The compilation of these Water Resources Notes makes students exam preparation simpler and organised.
An Introduction to Water Resources
Water – a must for all life forms on earth and the most important natural resource. We all know that about three-fourths of the earth’s surface is covered with water. But about 96.5% of the global water resources come from the oceans and seas. In India, the water resources amount to an estimated 1897 square kilometers per annum. However, we all know about the shortage of Water we are facing as a country. Let us learn more about the conversation of the water resource.
Some quick Facts and Figures
- The total volume of water on the earth’s surface – 96.5%
- The total volume of usable freshwater – 2.5%
- The volume of freshwater in ice-sheets and glaciers – 70%
- Stored groundwater – 30%
- Precipitation (rainfall) in India – 4% of earth’s total
- India’s rank in the world for water availability per person (per annum) – 133
Conservation & Management of Water Resources
‘Water water everywhere, not a drop to drink.’ It is a very old saying in a different reference to the situation. But, this is exactly what we fear will happen very soon, if we do not wisely use and conserve our water resources.
Research shows that by 2025, India, along with many other countries will face a serious scarcity of water. Many regions in our country are currently undergoing the process of ‘water stress’. According to research by Falken Mark, a Swedish expert on water, ‘water stress’ happens when the water availability falls below 1000 cubic meters per person per day.
How did we reach here?
Though blessed with large rivers like the Ganga, Yamuna, Godavari, Narmada, and others, India’s socio-economic development has a lot to contribute to decreasing water resources. Rising population, industrialization, urbanization and modernization of agriculture, are some of the main reasons for water shortages in many parts of the country. As a result, most of our prominent rivers, especially the smaller ones have become toxic with waste products and pollution.
Saving Our Water Resources
Water is indeed an essential resource for life on earth and it must be conserved. In fact, historically, humans had learned to conserve the available water resource by building dams.
Dams are simply hydraulic structures that act as a barrier between the source and destination of flowing water. Earlier, these dams were small and hand-made. In our modern society, engineering techniques and methods are used to construct most of these dams.
Depending on its need, the water flow can be obstructed, redirected, or slowed down using a dam. The barrier often creates a small reservoir or a lake, collecting the excess flow of water. People use most dams for irrigation. While some dams are used for generating electricity, which we know as ‘hydropower’ or ‘hydro energy.
Dams can be of different types and of various sizes. While timber dams are made from wood, the masonry or embankment dams are made with stones and concrete. Dams can also be low, medium, or high in height, depending on their location and usage. Though dams can be helpful in conserving water resources, too many of them can also cause over sedimentation of the river beds.
Also, over usage of dams can reduce the aquatic life of the river, on which they flow. That is why we also have more natural and long-lasting methods of saving our water resources. The two most widely used methods are:
You must have come across this term from multiple media sources. Rainwater harvesting is one of the most efficient and effective ways of conserving water. It is more like the recycling of natural water. In this, rooftop rainwater harvesting is a common practice in states like Rajasthan, West Bengal, Meghalaya, and major parts of South India, where rainfall is usually heavy. People connect PVC pipes to a drain on their roof and the rainwater is collected below in large storage tanks.
This water is then utilized for daily needs even after rains are over. Mostly, people do not collect the water off first rainfall but thereafter. In Shillong and other parts of Meghalaya and rain-prone regions of the North East, water from rooftop rainwater harvesting covers about 15-25% of household water requirements.
DIY: You can try a home experiment for your learning exercise. Collect the rainwater and store it. You can even filter the water for a clean output. Now, use this water for your household needs or plants. Did you know? In the state of Tamil Nadu, it is compulsory for every house/residential building to have a rooftop rainwater harvesting system!
Bamboo Drip Irrigation System
This is an indigenous method that has been in practice for about 200 years in the north-eastern states of India. While this practice helps conserve the region’s water resources, it also helps in the irrigation of local farms and fields. People use bamboo pipes for tapping the waters of streams and springs. About 18020 liters of water flow through a network of pipes and end up as drips on the farmlands.
What is water stress?
According to research by Falken Mark, a Swedish expert on water, ‘water stress’ happens when the water availability falls below 1000 cubic meters per person per day.
What are the different methods of water conservation?
We can conserve water resources using different methods:
- Dams: These are hydraulic structures that can either control, redirect or obstruct the flow of water from a water body. Dams are made from wood, stone, or concrete.
- Rainwater Harvesting: Rainwater is collected from rooftops or ground and stored in large tanks for later use. Rainwater harvesting is popular in Rajasthan, West Bengal, Meghalaya, and Tamil Nadu.
- Drip Irrigation: This method is most practiced in North-Eastern states, for irrigation of farms as well as save the local water resources. Bamboo pipes flow water over a long distance and end up in drips when they reach the plants.