Moreover, as the influence of atmospheric corrections and image sharpening can derive variations in the apparent surface reflectance, a robust analysis of the effects of these processing routines in a GEOBIA environment is lacking. Debris cover can induce challenges and requires additions of slope, temperature, and short-wave infrared data as supplements to enable efficient mapping. The mapping of glacier surface facies presents a unique problem to GEOBIA on account of its separable but closely matching spectral characteristics and often disheveled surface. The application of GEOBIA for glacier surface mapping, however, necessitates multiple scales of segmentation and input of supportive ancillary data.
This is of excellent use in analyzing very-high-resolution (VHR) data. This method of information extraction focuses on segregating correlated pixels into groups for easier classification. Climate data analysis shows increase in mean monthly temperature during the period in the study area supporting the changes observed in glaciers and lakes.Īdvancements in remote sensing have led to the development of Geographic Object-Based Image Analysis (GEOBIA). The new lakes are not proglacial but are glacier-fed, indicating retreat of glaciers. Glacial lake area, on the other hand, increased from ~ 3.8 (± 1.2) km² in 1988 to ~ 6.4 (± 0.0006) km² in 2018, and 61 new lakes formed during this period. Twenty smaller glaciers vanished, 12 fragmented, and 57 have retreated. The glacial area of 83.55 (± 6.2) km², which contributed to almost 10% of the total basin area in 1988, shrank to about 58.7 (± 1.6) km² covering only 7% of the total basin area in 2018. The number of glaciers was reduced from 92 to 86 during 1988–2018, whereas the glacial lakes increased from 134 to 195 in this period.
#Meaning of glims drivers#
Spatio-temporal changes in the glaciers and lakes extent and number in 19 are derived from Landsat TM and Sentinel-2 satellite imageries and major climatic drivers of change (temperature and precipitation) are analyzed from ERA5 reanalysis data. This study attempts to bridge the knowledge gap on depletion of glaciers and glacial lake changes in the Eastern Himalayas by concentrating on the Mago Chu basin. However, changes in glaciers and glacial lakes are rarely documented in the Eastern Himalayan region, especially from Bhutan and Arunachal Himalaya. Glaciers and glacial lakes are susceptible to variations in climate and are global indicators of climate change. Results show marked changes in that system over the last 30 years, but also point out the need for establishing clear protocols for glacier monitoring from remote-sensing data. The glacier and ASTER footprint layers may be queried for scalar attribute data, such as analyst name and date of contribution for glacier data, and acquisition time and browse imagery for the ASTER footprint layer.We present an example analysis of change in Cordillera Blanca glaciers, as determined by comparing data in the GLIMS Glacier Database to historical data. Map layers include glacier outlines, footprints of ASTER satellite optical images acquired over glaciers, and Regional Center information.
#Meaning of glims download#
There, users can browse custom maps, display various data layers, query information within the GLIMS database, and download query results in different GIS-compatible formats. The WMS, an Open Geospatial Consortium (OGC)-compliant web interface, makes GLIMS glacier data available to other data servers.The GLIMS Glacier Database is accessible on the World Wide Web at “”. Data received by the GLIMS team at the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado are ingested into a spatially-enabled database (PostGIS) and made available via a website featuring an interactive map, and a Web-Mapping Service (WMS).
Each institution (called a Regional Center, or RC) oversees the analysis of satellite imagery for a particular region containing glacier ice. The Global Land Ice Measurement from Space (GLIMS) project is a cooperative effort of over sixty institutions world-wide with the goal of inventorying a majority of the world's estimated 160 000 glaciers.
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