ABSTRACT
The Thar Desert (TD) in the hot arid tropics lies in the eastern margin of the world’s largest contiguous arid land between the Atlantic coast of North Africa and the Aravalli Ranges of western India. The Aravalli Ranges mark the eastern margin of the present-day aridity in India (i.e., moisture availability index at −66.6%) and TD. The area to the east of this boundary has many ‰elds of gullied stable sand dunes and other low
CONTENTS
3.1 Introduction ............................................................................................. 39 3.1.1 Issues............................................................................................. 41
3.2 Objectives ................................................................................................. 41 3.2.1 Climate and Population ............................................................. 42
3.3 Methodology ........................................................................................... 42 3.3.1 Data Sources ................................................................................ 42 3.3.2 Measurement of Driving Force and Pressure Variables ....... 44
3.4 Results and Discussion .......................................................................... 46 3.4.1 Sand Reactivation ....................................................................... 46
3.5 Quanti‰cation of Cultivation and Grazing Pressures ....................... 50 3.5.1 Cultivation Pressure ................................................................... 50 3.5.2 Grazing Pressure ......................................................................... 50 3.5.3 Multicriteria Evaluation of Deserti‰cation.............................. 53
3.6 From Local to Regional: Flagging the Key Variables ........................ 54 3.6.1 Will Groundwater Irrigation Lead to Wind Erosion? ............ 55 3.6.2 Tractor-Ploughing and Atmospheric Dust Load:
Is There a Pattern? ....................................................................... 57 3.7 Conclusion ............................................................................................... 59 References .......................................................................................................... 60
aeolian bedforms, which bear testimony to the desert’s former extensions during drier climates (Goudie et al., 1973), especially before and after the last glacial maxima (Kar et al., 2001, 2004; Singhvi and Kar, 2004).
