analyse the glacier surface changes at a local level. However, with an increase in spatial resolution, the spectral variability increases, giving rise to additional challenges (such as false changes and misregistration) in the change detection process. These challenges can preferably be dealt with using an object-based change detection (OBCD) approach rather than the conventional pixel-based change detection approach. Therefore, this study has proposed an OBCD methodology using high-spatial-resolution remote sensing images to detect changes in glacier features. Variability in glacier features has been further analysed by associating it with important climate variables, that is, air temperature and precipitation. As a case study, the changes in Gangotri Glacier (Uttarakhand Himalayas in India) features have been studied using high-spatial-resolution WorldView-2 and Linear Imaging Self-Scanning System (LISS)-4 images for a 3-year period 2011-2014. The spectral correspondences between glacier surface and non-glacier surface have been handled by considering brightness temperature and slope as ancillary data to improvise their distinction. A change detection accuracy of ~ 84% has been obtained using the OBCD approach. Results further show that the variations in glacier features are in congruence with the climatic observations.

Identification of sources of coarse mode aerosol particles (PM10) using ATR-FTIR and SEM-EDX spectroscopy over the Himalayan Region of India.

This study attempts to examine the morphological, elemental and physical characteristics of PM10 over the Indian Himalayan Region (IHR) using FTIR and scanning electron microscopy-energy dispersive X-ray (SEM-EDX) analysis. The study aimed at source identification of PM10 by exploring the inorganic ions, organic functional groups, morphology and elemental characteristics. The pollution load of PM10 was estimated as 63 ± 22 μg m-3; 53 ± 16 μg m-3; 67 ± 26 μg m-3 and 55 ± 11 μg m-3 over Mohal-Kullu, Almora, Nainital and Darjeeling, respectively. ATR-FTIR spectrum analysis revealed the existence of inorganic ions (SiO44-, TiO2, SO42-, SO3-, NO3-, NO2-, CO32-, HCO3-, NH4+) and organic functional groups (C-C, C-H, C=C, C≡C, C=O, N-H, C≡N, C=N, O-H, cyclic rings, aromatic compounds and some heterogeneous groups) in PM10 which may arise from geogenic, biogenic and anthropogenic sources. The morphological and elemental characterization was performed by SEM-EDX, inferring for geogenic origin (Al, Na, K, Ca, Mg and Fe) due to the presence of different morphologies (irregular, spherical, cluster, sheet-like solid deposition and columnar). In contrast, particles having biogenic and anthropogenic origins (K, S and Ba) have primarily spherical with few irregular particles at all the study sites. Also, the statistical analysis ANOVA depicts that among all the detected elements, Na, Al, Si, S and K are site-specific in nature as their mean of aw% significantly varied for all the sites. The trajectory analysis revealed that the Uttarakhand, Jammu and Kashmir, the Thar Desert, Himachal Pradesh, Pakistan, Afghanistan, Nepal, Sikkim, the Indo-Gangetic Plain (IGP) and the Bay of Bengal (BoB) contribute to the increased loading of atmospheric pollutants in various locations within the IHR.

Long term (1901−2021) trends and prediction of climatic variability in selected agro‐ecological zones of Himachal Pradesh using coupled statistical and machine learning approaches

This study analyses the trends of changing climatic elements in the hydrological regime of the Indian Himalayan Region with specific focus on Agro‐ecological zone II & III of Himachal Pradesh for the period of 1901−2021. The upper, middle, and lower catchment areas of Sutlej River Basin were studied to reveal regional trends in climatic parameters. The Mann‐Kendall test and Sen Slope analysis were used to estimate annual and seasonal trends and their magnitude. The results showed a significant decreasing trend in the lower catchment area, with a break point year estimated to be 1953 for the entire basin. Two blocks of analysis, 1901−1953 and 1954−2021, showed significant variations. Annual rainfall data revealed a statistically significant decreasing trend at different stations. The lower catchment area received a significant increase in rainfall compared to higher altitude stations. In terms of seasonal variation, the pre‐monsoon season showed a significant decrease, while the entire basin recorded a significant increase in average monthly temperature. The study concludes by generating future time series predictions using an ANN model for the period of 2022−2050. Overall, the study's findings indicate a significant change in climatic variables with signs of increasing monthly temperatures and decreasing annual rainfall.

Data synthesis for biodiversity science: a database on plant diversity of the Indian Himalayan Region

Data synthesis for biodiversity science: a database on plant diversity of the Indian Himalayan Region