干旱区生态环境知识资源中心

Global Positioning System is a comparatively new tool for measuring the location on any part of the earth's surface. In order to test its utility in measuring the terrain parameters in a desert, a Magellan ProMark V GPS with submeter kit was used over an inland parabolic sand dune in the Thar desert. Data was gathered through carrier phase mode and mobile tracking mode. The measured true height of the dune (315 m) and its relative height above the interdune plain (33.18 m) agreed with the information in large-scale topographical sheet. Digital elevation modeling suggest that the interdune corridor between the two arms of the dune has a series of troughs, separated by small ridges. The cross profile of the dune arms is asymmetric and suggest a strong contribution from interdune corridor towards accretion and redistribution of sand over the dune. The upper mid-slope and the crestal part, together, hold about 37% area of the sand volume in the dune. Such information is vital for an understanding of the process-form interactions.