So yesterday messed with numbers and forgot where I was going: or at least the perception I had in mind at the start disappeared. I still don’t know what it was: perception and insight is like that, it comes and goes in the blink of an eye.
Anycase, the mobile population comprises of people who:
- Move between rented houses, rented apartments and residential hotels. These people would tend to move every 5 to 10 years, using large removal vans.
- Move around using caravans and motor homes, vehicles with own bathroom/toilet facilities. They need access to sites where they can dispose of sewage. These people will typically move every 1 to 5 years.
- Move around using caravans and motor homes, vehicles without own bathroom/toilet facilities. They need access to sites with ablution huts. These people will be expected to stay mobile and move every 5 years. They will have to move a distance of at least 1 km to another camping ground.
- Move around using trailer tents, or just a vehicle. They will need access to sites with ablution huts. These people will be expected to stay mobile and move every year. They will have to move a distance of at least 1 km to another camping ground.
- The final group of people will use bicycles, backpacks or possibly handcarts. They will need access to sites with ablution huts. These people will be expected to stay mobile and move every year. They will have to move a distance of at least 1 km to another camping ground.
There may be some people who just have a car, or back pack and move from residential hotel to hotel, or even between rented houses.
We probably already have a significant mobile population, it is just that such population isn’t a formal part of town and urban planning: except maybe as something to reject. Though I suggest that it is better that we plan to have a mobile population and provide facilities to accommodate.
A few years back I looked through the Adelaide UBD street directory and investigated the dimensions of large industrial facilities, the largest were less than 1 km x 1 km, and typically associated with car assembly plants. From the news these facilities employ around 2000 people, possibly more. Therefore from previous need at least two cells 1 km in diameter for the population, and one cell for the facility: a total of three cells. A full cluster is expected to have 7 cells, a central cell surrounded by 6 satellites. Therefore for such facility preferable to combine the areas into a single cell with an industrial core and ring of houses. This would be a cell 1732 m diameter, with a 732 m wide residential ring, or rounded up to a 2 km diameter cell with a 1 km wide residential ring.
Looking at the city of Adelaide the main block centred around Victoria Square is approximately 2.66 km in diameter, ignoring the parklands. The area is mostly, industrial, commercial and government administration, with some residential. People from Gawler in the north around 43.4 km away work in the city, as well as people from Mount Barker in the east 36.5 km away. People commuting from the south of the city is also important, I know people who have commuted from Blackwood 19.4 km away. People may be commuting to the city from even greater distances. So that roughly gives us a city with 100 km diameter with a 2 km to 5 km diameter central hub. We have a state population around 1.5 million people. I have already declared a 10 million person population for a 100 km industrial city-state. South Australian government would like to prevent further urban sprawl by getting more people living in the city. I say the problem is dependency on the central hub in Adelaide. Urban sprawl is not so much a problem of the spread of the population but dependency on a centralised hub.
We have failed to develop towns. Elizabeth city was built as a satellite city: thus inferring dependency on Adelaide from the start. To avoid urban sprawl, the population has to spread like ground creepers, they send out satellites, but at some future time those satellites severe their ties with the origin. They sever ties because the satellite is close to food supply and too many resources are required to send food back to the origin. The creeper thus gains the ability that animals have, and that is the ability to move.
So rather than Elizabeth being built as a satellite city it should have been built as an independent city, Likewise City of Tea Tree Gully, City of Port Adelaide, City of Salisbury: there is little point in calling them cities when their suburbs are considered suburbs of the metropolitan area of Adelaide.
Golden Grove business area and Tea Tree Plaza are regions around 1 km diameter. Looking at the north of England, the hubs of towns and cities also seem to match 2 km to 5 km in diameter, though they tend to have larger populations than those around South Australia. For example Greater Manchester has a population of 2,756,200, in an area of 1,276 km2 : thats a city with a population greater than South Australia. So we may have a population problem, but that is further compounded by a water supply problem. We already have water rationing, what would happen if we increased the population, of the driest state of the driest continent on earth, to 5 or 10 million people?
Whilst around 2/3rds of the 1.5 million people living within the Adelaide metropolitan area, 1/3rd is scattered around the rest of the state in the mining and rural towns. Though less than 5% of the national population is employed directly in mining and agriculture. So some of the people in these towns are support services: retail, education, health care, transport.
Still something is not right with respect to the services and facilities provided in the central hubs of small towns. The big question however is what services and facilities should be provided? If we were to start a colony on the Moon, or Mars, or space station beyond Pluto: what services and facilities would be required? How large would the hub need to be? How small can the hub be made? What size population can such hub support? What is the minimum size population needed to provide services? When the population increases beyond 1 person what additional services are required?