ASSESSMENT OF SAND DUNE CHANGE DETECTION IN RAJASTHAN (THAR) DESERT, INDIA

Landsat MSS digital data provide an important means for the study of s and dune morphology and distribution, land cover change and desertific ation monitoring. Two images, one each of Landsat-I and Landsat-5 MSS were used to determine sand dunes, their change and desertification by human activities from 1973 to 1986. Five dune classes were observed: parabolic, barchan, longitudinal, transverse and sand sheet. Parabolic dunes and sand sheet are widely distributed and are dominant classes in this area. Other classes of land cover observed were canal, saline area, salt lake and protected plantation. Various changes in dune stru cture are observed due to human activities followed by wind erosion wh ich indicates that desertification is enhancing severely. But there wa s no major shift in previous dune boundaries from 1973 to 1986 in the study area. Excavation of parabolic dunes for a canal also affected th e dune patterns in the Bikaner district. Recent salinization in the vi cinity of the Indira Ghandhi Canal further accentuated the land degrad ation which is quite apparent in the Landsat image of 1986. A further study would be essential to know the present extent of sand dune morph odynamics and desertification.