Explanation: Two reports, two decades apart, predicted the desertification of the Punjab in 25 years. Here’s why they’re both right
The Punjab Vidhan Sabha committee, formed to study the depletion of groundwater tables, recently said the state will become a desert within the next 25 years if the current trend of drawing water from underground aquifers continues.
This is a prediction that has already been made – over two decades ago, a study into the depletion of the water table in the Punjab projected almost the same 25-year timeframe, claiming that the aquifers in the Punjab could be exhausted by 2025.
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How alarming is the water situation in Punjab really? Could both reports be correct? We explain.
What was the relationship two decades ago
According to officials of the Central Ground Water Board (CGWB), the study was called “The State of the World Report, 1998”, published by the World Watch Institute (WWI) based in Washington. He said the Punjab’s aquifers could be depleted by 2025.
Why will the Land of the Five Rivers (now 2.5 rivers after the partition of Punjab) turn into a desert?
Simply put, we take more water than we replenish, which leads to a drop in the water table. This represents a threat of desertification for the Punjab. The rate of water extraction in Punjab is 1.66 times of the replenishment rate.
Of the 138 blocks in the Punjab, 109 have already entered the ‘dark’ or overexploited zone, which means groundwater extraction is over 100% here. Two fall under the “dark / critical” zone (groundwater extraction is 90-100%), while five are in the semi-critical zone (groundwater extraction is 70-90%). This means that about 80 percent of the state’s blocs are already dry and four percent are about to be.
Only 22 blocks, located in southwest Punjab and the Kandi region, have experienced an increase in the water table over the past two decades. However, this is not good news, as the water in most of these blocks is either saline or brackish, and not suitable for irrigation or human consumption.
Experts said that the availability of water at 3 to 10 meters, which requires a centrifugal pump to extract the water, is the most desirable, but currently water is available at 20 to 30 meters, or more. 30 meters deep, in about 84 percent of the Punjab. It requires tube wells or submersible pumps for extraction, and farmers are spending huge sums of money to get deeper and deeper wells, resulting in financial debt.
Why does the Punjab overuse its groundwater?
Due to the adoption of a faulty cropping scheme.
With the advent of the Green Revolution in the state in 1966-67, paddy, historically never the main crop in Punjab, was adopted on a large scale. The area under it increased from 2.93 lakh hectares (LH) in 1966-67 to 31.49 LS in 2020, which was the largest area ever cultivated with rice in the history of Punjab. This is an almost 11-fold increase in rice area in five decades.
“We sacrificed this precious natural resource for rice cultivation, which also hinders water recharge due to the pond method used to prepare the fields for transplanting. The puddles have created a thick, hard layer over the agricultural fields, disrupting the recharge system and wasting rainwater through evaporation or creating flash floods, ”said Dr Rajan Aggarwal, senior research engineer, department of Soil and Water Engineering, Punjab Agricultural University (PAU) and Chief Scientist of the Whole India Coordinated Research Project (AICRP).
How to explain the two predictions at 25
Experts said the 25-year calculation was relevant two decades ago as it is today.
They said water was then available at a depth of 3 to 10 meters in most of Punjab, with the exception of a few districts where it could be as deep as 20 meters. But now it’s not available at that depth in 84% of the state, which feels like a desert situation as we can only get water through deep tube wells.
During the three decades (1966-67 to 1999) of the Green Revolution, with rice area growing from 2.93 LH to 26.12 LH in 2000, the water table of 73 blocks (53 percent) of the Punjab slipped in a dark / overexploited area in 1999, according to a report by the CGWB. The paddy takes at least 4000 liters of water to grow one kg of rice. The 1998 report estimates that based on this calculation, the remaining half of Punjab will also move into the Dark Zone over the next 25-27 years if control measures are not taken.
“This is also true because in almost two decades from 1999 to 2017, the number of dark / overexploited blocks has increased from 73 to 109. If seven critical and semi-critical blocks are added, the number rises to 116, ”said Dr. Rajan Aggarwal, adding that this puts a big question mark on the sustainability of agriculture.
“We don’t know if in the future water will be available at 200 meters or 300 meters, because it is in a sparse, non-linear form. Also, we don’t know what the quality of that water would be, ”said Dr Rajan, adding that like upper aquifers, deeper aquifers can also dry up if extraction is not controlled.
Speaking about the VS committee report, Sarabjit Singh, former NIT Jalandhar industrial and production engineering professor, said that instead of taking it literally, it should be seen as an indication of the scale of the threat facing the water table in Punjab. “In a few decades, we have dried up our upper aquifers. It could also happen to deep aquifers, and then Punjab will be like another Rajasthan. It is high time to stop senseless extraction and replenish our water, ”Singh said.
“Farmers must be encouraged to choose cultivation methods that require less water and to opt for drip irrigation or other water management mechanisms to save our only deeper aquifers available,” said added Singh.