CHANGE DETECTION OF MOUNTAIN GLACIER SURFACE USING AERIAL AND SATELLITE IMAGERY: A CASE STUDY IN IRAN, ALAMCHAL GLACIER

摘要

Glaciers are important components of Earth's natural system and of human environment, and are therefore obvious targets for mapping and monitoring. They serve as sensitive indicators of climate change. The surface topography of mountain glaciers is often subject to continuous spatio-temporal changes due to glacial phenomena. Hence, monitoring glacier changes not only can provide useful information on the glacial phenomena, but it also can reflect the effects of global wanning on the dynamics of ice-masses. In Iran, monitoring glaciers is of significant importance, due to the fact that a considerable portion of portable water is supplied by natural glaciers. Five main glacier zones have been identified in Iran of which the focus of this study would be on Alamchal glacier. Various measurement techniques can be applied in order to derive metric information of surface deformation and flow velocity. For this study, Optical image cross-correlation technique was chosen. In general, glacier surface deformation measurement studies are conducted either in short-term or long-term time interval. Satellite Radar Interferometry has proved to be adequate enough for measuring small displacements up to a few tens of cm on cloud covered areas over a short time. However on longer time intervals, interferometry is no more adequate.Long-term monitoring of glacier surface changes due to environmental factors can be used to assess the status of glacier reservoir. In the present work, changes of Alamchal glacier have been measured over a long period using aerial and optical satellite imagery.