Croydon was redeveloped rapidly in the late 1950s, however much of its old character has been retained, with 4 scheduled ancient monuments, 6 Grade 1 listed buildings, ten designated conservation areas and over 150 buildings listed as having special architectural or historic interest.
Introduction to the Urban Morphology Models
Bid-Rent Theory
In 1903 RH Hurd recognised large differences in land values in urban systems due to differing abilities of different functions to compete for land. As cities grew and remoter areas were brought into use the central locations became increasingly accessible, which gave more competition and thus a higher value. Only potential users who thought they could gain the most from an area would pay the higher prices so uses like farms and houses would be furthest from the central area (CBD or Central Business District) and offices and shops would be closer in. This is shown by this diagram, where Bid-Rent is the amount the uses are willing to pay for land in an area.
This diagram shows that retail will occupy most of the central area of a city (marked I) because they are willing to pay more for the more accessible land where they can get most customers, then manufacturing so they have access to a large workforce(in II) and finally residential so they have access to retail and jobs(at III). Another line for farming, with a lower gradient than housing could be added, so that it would pay the highest price furthest out from the CBD, but the least close in. This model has been criticised because it does not incorporate the changes that have come around since the second half of the 20th century, for example, de-centralisation, reduced attractiveness of the CBD, private car ownership, dispersion of population and the attraction of peripheral locations.
Burgess Model
In 1925, E.W. Burgess presented an urban land use model, which divided cities in a set of concentric circles expanding from the CBD to the suburbs. This representation was built from Burgess's observations of a number of American cities, notably Chicago.
According to this model, a large city is divided in concentric zones with a tendency of each inner zone to expand in the other zone. This means that urban growth is shown as a process of expansion and conversion of land uses. For instance on this figure zone II (Factory zone) is expanding towards zone IV (Working class zone), creating a transition zone with reconversion of land use.
This model has been criticised for having very clear cut boundaries, and also for being very specialized – it has been found that this model was quite accurate, but only for fast growing American cities pre-1950. This means that aspects of change in cities such as transport innovations (mainly the arrival of the private car) and de-centralisation have not been incorporated into this model.
Hoyt
The Hoyt model introduces the idea of sectors to the Burgess model, with new growth covering the end of each sector.
Ullman and Harris Model
Hypotheses
Hypothesising is important because it gives an aim to the data collection and conclusion, a definite theory to prove or disprove. Also, being based on the urban morphology models they help to compare Croydon to these models.
With increasing distance from the CBD building height will decrease
Bid-Rent theory says that land at the CBD is very expensive because of the competition for the ‘useful’, accessible land. This means maximum use is made of the expensive land by making the buildings very tall. Further out from the CBD there is less need for buildings to be so tall. Since the land is cheaper and there is more available to build on, smaller buildings should be seen. These are also more ‘appropriate’ for the hypothetically housing predominant areas, and present a more pleasant environment.
With increasing distance from the CBD office numbers will decrease
Offices need to locate in the most accessible area they can in order that the workers can all get there easily. The most accessible are in settlements is the CBD so this is where the offices will want to locate. Also, more offices might want to group together because of possible transport and logistical benefits, therefore accentuating the number found in the CBD. The offices will be willing and able to pay the high prices found in the CBD because they need the accessible location for their large firm, but at further distances it is not worth locating there as it would be harder to find employees .However, offices might locate just out of the CBD area in order to have enough space for a car park or for the cheaper land, while still being in accessible areas.
With increasing distance from the CBD there will be a decrease in the number of comparison shops
Comparison shops have a large threshold population and a large range since people will be willing to travel far to buy infrequently purchased, expensive goods and services. If people have to travel far to shop or work there, the shop will want a well known and accessible location, which will be the CBD. The large comparison shops will be able to afford the high land prices here. Further from the CBD the location will not attract as many customers so it would not be worth it for the shop to locate there.
With increasing distance from the CBD pedestrian traffic will decrease
There should be more people in the CBD, shopping and working at shops and offices with I expect to be predominant there. There is also good public transport, so it is likely that lots of people will be walking from these links after disembarking. The CBD is very accessible, it is easy for people to get there and lots of reason for them to do so. In the suburbs there is little reason for people to be walking since they will probably be going a long distance, and therefore will probably be in a car or bus.
With increasing distance from the CBD open space will increase
Open space does not make money, so it cannot afford to be located where businesses are competing for land at the CBD. It is often found in residential areas where it generates a pleasant environment. The land is also cheaper because less people are competing for it, so it is more affordable.
With increasing distance from the CBD residential area will increase
This is based on Bid-Rent theory, in that people will only be willing to pay for relatively cheap land to live on. However, people will also want to be located near enough to the CBD to work and shop there. People cannot afford residences at the CBD since housing does not make money directly. Also, they will not be willing to pay the high prices because they do not need an accessible location, and the CBD may not be considered an attractive location because of large buildings and lack of open space.
Methodology
On Friday 4th May I went to Croydon in order to collect data about land use. The weather on this day was warm and mostly sunny, so we knew that people would not be discouraged from walking, which would affect the pedestrian counts (these are explained later). I met with my geography year group, which was split into groups of four. In my group was Adrian Gray, William Glen, David Daniels and myself. We started the day at what we considered the Peak Land Value Intersect, which is meant to be the centre of the CBD, where land prices are highest.
At 8:40 am we took the first pedestrian count as demonstrated in the diagram below.
Two people performed the counts, one on either side of the pavement. We stayed there for five minutes and counted all the people going past, and at the end we compared results and recorded them. We then carried on along the route shown on the map (other groups went on separate routes for a wider area of data), and took more pedestrian counts, one every 20 minutes, each lasting five minutes, giving a cycle time of 25 minutes. We also collected data on all of the buildings we passed. This included street name, number of floors, function(s) of buildings (in terms of the code shown in the appendices) and width (in 5 metre units), from which we also calculated building units (where one building unit = 5 metres * one floor). All this data was taken so that the hypotheses could be measured quantitatively. Width was measured by counting strides for each different building (the same person did all of the measuring so we knew the stride length was the same throughout). We found the function of the building by looking for signs of plaques (if none were visible, for example with offices or housing we made some educating guesses based on the evidence available).
Analysis
For the analysis, all results need to be converted into percent to make it easier to see trends, patterns and anomalies over just raw figures. Also it is useful to perform Spearman’s rank on each of the result sets since it will give us a definite trend result.
Spearman’s Rank
The equation of Spearman’s rank is:
where R is the result, d is the difference between the two ranks (one in order from CBD, the other in order of number size) and n is the number of 100 building units.
With increasing distance from the CBD building height will decrease
This shows a weak negative correlation, and although it agrees with my hypothesis I would say that it is too weak too draw any strong conclusions from. I will say that my hypothesis is probably correct, but more data would be useful
With increasing distance from the CBD office space will decrease
This shows that there is a moderate negative correlation.
Looking at the graph of percentage office space it is obvious that the results do not entirely correlate. In particular there are areas of very high office space quite far out form the CBD, which shows particularly in the individual results at all the values from 400 to 800, which are very high (even up to 100%), but also in the group graph, where at around 600 is very high also. Although this does not entirely agree with my hypothesis, I can think of reasons why this might be so. Firstly, the offices may be located further out in order to have access to affordable land to provide parking space for employees. Also, they may be located around transport nodes away form the CBD. In Croydon this would include East Croydon train station, which was located around the area of the high anomalies.
Evaluation
