There is this common notion of people moving to cities for better asseciblity, convinience among all other things. Sometimes it is hard to believe people moving away from cities and setteling towards rural areas. If we look at history there are evidences where people have moved out of well established cities like Angkor, Pompeii.

Most of the times it is because of the planning or know how to address the floods, volcano etc. Even today it is very difficult of have a planning done to address issues forthcomming in the next few decades. We can see that in indian cities like central kolkata, central mumbai, roads of bangalore. All of these cities have lot of captial to allocate in comming up with plans for the next decades or so. I tend to belive that there are lot of plans in place.

If we look at Kolkata, the city is created when British bought the right from a mughal king to establish business in Kasipur village. It was essentially a collection of 58 villages.