Why does Delhi need urban ecology? How to implement the same?

With an ever increasing population and a layout that fosters various ways of embracing urbanisation, metropolitan cities must indicate a paradigm shift towards participation in the conservation efforts of nature and wildlife. An urban ecosystem involves the convolution of intense human population offering economies of scale and novel types of interactions between the components of nature

What is Urbanisation?

With over 95% of urbanised population, Delhi stands out as the embodiment of the urban age in the Indian subcontinent. Urbanised Delhi has grown into the central focus of economic development and has been known to tackle the challenges of the dynamic social, technological and economical structures quite well. But what forms the crux of urbanisation? What parameters go into gauging the scope and the implication of urbanisation?

Economic and technological progresses alone do not contribute in establishing urbanisation. Urbanisation must take into account a complex set of cultural, conservational and environmental processes that together nurture the effective sustenance, growth and development of the metropolitan city.

Why does Delhi need an urban ecology?

As much are the benefits of taking the urbanised route, it has also caused some irreversible damages. Hugely populated metropolitans such as Delhi become the point source of pollution, depletion of nature and the place of production for several toxic substances. Ecologists thus far have been unable to derive the essential ecological inputs from these cities and have eschewed metropolitan cities as insufficient contributors for solving current environmental issues and preventing potential trouble of the future. 

An urban ecosystem that encompasses all facets of holistic growth is a strong need to sustain and develop the socioeconomic setup of the city. Ecologists working with these urban ecosystems must engage in deeper understanding of the social and economic requirements and relate them to the ecological footprint of the city.

A strongly established urban ecology is the need of the modern era and it is only by means of an optimized urban ecosystem that we can differentiate a well-functioning city from a dysfunctional urban centre.

Measures to adopt an urban ecosystem in Delhi

The first approach to establishing an urban ecosystem is to understand the various perspectives of human participation and to integrate these patterns into establishing long term conservational programs. In other words, the social perspectives of the residents must be matched with the environmental perspectives through deeper collaboration. 

In order to successfully establish an urban ecosystem for the long term, interdisciplinary discussions between ecologists, scientists, urban engineers, eco-political researchers and economists must be facilitated. The participants must have a clear understanding of the long term goals of the programs and the versatility of the solutions must be highlighted through proper implementation.

Nature Unbound

The requisition of nature within the walls of wildlife sanctuaries and nature reserves and through restrictive laws may be good reminders of what we choose to conserve against human intervention but however they will not serve as the only means of the preservation of natural resources in the long run.  

Artificial Recharge: The Cure for India’s Groundwater Depletion

Water is the most precious natural element. Not surprisingly, it is also the most used and therefore, the fastest depleting resource.

While water is being used in several ways, urban cities mostly depend on groundwater consumption, owing to its wide availability and easy accessibility. From small-scale users like domestic households, to larger industries and agricultural farms, groundwater is needed on a daily basis. This has led to its indiscriminating extraction and use, facing the human population with a major crisis, which, if not dealt with in time, can result in catastrophic consequences.

The high rates of usage and limited natural recharge have led to the severe depletion of the water table, resulting in acute dearth of drinking water in several parts of the country. The problem escalates during summer, when the yield of several groundwater wells and tube wells often comes down to zero. Today, more than seventy-two percent of the country falls under the ‘crucial zone’ due to groundwater over-exploitation.

Groundwater levels in India. Red indicates depletion and blue indicates recharge

What’s the solution?

One compelling solution to combat groundwater depletion is artificial recharge, a method of manually augmenting the amount of groundwater. This method has been prevalent in India for some 30-40 years and has been successful in various parts of the country.

The first phase of artificial recharge was before 1960, during the Green Revolution, when groundwater was still abundant. The second phase was between 1960 and 1990, and the third phase is from 1990 till date, when groundwater depletion rate has risen to an alarming rate (Todd, 1980).

However, artificial recharge is not a new phenomenon. This method of conserving water has been in use since the ancient times and even now, tanks and ponds are found all over peninsular India that are used for drinking, washing, bathing and irrigation.

Methods of Artificial Recharge

Artificial recharge of groundwater can be done in either direct or indirect ways or a combination of both.

Direct Methods

Flooding: In this method, water is spread as a sheet on flat topography. This water then vertically infiltrates to replenish the amount of groundwater. This works well when the aquifer is shallow.

Basins: Another method for shallow aquifers, this involves filling basins with water. This water percolates into the soil and adds to the level of groundwater. The amount of water entering the aquifer depends on the infiltration rate, the percolation rate and the capacity for horizontal water movement. (Todd, 1980)

Source: www.nicra-icar.in

Natural wastewater treatment can also be used to recharge groundwater by allowing treated waste water to percolate into the soil.

Source: www.nicra-icar.in

Ditches and Furrows: In areas with irregular topography, ditches and furrows provide maximum water percolation. This technique requires less soil penetration and is less sensitive to silting. (0’Hare, at al 1986)

Recharge Wells: This works like a tube well and is used to pump in treated surface water. These wells can also be used as pumping wells during summer. This is a costlier method of artificial recharge as it requires a special kind of tube well construction. (Image below: bore well recharge. Source: sswm.info)

Indirect Methods

The indirect groundwater recharge is done by setting up pumping stations near hydraulically connected water bodies, like lakes and streams. The amount of surface water depends on natural factors like the amount of rainfall and its frequency. (0’Hare, et al1986)

Modular rain water harvesting can also be classified as a form of indirect recharge as this water is stored in an underground water storage tank and then diverted to existing wells. Water conservation can also be done by creating rooftop gardens that not only combat pollution and increase rainfall but also help in storm water management, resulting in less erosion and floods.

Source: sswm.info

Success Stories

Andhra Pradesh: The Andhra Pradesh Farmer Managed Groundwater System has taken voluntary steps to reduce groundwater pumping, successfully.

Gujarat: Several water conservation and recharge projects have been highly successful in Gujarat, like the Sardar Patel Water Recharging Programme, that built check dams in association with the villagers, and Gujarat Green Revolution Company, that propagated sprinkler and drip irrigation technology.

Check dam

Chennai: Rainwater harvesting was made mandatory by an ordinance in July 2003 and all buildings were required to have rainwater harvesting structure.

The Last Word

It is not too late to save Nature and prevent groundwater depletion. We cannot stop the use of water but we can take measures to stop indiscriminate and unsustainable exploitation of groundwater. Artificial recharge is a movement in India, promulgated by the government, NGOs, community leaders, farmers and local people. The challenge now is to carry it into the future with the help of research and development programmes that will resolve the water depletion problem to a great extent.

References:

Central Ground Water Board (1994), Manual on Artificial Recharge of Groundwater, Government of India

Todd, D.K. (1980), Groundwater Hydrology, Wiley, New York

O’Hare, M.P., Fairchild, D.M., 1986, Artificial Recharge of Groundwater