This means that there is an urgent need to update the global glacier database, as mentioned in the strategy of the Global Terrestrial Network for Glaciers (GTN-G) ( Reference Haeberli and EpifaniHaeberli, 2006).ģ. Since that time period, major changes have taken place in glaciers all over the world ( Reference Barnett, Adam and LettenmaierBarry, 2006 Reference Khromova, Osipova, Tsvetkov, Dyurgerov and BarryKaser and others, 2006 Reference MihalceaLemke and others, 2007). Data for the WGI were compiled mostly during the 1960s, 1970s and 1980s. Furthermore, glaciers in the WGI database are represented by point data rather than glacier outlines, making change detection for individual glaciers nearly impossible.Ģ. The World Glacier Inventory (WGI) was compiled from aerial photography, maps and satellite imagery acquired during the 1960s and 1970s and is not complete with respect to detailed glaciological information (World Glacier Monitoring Service, 1989).
Given the declining glacier mass on a global scale ( Reference MihalceaLemke and others, 2007 WGMS, 2007, 2008), the increasing importance of glacier meltwater as a water resource in the dry season in areas such as the Himalaya ( Reference Surazakov and AizenSingh and others, 1997 Reference Sun, Ranson, Kharuk and KovacsSingh and Jain, 2002 Reference Singh, Jain and KumarSingh and Bengtsson, 2004 Reference Bamber and RiveraBarnett and others, 2005) and the Andes ( Reference Bradley, Vuille, Diaz and VergaraBradley and others, 2006), as well as the contribution of alpine glaciers to global sea-level rise ( Reference Aniya, Sato, Naruse, Skvarca and CasassaArendt and others, 2002 Reference RöhlRignot and others, 2003 Reference RaupRaper and Braithwaite, 2006 Reference Narama, Kääb, Kajiura and AbdrakhmatovMeier and others, 2007), global glaciological data are required for four main reasons:ġ. The major aim of the Global Land Ice Measurements from Space (GLIMS) initiative is to generate a global snapshot of digital glacier outlines from satellite data and make them available to the wider scientific community via the internet ( Reference Khromova, Dyurgerov and BarryKargel and others, 2005 Reference Rignot, Rivera and CasassaRaup and others, 2007b). While the list of proposed methods and recommendations is not comprehensive and is still a work in progress, our goal here is to provide a starting point for the GLIMS regional centers as well as for the wider glaciological community in terms of documentation on possible pitfalls along with potential solutions. This paper summarizes the major results of the 2008 GLIMS workshop, with an emphasis on definitions, methods and recommendations for satellite data processing.
Glims define code#
Special emphasis was given to establishing standard protocols for glacier delineation and analysis, creating illustrated tutorials and providing source code for available methods. Talks presented examples and work in progress for each of these topics, and focus groups worked on compiling a summary of available algorithms and procedures to address and avoid identified hurdles. This workshop identified six themes for consideration by focus groups: (1) mapping clean ice and lakes (2) mapping ice divides (3) mapping debris-covered glaciers (4) assessing changes in glacier area and elevation through comparisons with older data (5) digital elevation model (DEM) generation from satellite stereo pairs and (6) accuracy and error analysis.
Despite the progress made in recent years, there still remain many cases where automatic delineation of glacier boundaries in satellite imagery is difficult, error prone or time-consuming. The findings are glim and reflect a significant portion of low-level readers.On 16–18 June 2008 the US National Snow and Ice Data Center held a GLIMS workshop in Boulder, CO, USA, focusing on formulating procedures and best practices for operational glacier mapping using satellite imagery. Wolfstack Docks glim and surface currency by this time I had enough echoes such that I simply bought my way in.Īnother Echo Bazaar Status Update | Spontaneous ∂erivation "Stay here - and keep that glim outside or you'll blow the town sky-high!"īadgerMatt was then unable to sell the tickets to people who had made lower bids, so he used a technique called the " glim-dropper" to trick the woman into paying what she owed.ĮBay User Turns Tables On Scammer With Great Trick, Serves Up Justice Republican: Obama must lead on Afghanistan It strikes me as 'ow it' ud be the proper thing for you to draw your jib, douse the glim, an 'turn in, seein' as 'ow it worrits you.īut also the democrates might very well establish another military objective in case a 2012 victory becomes glim.
0 kommentar(er)
