Desertification is a geo-environmental hazard triggered by either or combination of natural or man-made factors. It is imperative of any terrain condition worth qualifying for desertification to have undergone some kind of land degradation with respect to certain key indicators pointing towards the hazard. There have been numerous attempts by various observers to study the Great Indian Desert. The Thar for its possible expansion, especially towards east, through various theories and means. In the current study, the authors have tried to confirm and examine multi-decadal Survey of India (SOI) topographical sheets and IRS - 1D LISS III FCC for a small area between Jaipur and the Sambhar lake, close to the desert-fringe line. It has been observed that fresh sand accumulation has taken place around certain localities as evidenced from comparison of SOI topographical sheets surveyed in 1958 and 1978. Also the latest satellite data (1999) shows intensification and increment of spread area of sand around same locality. The sand accumulations are of permanent nature and do indicate a western origin due to their proximity to the Sambhar gap in Aravalli hill range on its east facilitating south-westerly wind corridor for lift and drift of desert sand. However, it is too primitive to establish the eastward drift of the Indian desert, though the observations do indicate towards fresh aeolian activity in hitherto sand free alluvial land parcels east of Aravalli hill range Systematic and detailed multi-temporal examination of entire fringe line of the Thar is suggested.
The observations made and the inferences drawn are indicative of the following facts:
- Multi-decadal spatial data distributed over four decades distinctly indicated spoors of eastward sand drift across Indian desert.
- The observations made represents a diminutive constituent of the vast stretch of desert fringe.
- It does not conclude the drift of the Indian desert in totality.
- The authors are of the view that systematic multi-decadal change detection along entire fringe line should be carried out inorder to establish the nature and extent of fringe line drift in totality.
- Further study should include both degradation as well as aggradation/reclamation inorder to classify land parcels, along the fringe line, accordingly.