Depleting ground water resources with an alarming rate in the great Thar Desert of India and an urgent need to check the uncontrolled exploitation of the ground water and to go for the artificial recharge in the region
|Location||International Geological Congress,oslo 2008|
|Author||Paliwal, Bhawani Shanker|
|Holding Date||08 September 2008|
Arid and semi-arid regions of the great Thar Desert to the northwest of India, known for frequent draughts have been facing acute scarcity of water. Scanty and erratic rains and lack of any perennial river system in the region, there is a total dependency on ground water for drinking, agricultural and industrial purposes (except the Himalayan water available in some parts through Indira Gandhi Canal).
The ground water in the region that accumulated in thousands of years is quite deep, at places, more than a thousand metres from the surface. Potential sources are crystalline, consolidated, semi-consolidated and unconsolidated aquifers belonging to various formations ranging from the Proterozoic to the Recent periods. Unfortunately, the potential sweet water aquifers generally lie above the saline aquifers. Climatic conditions cause insignificant replenishment.
On the other hand, advancements in exploration and exploitation techniques have increased the lust for ground water withdrawal for agriculture and industrial growth many times during the last a few decades. As a result, the ground water level in the region has lowered down significantly, i.e.up to 20 metres. Annual ground water recharge of the order of 13790.08mcm in 1984 has become 10382.58mcm in 2006.
The annual ground water draft of the region which was 4926.83mcm in1984 increased to 12991.20mcm in 2006. Similarly, the ground water balance in the region was of the order of 8863.25mcm in 1984 has reduced to -2608.60mcm in 2006. There has continuously been decline in the ground water resources of the region and the state of development has gone up to 125.13% in 2006 which was only 35.73% in 1984. Out of total 236 blocks only 23 blocks were in critical and over-exploited category and 203 blocks were in the white or safe category in1984 which became more than 190 blocks in the critical and over-exploited category and less than 30 blocks in the white or safe category in 2006.
There is a record lowering of ground water level in the region during the period from 1984 to 2006. The ground water level has gone down by 12.32m in Jaipur, 14.04m in Jalore, 11.09m in Jhunjhunu, 8.84m in Jodhpur, 13,47m in Nagaur, 10,19m in Pali, 8.29m in Sikar and 8.37m in Sirohi districts of Rajasthan. Climatic conditions of the region are not going to change dramatically in near future and we need water to drink in future if not for agriculture and industries. Political will is needed to enforce law for sustainable development and controlled exploitation of this vital natural resource. Artificial recharging of ground water, specially, utilizing the palaeo-channels of the lost Saraswati River may prove quite fruitful.