Urbanization, farming, and water

Can we support a projected population of 180 crores (1.8 billion) without a crisis in food, water, living standards, and ecosystems?

Transit Oriented Development

In high-rise "Transit Oriented Development" urban spaces, it's easy to get nice homes with an on-ground density of 100 sq.meter per home. Let's take a city size of 300,000 people so that it can support a good education and healthcare infrastructure. Assuming 2.5 people/home that gives a population density of 40 sq.m/head and a city size of 12 sq.km. This can fit into a 2 km radius, quite friendly for walking or cycling and with very short in-city commutes. Inter-city transport would be supported by high-speed mass transit, railways, highways, and waterways where feasible. Airports can serve sets of cities, say at scales ranging from 4 to 40.

Can we house and feed the population with high living standards?

People will need food. There are 3.7 kCal per gram of cereal. A fit man needs 2,500 kCal per day. That's 0.68 kg/head/day. Per https://data.worldbank.org/indicator/AG.YLD.CREL.KG, India produces 2,993 kg/hectare. There are 100 hectares per square kilometer. So India produces 299,300 kg/sq.km. That means 442,964 people can be fed per day per square km, or 1,214 people per year per square km. So a city of 300,000 people will need 247.2 square km of food-growing fields. Those fields can fit into a ring of 9.1 km radius -- an inner circle of 2 km radius for the city, with a ring of fields, 7.1 km wide, around the city. Farmers can live in the city and enjoy urban standards of living. Bye-bye rural distress. And those urban standards are comparable to Paris (France): 25,000 people/sq.km. in that inner city versus 20,000 for Paris. If you include the fields in the city area for density calculations, it's just 1,160 people/sq.km. Intercropping gets us vegetables and fruits. We haven't factored in any increase in farm productivity. and we've also not factored in the output of orchards, gardens, and plantations outside the city limits.

Will we have enough water?

Average annual rainfall is 300–650 millimetres in India. Let's take 300 mm for our city. We'll harvest water over the full 259.2 sq. km. (city and farmlands) to get a water budget of 77,759,525 cubic meters of water/year. That's 710 liters/person/day, (300,000 people, 1,000 liters/cubic meter, 365 days/year). That's a pretty nice water budget. And remember that water can be recycled, and we've not even talked of recycling that we would, of course, implement.

Will it scale?

Each city will be at least 18 km away from its nearest neighbor. With a transit speed of 120 km/hour, that distance is 9 minutes. A conurbation of 36 cities would comprise 10.8 million people, about the size of London, New York, or Seoul. That conurbation would be 154 km. from corner to corner (if those 36 cities are arranged in a 6 by 6 square). So the longest commute would be 77 minutes from corner to corner. Not too bad, and we haven't even explored any high-speed transit ideas, just plain decades-old transit technologies.

Is it feasible?

66% of the Indian population is rural, ref https://data.worldbank.org/indicator/sp.rur.totl.zs, and about 400 million have not been born as yet. So we can build thousands of cities by upgrading existing villages as greenfield projects. Next, factor in satellite-city development near existing cities to handle their growth. We can get most of the way to the end state without even getting near the brownfield projects of existing-city revitalization. These revitalizations will encounter historical roots and cultures that we will need to consider, possibly as one-off designs that would preserve and enhance the deep urban cultures of the existing Indian cities.

A growing country with lovely cities, local food production, and re-wilding nature 

India's population is still increasing, and expected to flatten out at about 180 crores (1.8 billion). That's going to require 6 thousand such cities of 0.3 million people per city. India has a land area of about 3.3 million sq. km. The 6 thousand cities will use 72,000 sq. km. Compare that to the 222,688 sq.km. of current "urban land area" in India, ref https://tradingeconomics.com/india/urban-land-area-sq-km-wb-data.html). The ring of agriculture around each city will add up to another 1,483,191 sq. km. Compare that to 1,797,210 sq.km. at present, ref https://tradingeconomics.com/india/agricultural-land-percent-of-land-area-wb-data.html. So we can plant orchards, gardens, timber and other plantations in another 494,000 sq. km (15% of the land) and maintain the remaining 1,237 sq.km. (38%) as wild: for forests, grasslands, wetlands, and other natural landscapes that will restore our unbroken wildernesses for our ecosystems to thrive.

Dense cities, highly interconnected into super-cities: a recipe for economic growth. Each city surrounded by greenery, people eating sustainable local produce, an urbanized population with high quality of life. Lots of land set aside for wilderness. We can do it.