Abstract
Abstract. A semi automated technique has been developed to extract the spatial extension of valleys and mountain glaciers. The method is based on morphological properties of glaciated area extracted from Digital Elevation Model (DEM). Identification of glacial boundary based on spectral information from optical remote sensing imageries produces errors due to misclassification of debris-covered ablation area with surrounding rocky terrain and perennially snow-covered slope with debris free glaciated area. Elevation information DEM of Shuttle Radar Topography Mission (SRTM), CartoDEM and ASTER DEM have been used. A part of western Himalayas was selected as the study area that contains large glaciated basins, e.g., Bhagirathi, Baspa, Chandra basin. First order derivatives, slope aspect, and second order derivatives like, profile and plan curvatures are computed from the DEM. The derivatives are used to quantify and characterise the morphological aspects of the glaciated area and used in the decision rule models to generate the glacial boundaries. The ridge lines of the study areas are also generated from the plan curvature and used in the model to delineate the catchments areas of the glaciers. The slope based boundary is checked for consistency with the boundary from profile curvature and combined manually to generate the final glacier boundary. Area and length under the derived boundary of Gangotri glacier of Bhagirathi catchments are 90.25 sq km and 30.5 km. The result has been checked with high resolution optical data. This objective approach is important to delineate glaciated area, measure the length, width and area and generate glacial hypsometry, concentration factor of the glaciers. Accuracy of the result depends up on the quality of the DEM. DEM generated by SAR interferometric technique is found superior over DEM generated from other interpolation techniques.
Highlights
Glaciers are important dynamic part of the environment
Glacial valleys are developed or modified according to the force and mechanism applied by the glacial mass, like abrasion, plucking and polishing
The plan curvature of the terrain contour is the derivative of slope in the horizontal direction is used to delineate mass flow lines
Summary
Glaciers are important dynamic part of the environment. It is the largest storage of fresh water over the earth’s surface. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XL-8, 2014 ISPRS Technical Commission VIII Symposium, 09 – 12 December 2014, Hyderabad, India in contact with lateral moraines This information is used to identify the glacial boundary (Bishop et al 2000). Optical remote sensing data combining with geomorphological information has been applied as another approach to differentiate the debris covered ice of the glacier from surrounding rocky sidewall or depositional features like lateral moraine (Paul, Huggel and Kaab, 2004, Bishop et al, 2001). Use of geomorphological information helps to identify the glaciated area even in the accumulation region In this context, delineation of complete glacial boundary using DEM is proposed as an objective and robust approach.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
