ADVERTISEMENTS:
List of evidences for increase of sand in Rajasthan arid zone.
(i) Wind direction:
The direction of wind is mainly from south-west and north-east. The spread of sand dunes also follow the same direction e.g. ushkar, Budha Pushkar.
ADVERTISEMENTS:
(ii) Advancement of sand movement:
Accumulation of Aeolian sands on le western and eastern flanks of Aravalli hill near Shapura-Ajitgarh area.
The direction of the wind might be responsible for all these deposits.
(iii) Chocking up of river bed:
The river bed of Mendha-one of the main feeders of the Sambhar salt lake has chocked up by Aeolian deposits.
(iv) An alarming increase and creation of wastelands due to intensification of desertification process.
(v) Cultivation of marginal areas in Indian arid zones has accelerated desertification process.
(vi) Large scale removal of vegetal cover on Aravalli and Malani hills.
(vii) Active ploughing of stable sand dunes enhance the advancement of sand movement.
(viii) Flattening of the river bed:
ADVERTISEMENTS:
Mendha river bed is very much impregnated with calcarious concretions and sand.
(ix) The width of river Mendha has narrowed down and the small ns’ sand dunes have deposited at some places.
(x) Northern part of Sambhar lake area is covered with recent sand dunes.
(xi) Felling of trees on hills has accelerated the soil erosion which is a says process. It hurts the land and people where it takes places, so also the land and people where it gets deposited.
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(xii) Drifting of sand sheet and sand dunes from magra area in Ajmer to Khetri hills in Jhunjhunu district.
(xiii) AVHRR pictures clearly indicate the increase of desert and decertified area on the fringe.
(xiv) Increase in frequency, intensity and duration of dust storms in Rajasthan.
(xv) Landsat mosaic of Rajasthan (1972 and 84) prove drifting of sand id dunes through 12 gaps in Aravalli hills from western desert to the eastern fertile plains. Out of 12 gaps the seven major gaps are nana-Digrota, 2-Gudha (Kantli) 3-Bajor-Rewasa 4-Ghat ki Mohana, 5-Ghatwa-Rupgarh, 6-Kuchaman-Mithri-Sambhar and (Pushkar) and other five minor gaps are 1-Bhuni, 2-Gagor, :d, 4-Ajwa and 5-Pilwa.
ADVERTISEMENTS:
The sand and sand dune concentrations through these 12 gaps to east of the Arvalli are given in table 19.1.
(xvi) The change of rainfall pattern, deforestation, soil erosion and overall degradation of environment has resulted into deepening of water table and drying up of aquifers in eastern Rajasthan near Aravalli.
ADVERTISEMENTS:
(xvii) Alarming decrease in carrying capacity of desert due to increasing density of human population during last three decades (Indian arid zone is one of the thickly populated arid zones of the world).
(xviii) Intensive exploitation of the limited resources of arid zones by exploding population has accelerated desertification.
(xix) The increased livestock population and livestock migration towards fringe area have further intensified the desertification.
(xx) Intensity of droughts/famines: The famine is a permanent guest of the arid zone. It is a ‘Trikal’ – three fold famine i.e. famine of food, famine of fooder and famine of water. Famine is a grand natural disease of the region. The recent famine years 1968, 72, 78, 80, – 82 and 1985 etc. have leading to widespread unemployment and migration of humans and live-stocks. These create desert like conditions.
(xxi) The TV picture entitled the Crowded Desert: Thar-The Great Indian Desert of Television Trust for the environment, London has shown an expansion of Thar Desert over 9000 Sq. Km during last thirty years. These 21 evidences suggest that there is a creep of arid zone from west to east in Rajasthan.
