How is Punjab leading to desertification ? How it is to going to become infertile in coming future?

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Punjab has an area of 50,362sq. km(1.54% of the country)  which is divided into 17 districts with 141 blocks.
 About 80 percent of the state’s geographical area is cultivated with cropping the intensity of more than 180 percent during 2005-06
So heavy water requirement is there.
82% area of the state is under wheat+rice. Out of which 35 Lakh Ha is under wheat and 30 Lakh Ha under rice.


71.99% (29.81 Lakh Ha) area is irrigated using tubewells and 28.01% (11.60 Lakh Ha) using Canal water.
Tubewells are increased from 0.19-1.15 million. i.e. there are 13 Lakh tubewells in the state in 2015.
Because of decreasing average rainfall annually from 739.1 (1980)-649 mm. Due to the increase in the number of tubewells, the water table is declining in about 80% of the area in the state. In Central Punjab, 66% of tubewells are located

.

Groundwater depletion rate was 55cm/year in 2015, which has given rise to an endless cycle in which farmers keep on extracting groundwater and it goes deeper and deeper. As a result, the well is deepened by the farmer, and water is extracted which leads to an increase in the cost of boring and strong and expensive submersible pumps which directly increase the cost. Many farmers use to take loans to do bore for tubewell. 
Only a small % of farmers can repay the loan. Some farmers take some extreme steps to save themselves from the loan. Recently I read about the suicide of a farmer of Mandiani near Ludhiana because he couldn't pay back the loan of Rs 4,00,000 for getting a borewell. This is very sad and farmers must avoid this extreme step and think about their families first. 
Soil and Water Engineering department of PAU showed that in 2003-04, the sale of centrifugal pumps decreased to 22% while the sale of submersible pumps increased to 32%.
 
The groundwater of Punjab: Sweet, good for irrigation, EC(Electrical Conductivity)<2000 micro-mhos/cm at 25°C & Residual Sodium Carbonate(RSC) less than 2.5 milli-equivalent per litre in 80% of area of Punjab.
Natural Recharges of groundwater:
1. Infiltration due to rainfall
2. Seepage from the canal system
3. Return flow from surface irrigation

Rainfall+Seepage contribute to 1.65 MHa-m of groundwater (Aulakh,2004)
Out of 141 blocks, 103 are over-exploited, 5 are under critical range and 4 under semi-critical.
The rest of the blocks are under the white category where most of the blocks have brackish to saline groundwater.

Parihar et al (1993) estimated that total water requirement be equal to 4.37 MHa-m. Available water is 3.13 MHa-m & so there is a water deficit of 1.24 MHa-m.

Management Strategies:
1. To reduce water withdrawal.
2. To increase the recharging of groundwater.
3. Effective management of brackish water aquifers.

ET(Evapotranspiration) measured on June 10, 
  • Transplanted Rice=60 cm
  • Wheat=40 cm
   
To increase recharging:
In Kandi areas out of 1100 mm annual rainfall, 40% is converted to runoff during the rainy season.
  1. Reduction in the runoff to 20% by adopting different soil and water conservation practices can save 0.1 MHa-m water annually, by the construction of 
    • Terracing
    • Land leveling
    • Contour Bunding
    • Conservation tillage
    • Mulch farming
  1. Recharging by existing or excavating village ponds
  2. 66.66% of the water applied in irrigation goes back to the ground.
  3. Recharge from river surroundings.
  4. Recharge through Beins.
    • Beins are natural drains flowing in Doaba and end in the Sutlej river.
    • Beins flowing in the Eastern region are called White Beins.
    • and that in the Western region are Black Beins
Two ways to recharge through Beins
  1. By widening & regrading the beds of beins raising bank.
  2. By construction of seepage tanks on banks of beins after performing hydro-geological studies.
Rooftop Harvesting: 11.44 Km³ of rainwater could be harvested through Indian rooftops (30% of domestic water requirement)

Managing Saline water: 
  • Use of gypsum: Recommended when RSC of irrigation water exceeds 2.4 me/liter. The quantity of gypsum for every additional 1 me/liter of RSC works out 86 kg per 1000 m³ of water.
    1.5 quintal gypsum of agriculture grade is recommended after every 4 irrigations to neutralize the adverse effect of 1 me RSC/liter. This is done by the construction of gypsum beds.
  • Conjunctive use of poor and good quality water.
  • Green Manuring: This increases the water infiltration rate & CaCO3 solubility to some extent, hence this method mitigates the adverse effects of sodic waters.
  • Multiple WellPoint System.
Conclusion:
In the end, I would like to say that there is an urgent need of research & study in:
  • Artificial Recharge
  • Groundwater Modelling
  • Watershed Management 
  • Quality Monitoring
  • Aquifer Treatment

References:

STATUS OF WATER RESOURCES IN PUNJAB AND ITS MANAGEMENT STRATEGIES by Ajay Kumar Vashisht. J. Indian Water Resour. Soc. Vol. 28 No. 3, July 2008.

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