Yulong Snow Mountain Research Articles

Estimation of Ice Thickness and the Features of Subglacial Media Detected by Ground Penetrating Radar at the Baishui River Glacier No. 1 in Mt. Yulong, China

Using ground-penetrating radar (GPR), we measured and estimated the ice thickness of the Baishui River Glacier No. 1 of Yulong Snow Mountain. According to the position of the reflected media from the GPR image, combined with the radar waveform amplitude and polarity change information, the ice thickness and the changing medium position at the bottom of this temperate glacier were identified. Water paths were found in the measured ice, including ice caves and crevasses. A debris-rich ice layer was found at the bottom of the glacier, which produces strong abrasion and ploughing action at the bedrock surface. This results in the formation of different detrital layers stagnated at the ice-bedrock interface and numerous crevasses on the bedrock surface. Based on the obtained ice thickness and differential GPS data, combined with Landsat images, the kriging interpolation method was used to obtain grid data. The average ice thickness was 52.48 m and between 4740 and 4890 m above sea level, with a maximum depth of 92.83 m. The bedrock topography map of this area was drawn using digital elevation model from the Shuttle Radar Topography Mission. The central part of the glacier was characterized by small ice basins with distributed ice steps and ice ridges at the upper and lower parts.

Summer Mass Balance and Surface Velocity Derived by Unmanned Aerial Vehicle on Debris-Covered Region of Baishui River Glacier No. 1, Yulong Snow Mountain

Glacier retreat is a common phenomenon in the Qinghai-Tibetan Plateau (QTP) with global warming during the past several decades, except for several mountains, such as the glaciers in the Karakoram and the western Kunlun Mountains. The dynamic nature of glaciers significantly influences the hydrologic, geologic, and ecological systems in the mountain regions. The sensitivity and dynamic response to climate change make glaciers excellent indicators of regional and global climate change, such as glacier melting and retreat with the rise of local air temperature. Long-term monitoring of glacier change is important to understand and assess past, current, and possible future climate environments. Some glacier surfaces are safe and accessible by foot, and are monitored using mass balance stakes and snow pits. Meanwhile, some glaciers with inaccessible termini may be surveyed using satellite remote images and Unmanned Aerial Vehicles (UAVs). Those inaccessible glaciers are generally covered by debris in the southeast QTP, which is hardly accessible due to the wide distribution of crevasses and cliffs. In this paper, we used the UAV to monitor the dynamic features of mass balance and velocity of the debris-covered region of Baishui River Glacier No. 1 (BRG1) on the Yulong Snow Mountain (YSM), Southeast QTP. We obtained the Orthomosaic and DEM with a high resolution of 0.10 m on 20 May and 22 September 2018, respectively. The comparison showed that the elevation of the debris-covered region of the BRG1 decreased by 6.58 m ± 3.70 m on average, and the mean mass balance was −5.92 m w.e. ± 3.33 m w.e. during the summer, correspondingly. The mean displacement of debris-covered glacier surface was 18.30 m ± 6.27 m, that is, the mean daily velocity was 0.14 m/d ± 0.05 m/d during the summer. In addition, the UAV images not only revealed the different patterns of glacier melting and displacement but also captured the phenomena of mass loss due to ice avalanches at the glacier front and the development of large crevasses. This study provides a feasible method for understanding the dynamic features of global debris-covered glaciers which are inaccessible and unobservable by other means.

Investigation of the spatio-temporal heterogeneity and optical property of water-soluble organic carbon in atmospheric aerosol and snow over the Yulong Snow Mountain, southeastern Tibetan Plateau

Atmospheric aerosols are a branch of active research in recent decades. The deposition of light-absorbing substances on high-altitude glaciers causes substantial adverse impacts on the cryospheric environment, cryosphere-hydrology, and climate system. Although, the concentrations of water-soluble organic carbon (WSOC) in snow/ice on glaciers of Tibetan Plateau (TP) have been reported, their transfer processes and optical properties in the context of summer precipitation-atmosphere-snow-river water continuum are seldom studied. In this study, we have systematically examined some scientific issues associated with WSOC concentrations and light absorption properties of WSOC in various forms of samples from the Mt. Yulong region. Statistical results demonstrate that the spatial distribution of WSOC in the snow of Baishui glacier was heterogeneous. The average WSOC concentrations of each snowpit were significantly decreased, and its light-absorbing properties were significantly elevated with the time extension. Aerosol WSOC concentrations and light absorption have distinct spatial disparity and seasonal variation. Pre-monsoon and monsoon have the highest and lowest WSOC content, respectively. Whereas the light-absorbing properties present contrasting seasonal trends. Rivers of which runoff was supplied by glacier meltwater have significantly lower WSOC concentrations (e.g., 0.42 ± 0.03 mg L−1) compared with other forms of water bodies. Mass absorption cross-section of WSOC (MAC-WSOC) in multiple snow and meltwater samples was significantly different and type-dependent. Atmospheric aerosol has the lowest MAC-WSOC value among the four types of samples, which was likely associated with exhaust emissions from private vehicles and tour buses. Statistical results indicated that the average AAE330-400 values of various snow/ice samples are subequal. Snow of glaciers supplies a desirable platform for the deposition of gaseous materials which experienced long-range transport in high altitude zones. Biomass-burning emissions made an immense contribution to the WSOC deposition over the study area, as demonstrated by the distribution of active fire points. However, this preliminary study represents the first systematic investigation of WSOC deposition in southeastern TP. Further robust in-situ field investigations and laboratory measurements are urgently necessary to improve our understanding of the transfer process and optical property of WSOC.

New insights into heavy metal elements deposition in the snowpacks of mountain glaciers in the eastern Tibetan Plateau

Atmospheric heavy metals have important environmental and health threats. To investigate atmospheric deposition and contamination of heavy metal elements in the glaciers of the eastern Tibetan Plateau (ETP), we collected the surface snow (cryoconites) samples in the Lenglongling Glacier (LG), the Gannan Snowpack (GS), the Dagu Glacier (DG), the Hailuogou Glacier (HG) and Yulong Snow-mountain Glacier (YG) in summer 2017. Samples were analyzed for concentrations and enrichment factors (EFs) of Al and trace elements (Pb, Co, Cd, Ba, Mn, Ga, Sc, V, Zn, Cr, Ni, Cu, Rb, Sb, Cs, As, Mo, Li) using inductively coupled plasma-mass spectrometry (ICP-MS). Results showed that the concentrations and EFs of heavy metals (e.g. Sb, Cu, Cr, Ni, As, Mo) were generally high value in YG, GS and LG, while were relatively low value in DG and HG, implying that ETP glaciers may have been affected by atmospheric anthropogenic pollutants deposition to varying degrees. Comparing the heavy metal concentrations in the glaciers with those in the precipitation of middle/eastern China cities and also the South Asian cities, we find that the glacial heavy metal concentrations were generally low level, though the anthropogenic pollutants were still significantly enriched. Taking the spatial distribution of As and Ni concentration/EFs in the glaciers and surrounding urban precipitation as an example, we find that the heavy metal pollutants were probably transported to the glaciers through three routes from the surrounding densely populated area of Asia. The MODIS AOD and NCEP/NCAR wind vector also demonstrated that the atmospheric pollutants originated from anthropogenic emissions of urban areas of both South Asia, and northwest and east China, mainly caused by the large scale atmospheric circulation (e.g. the South Asian Monsoon, westerlies and Eastern Asian Summer Monsoon). Therefore, control of these potential pollution emission sources of the surrounding densely populated areas in Asia could be important to ETP glaciers in future perspectives.

Spatial distribution and potential sources of methanesulfonic acid in High Asia glaciers

As a receptor of atmospheric deposition, glaciers are considered an ideal archive in the study of climate change and geochemical cycles. The deposition of methanesulfonic acid (MSA) in the glaciers provides good opportunities to study the biogeochemical cycle of sulfur in the cryosphere. In the present work, snow samples were collected from six High Asia glaciers along a north-to-south transect to determine the spatial distribution of MSA and elucidate its potential sources. The median MSA concentration in the Urumqi Glacier No.1 of Tien Shan was 138.8 ng mL−1, which was distinctly higher than those observed in the Tibetan Plateau (TP) glaciers and polar regions. The levels of MSA in the interior TP glaciers were higher than those observed in the margins of northeastern and southeastern TP. Good correlations between MSA and K+ (r = 0.86, n = 30, α = 0.01), Mg2+ (r = 0.86), and NH4+ (r = 0.73) were observed in continental glaciers. Principal component analysis indicated that MSA may have terrigenous material inputs. At Yulong Snow Mountain, MSA was correlated with Na+ (r = 0.76, n = 8, α = 0.1), a sea-salt tracer ion, suggesting that MSA may be derived from marine environments. According to dimethyl sulfide (DMS) production and NH3 emissions in High Asia, we deduced that the high concentrations of MSA in continental glaciers are possibly related to the sources of hypersaline soil environments and animal husbandry in nomadic areas. This work is useful for further studies on regional sulfur cycling and the impacts of human activities on climate change.

New insights into trace elements in the water cycle of a karst-dominated glacierized region, southeast Tibetan Plateau

Trace elements (TEs) in water are crucial parameters for assessing water quality. However, detailed studies are limited on TEs in the hydrological system of the Tibetan plateau (TP). Here, we sampled snow, river water, and groundwater in Yulong Snow Mountain (Mt. Yulong) region, southeast TP, in 2016 and analyzed the concentrations of nine TEs (namely Al, Mn, Fe, Cr, Ni, Cu, Zn, As, and Pb). In snow, the average concentrations of Fe, Zn, and Al were >10 μg/L, whereas other elements, including Cr, Ni, Cu, As, Hg, and Pb, exhibited average concentrations <1 μg/L. The concentrations of Al, Mn, Fe, Zn, and As were higher in rivers than in snow. According to enrichment factors (EFs), Zn concentration in snow was highly influenced by anthropogenic activities, whereas Mn, Fe, Cr, and As were uninfluenced. River and lake/reservoir water near human settlements were affected by anthropogenic activities. However, groundwater around Mt. Yulong is not contaminated yet. The increasing EFs in Mt. Yulong snowpit are consistent with those of southern TP snowpits, suggesting that the area has been affected by anthropogenic activities both from local emissions and long-distance transport of pollutants from South Asia. A conceptual model was proposed to show TEs in the water cycle. Although water quality is good overall in Mt. Yulong region, threats to the water environment still exit due to increasing anthropogenic activities and climate warming. The accelerated ablation of cryosphere due to climate warming could be a source of TEs in rivers and groundwater, which should be paid attention to in the future.

Accelerated changes of glaciers in the Yulong Snow Mountain, Southeast Qinghai-Tibetan Plateau

The Yulong Snow Mountain (YSM) is a region of temperate glaciers in the southeast Qinghai-Tibetan Plateau. The present study systematically assessed the glacier changes during the past several decades using ground-based and remotely sensed observations and referencing topographic maps. The images and maps revealed that the glaciers area in the YSM retreated by 64.02% from 1957 to 2017. The length of Baishui River Glacier No. 1 decreased by 12.5 m/year during this period, whereas the front elevation of this glacier increased by 10.83 m/year. The mean annual mass balance of this glacier was at − 0.42 metre water equivalent from 1957 to 2017, and its accumulative mass balance was − 27.45 metre water equivalent. The glacier retreats of glacier area, glacier front, and mass balance in the YSM primarily resulted from the increasing air temperature. These glacier retreats not only will have a negative impact on glacier tourism in the future, e.g., the retreat or disappearance of glaciers will reduce the attractiveness of mountainous scenic spots, but also will create new opportunities for the development of local tourism, e.g., “last chance” will simulate tourists’ curiosity. Hence, the findings of our present study help to understand the mechanism between accelerated ablation of temperate glaciers and climate change in southeast regions of Qinghai-Tibetan Plateau and provide references for local tourism administrations.

Difference of soil nematode communities between the humus and soil surface layer in the cold temperate coniferous and broadleaved mixed forest of Yulong Snow Mountain Nature Reserve, Yunnan, China

A high-throughput sequencing approach was used to differentiate the nematode communities in the humus and soil surface layer (0-10 cm) in 20 hm2 plot located in the cold temperate coniferous and broadleaved mixed forest of Yulong Snow Mountain Nature Reserve, Lijiang, Yunnan. A total of 5744582 sequences were obtained, which were further annotated to 44 nematode families. In the humus layer, 37 families were recorded, with Tylenchidae (18.1%) being the most dominant family. For trophic groups, bacterivorous, fungivorous and herbivorous were predominant. The soil surface layer had 41 families, with Mononchidae (45.4%) being the most dominant family. The relative abundance of predatory nematode was highest in the soil surface layer. There was no significant difference in the α diversity indices (Shannon, Simpson and Chao1 index) of nematode communities at the OTU level between two habitats. At the family level, however, α diversity of nematode community in the humus layer was significantly lower than in soil surface layer. β diversity of the nematode community was significantly different in the two habitats, with lower Cody index but high Sorensen non-similarity index in the humus habitat. Results of non-metric multidimensional scaling (NMDS) analysis showed that the internal structure difference of nematode community in the soil surface layer was higher than that in the humus layer.

Characteristics of total suspended particulates in the atmosphere of Yulong Snow Mountain, southwestern China

Characteristics of total suspended particulates in the atmosphere of Yulong Snow Mountain, southwestern China

Biomass burning source identification through molecular markers in cryoconites over the Tibetan Plateau

Cryoconite is a dark, dusty aggregate of mineral particles, organic matter, and microorganisms transported by wind and deposited on glacier surfaces. It can accelerate glacier melting and alter glacier mass balances by reducing the surface albedo of glaciers. Biomass burning in the Tibetan Plateau, especially in the glacier cryoconites, is poorly understood. Retene, levoglucosan, mannosan and galactosan can be generated by the local fires or transported from the biomass burning regions over long distances. In the present study, we analyzed these four molecular markers in cryoconites of seven glaciers from the northern to southern Tibetan Plateau. The highest levels of levoglucosan and retene were found in cryoconites of the Yulong Snow Mountain and Tienshan glaciers with 171.4 ± 159.4 ng g−1 and 47.0 ± 10.5 ng g−1 dry weight (d.w.), respectively. The Muztag glacier in the central Tibetan Plateau contained the lowest levels of levoglucosan and retene with mean values of 59.8 ng g−1 and 0.4 ± 0.1 ng g−1 d.w., respectively. In addition, the vegetation changes and the ratios of levoglucosan to mannosan and retene indicate that combustion of conifers significantly contributes to biomass burning of the cryoconites in the Yulong Snow Mountain and Tienshan glacier. Conversely, biomass burning tracers in cryoconites of Dongkemadi, Yuzhufeng, Muztag, Qiyi and Laohugou glaciers are derived from the combustion of different types of biomass including softwood, hardwood and grass.

Recreational value of glacier tourism resources: A travel cost analysis for Yulong Snow Mountain

Glaciers, with their unique and spectacular appearances and rich and varied terrain, have received widespread attention and become important tourist attractions. This paper uses the travel cost method to estimate the recreational value of the glacier tourism resources of Yulong Snow Mountain (also called Jade Dragon Snow Mountain), which is the most developed glacier tourist attraction in China. First-hand information was obtained through field surveys, and the travel costs of visitors visiting the Yulong Snow Mountain glacier were calculated before the method was applied to evaluate the recreational value of the focal glacier resource. The results show that the Yulong Snow Mountain consumer surplus associated with its glacier resources in 2016 ranged from 645.59-3439.10 million CNY, and the total recreational value ranged from 1.97-8.17 billion CNY. Approaches allocating travel costs across multiple recreational sites, however, can vary, and there is large difference in estimated results depending on used approaches. Nevertheless, the results of the analysis can help understand the socio-economic value of glacier resources and provide a reference for their development and protection.

Relationship between radial growth of Abies georgei and climate factors at different altitudes on the eastern slope of Yulong Snow Mountain, China.

Based on dendrochronological methods, we established residual chronologies (RES) of Abies georgei at low, middle and high altitudes with ring width data on the eastern slope of Yulong Snow Mountain. We examined the relationship between the radial growth and climate factors (temperature and precipitation) by response function analysis and redundancy analysis (RDA) to identify the key climatic factors driving the radial growth of A. georgei. The results showed that the responses of radial growth of A. georgei to climates were consistent at three altitudes, which was jointly controlled by temperature and precipitation. This consistency was related to the steep terrain of Yulong Snow Mountain, the high-altitude distribution, and shallow root characteristics of A. georgei. At all three altitudes, tree growth showed significantly positive correlation with mean temperature of the current July, mean temperature of the previous November, and precipitation of the current January, but negative correlation with precipitation of the current June. The comprehensive application of response function analysis and redundancy analysis could accurately reveal the relationship between tree growth and climatic factors along environmental gradients. Our results provided a scientific basis for climatic reconstruction and forest management in the area.

Radial growth responses of Picea likiangensis to climate variabilities at different altitudes in Yulong Snow Mountain, southwest China

Radial growth responses of Picea likiangensis to climate variabilities at different altitudes in Yulong Snow Mountain, southwest China

Research on Evaluation of Popularity of Lijiang Scenic Area Based on Microblog Data

The rapid development of LBS services and big data, massive check-in data provide a basis for the study of the popularity of scenic spots. Taking Lijiang scenic area as the research object, this paper made use of microblog check-in data, and made an evaluation on the popularity of tourist attractions by analyzing the spatial-temporal characteristics of tourist emotion and behavior. Emotion analysis, statistical analysis, spatial analysis and other methods were used to explore the spatial-temporal characteristics of tourist emotion distribution. The study finds that foreign tourists are the main force of tourism activities, in which female tourists are more emotional, and the young and middle-aged tourists are the most active. The emotional value of tourist in tourism activities is positive, give priority to with 43.82% of positive emotions. Scenic spots such as Old Town of Lijiang, Lugu Lake, Yulong Snow Mountain and other places of high popularity, while the Baisha Mural, Shigu Town attractions such as low popularity. The spatial distribution of tourist emotion is consistent with the development of key tourist areas in Lijiang.

玉龙雪山3个针叶树种在海拔上限的径向生长及气候响应

玉龙雪山3个针叶树种在海拔上限的径向生长及气候响应

Drivers of macrofungal composition and distribution in Yulong Snow Mountain, southwest China

Although environmental factors strongly affect the distribution of macrofungi, few studies have so far addressed this issue. Therefore, to further our understanding of how macrofungi respond to changes in the environment, we investigated the diversityand community composition of fungi based on the presence of fruiting bodies in different environments along an elevation gradient in a subalpine Pine forest at Yulong Snow Mountain in southwest China. Two-hundred and twenty-eight specimens of macrofungi from twelve plots were identified using macro-morphological characteristics. We found that soil temperature had a significantly positive influence on total macrofungal and ectomycorrhizal species richness and diversity, while elevation gradients had a significantly negative influence. Furthermore, total macrofungal and ectomycorrhizal species community composition were significantly influenced by soil temperature and elevation gradients. No significant relationships were found between environment variables and the diversity and community composition of saprotrophic fungi in subalpine pine forest.

Resources Evaluation of Seed Plants in Yulong Snow Mountain, Lijiang, Northwestern Yunnan

Resources Evaluation of Seed Plants in Yulong Snow Mountain, Lijiang, Northwestern Yunnan

Chemical composition of rainwater in the Yulong Snow Mountain region, Southwestern China

We evaluated the chemical composition of rainwater samples in the Mt. Yulong region, southeastern Tibetan Plateau. A total of 176 rainwater samples were collected from Lijiang City and Ganhaizi Basin in the study area. All samples were analyzed for total dissolved solids (TDS), conductivity, pH, major cations (Na+, K+, NH4+, Ca2+, Mg2+) and anions (F−, SO42−, Cl−, NO3−). The daily rainwater pH values ranged from 4.55 to 7.43, with an average value of 5.95 for the region. High values of pH were attributed to the neutralization by natural alkaline of local dust particles with rich CaCO3. The average total dissolved solid was 5.27mg/L, and the EC ranged between 2.14 and 57.2μscm−1 with an average value of 11.5μscm−1. These parameters indicated low chemical concentrations in the rainwater. The major ions showed relatively high Ca2+, SO42−, and NH4+ concentrations, accounting for 40%, 25%, and 16% of the total ion mass, respectively. Linear regression analysis confirmed that the rainwater pH was mainly controlled by the species of SO42−, NO3−, NH4+ and Ca2+. Factor component analysis applied to the studied variables indicated that the extracted three components accounted for 90% of the total variance for Ganhaizi Basin, and the extracted two components accounted for 73% of the total variance for Lijiang City. The study identified association of the three ion groups: Ca2+, Mg2+, K+ and F−, related to the origins of crustal sources; NH4+, SO42− and NO3− associated with local anthropogenic activities (agriculture, biomass burning, vehicle emissions), and Cl− and part of Na+ related to the contribution of sea salts from long-range atmospheric transport.

Test Research on the Meso-Fabric Properties of Undisturbed Moraine Soil on the West Side of Yulong Snow Mountain

Meso-fabric of gravel particles is not only a reflection of the unique sedimentary history, but also directly affects the geotechnical properties of moraine soil. However, there are few researches on it so far in geotechnical engineering field, due to the difficulty of obtaining undisturbed moraine soil sample. To change this situation, we succeeded in getting undisturbed moraine soil samples from the west side of the Yulong Snow Mountain with the delicate manual cutting work. We scaned the 6 pieces of moraine soil samples by CT instrument and obtained the real meso-fabric images of internal moraine soil for the first time. After CT images binarization and denoising processing with the help of Matlab, section fabric indexes of stone area ratio, grain orientation and particle shape of moraine soil gravel particles were described with conventional statistical methods. The results show that the differences between vertical sections are little, but the differences between vertical sections and horizontal sections are much more obvious.

Characteristics of inorganic ions in precipitation at different altitudes in the Yulong Snow Mountain, China

The present study investigated the chemical composition of summer precipitation at different altitudes in Yulong Snow Mountain, hoping to obtain some basic information about the chemical characteristics of precipitation. A couple of precipitation samples at different altitudes in the Yulong Snow Mountain area in southeastern China were collected from July 26 to July 31, 2005 for chemical analyses. Sea-salt tracer analysis showed that Cl- and Na+ had high proportion from marine sources, while the other ions mainly were from non-marine sources. Statistics showed that the cation concentrations ranged from 0.51 to 5.26 mg L-1 and anion concentrations ranged from 0.99 to 4.90 mg L-1. Further analysis showed that terrestrial ions, especially from the proximal terrestrial sources, largely affected the ion concentrations in precipitation. Ion concentrations of precipitation were correlated significantly with local atmospheric circulation at altitude 2,950-4,800 m, and also correlated closely with human activities at altitude 2,400-2,950 m. Limestone, the majority of local rocks, caused high cation concentrations in precipitation, such as Ca2+ and Mg2+. The majority of vapors in the region came from the Indian Ocean whereas parts came from the eastern Pacific. The inorganic ions in precipitation increased significantly in the Yulong Snow Mountain area during this century. Compared with most of the high altitude Mountains in China, the precipitations in the Yulong Snow Mountain area had higher concentrations of inorganic ions and low acidic ion concentrations. The conclusions can provide a basis for study of regional climate characteristics, environment and ecological characteristics of Yulong Snow Mountain area.