Prof. Arup Dasgupta
When Apollo 11 astronauts looked back at the earth from the moon they saw a beautiful blue marble; 70% water and only 30% land, that they called their home. A scientist on Mars, suffering from acute water shortage, might draw a conclusion that as this world was composed of 70% water, this must be Elysium. May be the Martian military would use this information to launch an expedition to colonise Earth and use its ‘overabundant’ resource of water which is so much in short supply on Mars.
In the H G Wells classic War of the Worlds; the Martians were defeated by microbes. Had Wells written this story in the 21st Century, he would have probably had the Martians be defeated by water scarcity.
In fact the world is in the midst of Water Wars. In the past half a century there have been over 1,800 disputes between countries, of which 21 led to military violence, Darfur being a prime example. This situation is likely to be exacerbated because only 0.0076% of the 2.5% fresh water sources like lakes, rivers and streams are actually available for human use. This is further compounded by the skewed distribution of water resources; Asia which carries 60% of the world’s population has access to only 30% of the global water resources. The implication of these statistics is clear; we have to optimise the use of this precious resource, control its wastage and maximise its reuse. Thankfully, the last task is made easier because water is a renewable resource. The task of using g-tech to manage water supply, distribution and reuse is the lead story of this issue. The applications range from discovery of groundwater through remote sensing, managing surface water, managing and optimising water distribution networks, managing waste water and finally groundwater recharging. Perhaps the most dramatic example is the use of NASA’s GRACE satellite to show the depletion of groundwater due to over pumping for irrigation in the plains of Punjab, India.
In this issue, we have also covered the use of g-tech in other disaster situations, from manmade disasters to natural calamities like tsunamis, cyclones and floods when water turns from a life giver to a life taker. An aspect of manmade disasters is the acts of terrorism and the use of g-tech to interdict such events is also growing and proving to be very effective.
The applications covered in this issue bring to the fore a simple fact that g-tech is playing an increasingly critical role in the well being of the third rock from the sun.