Multi Nuclie Modal

City and metropolitan planning
Assignment submission Topic: - (1) multi-nuclei planning (2) Urban hierarchy and functional linkage

SUBMITTED BY: SANJEEV KUMAR MAHATO, ROLL NO. [1230002] 2ND SEM, MURP, [AR2207]
DEPARTMENT OF ARCHITECTURE, NIT, PATNA

Multi-nuclei planning
INTRODUCTION
The multi-nuclei development in a metropolitan planning is based on the observations that frequently, there are series of nuclei in the pattering of the urban land uses. It is a modal of urban land uses in which a cities grows from one central business district (C.B.D.).

CHARACTERISTICS * The number of nuclei and the function each vary one metropolitan area to another. * Each nuclei acts as a growth centre from a particular kind of land use such as industry, retails or high quality housing. * It merge to form a single urban area. * Central business district is not only the generator of change.

CONCEPT
C. harris and Edward ullman (1945) expanded this concept in their article on “The nature of cities” they have observed and studied many planning tools and modals and came to a conclusion that C.B.D. as the major centre of commerce. They suggested that, there should be appropriate specialized cells and area for particular activity. * C.B.D.--- Light manufacturing and whole-saling located along the transport routes. * OUTER EDGE OF CITY --- Heavy industries surrounded by the lower income house-holds. * URBAN PERIPHERY --- Occupy by suburbs and smaller service centres.

MULTIPLE NUCLEI MODAL * According to modal a city includes more than one centre that activity revolve. * Even distribution of resources, residential areas and transportation costs. * The ecological modal created by harris and ullman in his article (1945). * This modal is suitable for the big and expanding cities. * Certain activity require specialized facility such as ports, railways etc. * Certain activity require to stay apart such as heavy industries, airport, steel plants etc * Certain activities are found together to their mutual advantages such as universities, hotels, shops, hospitals etc. * Certain activity requires the facility to be set in rare areas in a city like the C.B.D. needs the convenient traffic and factories needs abundance source of water. * Certain events are benefited from the adjacent distance like the position of work stations (places) and residential zones. * Certain events easily leads negative influences such as steel factories near green belt. * Certain constructions have to build in a suitable spaces and areas.

FACTORS OF MODALS * Interdependence of certain types of activity and their needs for close physical proximity. * Natural clustering tendency among certain types of activities that find mutually profitable to locate together. * The appearance of centres accommodates activities that may have no particular affinity for one another, but are inimical to another uses by virtue of the traffic they generates. * Related factor of high rents or high land costs which have the effects of attracting of repelling users in the process of nucleation.

ADVANTAGES * Locations of each nuclei reflects its economic needs eg:- heavy industry locates close to the port. * Different centres attract growth and encourage further development. * All nuclei grow until they merge and form one large urban area.

CRITICISM * The concept may not totally applicable to oriental cities with different cultural, economic and political backgrounds. * Negligence of height of buildings. * Non-existence of divisions between zones. * No consideration of physical relief and government policies.

CONCLUSION * There is no clean C.B.D. * The modal predicts the movement allows for the specialization of regional centres. * This modal is most applicable to new and fast growing cities.

Urban hierarchy and functional linkage
INTRODUCTION
A settlement hierarchy is a way of arranging settlements into a hierarchy based upon their population or some other criteria. The term is used by landscape historians and in the National Curriculum for England. The term is also used in the planning system for the UK and for some other countries such as Ireland, India and Swaziland. The term was used without comment by the geographer Brian Roberts in 1972.

The greater the population in a settlement, the larger geographic area, the higher the status and the greater the availability of services. Position in a settlement hierarchy can also depend on the sphere of influence. This is how far people will travel to use the services in the settlement; if people travel further the town becomes more important and ranks higher in settlement hierarchy.

Urban hierarchy a term that relates the structure of towns within an area. It can typically be illustrated by dividing towns into four categories: * 1st-order towns * 2nd-order towns * 3rd-order towns * 4th-order towns

1st-order towns provide the bare minimum of essential services, such as bread and milk. The services that 1st-order towns provide require only a very low threshold population to survive, which make them suited to small communities. Services that require more customers to remain viable are not found in 1st-order towns. 3rd- and 4th-order towns are larger cities and communities. They are home to services that people are willing to travel longer distances to get to, as they are more important or rarer. The services in 3rd- and 4th-order towns require large threshold populations to survive, which is why they are only found in more developed areas. It is clear, therefore, that there should be more 1st-order towns than 4th-order towns, as 1st-order towns only require a small number of people in their hinterland to remain viable.

EXAMPLE OF URBAN HIERARCHY
In this example, an isolated building is at the lowest point, and the ecumenopolis is at the top with the greatest number of people: Note: This settlement hierarchy is adapted from the work of Konstantinos Apostolos Doxiadis for the actual current world situation as of 2010 as opposed to Doxiadis' idealized settlement hierarchy for the year 2100 that he outlined in his 1968 book Ekistics. * Ecumenopolis - theorical construction in which the entire area of Earth that is taken up by human settlements, or at least, that those are linked so that to create urban areas so big that they can shape an urban continuum through thousands of kilometers which cannot be considered as a megalopolis. As of the year 2009, the United Nations estimated that for the first time more than 50% of the world's populations lived in cities, so if these were linked, the total population of this area would be about 3,400,000,000 people as of 2010. * Megalopolis - a group of conurbations, consisting of more than ten million people each. * Conurbation - a group of large cities and their suburbs, consisting of three to ten million people. * Metropolis – a large city and its suburbs consisting of multiple cities and towns. The population is usually one to three million. * Large city – a city with a large population and many services. The population is