Detection and delineation of various desert terrain features using Landsat-TM derived image transforms

Globally, deserts cover an estimated 36•3 per cent of the earthʹs land surface. Of this, 0•32 million km2 occurs in India. Timely and reliable information on various natural resources of deserts and the processes operating within the region are prerequisites for combating desertification and for checking further encroachment into adjoining fertile lands. Spaceborne multispectral data offer a great potential in providing such information. Landsat-TM data over part of Jodhpur district, Rajasthan was used to generate various spectral indices such as principal components transform, perpendicular vegetation index and soil brightness index. Their potential in delineating various features is evaluated. The methodology and merits and limitations of each transform are discussed in detail.