Dehradun, Nov. 25 -- When civilisation began, humanity was compelled to settle along water sources and rivers. If there was climate change, people would either migrate or make the effort to transport water by canals and other means to where they lived. This led to extraordinary feats of engineering, many of which can be seen to this day, such as the Roman aqueducts, flood basins in ancient Egypt, tanks and ponds in India, etc. What was thought to be religious mumbo jumbo regulating irrigation and cropping proved actually to be scientific water management so that people upstream and downstream of a river could fully utilise rising water levels in rivers. If there were differences, these were resolved on a utilitarian basis - kings served the...