Water Scarcity | Environmental Science | EVS | LetsTute - YouTube

In our previous sessions on HYDROSPHERE we had seen:

The exact distribution of water on our planet, The various uses of it and

How it is replenished in a continuous manner through water-cycle.

So by now, we know, how much essential, water is to human life and also to other living

organisms on earth. And, of the total water available on the earth, the water which is

present in rivers, lakes, ponds as well as the underground water is what actually are

available for our various uses. So, these freshwater sources can be rightly called �the

life blood of our planet�. And we all know, only 3%

Of the total water available on the earth, is fresh water.

Water is not just important for the biotic (living) components, but water is equally

valued from the ecosystem and environmental (non living) point of view.

But friends, this essential natural resource (water) is under a threat, as the water usage

has been growing, at more than twice the rate of population increase. And moreover, the

water distribution throughout the globe is uneven, which simply means that water is in

abundance at some places whereas it is scarce at some other. Regions like Australia, Africa,

Middle-east has a very little natural fresh water resource, and so also they face problems

of water shortage. The continent of Australia being dry faces frequent incidents of drought.

In certain regions of Africa, more than quarter of the population spends more than an hour

per round trip to collect water. The Arab countries again face problems of water scarcity

and also these regions have a threat to desertification and land degradation.

And friends, one thing we must remember here is, whenever we talk about water scarcity,

it is always associated with the fresh water resources.

So , let us all try to understand- A. This problem of water scarcity,

B. Some of the causes of it and C. The various ways to address this problem

a little better.

A. Concept of Water Scarcity- Water scarcity in simple terms could be said

as either lack of enough water (quantity) or lack of access to clean water (quality).

Water can be made clean only if its available. We can relate it as an imbalance between supply

and demand that varies according to local conditions. We will get back to it in a while.

Water scarcity could be of two different TYPES: a) Physical water scarcity-

Is exactly how it sounds like i.e. there is a limited physical access to water resource.

When the demand outstrips the lands ability to provide the needed water you have physical

scarcity. Here I give you three situations and you need

to identify whether there is water scarcity or not?

i) Situation 1: Suppose there is a desert region, where the water availability is low

as well the actual usage is low so can we call this area to be water scarce?

Explanation: No, because we said water scarcity to be imbalance in the demand and supply,

in the above case the availability i.e. the supply is less but the demand i.e. the use

is also less. ii) Situation 2: However, if there is a place

where natural water availability is abundant but the area has excessive population growth,

problems of pollution and unsustainable consumption, then can we call that place to be water scarce?

Explanation: Yes, we call this place to be water scarce, even though this place has water

supply, there is a growing demand of it causing an imbalance between the two.

iii) Situation 3: Now suppose, if there is a place where there is sufficient ground water

resource but due to very high cost of extracting this resource people are not able to use it

then can we call that place to be water scarce? Explanation: Yes, we call this region to be

water scarce. But here it is not a case of physical scarcity. This is because, there

is water available in this region, but because of economic constrains i.e. lack of financial

aid or due to less infrastructural facilities people are not able to access this available

water. So, the second type of water scarcity is economic water scarcity.

b) Economic water scarcity- It exists when there is an adequate source

of water in an area, but there are no proper means to utilize it in terms of money or technological

know-how.

There are certain indicators that reflect whether a country is water scarce or not:

when water supplies drops below1000 cubic meters per person per year, the country faces

water scarcity. But when these water supplies drop below 500 cubic meters per person per

year, the country faces absolute scarcity.

I hope the concept of water scarcity is clear now.

We have already seen how the various water resources are distributed in India and the

country is blessed with almost all types of water resources, but why do we still hear

cases of water shortage or scarcity in India?

B. Causes of Water Scarcity-

� With a large diverse population, India ranks second in the world in terms of its

population density and this growing population has resulted in a growing demand for water.

And we humans are a lot more careless, we waste more water than what we actually need.

Thus, population explosion is one of the reasons for water scarcity.

� This population also tends to shift from rural to urban areas, resulting in gradual

increase in the urban population. This urbanization further increases the water requirement for

construction or for any other developmental activities.

The rapidly growing population has also resulted in an increasing number of industries. Water

is required at almost every stage of production. This puts a heavy load on the total freshwater

available. Nearly 60% of the Indian population depends

on agriculture for their livelihood and uses nearly 90% of all water for irrigation. Farmers

have exploited the groundwater resources by uncontrolled use of bore well technology as

there is no proper irrigation facility available in the country.

In order to meet the basic needs of food, clothing and shelter for the growing population

many of the forested areas are cut down, leading to deforestation. When part of a forest is

removed, the trees no longer transpire this water, resulting in a much drier climate.

Deforestation reduces the content of water in the soil and groundwater.

Pollution of water resources is another major concern which is affecting the water supply

as well as human health. Many water resources of the country are polluted or contaminated

by chemical as well as biological pollutants. This is due to the discharge of untreated

sewage from homes, toxic chemicals from industries and pesticides and insecticides used in agriculture

into the nearby water bodies. These were some of the reason that is affecting

the water quality as well as quantity and making it a scarce resource.

But friends how do we tackle this problem? Is there a solution to it?

To find the answer to this question please tune into our coming session. Till then you

may suggest some the measures we can take to address this problem, through your comments.