PUBLIC SPACE, PLACE OF URBAN LIFE

Francisco M. Serdoura1,2 Jorge M. Ribeiro1,3

fs@fa.utl.pt jribeiro@fa.utl.pt

1Faculdade de Arquitectura. Universidade Tcnica de Lisboa Rua S Nogueira, Plo Universitrio, Alto da Ajuda

1349-055 LISBOA Portugal 2CIAUD Centro de Investigao de Arquitectura, Urbanismo e Design

Rua S Nogueira, Plo Universitrio, Alto da Ajuda 1349-055 LISBOA Portugal

3CERENA Centro de Recursos Naturais e Ambiente do IST Av. Rovisco Pais, 1049-001 LISBOA Portugal

ABSTRACT

This paper aims to contribute to the comprehension of the conditions that allow or support urban living within towns public space. This research work relies in the affinity that seems to exist between the configurations of urban fabric, drawn by the net of public spaces, the location of land uses and the patterns of urban living that were observed in these spaces. The data collected was submitted to a Principal Component Analysis (PCA) algorithm in order to characterise the public life in public spaces.

1. INTRODUCTION

Nowadays, there is a lack of methodologies for analysis and characterization of public life, land use and environmental issues in an integrated mode in the design of the new public spaces and intervention in pre-existent ones.

This paper proclaims that the analysis and evaluation methodologies to be use must have a scientific support that sustains the liability of the results to be obtained. In this context, space syntax analysis and multivariate data analysis, namely PCA, techniques were applied to an area of Lisbon Parque das Naes which presents the particularity of having been built from the ground during the last decade. This area is located in the East part of Lisbon, near Rio Tejo (Tagus River).

Urban life, as observed and studied in Parque das Naes, reflects an integrated vision on the way people use that part of the city, allowing to integrate in the study their perception/understanding of the urban shape, as well as the socio-cultural aspects inherent and the potential (environmental and functional) that the urban structure shows.

This study allowed the demonstration of how the quality of the urban design proved to be decisive to enhance people affluence to Parque das Naes area. It is also intended to demonstrate how the urban design quality influence people to develop there different patterns of activities, which enabled urban living in those spaces.

2. THEORETICAL ASPECTS

2.1 URBAN SPACE

Kevin Lynch (Lynch, 1981) sustains the importance of the procedure of urban drawing in the construction of modern cities, where public space enhances an intense urban living as long as it contains vitality, sensation, adequacy, accessibility and control.

Also Jacobs and Appleyard (1987) refer to these concepts in the manifest about urban design that determined the change between modern ideals1 and the new ideas about the city model that attempted the rehabilitation of the traditional city2. These two authors state seven objectives for the construction of high quality public spaces: life; identity and control; the access to opportunities, imagination and distraction; authenticity and meaning; public and communitarian live; urban self-confidence and good environment for everybody.

Tibbalds (1988), by his turn, makes the synthesis between traditionalist vision and human needs within public urban space, considering that the drawing of urban space, so that in it can occur urban living, must respect the heritage of the past and insert new interventions within the existing context, encouraging the diversity of urban functions in public space and people freedom of circulation in those spaces, satisfying needs of fulfilment to every social sectors and, simultaneously, avoiding large scale transformations. To public space planning should be given priority rather than to constructions; new urban spaces must be drawn to human scale and satisfy its needs, and should be built with legibility and durability, enabling interaction between people and public space and vice-versa.

2.2 THE PUBLIC LIFE

Hilliers theory of Natural Movement (Hillier et al.,1984, Hillier, 1988, Hillier et al.,1993 and Hillier, 1996) explores the relation between mainly pedestrian moves and the configuration of urban space, as well as between pedestrian flows and land uses. Subjects like accessibility and the character of urban spaces are important: for instance, a pedestrian flow in an unfriendly environment can be significantly increased if that space becomes friendlier, from the pedestrian point of view (Hass-Klau et al., 1999; Gehl and Gemze, 2000). Gehl (1986) also states that, in public spaces of reduced quality, only activities that are strictly necessary (ex. walking) can occur.

On the other hand, in spaces of high quality, necessary activities occur approximately with the same frequency, although people chose to spend more time in its practice, and more important, they tend to incur in an increased number of optional activities. The desire characteristic of persons to practice certain activities, subject to the condition of existing urban environment or to climatic conditions, allows people to develop optional activities

1 The urban model justified in the Athens Charter is considered as reflex and vehicle of a new social life, where it was believed that the configuration of spaces would determine behaviours and would change mentalities.

2 Where buildings shouldnt be regarded as the positive placed upon a free space (negative), but where public outside space (streets and squares) regains an ordering role and not as remaining, shapeless and insignificant (Portas, 1987).

within public spaces (Gehl, 1986). When people interact between them in public space social activities are developed, the character of the latter depend on the existing context, occurring in residential areas, multi-functional central areas and in those dominated by employment.

The role of public space, as well as the nature and the content of social interaction that occurs there, changes accordingly to social class, ethnic group, age, structures and type of urban dominant functions of the neighbourhood where it is located (Levitas, 1986). Ellin (1986) noticed how dominance and separation activities increased to contribute, in the present society, to the displacement towards the interior of the buildings of many activities that previously occurred in the streets. On the other hand, we must recover the argument sustaining that the city, while consisting in a system, promotes human connections. In this way, central areas of the city become guides, when allowing the opportunity for people to meet (Tibbalds, 1992). Therefore, public spaces must be accessible to all, regardless of age, capacities, origins or income.

Gehl and Gemze (2000) consider that the use of public space, as social and leisure places, has been growing gradually. In this way, urban planning recognizes more and more the importance to urban living of the different ways of public life in public spaces. The 90s (XX century) were marked by changes in institutional condition, both social and political, which drove to a new urban mentality. Strategic objectives were established in order to promote the sustained and maintainable development of the city, which enhanced the need to bring nearer its centre and the peripheries, through the improvement of the quality of public space, the integration of social dynamics and the proper completions of the first, which, in turn, are related with aesthetic concerns as well as functional arrangement concerns.

The perception of public space quality appears as a consequence of the perceived images of the local (where functional and formal aspects are melted), and as a result of who and how they are understood. The interaction between urban form and behaviour can be harmonizing or conflicting with human demands of urban life, but can not be separated from them. Changes and substitutions of human activities related with the use of space are the consequence of individual and social perception over that space, differing from case to case.

It can be said that, in order to better satisfy people that daily use public space, one must try to relate public spaces with urban context in which they are inserted, so that it can be possible to identify and analyse cultural and urban life changes that people promote whether individually or in group, since those are the changes that promote new needs and new spaces. It will be then desirable to encourage ways of drawing public space which work in the way of dedicating the city to everyone; it will be considered necessary to leave behind physical barriers that stipulate the access and movements of certain parts of the community, whether they derive from its situation within the cycle of life (children and aged people), whether they are unable (permanent or temporarily) of moving themselves normally.

3. URBAN MORPHOLOGY AND LAND USE PATTERN

3.1 OVERVIEW OF THE CITY OF LISBON IN 2001

In the beginning of the 90s (XX century), the priority given to the Municipal Master Plan (MMP) meant the establishment of occupation, use and transformation rules of the municipal

territory, by implementing options and urban concepts considered in the scope of the Strategic Plan of Lisbon. The MMP has recommended the reinforcement of the functional centre (office buildings concentration) in the Avenidas Novas (centre of town) and in less centralized areas, such as Chelas area (SE of town), Olivais (NE of town), in the area of intervention of Expo98 (E of town), in Aterro da Boavista (S of town) and in Alcntara industrial area (SW of town); as well as in different spots throughout the northern periphery of the city. The concentration of commercial uses (office and retail) foreseen in the MMP seems to contribute to justify the dimension of the central area of the town core, the Avenidas Novas (vd. Fig. 1). The privileged accessibilities between the geographical centre Avenidas Novas and the new urban expansion of the city Expo98 contributed to the emergence of a new centrality in that area of the city. The expansion of the centre towards North suggests that the growth of the city was due to the fulfilment of previously empty spaces, promoting a higher density in the urban structure of the Peripherical Ring area (vd. Fig. 1).

Figure 1: Integration (rn) of Lisbon 2001.

The towns new urban settlement, located by the Rio Tejo and resulting from the urban regeneration following the Expo98 actually included in Parque das Naes is one of the main centralities in Lisbon. The concentration of axis of strong global integration (rn) in the Eastern area of the town offers a stabilising condition to that area of the city, whether through the consolidation of proposed urban configuration whether through order in the structure of public spaces that have been planned. It is important to emphasize that the centre of the city coincides with urban areas whose spatial patterns are based in squares, morphologies that show a good degree of permeability.

The Parque das Naes new centrality of Lisbon generated a new functional dynamic in the city, contributing in this way to the morphologic stabilisation of the Eastern area of Lisbon, through the construction of an harmonious urban structure strongly articulated with its surroundings (ex. Olivais e Moscavide) and with the centre of the town (ex. Avenidas Novas). The morphologic quality of the squares, that configures the urban structure of Parque das Naes, allows each part to maintain its own identity, without distressing the whole (the global area).

3.2 THE SPATIAL PATTERNS OF PARQUE DAS NAES AREA

The space syntax analysis of the urban configuration of Parque das Naes contributes to understanding how the urban structure can enhance the mobility of people in urban space. The strong integration (rn) of the central area of Parque das Naes (vd. Fig. 2), reinforced with cautious urban fabric, appears to demonstrate that public space holds favourable conditions to people uses.

Figura 2: Integration (rn) of Parque das Naes 2001.

The importance of Parque das Naes as a spot of centrality in Lisbon is shown by the dimension of its urban structure. This fact helps understanding of how the centre of the city leaned towards the Eastern periphery of Lisbon. The accessibility that the Parque das Naes net shows, establishes an important factor allowing comprehension of the relation between people and public space, within the development of urban life.

4. METHODOLOGY FOR PUBLIC LIFE ANALYSIS

4.1 DATA SET OVERVIEW

In the study for public living in Parque das Naes, it has been considered a set of variables representing land uses, design characteristics of public space, environmental characteristics of that space and developed human activities observed in public spaces. It is also worth mentioning that the variables deducted from the space syntax analysis of the urban net were equally considered in the analysis.

As potential generators of intense pedestrian moves, the areas of: offices, retail, restaurants and civic facilities, form the main set of variables used in this study. Other land uses able to show flow peaks of concentration were also considered, although they usually do not generate intense moves, namely: housing, local facilities, tourist equipments and logistic.

The environmental variables considered, were: tree alignments and artificial elements providing shadows, green spaces (gardens, parks, green areas and river promenades) and water elements. The variables of urban design considered in the study were: side walk width and their useful area, markers and parking. The elements of urban furniture in public space, which promote the conditions of occurrence of human activities, were also assumed as factors attracting pedestrian moves or leisure and public social contacts. As variables analysed in this scope were considered: benches for resting/relaxing, aesthetic elements and public art.

The use of axial maps, representing the system of public spaces, allowed the calculation and measurement of different properties of the urban system. A set of those properties (measured) was tested according to its importance in relation to the empiric information used in this work, specifically: uses, environmental factors, number of persons present in public spaces and number of persons engaged in activities. The measures of space syntax analysis that were used against the empirical data are: integration (rn), mean depth of lines, measure R (radius 3 r3), control, connectivity and axial lines length.

The principal human variables considered in this study were the different groups of users of public spaces sorted by groups according to age (children, youth, adults and elderly persons) and by gender. It was also considered persons with locomotion difficulties or disabled persons, tourists, construction workers, security officers (employees of Parque Expo98, S.A.) and suppliers (people that support the running of commercial activities). Secondly, different groups of activities developed by people in public spaces were considered, as they are potentially generators of public life, grouped by: strictly necessary (walking), optional (eating, staying in the sun, reading, sitting and smoking) and social (talking/mobile phone talking, running/jogging, cycling, roller skating/skating and walking the dog).

4.2 MULTIVARIATE DATA ANALYSIS METHOD

The simultaneous study of multiple variables vs. public spaces, sustained upon advanced statistical techniques, is considered as part of the Multivariate Data Analysis, while using statistics with a multi-dimensional incidence. The variables above presented were organised in a matrix of 47 variables by 67 urban spaces. This data set was submitted to a Principal Component Analysis (PCA) algorithm in order to characterise the relationships between

variables, urban spaces and variables & urban spaces. The similarities or differences between activities performed by people in public space, at different periods, was one of the objectives of the analysis. It was considered that, if different groups of persons performed the same type of activity in different environments, it was possible to make that analysis with the help of this factorial method which allows a graphical representation of these proximities between groups of persons.

In the study of relationships between the variables, it has been considered that two variables are correlated if there dispersion behaviour relies upon a linear structure (Ribeiro, 1999). Similarly to the idea underlying the bivariate analysis, the PCA is a powerful tool in the establishment of relationships between different variables, combining them. The preliminary univariate and bivariate variables analysis, usually is not enough to explain some of the information that is hidden in a set of data. Therefore, the multivariate data analysis is a precious tool in this field, enabling the description and analysis of the data as a whole, redrawing information that in another way remained disguised.

The previous matrix3 was divided in six sub-matrixes referred to different periods of time of the day. Each one of these sub-matrixes was submitted to PCA algorithm in order to allow the analysis, in descriptive terms, of the existing relationships between the activities and the public spaces where they occurred. The co-ordinates of the variables in the factorial axis correspond to the correlation coefficient with the associated factors, i.e. the axis, contained in the interval [-1;1] (vd. example of Fig. 3 for one of these time periods).

Figure 3: Projection of the variables on the factorial plan F1/F2, for the period between 8 and 10 am.

3 The matrix was built and organised in a way so that the columns (variables) and the rows (individuals), allow the crossing of the information referring to the activities developed by people in public space, meaning that each element of the matrix ija represents the number of people that perform one given activity (column j) in a given public space (row i).

It is considered that the variables projected in the interior of a circumference centred in the origin and a 0.5 radius, are not explained in that factorial plane. The variables projected outside of this circumference are explained by the respective factorial axis.

In Figure 4 the relations between used public spaces are showed. The concentration of dots around the origin projects public spaces without distinction between human activities, while the public spaces projected outside, revealed diversity and intensity of use and human activities.

Figure 4: Projection of the spaces on the factorial plan F1/F2, for the period between 8 and 10 am.

5. CASE STUDY URBAN LIFE AT PARQUE DAS NAES

The analysis of the results obtained by PCA allowed the spatial mapping of the human activities in the public spaces that were revealed as more important in terms of public life. At the first hours of the day (8:00 10:00 am) the urban life in Parque das Naes was dominated by people necessity to reach their working places, or by the option of paying a visit to local shopping areas to purchase goods or services in spaces as Avenida D. Joo II (1), the axis with greater concentration of services in the area, and in the beginning of Avenida do Pacfico (2) (vd. Fig. 5).

Figure 5: Patterns of public life in Parque das Naes, 8:00 10:00 am working days.

Also, in the beginning of the morning, urban life is filled with the significant presence of children. Their presence in public space had more impact in Passeio de Ulisses (3), as this is

the best access to Oceanrio (4). Besides using that area to access the above mentioned equipment, they also used public space to perform other activities, namely the well being and urban leisure, having their morning meal there, enjoying the space dimension and for safe entertainment.

Simultaneously, in this period, elderly persons enjoyed an urban life more individualised, guided by permanence. They have chosen places with benches or low walls where they can seat, spending some time in quiet privacy, although in the vicinity of other people, watching other peoples activities. This occurs preferably by the riverside spaces, Passeio das Tgides (5) and Rua da Pimenta (6) (vd. Fig. 5). By the other hand, groups of young people and adults used those two spaces for conventional leisure, particularly running/jogging, and non conventional leisure, using the space for cycling. Environmental characteristics and drawing of urban space, with quite big dimension, where the division in sub-spaces (Garcia da Horta gardens (7)) is subtle but clear, enhance the diversity in the use by the different groups (adults, youth and elderly persons), and proved to be more suitable to activities whether occasional or social. Also due to the same characteristics, some people have chosen Alameda dos Oceanos (8) (central space) to perform some activities of well being and urban leisure (vd. Fig. 5).

In the mid morning period (10:00 12:00 am) the necessary activity (commuting) had been observed according to flow patterns, where people passing trough the area profit of their presence in the area to enjoy the environment, trying to take advantage of such a pleasant space and surrounding landscape (vd. Fig. 6).

Figure 6: Patterns of public life in Parque das Naes, 10:00 12:00 am working days.

According to the different age groups in public space, lunch time (12.00 14:00) registered movement patterns showing the good use of the working pause. People going out of their working places and walking to the locals where they regularly have their meals (Shopping Mall (12), bars and restaurants by the river (13)) usually go in small groups (2-4 persons) in a relaxing way, talking together, smoking or talking in the mobile phones. The most used space in these moves is Avenida D. Joo II (1), where the promenades have a comfortable width (4 meters), allowing people to walk side by side, also being the shortest distance to the Shopping Mall (12) (vd. Fig. 7).

Figure 7: Patterns of public life in Parque das Naes, 12:00 14:00 working days.

Those who preferred the bars and restaurants by the river for their noon meal, had to cross the area in the East/West direction, having to change direction at least twice; therefore these moves formed a sinuous pattern. In this case, people tried to take advantage of the pleasant environment, by choosing spaces with trees or water elements. People opting to remain in this area, were influenced by security reasons (the presence of more persons), and by the comfort associated to the presence of urban furniture suitable to their needs, for instance, benches.

In early afternoon, after lunch time (14:00 16:00), people that used Parque das Naes showed availability to remain for longer periods. Among the groups present in the area, the adults were the ones that registered the greater number of presence in the space. The children and youth groups were also active in the area. Passeio das Tgides (5), Rua da Pimenta (6) and Jardins de gua (14), were the spaces with higher people concentration, as a consequence, on one hand, of the urban fabric and of environmental comfort and, on the other hand, due to the large dimensions, allowing great diversity of use to all different users (vd. Fig. 8).

Figure 8: Patterns of public life in Parque das Naes, 14:00 16:00 working days.

In mid afternoon (16:00 18:00) the observation of urban life in Parque das Naes provided the record of different types of pedestrian movements (vd. Fig. 9). Between 17:00 and 18:00, a pattern of direct movements was recorded, strongly related with the first period of people leaving the offices. This movement was again registered along the axis where the services are located (Avenida D. Joo II (1)).

Figure 9: Patterns of public life in Parque das Naes, 16:00 18:00 working days.

In the end of the afternoon (18:00 20:00), patterns of urban life associated to the concentration of employment in that area were again observed. Between 18:00 and 19:00 people used public space as an interface between the offices and the means of conveyance (vd. Fig. 10). This pattern of direct movement was observed in Avenida D. Joo II (1) (space where services are located), towards the bus and train station (Gare do Oriente (16)), transforming Praa do Oriente (17), the beginning of Avenida do ndico (18) and Avenida do Pacfico (2), in spaces of convergence (vd. Fig. 10). The necessary activity (walking) has always been associated to other three: talking, smoking and using mobile phones, which allowed the association between movements and the social contact among persons.

Figure 10: Patterns of public life in Parque das Naes, 18:00 20:00 working days.

Later, between 19:00 and 20:00, the pattern of urban life observed showed a higher diversity related to urban living (ex: eating), leisure (ex: sitting while watching the sunset) or non conventional recreation (ex: cycling and walking the dog). The observation of such diversity of activities in only one space (Passeio das Tgides (5)), validates the quality of urban fabric, the identity of the local, the control that people have upon the space and the diversity of opportunities that they can delight while using it.

6. CONCLUSIONS

The study of public life in Parque das Naes allowed the evaluation of the way people interact with urban space (public and private) and how it has stimulated people to do a variability of human activities. The space syntax analysis allowed to statement the existence

of public spaces with less activity, where urban life was scarce or occurred occasionally (to which correspond spaces of less accessibility and therefore less integrated) and the existence of spaces with good accessibility, where urban life was more intense and diversified, becoming spaces of compulsory passage. The study confirmed the belief that the central zone of Parque das Naes is a place where people enjoy staying in their day to day activities or in leisure. The permeability of the urban fabric proved to be very good, particularly in the periods of higher affluence and concentration of people in the public space (8:00 10:00 am, 12:00 14:00 and 18:00 20:00).

This research work also allowed the identification of urban functions that contributed more to the occurrence of urban life in Parque das Naes. Although the studied area showed a diversity of urban functions, only some (offices, retail, restaurants and civic facilities) revealed the existence of relations of dependence with the number of persons present in the public space. The quality of urban drawing (side walks width, area of pedestrian public space), the presence of urban furniture in most public spaces (benches, markers, etc.), the environmental quality of the space (shadow areas and water elements), where factors that allowed testing the pleasantness of the space and the dynamic of the relations between space and people, showing that the former stimulated the latter to stay in the area for longer periods of time.

The results of multivariate data analysis drove to the conclusion of the existence of an important correlation between variables that characterise the pleasantness of the urban environment and the diversity of existing functions and the number and time of people permanence in public space, as well as with the activities that they developed there. In fact, positive correlations beyond 0.60 were found between the following variables: totality of people TP, totality of adults TA, total area of construction TAC, special land uses EU, retail/restaurants C/R, useful length of the streets LUt, side walks width pass, green spaces EVerd, benches Banc, water elements H2O, walking And, sitting sent, drinking bebe, eating come, talking Conv, smoking fumo, global integration (rn) Tint and connectivity Conn. In this way, it was possible to conclude that not only the quality of the public spaces and their functions diversity influence the way it is used by people, as well, different behaviours of people are observed as a function of the type of activity they want to perform in the public space, which leads to a intensive use of these spaces in detriment of others, as a function of its physic and urban characteristics and of the position they hold in the net of urban connections that they guarantee.

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