Recent efforts by the GLIMS community and projects like GlobGlacier (ESA) and ice2sea (EU FP7) aim at generating a globally complete inventory of glaciers and icecaps (vector outlines with topographic attributes) from remote sensing data. Due to the high variability of glacier types and characteristics in different parts of the world, this is still a challenging task. This session is intended to present and discuss the challenges related to the creation of a glacier inventory from optical remote sensing data (e.g. Landsat or ASTER) and the related change assessment (length, area). The focus will be on the technical and methodological challenges (e.g. debris cover, seasonal snow, orographic clouds) as found in different parts of the world, and potential solutions to these challenges. The questions to be presented and discussed might include (among others):
Which algorithm(s) should be used to map glaciers? Is manual digitization more accurate? What is the best method to map debris-covered glaciers efficiently? How can we assess the accuracy of the generated glacier outlines? Which DEM should be used to create topographic inventory parameters or drainage divides? Should an icecap or compound glacier be divided into separate entities, e.g. as required for a hydrological purpose of the inventory? What is the impact on the inventory parameters or glaciological calculations in these cases? What are the best methods for merging scenes from different years in the case of local cloud cover or seasonal snow? What are the challenges and uncertainties for the change assessment from inventory data based on different sources?
These are only some examples of questions that typically occur during data creation or application and are difficult to solve in most cases. Contributions that also present answers to the above questions as realized in practice are welcome. The session aims at bringing together all scientists confronted with the numerous practical challenges of glacier inventory work and might have a discussion section within the oral session. A more detailed discussion of specific topics is planned for the poster session and/or a dedicated splinter meeting.