10 billion tonnes. This amount of water is used in one day in the world. Out of this potable water is about 6 billion tons. 4.3 trillion cubic meters of potable water is used in the world every year. Yet 150 crore people in the world suffer from water scarcity. In 2050, the world’s population will increase by 270 crores, so after 30 years, twice the amount of potable water that is used will be required. An average person consumes 2171 liters of water a day! This includes the amount of water used from bathing to drinking and water used from washing clothes to cooking. Apart from that, the amount of water used in making the various products that we use has also been calculated in this.
If water-management is proper, no person in the world will remain thirsty. As an average American citizen consumes a maximum of 7000 liters of water per day. On the other hand, citizens of poorer countries have an average of 1000 litres. As many as 150 crore people are facing severe water scarcity due to unequal distribution. By 2030, the number of people struggling with water scarcity is likely to double to 300 crore.
A US-France Joint Water Quantitative Assessment Mission has been undertaken with the aim of combating the acute water scarcity situation and developing sustainable methods of water management in the long term. The American space agency NASA and France’s National Center for Space Research have jointly launched the Surface Water and Ocean Topography (SWOT) satellite in collaboration with Canada-Britain.
In 1978, NASA launched a satellite called CSAT. All the Earth’s oceans, their currents and water levels were scientifically observed for the first time. Thanks to this satellite, NASA studied things like rising and falling air in the world’s oceans, changing sea surface temperature, ups and downs of waves, internal currents and opened a new direction for researchers. Following this, USA-France jointly launched Jason series of satellites. The efforts of those satellites had started since 1992. After ten years of hard work, the mission was launched in 2001, and three satellites were used to study the water levels of selected rivers and lakes in the Americas and Europe in addition to the oceans. A decade and a half long mission yielded very useful information. Especially, these satellites gave accurate findings that the water of the rivers is drying up as the sea level is rising.
After a decade and a half of successful study of water volume on fixed terrain, America-France in collaboration with Canada-Britain took the lead of a global project and SWOT was born. The mission was not launched overnight, space agencies including NASA have worked for two decades on this global project. The help of techno-experts from all over the world has been taken to improve each and every device and make it efficient to get accurate information. A unique combination of the world’s top scientists and first-line techno-experts has taken place in this project. 1.2 billion dollars has also been spent on the project.
On December 16, this satellite was sent into space with the help of SpaceX’s Falcon rocket, and a new chapter was written in the field of water management and global water analysis. This satellite will be operational for 3 years and will orbit over the earth to assess all water sources. What factors are responsible for drying up of river water and what are its patterns? How and to what extent does climate change affect river water? How much of the ocean runoff can be saved? How much water melts into the ocean each year from melting ice? How much does that raise the sea level? It is hoped that SWOT will provide answers to many such questions.
SWOT is equipped with modern equipment. Since its purpose is only to collect water quantity data, it will monitor very closely. A device called Band Radar Interferometer will study the river-lake-ocean with 10 times finer detail. Usually what we call weather satellites collect only a fraction of the data. SWOT will prove to be a truly global satellite and will measure the amount of water in all countries of the world. It is estimated that this satellite will ‘watch’ and measure the water of about 50-60 lakh rivers and lakes in the Earth’s belt.
Its working method will be very unique. SWOT will also operate in the dark of night and continue to collect data. The barrier of darkness and cloud will not budge it. It is able to penetrate these barriers. According to experts, this satellite will make a 3D map of a river larger than 330 feet at once and can tell the real-time amount of water based on width, depth. Similarly, it will measure the surface of the sea up to 100 kilometers at a time. NASA will receive this figure twice every 21 days, which is collected by the radar system installed in the satellite.
As this is still at the primary level, its coordination work will also be arranged gradually. After that, how much water is in a big river now and how much it will decrease in the coming months and how many people will have to face water scarcity – all this will be told by SWOT. NASA believes that SWOT will save inland areas from water scarcity. Simultaneously, water-management can be improved in metros. Scientists around the world are calling SWOT a very promising mission. If this mission alleviates even a small amount of water scarcity, it will prove to be a boon for crores of people. Hope for the best!