High Mountain Regions Research Articles

Large-Scale Gravity Current over the Middle Hills of the Nepal Himalaya: Implications for Aircraft Accidents

AbstractNepal has been the location of a series of fatal aircraft accidents, raising serious concerns about civil aviation security and the safety of passengers. However, significant studies on weather patterns associated with the airports and air routes of the Himalayan complex terrain and their implications for aviation activities are yet to be carried out. The present study numerically reconstructs the prevailing weather conditions and puts forward some possible causes behind the most recent fatal aircraft accident in the foothills of the western Nepal Himalaya at 0730 UTC (1315 LST) 16 February 2014. The weather patterns have been numerically simulated at 1-km2 horizontal grid resolution using the Weather Research and Forecasting (WRF) modeling system. The reconstructed weather situation shows the existence of a low-level cloud ceiling, supercooled cloud water and hail, trapped mountain waves, supercritical descent of a strong tail wind, and the development of turbulence at the altitude of the flight path followed by the aircraft. The aircraft might have gone through a series of weather hazards including visibility obstruction, moderate turbulence, abnormal loss in altitude, and icing. It is concluded that the weather situation over the region was adverse enough to affect small aircraft and therefore that it might have played an important role leading to the fatal accident. The development of hazardous weather over the region may be attributed to a previously unanticipated large-scale easterly gravity current over the middle hills of the Nepal Himalaya. The gravity current originated from the central high Himalayan mountainous region located northeast of the Kathmandu valley and traveled more than 200 km, reaching the foothills of the western Nepal Himalaya.

An Environmentally Friendly Integrated Development Approach for Nepal (Experiences from Irrigation Sector Projects)

Nepal has distinctly three ecological regions: (i) high mountain, (ii) mid-hills, and (iii) terai with their varying climatic and physiographic features. The experiences gathered from Irrigation Sector Projects implemented under various donor agencies such as the World Bank (WB), Asian Development Bank (ADB), and UN/ILO have shown that successful irrigation projects must be defined and planned according to specific ecological regions and pertinent to the local environment. An integrated development approach considers the land use, roads, market, and other economic activities as they relate to prospects for poverty alleviation. Land evaluation and subsequent land use planning according to the soil, climate, land profile, and suitability of agriculture practices should be considered in the development works to ensure true benefit to the rural populations. The integrated approach as such will provide long term sustainability through environmentally sound practices. This approach has been widely applied in the European countries, Korea, Japan, and Sri Lanka.This paper primarily focuses on the irrigation and development approaches most suitable to Nepal’s three ecological regions. High mountain regions should be developed with pasture land, horticulture, organic vegetable farming, and tourism. Irrigation technology in these areas should be simple pipe conveyance, and tank irrigation. In the mid-hills horticulture on the sloping terrain and cereal crops in the river valleys with other diversified cropping systems should be applied. The Terai region is the ‘Bread Basket’ of Nepal, and has high potential for diversified agriculture and industrial development.For development in these regions to succeed, road networks and transportation facilities are essential to economic growth. Road transportation maximizes opportunity for tourism and other economic activities. Development work must be planned in an integrated approach, which should be based on appropriate land use patterns for environmentally sustainable practices. An ideal solution would be to envision the watershed as the unit for eco-friendly sustainable development planning involving all the stakeholders under the watershed purview. As an example, the principles of Integrated Water Resources Management Planning (IWRMP), and Integrated Watershed Management Plan (IWMP) have been successfully applied in the USA and Australia (Box 1). It has illustrated that vegetative covered catchment stores large amount of rain water, increases groundwater table, reduces erosion of soil, and lastly decreases the intensity of flood hazard. Whereas, the naked catchment areas are highly erodible, does not store rain water, susceptible to high erosion and landslides, and increases the flood intensity by three fold than a vegetative covered one. The vegetative cover increases the water resources availability for over all development for agriculture. HYDRO Nepal JournalJournal of Water Energy and EnvironmentIssue: 20Page: 31-40

Evaluation of wind resource potential in mountainous region considering morphometric terrain characteristics

In South Korea, where 64% of the national territory is mountainous, good wind resources in inland areas are mostly situated in high mountain regions. To develop a wind farm in a mountain region, the sloping of mountains and their shielding from wind by the surrounding topology should be considered. It is generally most advantageous to install wind turbines along a ridge that is open in all directions. This article presents a methodology for evaluating suitable sites for wind farm development by identifying suitable ridges using morphometric analysis, while excluding the geographical and social environmental exclusion factors and superposing them on the wind resource map to find the area having a specific level or higher wind power density. The result of the proposed suitable site analysis and existing wind farms was assessed to verify the feasibility of the method of analyzing suitable sites on ridges. The wind resource potential in Gangwon Province when calculated using a method based on conventionally suitable site and the method based on ridge analysis was 9 and 5 GW, respectively. The result confirmed that the conventional area-based potential calculation without consideration of the morphometric terrain characteristics overestimated wind resource potential by around 80% compared to the ridge analysis method of calculation presented in this article.

Obstructive sleep apnea at high altitude

Obstructive sleep apnea (OSA) is an important and socially relevant problem of modern medicine, which is referred to as a most common pathological condition. The problem of OSA is especially urgent for inhabitants of high mountainous regions, as a combination of climatic, social, and cultural factors can significantly affect the course of the disease in both indigenous highlanders and people temporarily residing at high altitude. The paper reviews the current literature covering the problem of OSA at high altitude. It gives the data of Russian and foreign literature on the pathogenesis and clinical presentation of OSA. The author also analyzes an update on the impact of high altitude on the course of OSA in indigenous highlanders and people temporarily living at high altitude. She emphasizes the role of hypobaric hypocapnia as the most important factor for the development of central sleep apnea in the presence of conditions that are obstructive and aggravating the course of the disease.

Микроэлементный состав вод реки Черек-Безенгийский

Urgency of the issues concerning studying water quality in mountain-glacial high-mountain regions of the Caucasus where the rivers feeding the Kabardino-Balkar Republic lowland parts originate has been highlighted. The Bezengiysky Canyon river waters have been investigated for Mn, Zn, Cu, Pb, Ag, Ni, Cr, and Cd content. The high-mountain glacial/mountain fed Cherek Bezengiysky River microelements’ concentration values have been compared from the source to the mouth both during winter low-water and glacial flood periods. It has been stated that river water microelements contamination in the high-mountain region is caused by natural geochemical and geo/morphological background and is connected with the microelements washing out mountain rocks. Earlier investigations have shown that the microelements concentration significantly drops in comparison with the upper reach when the river enters the lowlands. It was found that the Cherek Bezengiysky River waters under study in terms of Mn, Pb, Cr, Cd, Ni, Cu, and Ag content could be classified as clean water excluding Zn which made the water very polluted. Minimal, maximal and average values of the main ion and nitrogen-containing substances concentrations during winter low-water and glacial flood periods have been presented. The value of the conducted investigation is determined by the fact that the Cherek Bezengiysky River inflows to the Terek River and forms the Caspian Sea river basin.

Spatiotemporal Assessment of Forest Biomass Carbon Sinks: The Relative Roles of Forest Expansion and Growth in Sichuan Province, China.

Spatiotemporal patterns of forest carbon (C) sinks and accurate estimation of such patterns are crucial to sustainable forest management. We combined individual tree biomass equations and a Random Forest algorithm to assess the spatiotemporal changes in biomass C sequestration and to further quantify the relative contributions of forest areal expansion and growth to biomass C sinks in Sichuan Province, China, over the past 25 yr. Forest area and average biomass C density increased from 10.5 million ha and 45.7 Mg C ha in 1988 to 14.2 million ha and 52.3 Mg C ha in 2012. Average C density was generally larger in the north and west of Sichuan Province compared with other regions. The expanded forest area and enhanced C density have jointly led to a rise in total C storage by 54.9% over this period in Sichuan Province. It was estimated that the forest areal expansion has been a larger contributor to C sinks than forest growth in Sichuan Province (69 vs. 31%), especially in the regions of the northwestern high mountains and the hilly country of the Sichuan basin. However, the relative contributions of areal expansion exhibited different trends in five subregions and 15 forest species groups in this province. Our study suggests that it is necessary to develop a new forestry management mode to maintain the long-term health of forest ecosystems in Sichuan Province, which should attach more importance to improving forest quality and selecting tree species in different subregions while increasing forested area in the future.

Characterization of Nepalese Barley Gene Pool for Leaf Rust Resistance

Barley (Hordeum vulagare L) is the major crop for the people living in the high hills and mountainous region of Nepal. Leaf rust (caused by Puccinia hordei) is one of the major production threats for barley cultivation. A lot of variation can be observed on Nepalese barley accessions with respect to leaf rust resistance characteristics. Two hundred and forty one barley accessions were screened for leaf rust resistance characteristics on heading stage at Khumaltar, Lalitpur, Nepal. Among them, one hundred and nine Nepalese barley accessions showing promising for disease resistance were screened using six SSR markers linked to leaf rust resistance genes. Bonus and Local Jau was used as the resistant and susceptible check respectively. Leaf rust resistance genes Rph1, Rph2, Rph3, Rph7, QBLR-P and QTL on chromosome 5HS were detected on Nepalese barley accessions using respective SSR markers. Eight Nepalese barley accessions showed presence of three and more leaf rust resistant genes. The poor relationship between the field disease resistance and molecular markers linked with specific leaf rust resistance gene proved that Nepalese barley gene pool contains other leaf resistance genes.

Temporal analysis of GLOFs in high-mountain regions of Asia and assessment of their causes

Glacial lake outburst flood (or shortly GLOF) has become a well-known phenomenon, one of natural hazards occurring in glaciated high mountain areas of the world. The aim of this study was to investigate temporal distribution of these events in Asia and to assess causes of lake outbursts. Therefore, a search of scientific literature and reports was carried out resulting in 219 flood cases found. In order to detect possible differences in temporal distribution a group of ice-dammed lakes was detached and compared with the rest. Concerning spatial distribution of GLOFs, it is influenced by availability of scientific literature which is determined by research teams’ region interest. Temporal analysis revealed a certain pattern in ice-dammed lake outburst distribution and notable difference between the two lake groups in terms of outburst occurrence within a year. The moraine-dammed lake outbursts were recorded earlier in an ablation season (compared to ice-dammed lakes) which could be attributed to different mechanism of dam failure. Majority of lake outburst causes were included in the category of dynamic causes (e.g. ice avalanche), long-term causes (e.g. dead-ice melting) were less represented. Results of the study imply there can be notable variations of temporal distribution and causes of GLOFs among individual mountain regions even within one continent. Therefore, varying behavior of potentially dangerous lakes should be taken into consideration when, for instance, proposing mitigation measures.

Ethno-ecological contexts of the Skhalta Gorge and the Upper Svaneti (Georgia, the Caucasus)

The applicability and analytical power of political ecology is improved by study of the 'ethno-ecological context', which is based on the concept of socio-ecological systems (SES). It represents an operating principle of interactions between the ecological and social systems of a specific locality, developing under different historical, political and climatic regimes. We compare two socio-ecological systems in the high mountain regions of Georgia – the Skhalta Gorge and the Upper Svaneti. These are on the southern and northern borders of Georgia. Historically, their socio-ecological systems were similar but today the Skhalta Gorge is rapidly depopulating, whilst in the Upper Svaneti the population is stable. The comparison of the ethno-ecological context and today's state of affairs suggests that (i) "self-regulation" and conserving local culture and traditions, whilst the country undergoes rapid social and political changes, can lead to degradation or even destruction of either the ecological or the social components; (ii) conversely, sustainable development results from active intervention rather than abstaining from it; (iii) tourism appears as a mechanism that restores the ethno-ecological context by providing a source of income - under certain conditions, it supports traditional agriculture.Key words: Political ecology, ethno-ecological context, socio-ecological systems, Georgia, Adjara, Svaneti, Mulakhi community, Skhalta Gorge, sustainability, tourism.

Diurnal variations of grassland evapotranspiration over different periods in the Pailugou basin in the upper reach of the Heihe River, Northwest China.

Evapotranspiration (ET) is an important component of water cycle, but its measurement in high altitude mountainous region is quite difficult, resulting in the poor understanding of the temporal and spatial variations of actual ET in high altitude mountainous region. In this paper, a weighing lysimeter was used to measure the hourly ET in a grassland in the Pailugou basin in the upper reach of the Heihe River, Northwest China. Based on the measured data, diurnal variations of grassland ET over different periods were analyzed. Results indicated that snow and ice sublimation appeared during the freezing period, with a very different diurnal variation pattern compared with other three periods. During the period without sunshine, the amount of snow and ice sublimation was nearly constant. When the highest global radiation and lowest relative humidity appeared in the same period, the amount of snow and ice sublimation increased a little. The early growth period was a period when snow and ice started to melt, during which snowmelt evaporation and soil evaporation occurred at the same time. The growth period had the highest ET rate. Due to continuous rainfall events, maximum and minimum ET values appeared at the same hour. ET in the late growth period mainly came from soil evaporation, producing 3 peaks in diurnal variation, which was different from only one peak in both the early growth period and the growth period.

Effect of the Resolution of Tipping-Bucket Rain Gauge and Calculation Method on Rainfall Intensities in an Andean Mountain Gradient

A laser-optical disdrometer served as reference to assess the absolute percent bias of calculated rainfall intensity using the data of different-resolution tipping-bucket rain gauges classically applied by climatologists and hydrologists in the Andean region. Additionally, the impact of the calculation method (tip counting versus cubic spline interpolation) was examined. The combined effect was assessed for different rainfall intensity classes (0–0.99, 1–1.99, 2–4.99, and 5–10 mm·h−1) and timescales (5, 10, 30, and 60 min). Additionally, the variation in percent absolute bias of the Davis rain gauge, the collector most widely used in the study region, was defined with respect to the Texas rain gauge along an elevation gradient between 3300 and 4000 m a.s.l. Results reveal that the value of the percent absolute bias is largest for small rainfall intensities (≤2 mm·h−1) and short timescales (≤10 min), and decreases when the cubic spline interpolation is used. No relation was found between the error, the elevation, and rainfall depth along the gradient. Based on the research findings, it is recommended to measure precipitation in the high Andean mountain region with a high-resolution sensor and to consider cubic spline for the computation of intensities.

Nanga Parbat Revisited: Evolution and Dynamics of Sociohydrological Interactions in the Northwestern Himalaya

Regular availability of glacier and snow meltwater is essential for irrigated crop cultivation in the northwestern Himalaya. Based on a case study from the Nanga Parbat region in Gilgit-Baltistan, Pakistan, general patterns and site-specific particularities of irrigation networks in semiarid high mountain regions are conceptualized as continuously evolving sociohydrological interactions. These interactions are shaped by an interplay of glacio-fluvial runoff, water distribution, socioeconomic setting, institutional arrangements, external development interventions, and historical trajectories. Building on the paradigm of sociohydrology that changes in water availability coevolve with socioeconomic and land use transitions, this article explores glacier fluctuations and associated developments in meltwater-dependent crop cultivation in the Rupal Valley. The evolution of irrigation networks is analyzed using multitemporal high-resolution satellite imagery, repeat photography, and primary socioeconomic data collected in successive field surveys. Changes are historically contextualized with the help of archival material such as colonial reports and cadastral maps. This integrative study discovered the extension of cultivated areas, an increase in individual field numbers, and a reduction in average field size against the background of population increase and glacier retreat. Despite socioeconomic and environmental changes, the strong coupling of the human–water system remains intact, demonstrating a high degree of persistence of sociohydrological features over time. Adaptive strategies, however, often fail in the face of unpredictable natural processes.

Indoor pollution in high-altitude dwellings: An assessment of affecting factors across four Sherpa villages in the Khumbu region, Nepal

Household air pollution (HAP) from biomass fuel smoke is a major health risk, especially in developing countries. The ventilation of buildings and the type of fume discharge could also affect HAP. The present study aims to investigate the impact of stove type and kitchen characteristics on levels of pollutants. In particular, we investigated the potential geometric ventilation of buildings using geometric ventilation index (GVI), the presence of chimneys, the type of fuel and the environmental carbon monoxide level (a marker of indoor pollution) in the households of four Sherpa villages located in a mountain region of Nepal at altitudes between 2500 and 3900 m. We analysed 114 buildings (76 private residences and 38 lodges that accommodate tourists). Lodges had a more effective discharge system and a higher GVI, which had an inverse, significant correlation with indoor CO levels (r = 0.52). The level of indoor CO was more than 50% higher in private residences than in lodges. In the univariate analysis, only the absence of a chimney was associated with higher indoor CO (OR 3.4 (CL95%, 1.2–10.0), p = 0.02). We conclude that the adoption of chimneys and sealed stoves with exhaust pipes should be the first measure taken to reduce pollutants inside the households of high mountain regions until a switch to clean fuels can be achieved.

Animal Fascioliasis: Perspectives from high altitudinal regions

The parasitic flukes of the genus Fasciola (Platyhelminthes: Trematoda: Digenea) cause fascioliasis or liver-rot disease in ruminant livestock in tropical and sub-tropical regions of the world. Classically, two species of Fasciola- F. hepatica and F. gigantica, are universally recognized as taxonomically valid species. Our survey studies on ovid and bovid animals including yak and mithun from high altitudinal mountainous regions in Northeast India revealed the occurrence of Fasciola gigantica and also Fasciola sp.- an intermediate form, at altitudes between 5000 and 14,085 feet above sea level (asl). Two morphotypes- F. hepatica – like and F. gigantica – like, of Fasciola species were reported from the high altitudinal areas of Northeast India; most of these locales constitute new-locality and first records for the occurrence of these liver flukes.

Contributions and source identification of biogenic and anthropogenic hydrocarbons to secondary organic aerosols at Mt. Tai in 2014

Ambient fine particulate matter (PM2.5) and volatile organic compounds (VOCs) collected at Mt. Tai in summer 2014 were analysed and the data were used to identify the contribution of biogenic and anthropogenic hydrocarbons to secondary organic aerosols (SOA) and their sources and potential source areas in high mountain regions. Compared with those in 2006, the 2014 anthropogenic SOA tracers in PM2.5 aerosols and VOC species related to vehicular emissions exhibited higher concentrations, whereas the levels of biogenic SOA tracers were lower, possibly due to decreased biomass burning. Using the SOA tracer and parameterisation method, we estimated the contributions from biogenic and anthropogenic VOCs, respectively. The results showed that the average concentration of biogenic SOA was 1.08 ± 0.51 μg m−3, among which isoprene SOA tracers were dominant. The anthropogenic VOC-derived SOA were 7.03 ± 1.21 μg m−3 and 1.92 ± 1.34 μg m−3 under low- and high-NOx conditions, respectively, and aromatics made the greatest contribution. However, the sum of biogenic and anthropogenic SOA only contributed 18.1–49.1% of the total SOA. Source apportionment by positive matrix factorisation (PMF) revealed that secondary oxidation and biomass burning were the major sources of biogenic SOA tracers. Anthropogenic aromatics mainly came from solvent use, fuel and plastics combustion and vehicular emissions. However, for > C6 alkanes and cycloalkanes, vehicular emissions and fuel and plastics combustion were the most important contributors. The potential source contribution function (PSCF) identified the Bohai Sea Region (BSR) as the major source area for organic aerosol compounds and VOC species at Mt. Tai.

A Fuzzy Logic Based Method for Modeling the Spatial Distribution of Indicators of Decomposition in a High Mountain Environment

ABSTRACTUpscaling of sample data on indicators of decomposition to the landscape scale is often necessary for extensive ecological assessments. The amount of such data is mostly scarce even with high sampling efforts. Moreover, environmental conditions are very heterogeneous in high mountain regions. Therefore, the aim was to find a suitable technique for spatial modeling under these circumstances.A method combining decision tree analysis and the construction of fuzzy membership functions is introduced for a GIS-based mapping of decomposition indicating parameters. It is compared with an approach solely based on decision trees. Within a case study in the Italian Alps the spatial distribution of humus forms, classified by the occurrence of an OH (humified residues) horizon, is examined. There appears to be a strong relationship with elevation and a minor correlation with slope exposition.The fuzzy logic-based approach proves to be suitable for modeling the spatial distribution of indicators of decomposition. Mapping fuzzy values allows for the representation of small-scale variability and uncertainty of data due to a relatively low sample size in a very heterogeneous environment.

Taking Advantage of the ESA G-POD Service to Study Ground Deformation Processes in High Mountain Areas: A Valle d’Aosta Case Study, Northern Italy

This paper presents a methodology taking advantage of the GPOD-SBAS service to study the surface deformation information over high mountain regions. Indeed, the application of the advanced DInSAR over the arduous regions represents a demanding task. We implemented an iterative selection procedure of the most suitable SAR images, aimed to preserve the largest number of SAR scenes, and the fine-tuning of several advanced configuration parameters. This method is aimed at minimizing the temporal decorrelation effects, principally due to snow cover, and maximizing the number of coherent targets and their spatial distribution. The methodology is applied to the Valle d’Aosta (VDA) region, Northern Italy, an alpine area characterized by high altitudes, complex morphology, and susceptibility to different mass wasting phenomena. The approach using GPOD-SBAS allows for the obtainment of mean deformation velocity maps and displacement time series relative to the time period from 1992 to 2000, relative to ESR-1/2, and from 2002 to 2010 for ASAR-Envisat. Our results demonstrate how the DInSAR application can obtain reliable information of ground displacement over time in these regions, and may represent a suitable instrument for natural hazards assessment.

New Data on Habitats and Distribution of the Caucasian Agama, Paralaudakia caucasia (Eichwald, 1831) in Dagestan

The new data on the distribution and habitats of the Caucasian agama in Dagestan are described and analyzed in this report. In 2004 – 2014 36 new localities were recorded during multiple visits in all parts of the mountainous Dagestan and all previously reported 14 records were confirmed. The Caucasian agama refers to a group of mountain petrophilous lizards; its habitats in Dagestan as well within the whole vast distribution range are associated with the arid foothills and mountainous landscapes. Approximate area of the regional area was calculated using Arc Gis 10. We provide a description of typical habitats in every region of Dagestan: in the Lowland part and in three physiographic regions of mountain Dagestan: Extramountain (foothill), Intramountain and Alpine (highmountain) regions characterized by diversity and mosaic of landscapes.

Spatio-temporal variation of net anthropogenic nitrogen inputs in the upper Yangtze River basin from 1990 to 2012

Abstract The net anthropogenic nitrogen input (NANI) is an important nutrient source that causes eutrophication in water bodies. Understanding the spatio-temporal variation of NANI is important for regional environment assessment and management. This paper calculated NANI in the upper Yangtze River basin (YRB), upstream of the Three Gorges Dam (TGD), from 1990 to 2012, and analyzed its spatio-temporal characteristics. Over the past 23 years of the study, the average annual NANI increased from 3200 kg N km - 2 to 4931 kg N km - 2. The major components were fertilizer N application, atmospheric N deposition, and net food and feed N import. In the northwest high mountainous region with a sparse population, the main component was atmospheric N deposition. Fertilizer N application and net food and feed N import were concentrated in the Chengdu Plain because of the high population density and large areas of farmland. This research found that NANI increased with rapid urbanization and increasing population. The Pearson correlation results illustrated that the spatial distributions of NANI and its major components were affected by land cover/use, agricultural GDP and total population. Increasing NANI has been the major cause of the degrading stream water quality over the past 20 years and is becoming a major threat to the water quality of the TGD reservoir.

Consistent seasonal snow cover depth and duration variability over the Western Himalayas (WH)

Precipitation in solid form, i.e., snow, during winter season over the Western Himalayas (WH) leads to the build-up of seasonal snow cover. Seasonal snow cover build-up (snow cover depth and duration) largely depends on atmospheric variables such as temperature, precipitation, radiation, wind, etc. Integrated (combined) influence of atmospheric variables on seasonal snow cover gets reflected in terms of spatial and temporal variability in seasonal snow cover build-up pattern. Hence spatial and temporal variability of seasonal snow cover build-up can serve as a good indicator of climate change in high altitude mountainous regions like the WH. Consistent seasonal snow cover depth and duration, delay days and early melt days of consistent seasonal snow cover at 11 stations spread across different mountain ranges over the WH were analyzed. Mean, maximum and percentiles (25th, 50th, 75th, 90th and 95th) of consistent seasonal snow cover depth and duration show decline over the WH in the recent past 2–3 decades. Consistent seasonal snow cover is found to melt early and snow cover build-up pattern is found to show changes over the WH. Decline in consistent seasonal snow cover depth, duration and changing snow cover build-up pattern over the WH in recent decades indicate that WH has undergone considerable climate change and winter weather patterns are changing in the WH.