Glacier Inventory Data Research Articles

Spatiotemporal Changes of Glaciers in the Yigong Zangbo River Basin over the Period of the 1970s to 2023 and Their Driving Factors

The glaciers in southeastern Tibet Plateau (SETP) influenced by oceanic climate are sensitive to global warming, and there remains a notable deficiency in accurate multitemporal change analyses of these glaciers. We conduct glacier inventories in the Yigong Zangbo River Basin (YZRB) in SETP for the years 1988, 2015, and 2023 utilizing Landsat and Sentinel-2 imagery, and analyze the glacier spatiotemporal variation incorporating the existing glacier inventory data. Since the 1970s until 2023, the glaciers significantly retreated at a rate of 0.76 ± 0.11%·a−1, with the area decreasing from 2583.09 ± 88.80 km2 to 1635.89 ± 71.74 km2, and the ice volume reducing from 221.7017 ± 7.9618 km3 to 152.7429 ± 6.1747 km3. The most significant retreat occurred in glaciers smaller than 1 km2. Additionally, glaciers on southern aspects retreated slower than the northern counterparts. The glaciers in the western YZRB witnessed a significantly greater shrinkage rate than those in the eastern section, with the most pronounced changes occurring in Aso Longbu River Basin. Furthermore, severe glacier mass deficits were observed from 2000 to 2019, averaging a loss rate of 0.57 ± 0.06 m w.e. a−1. The continuous rise in air temperature has primarily induced a general widespread glacier change in the YZRB. However, diverse topography led to spatial variability in glacier changes with discrepancies as large as several times. The features of individual glaciers, such as glacier size, debris cover, and the development of ice-contact glacial lakes enhanced the local complexity of glacier change and elusive response behaviors to climate warming led by the different topographic conditions.

A new global dataset of mountain glacier centerlines and lengths

Abstract. The length of a glacier is a key determinant of its geometry and is an important parameter in glacier inventories and modeling; glacier centerlines are the lines along which the main flow of glaciers takes place and, thus, are crucial inputs for many glaciological applications. In this study, the centerlines and maximum lengths of global glaciers were extracted using a self-designed automatic extraction algorithm based on the latest global glacier inventory data, digital elevation model (DEM), and European allocation theory. The accuracy of the dataset was evaluated through random visual assessments and comparisons with the Randolph Glacier Inventory (RGI) version 6.0. A total of 8.25 % of the outlines of the RGI were excluded, including 10 764 erroneous glacier polygons, 7174 ice caps, and 419 nominal glaciers. A total of 198 137 glacier centerlines were generated, accounting for 99.74 % of the input glaciers. The accuracy of glacier centerlines was 89.68 %. A comparison between the dataset and the previous dataset suggested that most glacier centerlines were slightly longer than those in RGI v6.0, meaning that the maximum lengths of some glaciers had been likely underestimated in the past. The constructed dataset comprises 17 sub-datasets, including global glacier centerlines, maximum lengths, and DEMs, all of which can be found at https://doi.org/10.11922/sciencedb.01643 (Zhang and Zhang, 2022).

Variations in glacier coverage in the Himalayas based on optical satellite data over the past 25 years

Because of the large area covered by glaciers, their extent and importance demands continuous assessment of the glaciers. In this study, we analysed the distribution and changes in glacier coverage throughout the Himalayas from 1990 to 2015. The results showed that 12,211 glaciers were identified in the whole mountain range, covering an area of 23229.27 km2 in 1990. Over the past 25 years, the glacier area decreased by 10.99% (2553.10 km2) with an accelerated shrinkage in the period 2010–2015. There was a normal distribution between glacial area and elevation with maximum glacier area between 5400–5600 m. The glacier area decreased at all elevations, and the highest absolute ice loss occurred in 5200–5400 m. The total area of debris-free glaciers was larger than debris-covered glaciers, and in consequence, the annual shrinking rate was three times higher (15.56% versus 5.22%). The features of these two types of glaciers suggest moraine can inhibit glacial ablation. The debris over Himalayas is mainly distributed in gentle zones where elevations are in the range of 4400–5200 m. The ice coverage of the temperate glaciers is larger than that of continental glaciers with greater area loss but lower shrinkage rate (9.84%·versus 13.73%) in 1990–2015. These findings provide detailed glacier inventory data for the entire Himalayan region and updated information for the study of glaciers on a large scale.

Spatial and Temporal Variation Characteristics of Glacier Resources in Xinjiang over the Past 50 Years

Changes in glacier resources and their meltwater runoff contributions in Xinjiang are significant to the hydrological processes and water resources utilization. This study used the first and second Chinese Glacier Inventory, geomorphological and meteorological data. GIS spatial analysis technology was used to explore the characteristics of glacier change and its response to topography and climate change in Xinjiang in the last 50 years. The results show that there are currently 20,695 glaciers in Xinjiang with a total area of 22,742.55 km2 and ice reserves of about 2229.17 km3. Glaciers in Xinjiang are concentrated at 5100–6000 m. The Tianshan mountains have the largest number of glaciers. However, the Kunlun mountains have the largest glaciers and ice reserves. The scale of glaciers is significantly larger in the south than that in the north. The changes in glaciers in Xinjiang during the last 50 years are mainly receding and splitting, and their number, area, and ice reserves have decreased by 1359, 7080.12 km2 and 482.65 km3, respectively. Small glaciers are more sensitive to climate change. Glaciers are basically unchanged in regions above 6000 m. The glaciers on the south slope of mountains are more susceptible to climate change. The phenomenon of an increase in the number of glaciers but decreasing total area in the southern mountains is related to glacier extinction and splitting. Glacier development and formation are determined by the combination of topography and hydrothermal material conditions. The change of glacier areas in Xinjiang is jointly affected by climatic conditions (53.45%) and topographic conditions (46.55%), among which climatic conditions are more prominent.

Variation of Runoff and Runoff Components of the Upper Shule River in the Northeastern Qinghai–Tibet Plateau under Climate Change

Quantifying the impact of climate change on hydrologic features is essential for the scientific planning, management and sustainable use of water resources in Northwest China. Based on hydrometeorological data and glacier inventory data, the Spatial Processes in Hydrology (SPHY) model was used to simulate the changes of hydrologic processes in the Upper Shule River (USR) from 1971 to 2020, and variations of runoff and runoff components were quantitatively analyzed using the simulations and observations. The results showed that the glacier area has decreased by 21.8% with a reduction rate of 2.06 km2/a. Significant increasing trends in rainfall runoff, glacier runoff (GR) and baseflow indicate there has been a consistent increase in total runoff due to increasing rainfall and glacier melting. The baseflow has made the largest contribution to total runoff, followed by GR, rainfall runoff and snow runoff, with mean annual contributions of 38%, 28%, 18% and 16%, respectively. The annual contribution of glacier and snow runoff to the total runoff shows a decreasing trend with decreasing glacier area and increasing temperature. Any increase of total runoff in the future will depend on an increase of rainfall, which will exacerbate the impact of drought and flood disasters.

Glaciers in Xinjiang, China: Past Changes and Current Status

The Xinjiang Uyghur Autonomous Region of China is the largest arid region in Central Asia, and is heavily dependent on glacier melt in high mountains for water supplies. In this paper, glacier and climate changes in Xinjiang during the past decades were comprehensively discussed based on glacier inventory data, individual monitored glacier observations, recent publications, as well as meteorological records. The results show that glaciers have been in continuous mass loss and dimensional shrinkage since the 1960s, although there are spatial differences between mountains and sub-regions, and the significant temperature increase is the dominant controlling factor of glacier change. The mass loss of monitored glaciers in the Tien Shan has accelerated since the late 1990s, but has a slight slowing after 2010. Remote sensing results also show a more negative mass balance in the 2000s and mass loss slowing in the latest decade (2010s) in most regions. This needs further investigation on whether the slowing is general and continuing. In addition, glacier surging occurs more frequently in the Karakoram and Kunlun Mountains.

Permafrost model in coarse-blocky deposits for the Dry Andes, Argentina (28°-33° S)

In this work, a statistical permafrost distribution model for coarse-blocky deposits in the Dry Andes of Argentina (28-33°S) is presented. The empiric mathematical formulation was based on a logistic regression. The final model is a combination of two independent occurrence probability models: a) a mean annual air temperature-terrain ruggedness model and, b) a mean annual air temperature-potential incoming solar radiation model. For all cases, calibration was made according the complete geomorphological characterization of a periglacial basin with 250 km2. Lately, the results of probabilistic model were extrapolated to the whole study area in the Dry Andes and compared with the Argentine rock glacier inventory data base. High permafrost likelihood, in coarse debris, is expected above 4200 and 5700 m a.s.l., from south to north in the study area and covers a surface of approximately 1200 km2. Medium permafrost likelihood is expected above 3400 and 4200 m a.s.l. with a surface of 6178 km2 while low permafrost likelihood, occurs between 3000 and 3400 m a.s.l. with an area of 11.060 km2. These findings indicate that permafrost may occur in several types of coarse-blocky deposits in the Dry Andes, not only restricted to rock glaciers. Thermal properties of the ground in coarse-blocky deposits allow permafrost permanence, even under unfavourable climatic conditions.The performance of the permafrost model was also tested, considering the transition from cold paleoclimate Tardiglacial to present climatic conditions. During the warming, likely permafrost surface reduced from 56 to 13%. In the same way, rock glaciers with high and medium permafrost likelihood decrease from 62 to 30%, respectively while, rock glaciers with low likelihood and no permafrost category, increased 75% and 474%, respectively. Moreover, we identified some sites in which permafrost degradation is arguably expected. About that, 0.9% of the rock glaciers in the study area display possible permafrost degradation and 33% of them, likely permafrost degradation.

Projecting climate change impacts on hydrological processes on the Tibetan Plateau with model calibration against the glacier inventory data and observed streamflow

Analyzing the impacts of climate change on hydrology and future projections of water supplies is fundamental for the efficient management and planning of water resources in large river systems on the Tibetan Plateau (TP), which is known as the “water tower of Asia.” However, large uncertainties remain in the projections of streamflow and glaciers in these cryospheric catchments due to great uncertainties in climate change projection and modeling processes. In this work, we developed an extended Variable Infiltration Capacity (VIC) macroscale hydrological model (named VIC-CAS), which was coupled with glacier melting and glacier evolution schemes. A two-stage calibration procedure that used glacier inventory data and the observed streamflow was adopted to derive the model parameters. The calibrated VIC-CAS model was then used to assess the future change in glaciers and runoff using downscaled climate model data in the upstream regimes of the Yellow, Yangtze, Mekong, Salween, and Brahmaputra rivers on the TP. The results indicated that both temperature and precipitation were projected to increase, resulting in a greater than 50% decline of the glacier area by the end of the 21st century in the five catchments. Glacier runoff was already beyond its tipping point at the beginning of the 21st century with a greater than 20% loss of the glacier area except in the upstream of the Yangtze River, where glacier runoff was projected to decrease after the 2030 s. Annual streamflow was projected to increase significantly as a result of increased rainfall-induced runoff, compensating for the reduced glacier/snow melt water in the five major upstream river basins. The increasing rate of warm season streamflow was clearly less than that of annual runoff. A negative trend in warm season streamflow was expected if precipitation did not sufficiently increase. The annual hydrograph remained largely unchanged, except in the upstream of the Yellow River, where peak streamflow was predicted to occur 1 month earlier because of the earlier snowmelt and greater rainfall/precipitation ratio from May to June.

Twentieth-century contribution to sea-level rise from uncharted glaciers.

Global-mean sea-level rise (GMSLR) during the twentieth century was primarily caused by glacier and ice-sheet mass loss, thermal expansion of ocean water and changes in terrestrial water storage1. Whether based on observations2 or results of climate models3,4, however, the sum of estimates of each of these contributions tends to fall short of the observed GMSLR. Current estimates of the glacier contribution to GMSLR rely on the analysis of glacier inventory data, which are known to undersample the smallest glacier size classes5,6. Here we show that from 1901 to 2015, missing and disappeared glaciers produced a sea-level equivalent (SLE) of approximately 16.7 to 48.0 millimetres. Missing glaciers are those small glaciers that we expect to exist today,owing to regional analyses and theoretical scaling relationships, but that are not represented in the inventories. These glaciers contributed approximately 12.3 to 42.7 millimetres to the historical SLE. Additionally, disappeared glaciers (those that existed in 1901 but had melted away by 2015, and that therefore cannot be included in modern global glacier inventories) made an estimated contribution of between 4.4 and 5.3 millimetres. Failure to consider these uncharted glaciers may be an important cause of difficulties in closing the GMSLR budget during the twentieth century: their contribution is on average between 0.17 and 0.53 millimetres of SLE per year, compared to a budget discrepancy of about 0.5 millimetres of GMSLR per year between 1901 and 1990. Although the uncharted glaciers will have a minimal role in sea-level rise in the future, and are less important after 1990, these findings imply that undiscovered physical processes are not required to close the historical sea-level budget.

Inventory of Glaciers in the Shaksgam Valley of the Chinese Karakoram Mountains, 1970–2014

The Shaksgam Valley, located on the north side of the Karakoram Mountains of western China, is situated in the transition zone between the Indian monsoon system and dry arid climate zones. Previous studies have reported abnormal behaviors of the glaciers in this region compared to the global trend of glacier retreat, so the region is of special interest for glacier-climatological studies. For this purpose, long-term monitoring of glaciers in this region is necessary to obtain a better understanding of the relationships between glacier changes and local climate variations. However, accurate historical and up-to-date glacier inventory data for the region are currently unavailable. For this reason, this study conducted glacier inventories for the years 1970, 1980, 1990, 2000 and 2014 (i.e., a ~10-year interval) using multi-temporal remote sensing imagery. The remote sensing data used included Corona KH-4A/B (1965–1971), Hexagon KH-9 (1980), Landsat Thematic Mapper (TM) (1990/1993), Landsat Enhanced Thematic Mapper Plus (ETM+) (2000/2001), and Landsat Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) (2014/2015) multispectral satellite images, as well as digital elevation models (DEMs) from the Shuttle Radar Topography Mission (SRTM), DEMs generated from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images (2005–2014), and Advanced Land Observing Satellite (ALOS) World 3D 30 m mesh (AW3D30). In the year 2014, a total of 173 glaciers (including 121 debris-free glaciers) (>0.5 km2), covering an area of 1478 ± 34 km2 (area of debris-free glaciers: 295 ± 7 km2) were mapped. The multi-temporal glacier inventory results indicated that total glacier area change between 1970–2014 was not significant. However, individual glacier changes showed significant variability. Comparisons of the changes in glacier terminus position indicated that 55 (32 debris-covered) glaciers experienced significant advances (~40–1400 m) between 1970–2014, and 74 (32 debris-covered) glaciers experienced significant advances (~40–1400 m) during the most recent period (2000–2014). Notably, small glaciers showed higher sensitivity to climate changes, and the glaciers located in the western part of the study site were exhibiting glacier area expansion compared to other parts of the Shaksgam Valley. Finally, regression analyses indicated that topographic parameters were not the main driver of glacier changes. On the contrary, local climate variability could explain the complex behavior of glaciers in this region.

DEVELOPMENT OF WEB BASED HIMALAYAN GLACIER INFORMATION SYSTEM USING OPEN SOURCE

Abstract. Systematic inventory of glaciers is required for a variety of applications needed for the comprehensive development of the Himalayan region such as: a) disaster warning, b) estimation of irrigation potential, c) planning and operation of mini and micro hydroelectric power stations, etc. A systematic inventory of the Himalayan glaciers at 1 : 50,000 scale was created for Indus, Ganga and Brahmaputra basins using Indian Remote Sensing Satellite data and attempted to modified global standards in GIS environment (Sharma et al, 2013). A robust, user- friendly web-based Himalayan Glacier Information System (HGIS), a first of its kind in the country is developed which facilitates any user to selectively display, query, analyse, compose maps and graphs and print, spatial and aspatial information on glaciers relevant to respective interests. The HGIS architecture is based on Open Geospatial Consortium (OGC) standards and utilises OpenGeo Suite bundled software comprising of Postgresql (PostGIS), Geoserver, GeoWebCache and GeoExplorer each of those having a different function (Anonymous 2010). The spatial and aspatial glacier data sets were stored in a pre-defined format (Sharma et al, 2008) and imbibed into spatially enabled database (PostGIS), having sophisticated functions for spatial data analysis and query. For publishing the data on web page OGC-compliant services are used. The HGIS information content comprise of a) glacier inventory maps and b) inventory data sheet. The map displays the glacier morphology features like accumulation zone and ablation (ice exposed and debris covered) zones, snout location, de-glaciated valleys, moraines and glacier lakes. The basin, sub-basin and administrative boundaries form the background. The inventory data sheet attributes for each glacier provides information on glacier Location, Identification, Dimension, Orientation, Elevation, Classification, etc. The spatial map and datasheet are linked by unique glacier identification number (galc_id) which is a key field present in all corresponding glacier related point, polygon or line layers. All the glacier attribute were made amenable to query and analysis by users. HGIS represents a significant step towards mapping and compiling individual glacier level inventory data in spatial form to fill the void in data and information on the status of Glaciers in the Himalaya and Trans-Himalayan Karakoram region. HGIS provides a basis for assessing the glacier inventory data which has applications in studies related to climate change, water resource planning, hydropower site selection and mitigation of glacial lake outburst flood (GLOF) hazards.

1967-2014年科西河流域冰湖时空变化

PDF HTML阅读 XML下载 导出引用 引用提醒 1967-2014年科西河流域冰湖时空变化 DOI: 10.5846/stxb201611012223 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41261016）；中国科学院冰冻圈科学国家重点实验室开放基金项目（SKLCS-OP-2016-10） Spatial-temporal variations of glacial lakes in the Koshi River basin from 1967 to 2014 Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:冰湖是高山寒区气候变化的灵敏指示器和诱发山地溃决洪水或泥石流的灾害源。基于1960s-2010s多源遥感影像数据（Corona、Landsat MSS/TM/ETM+OLI）、地形图、冰川编目和气象数据，利用RS和GIS技术综合分析科西河流域近50年冰湖（≥ 0.05 km2）时空变化特征及其对冰川变化影响。研究结果表明：（1）近50年来科西河流域冰湖整体经历了"先平稳后扩张"的过程，其中1960s至1980s初期，科西河流域有37个冰湖消失，但总面积趋于平稳状态；1980s中期至2010s初期，流域内冰湖规模迅速扩张，且2000s之后冰湖扩张速率明显加快，至2010s初期增加为321个冰湖（88.43 km2）。（2）科西河流域冰湖集中分布于海拔5000-5500 m，面积小于0.25 km2的小规模冰湖占总数量的74.45%，而面积大于1 km2和介于0.05-0.25 km2的冰湖占总面积的64.18%。（3）除利库科拉（Likhu Khola）流域外，科西河流域其他5个子流域冰湖均呈扩张趋势，其中尤以阿润（Arun）流域冰湖扩张最为显著。（4）气候变暖及其引发的冰川退缩是科西河流域冰湖扩张的根本原因，当冰川末端伸入冰湖时，冰水物质与能量交换在一定程度上加速了冰川消融与退缩。 Abstract:Glacial lakes play an extremely important role in the fragile plateau eco-environment because they are sensitive indicators of climate change in alpine cold areas and can be a source for mountain outburst flood or cause mudflow disaster. Based on multi-source remote sensing image data (Corona, Landsat MSS/TM/ETM+/OLI) from the 1960s to 2010s, topographic maps in the 1970s, glacier inventory and meteorological data, we performed a comprehensive assessment of the spatial-temporal variations of glacial lakes (≥ 0.05 km2) in the Koshi River basin and examined their influence on glacier changes. The major results of these studies are as follows. First, the area of glacial lakes in the Koshi River basin remained constant between the 1960s to the early 1980s before rapidly expanding between the mid-1980s and early 2000s. The most rapid expansion was observed after the 2000s. Second, the lakes were centrally distributed in altitude band of 5000-5500 m in this river basin. Glacial lakes with an area of 0.05-0.25 km2 constituted the highest proportion of lakes (74.45%), and the largest area was covered by 0.05-0.25 km2 and above 1 km2 lakes (64.18%). Third, the glacial lakes in each sub-catchment of the Koshi River exhibited a trend of expansion, with the exception of the Likhu Khola basin. Furthermore, there were significant changes in the areas of glacial lakes in the Arun basin. Climate warming and glacial retreat are the main causes of glacial lake expansion in the Koshi River basin. Furthermore, when the terminus of a glacier extends into a glacial lake, there is a significant exchange of matter and energy. We infer that this may accelerate ice melting and the consequent glacier retreat. 参考文献 相似文献 引证文献

Multi-criteria technique for mapping of debris-covered and clean-ice glaciers in the Shaksgam valley using Landsat TM and ASTER GDEM

Glaciers in the Shaksgam valley provide important fresh water resources to neighbourhood livelihood. Repeated creation of the glacier inventories is important to assess glacier–climate interactions and to predict future runoff from glacierized catchments. For this study, we applied a multi-criteria technique to map the glaciers of the Shaksgam valley of China, using Landsat Thematic Mapper (Landsat TM) (2009) and Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model version two (ASTER GDEM V2) data. The geomorphometric parameters slope, plan, and profile curvature were generated from ASTER GDEM. Then they were organized in similar surface groups using cluster analysis. For accurate mapping of supraglacial debris area, clustering results were combined with a thermal mask generated from the Landsat TM thermal band. The debris-free glaciers were identified using the band ratio (TM band 4/TM band 5) technique. Final vector maps of the glaciers were created using overlay tools in a geographic information system (GIS). Accuracy of the generated glacier outlines was assessed through comparison with glacier outlines based on the Second Chinese Glacier Inventory (SCGI) data and glacier outlines created from high-resolution Google Earth™ images of 2009. Glacier areas derived using the proposed approach were 3% less than in the reference datasets. Furthermore, final glacier maps show satisfactory mapping results, but identification of the debris-cover glacier terminus (covered by thick debris layer) is still problematic. Therefore, manual editing was necessary to improve the final glacier maps.

Glacier changes in the eastern Nyainqêntanglha Range of Tibetan Plateau from 1975 to 2013

Maritime-type glaciers in the eastern Nyainqentanglha Range, located in the southeastern part of the Tibetan Plateau, are an important water source for downstream residents and ecological systems. To better understand the variability of glaciers in this region, we used the band ratio threshold (TM3/TM5 for the Landsat TM /ETM+ and TM4/TM6 for Landsat OLI) to extract glacier outlines in ~1999 and ~2013. After that, we also generated a series of glacier boundaries and monitored glacier variations in the past 40 years with the help of the Chinese Glacier Inventory data (1975) and Landsat TM, ETM+ and OLI data. The total glacier area decreased by 37.69 ± 2.84% from 1975 to 2013. The annual percentage area change (APAC) was ~1.32% a-1 and ~1.29% a-1 in the periods 1975-1999 and 1999-2013, respectively. According to the lag theory, the reaction time is probably about 10 years and we discuss the variations of temperature and precipitation between 1965 and 2011. Temperature and precipitation increased between 1965 and 2011 at a rate of 0.34°C /10a and 15.4 mm/10a, respectively. Extensive meteorological data show that the glacier shrinkage rate over the period may be mainly due to increasing air temperature, while the increasing precipitation partly made up for the mass loss of glacier ice resulting from increasing temperature may also lead to the low APAC between 1999 and 2013. The lag theory suggests that glacier shrinkage may accelerate in the next 10 years. Small glaciers were more sensitive to climate change, and there was a normal distribution between glacier area and elevation. Glaciers shrank in all aspects, and south aspects diminished faster than others.

A Revised Glacier Inventory of Bhaga Basin Himachal Pradesh, India : Current Status and Recent Glacier Variations

Abstract. Himalayan glaciers show large uncertainty regarding their present and future state due to their sensitive reaction towards change in climatic condition. Himalayan glaciers are unique as they are located in tropical, high altitude regions, predominantly valley type and many are covered with debris. The great northern plains of India sustain on the perennial melt of glaciers meeting the water requirements of agriculture, industries, domestic sector even in the months of summer when large tracts of the country go dry. Therefore, it is important to monitor and assess the state of snow and glaciers and to know the sustainability of glaciers in view of changing global scenarios of climate and water security of the nation. Any information pertaining to Himalayan glaciers is normally difficult to be obtained by conventional means due to its harsh weather and rugged terrains. Due to the ecological diversity and geographical vividness, major part of the Indian Himalaya is largely un-investigated. Considering the fact that Himalayan glaciers are situated in a harsh environment, conventional techniques of their study is challenging and difficult both in terms of logistics and finances whereas the satellite remote sensing offers a potential mode for monitoring glaciers in long term. In order to gain an updated overview of the present state of the glacier cover and its changes since the previous inventories, an attempt has been made to generate a new remotesensing- derived glacier inventory on 1:50,000 scale for Bhaga basin (N32°28'19.7'' - N33°0'9.9'' ; E76°56'16.3'' - E77°25'23.7'' ) Western Himalaya covering an area of 1695.63 km2. having 231 glaciers and occupying glacierized area of 385.17 ±3.71 km2. ranging from 0.03 km2. to 29.28 km2. Glacier inventory has been carried out using high resolution IRS P6 LISS III data of 2011, ASTER DEM and other ancillary data. Specific measurements of mapped glacier features are the inputs for generating the glacier inventory data sheet with 37 parameters as per the UNESCO/TTS format, 11 additional parameters associated with the de-glaciated valley as per the suggestions of Space Application Center Ahmadabad and 9 newly introduced parameters of present study. The data sheet provides glacier wise details for each glacier on the significant glacier parameters like morphology, dimensions, orientation, elevation, etc. for both the active glacier component as well as the associated de-glaciated valley features. Assessment of recent variation in the glacierized area between 2001 and 2011. Results indicate that 231 glaciers covering an area of 391.56 ±3.76 km2. in 2001 has been reduced to 385.17 ±3.71 km2. in 2011; a loss of 1.63 ±1.0% in glacierized area within a period of 10 years. The present paper brings out the methodology adopted and salient results of the glacier inventory carried out which will help to enrich the existing database required for water resources assessment of the country and also meet the requirements of various researches working on climate change related studies.

Glacier Inventory in Indus, Ganga and Brahmaputra Basins of the Himalaya

Systematic inventory of all the glaciers in the Indus, Ganga and the Brahmaputra basins encompassing the Himalayas, Transhimalaya and Karakoram regions have been carried out on 1:50,000 scale using Resourcesat-1 satellite data of 2004–2007 periods. Modified UNESCO-TTS guidelines have been downloaded and used to create glacier inventory and the spatial data base in GIS environment. The modified global inventory standards and updated procedures are used in a GIS environment to create sub-basin wise details for Ganga, Brahmaputra and Indus basin. Inter and intra basin level analysis of glacier inventory data is carried out to understand the characteristics of the glacial systems. The total glacierized area for the three basins put together is 71,182 km2 in 32,392 glaciers. Indus basin has 20.6 % of the glaciers under debris cover, the glaciers in Ganga and Brahmaputra basins have 26.3 and 25.6 % debris cover respectively. 71.7 % of glaciers in the Indus basin are smaller than 1 km2, as compared to 45.2 and 64.5 % in Ganga and Brahmaputra basins respectively. The Indus basin has a mean size of 0.05 and 0.07 km2 for supra glacial and pro-glacial lakes as compared to Ganga 0.17 and 0.33 km2 and Brahmaputra 0.15 and 0.31 km2.

An estimate of global glacier volume

Abstract. I assess the feasibility of using multivariate scaling relationships to estimate glacier volume from glacier inventory data. Scaling laws are calibrated against volume observations optimized for the specific purpose of estimating total global glacier ice volume. I find that adjustments for continentality and elevation range improve skill of area–volume scaling. These scaling relationships are applied to each record in the Randolph Glacier Inventory, which is the first globally complete inventory of glaciers and ice caps. I estimate that the total volume of all glaciers in the world is 0.35 ± 0.07 m sea level equivalent, including ice sheet peripheral glaciers. This is substantially less than a recent state-of-the-art estimate. Area–volume scaling bias issues for large ice masses, and incomplete inventory data are offered as explanations for the difference.

Controls on mass balance sensitivity of maritime glaciers in the Southern Alps, New Zealand: The role of debris cover

The “mass balance sensitivity” of a glacier provides a means for assessing its response to future warming and contribution to sea level rise. Many studies have concluded that the first‐order control on mass balance sensitivity is climatic, where higher‐precipitation (and less continental) glaciers are most sensitive while lower‐precipitation (and more continental) glaciers are least sensitive. The Southern Alps in New Zealand experience a limited range of continentality (9–13 K) but strong gradients in precipitation (2.5–11 m a−1). Using an energy balance model applied on a regional scale we find that the central Southern Alps glaciers are very sensitive to temperature change (1.9 m w.e. a−1 K−1, with a range of −1.1 to −4.0 m w.e. a−1 K−1) and that an 82% increase in precipitation is required to offset a 1 K warming. Spatial variations in mass balance sensitivity cannot be simply explained as a function of precipitation. Topographic effects are important, and we find that debris cover reduces mass balance sensitivity. Mass balance amplitude, which takes into account debris cover, hypsometry and other topographic characteristics, is a better predictor of mass balance sensitivity than precipitation. The mass balance gradient is almost as good a predictor indicating that hypsometry is not a necessary component of sensitivity calculations. Estimating mass balance sensitivity as a function of mass balance gradient allows for parameterizations of mass balance sensitivity based on glacier inventory data. This provides a simple and robust way to assess glacier mass balance sensitivity on a global scale, which may refine future predictions of valley glacier melt and its contribution to sea level rise.

冰川变化研究近况 Study on Recent Change of Glacier

全球冰川面积1600万km2，中国冰川面积约6万km2。冰川中储存了古代气候与环境变化的大量的精度高的信息，它可通过冰芯研究取得。中国在高山冰川的冰芯研究已处于世界前列。冰川对气候变化的反应敏锐，主要反映在物质平衡的波动上，全球现已有226条冰川进行了冰川物质平衡的监测。近数十年来表现为不断增大的负平衡。应用卫星遥感资料与冰川编目数据对比可以获得广大地区冰川近数十年的变化资料，初步结果表明，中国西北冰川面积在近30年中约退缩4.5%，其中边缘山脉退缩较快，青藏高原西北部退缩最慢。应用冰川系统模型可以预测冰川未来变化趋势，与冰川近期变化的实况对比，差别不大。 The global glacier area is 16 million km2 and there is 60 thousand km2 in China. The steady and high accuracy information about the old climate and environmental change that stored in glaciers can be got by ice core studies. Chinese studies in ice core of alpine glacier has been equivalent to the world advanced level. The glacier responses to climate change sensitively, which mainly reflected in the fluctuation of mass balance, and there have 226 glaciers been monitored about glacier mass balance in the world. In recent decades it shows the increasing negative mass balance. The change information about the glaciers in vast area in recent decades can be got by comparing the satellite remote sensing data with the glacier inventory data. Preliminary results suggest that the glacier area in the northwestern China has retreated about 4.5% in recent thirty years, among which the edge of mountains retreats faster and the northwestern Tibet Plateau retreats the slowest. The tendency of glacier change can be forecasted by the application of the model of glacier system. That has no evident difference compared with that of the recent change of glacier.

Glaciers, snow and ski tourism in Austria’s changing climate

AbstarctThis study illustrates the relevance of cryospheric changes for, and their impact on, ski tourism in Austria. The results of several case studies on snow reliability, snow production and mass balance in glacier ski resorts in the Ötz and Stubai valleys are summarized. Climate data from Obergurgl (1936ma.s.l.) in the Ötz valley are analyzed with respect to the amount and duration of natural snow cover and the possibility of snow production. A case study on Mittelbergferner focuses on the impacts of glacial recession on a ski resort and possible adaptation measures. From long-term glacier inventory and short-term mass-balance data, the effect of operating ski resorts on glaciers is investigated. At Obergurgl, the probability of both snow cover and snow production is >80% from December to March and decreases significantly in the months before and after this peak season. The interannual variability of snow cover and production is low during the main season and higher in other months. Year-to-year differences are larger than any long-term trend. Glacier ski resorts must adapt to shrinking glacial area and falling glacier surface. Covering the glacier with textiles reduces ablation by 60% and results in significantly less volume loss than on uncovered parts of the glacier. Neither the mass-balance comparison between groomed and ungroomed areas nor the comparison of long-term volume changes between 10 ski resort glaciers and 100 surrounding glaciers showed evidence for an impact of the operation of ski resorts on the glaciers.