Listed here are 5 methods to counter groundwater depletion within the Ganga basin

Managements of river catchments, floor waterbodies, wastewater and the agricultural sector, along with a water sources database can restore groundwater and enhance the Ganga’s circulate

Groundwater is the most important supply of contemporary water on Earth. It, nevertheless, stays uncared for as it’s out of sight and never seen like floor water sources.

The Ganga basin is one of the world’s most important and heavily exploited aquifers for groundwater. Depleting groundwater within the basin is thus a matter of grave concern. Virtually 25 per cent of the world’s groundwater extraction is going on right here. 

Groundwater growth classes
of blocks within the Ganga basin
No.ClassVariety of blocks

The basin, with a density of 520 individuals per sq. kilometre (sq km) is home to around 600 million people. The depleting water desk within the basin will immediately have an effect on 40 per cent of the Indian inhabitants that relies upon upon it for consuming water, irrigation, ecosystem providers and livelihood.

Some 407 (14.27 per cent) of a complete 2,852 administrative blocks within the 11 states of the Ganga basin (Uttarakhand, Uttar Pradesh, Madhya Pradesh, Rajasthan, Haryana, Himachal Pradesh, Chhattisgarh, Jharkhand, Bihar, West Bengal and Delhi), are already beneath the ‘overexploited’ class.

That is in response to the Dynamic groundwater Resource of India-2020.

A analysis revealed in Environmental Research Letters IOP Publishing (2021) famous that in 2002-2016, the Ganga basin misplaced round 226.57 ± 25.22 cubic kilometres of groundwater — about 20 instances the storage capability of the most important reservoir (Indira Sagar dam) in India.

This analysis supported the information revealed within the journal Nature (2018) that the groundwater storage within the adjoining Ganga plain aquifer had depleted by 30 centimetres (cm) per 12 months and the water degree of the Ganga river had decreased at completely different factors from 0.5 to 38.1 cm per 12 months between the summers of 1999 and 2013.

The Ganga is a gaining or effluent river, because the water circulate is contributed by means of the melting of Himalayan glaciers and baseflow of the groundwater throughout the non-monsoon interval. An outflow of about 13.28 billion cubic metres of groundwater (2011) is estimated throughout the non-monsoon months as a base circulate to the river.

Aquifer typologies 

The Ganga basin’s sediments are primarily derived from the erosion of the Himalayas and additional redistributed and deposited by the Ganga and its tributary rivers. 

The thickness of those aquifer-forming sediments varies from 1,500-2,000 meters bgl (beneath floor degree). The highest 200 metres of the basin sediments maintain about 30,000 ± 14,000 cubic kilometres of groundwater. 

Furthermore, the shallow aquifers (~50 metres) within the Gangetic alluvial deposits maintain about 30 per cent of the whole replenishable groundwater sources of India. About 8,300 billion cubic metres of groundwater is present in the basin of which, 99 per cent is in alluvium and one per cent is in exhausting rock aquifer.

These aquifers have been initially thought of to be a single, homogeneous aquifer system. Nonetheless, these might be subdivided into completely different typologies based mostly on groundwater recharge, permeability, storage, groundwater chemistry and sediment sorts. 

The major typologies are:

  • Piedmont margin
  • Higher Ganges
  • Mid Ganges
  • Decrease Ganges
  • Fluvial-influenced deltaic space of Bengal
  • Marine-influenced deltaic areas

The variations in typologies decide the high quality, quantity and price of circulate of groundwater from the aquifers.

Aquifer typologies within the Ganga basin

A map of the Indo-Gangetic Plain

Groundwater aquifers have two sorts of storage — renewable and non-renewable. Renewable storage might be simply replenished throughout the monsoon interval compared to non-renewable storage. The over-extraction of those non-renewable aquifers is the most important reason behind the depletion of groundwater within the Ganga basin. 

Aquifer challenges

The Ganga basin is dominated by groundwater use for its water requirement regardless of having floor water sources like rivers, streams, lakes, and so forth. Human interference has elevated the unsustainable exploitation of groundwater.

A number of elements have been recognized within the Ganga basin as essential challenges for groundwater aquifers’ sustainability. These embody:

  • In depth use of non-renewable groundwater
  • Local weather change
  • Enhance in floor temperature
  • Precipitation deficit
  • Fewer wet days
  • Decreased river flows within the non-monsoon interval
  • Ceaselessly occurring droughts
  • Quickly rising inhabitants and urbanisation
  • Land use and land cowl adjustments
  • Industrialisation
  • Indiscriminate waste (strong and liquid) and untreated sewage disposal in water sources
  • Deteriorating water high quality
  • Salinisation of shallow aquifers
  • Sea water intrusion
  • Mobilisation of naturally occurring arsenic
  • Rising nitrate concentrations
  • Improper administration

These elements have additional affected water and meals safety.

Stopping extra extraction 

The Ganga basin performs a major function within the livelihood, financial actions and socio-cultural views of tens of millions. Legal guidelines, insurance policies and administration frameworks must be reinvented and reframed to make sure water conservation and enhance water safety.

Listed here are some potential methods for groundwater restoration and environmental circulate enchancment of the Ganga river.

1. River catchment administration: Conservation of inexperienced corridors, restoration and rejuvenation of small rivulets and tributaries, mapping of paleochannels for potential recharge zone to retailer floodwater, necessary rainwater harvesting (RWH) and synthetic groundwater recharge buildings within the city areas (the place groundwater is five-six metres beneath the floor), will subsequently contribute to groundwater and river circulate. The usage of dysfunctional bore wells for recharging groundwater with clear rainwater can even be a superb possibility.

2. Floor waterbody administration: Restoration of ponds, lakes and different conventional water useful resource buildings must be an integral a part of the event initiatives of city and rural areas and it’ll considerably develop groundwater potential.

3. Wastewater administration: Twin sewage system for gray water and black water and selling reuse of the recycled water in agriculture and horticulture. Industries must also be inspired to extend water use effectivity, effluent therapy, reuse of used water, zero liquid discharge, and so forth. The Nationwide Inexperienced Tribunal in its order on December 6, 2019, additionally directed city native our bodies and anxious departments for the therapy of 100 per cent of sewage pouring into the river.

4. Agriculture sector administration: Agriculture alone consumes greater than 80 per cent of groundwater within the Ganga basin. On a worldwide scale, we’re solely 25-40 per cent irrigation environment friendly. Water-efficient irrigation methods like drip, sprinkler, avoiding water-extensive crops and use of handled wastewater for irrigation must be adopted.

5. Growth of database: An open / public database on all elements of water sources might assist policymakers and different stakeholders in correct administration and mitigation of challenges and issues.

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