Contents
From genetics to ecology, Biology Topics cover a vast array of life sciences.
Distribution of Water on Earth In Briefly and Things You Can Do To Prevent Water Waste
The distribution of water over the earth is quite uneven (or unequal) due to a number of factors. The most important factor responsible for the uneven distribution of water in various parts of the earth is the rain. Some places on the earth have good amount of rain and are water-rich. On the other hand, there are some places on earth (such as deserts) which have little rainfall and face water scarcity.
India is a vast country and the rainfall is not the same everywhere. Some regions of India have excessive rainfall whereas some other regions of India have little rainfall. Excessive rainfall causes floods whereas very little rainfall (or absence of rainfall) causes drought (sookha). Due to this, some regions in our country may have floods while other regions may suffer from drought at the same time. For example, Assam State in our country gets an average annual rainfall of 280 centimetres (which is very high) whereas Rajasthan gets an average annual rainfall of only about 49 centimetres (which is quite low). Due to this, Assam gets floods every year whereas Rajasthan has to face water shortage.
Mismanagement of Water
It may be possible that we are living in an area where there is sufficient rainfall and yet there is shortage of water. This can happen if there is mismanagement of water resources leading to the wastage of water. Mismanagement of water resulting in wastage of water will become clear from the following examples.
(i) Mismanagement of Water by Water Supply Department. At many places water is supplied through a well-planned network of big and small pipes. When water is supplied by the Water Supply Department through pipes, not all the water may reach the destination. Many times we have seen the big water supply pipes leaking and a lot of water gushing out of these pipes.
The leaking pipes lead to the wastage of precious water. It is the responsibility of the Water Supply Department of the town or city to stop this mismanagement of water by fixing the leaking water pipes quickly. Sometimes the dirty sewer water also gets mixed with the drinking water supply. This is also a case of mismanagement of water on the part of Water Supply Department.
(ii) Mismanagement of Water at the Individual Level. All of us, knowingly or unknowingly, waste a lot of water while brushing teeth, shaving, bathing, washing clothes, washing utensils, watering the plants and during many other activities. Leaking taps in our houses are another source of huge water wastage.
(iii) Mismanagement of Rainwater. Most of the rainwater which falls around us during rainy season just flows away into dirty water drains and becomes useless. This is a wastage of precious natural resource of water. The concerned Government Department as well as the public are responsible for the mismanagement and wastage of this rainwater. This is because rainwater can be used to recharge groundwater for future use.
Proper Management of Water
The scarcity of water (or shortage of water) can be overcome by the proper management of available water which helps in the conservation of water and minimises its wastage. Some of the steps which can be taken for the proper management of water are given below :
(i) Rainwater Harvesting. One way of increasing the availability of water to overcome its shortage is rainwater harvesting. The most important technique of rainwater harvesting is to make rainwater seep into the ground more efficiently by constructing percolation pits and recharge wells so as to recharge groundwater. This water can be pumped out in the times of water shortage.
(ii) Revival of Bawris. Bawri is a step-well (in which a person can go down by using steps to fetch water). Bawris were the ancient water storage and water recharge systems. Bawris were mainly set up in cities and big towns for collecting water so as to provide a water supply to the people during drought periods. With the introduction of piped water supply, the bawris fell into disuse and garbage started piling in them. However, due to the acute water shortage faced by the people in some places, the bawris are being renovated and revived. And because of revival of bawris, the people in these places are managing their water needs well inspite of scanty rains in their area.
(iii) Drip Irrigation. The proper management of water in agriculture can be done by using the ‘drip irrigation’ technique. Drip irrigation is a technique of watering plants by making use of a system of narrow pipes or tubes with small holes, which deliver water directly at the base of the plants (see Figure). Drip irrigation gives water directly to the root zone of plants at a slow rate so that it can be absorbed by the soil without any runoff (or wastage). Thus, drip irrigation minimises the use of water in agriculture. A farmer using water in the fields can use water economically by making use of the drip irrigation technique. Suppose we have been asked to maintain a garden. We can minimise the use of water for the irrigation of plants and trees in the garden by using the drip irrigation technique.
(iv) The wastage of water during the supply of water through pipes, and by the leaking taps in houses and other buildings should be prevented.
(v) Unnecessary use of water and over-drawing of groundwater (through tube-wells, etc.) should be avoided.
What Role You Can Play to Minimise Wastage of Water
We can save water (or conserve water) at home by minimising its wastage. The various ways to minimise the wastage of water at home are given below. We can call them water-wise habits.
- Get the leaking taps repaired immediately. Leaking taps waste a lot of water. Turn off the tap immediately after use. Do not keep the tap running all the time while brushing the teeth.
- Take bath by filling water in a bucket and not directly under the flowing tap. Wash the utensils by filling water in a basin and not under the running tap.
- Use the water from washing rice, vegetables or fruits for watering the plants at home.
- Do not use a full flush from the cistern in the toilet when a half flush is sufficient.
- Mop the floor instead of washing it daily.
The need of the hour is that every person should use water carefully, wisely and economically, and prevent its wastage. In order to attract the attention of everybody towards the importance of conserving water, 22nd March is celeberated as World Water Day every year. And the year 2003 was observed as the International Year of Freshwater to make people aware of this dwindling natural resource (gradually diminishing natural resource).
Effect of Water Scarcity on Plants
We grow many plants in pots in our homes. These are called potted plants. The potted plants are watered regularly. If the potted plants are not watered even for a few days, the plants will ‘wilt’ (become limp) and ultimately ‘dry up’. And if potted plants are not given water for a considerable time, they will die. Thus, sufficient water is essential for maintaining the life of plants. Plants need water to obtain nutrients from the soil, and to make food by the process of photosynthesis.
(i) The scarcity of water will affect the nutrient uptake by the plants and the process of food making (photosynthesis) in plants. So, due to scarcity of water, the plants will not be able to make sufficient food for themselves and for animals (including human beings). This will lead to severe shortage of food leading to famine.
(ii) Due to decreased photosynthesis caused by the scarcity of water, the plants will not be able to release sufficient oxygen into the air. The shortage of oxygen in air for breathing will harm all the animals (including human beings).
(iii) Plants help in bringing rain by releasing a lot of water vapour into the atmosphere through transpiration. Scarcity of water for plants will reduce transpiration. This will result in lesser rainfall.
From the above discussion we conclude that : Some of the effects of scarcity of water on plants are :
(i) shortage of food
(ii) shortage of oxygen for breathing, and
(iii) lesser rainfall. If water is not available to plants at all, then all the plants will wilt permanently and then die. When there will be no plants, the green nature of our planet (earth) will be lost. In the absence of plants, there will be no food for anyone to eat, no oxygen to breathe, and no enough rainwater. This may lead of the end of all life on the earth.
The Best Way of Overcoming Water Shortage : Rainwater Harvesting
We will now describe two cases in which the people have been successful in overcoming the acute water shortage in their area by practising rainwater harvesting.
Case 1. A place called Bhujpur in the Kutch area of Gujarat State has a very erratic rainfall (very irregular rainfall). The only source of freshwater in this area is the groundwater because the rivers in this area do not have water throughout the year. With the increase in population, the demand for water has grown too much over the years. Due to this, the drawing of groundwater (through wells and tube-wells, etc.) has far exceeded the natural recharge by the seepage of rainwater. As a result of this, the water table in this area went down too much and some of the wells and tube-wells dried up completely.
In 1989, the village people alongwith a Non-Governmental Organisation (NGO) decided to harvest rainwater. For this purpose, 18 check-dams were built on Rukmavati river and its many tributaries flowing through the area. The rainwater held by check-dams seeped into the ground and recharged the groundwater in aquifers. As a result of this, all the wells and tube-wells in this area have sufficient water now. In this way, the river water (which is basically rainwater) which earlier used to flow into the sea and get wasted has now become available as groundwater for irrigation and other purposes.
Case 2. Rajasthan is a hot and dry place which gets a meagre rainfall. The challenge of natural scarcity of water has been successfully overcome by the collective action of the people. A number of social workers have revived five dried up rivers, Arveri, Ruparel, Sarsa, Bhagani, and Jahazwali, by constructing rainwater harvesting structures. The increased water thus available has transformed a dry area in the Alwar District of Rajasthan into a lush green area.