Introduction

1The Algerian urban planning still depends on the creation of new cities. The first new cities in Algeria were intended to relieve congestion in the big cities and to rebalance the interior of the Algerian territory (Sidi Boumediene and Signoles, 2017) until the 2000s when sustainable urban development was introduced with its charters and requirements. Presently, one of the main objectives in the Algerian national land use planning scheme (in French, schéma national d’aménagement du territoire SNAT) is to achieve sustainable new cities: cities created by political decision within an environmentally urban planning framework in terms of processes, techniques, materials of construction and planning by promoting the use of local resources. These cities must also be designed on a human scale in metropolitan areas and promote the economic potential of the regions in which they are integrated. (Achaibou Younsi, 2013).

2This trend of sustainability is also starting to be applied for a while in new cities around the world. France is an example with the experience of Marne-la-Vallée, the Netherlands because of the exiguity of its territory which fights against urban sprawl and the preservation of its natural resources, followed by the Moroccan example in the Maghreb with its new projects of sustainable new cities inspired by the model of traditional cities commonly named "the medinas". Algeria is still relatively late in implementing sustainability requirements in urban projects (Bekkouche, 2014) despite the legal arsenal made available over the last twenty years (law n° 01-20, law n° 02-08, law n° 10-02, law n° 11-76 and law n° 06-06). For this purpose, several questions arise on the conditions of realization of the Algerian new cities: How can this be possible when we adopt an unchanged linear urban planning based on the principles of modernism since the Athens Charter, a charter that promotes spatial zoning and therefore contributes for a separation of functions? Why is the recently emerging concept of multifunctional land use relatively neglected in Algeria while it is increasingly studied in the world? How to assess the multifunctionality of new cities in Algeria? Based on this study, can we establish an assessment grid of multifunctionality for Algerian new cities to be generalized in other countries of the world?

3The main Algerian cities are experiencing a rapid and uncontrolled expansion in relation to the rest of the country, creating an imbalance: five relatively developed metropolises versus the rest of the Algerian territory with a major lack of infrastructure and urban facilities (Sidi Boumediene and Signoles, 2017). The SNAT outlines a new policy of rebalancing the territory with new cities, cities designed in a sustainable manner in a form of compactness, diversity and integration of functions or specifically the multifunctionality of spaces.

4In this context, the question then arises as to: What types of cities will be established in reality? How will the distribution of functions in this city respect the new concepts and ensure the conditions fulfilled in the SNAT?

5This work aims to assess the multifunctionality of the spaces of one of these cities, Sidi Abdellah, in order to verify the relevance of the discourses on the new city and their accordance with reality.

6This work is basically a study of the new cities in Algeria and their current situation. Their description by some inhabitants and professionals as dormitory towns is a source of concern and interest for scientific researches. After an extended analysis of the presentation reports and speeches about these cities, which confirmed the existence of an integration of functions and multiple activities in the same spaces, it is a question of checking where this contradiction between words and reality comes from, and of trying to find out if this multifunctional use of spaces has really been realized in the field and to evaluate its nature and degree. This paper aims to improve the adoption of this urban paradigm in new towns by involving a new evaluation methodology which has not been applied before in this type of towns in Algeria.

7We choose to study multifunctionality as it is an urban concept which synthesizes several urban parameters which can distort the research by analyzing them separately. Through the study of multifunctionality, we can group together in a single analytical study by measuring multiple urban forms in a single paper (Song and Knaap, 2004): the study of density, diversity and distance (as named in our case proximity of facilities) from the 3D (Cervero, 1997) and mixity (social and functional mixity through its different indicators) (Jabareen, 2006).

8The choice is therefore made to use the MLU because its evaluation allows the precision of the results to be given by studying several parameters combined, despite their quantitative and qualitative indicators which can be very complex to study (Le Néchet, 2012).

9Multifunctionality has several benefits: it reduces the car-dependent trips (Le Néchet, 2012; Cervero, 1997) by offering a diversity of functions in the same space and then avoids the urban sprawl in the future. The impact of density and mixed land use on utilization of car and transportation and the impact of the urban forms and built environment have a great influence on the lifestyle and travel behavior of users (Handy, 2005) as well as socio-economic effects (De Groot et al., 2004).

Methodology

10This paper is composed of three parts: the first part reviews the concept of multifunctionality of the urban space in general. It is based on the bibliographical research carried out mainly on the "web of science" database. The results are processed with the bibliometric software VOSviewer (version 1.6.15, free and downloadable). This first part is a literature review focusing on scientific productions directly related to the concept and its application in urban planning. This led to the development of an analytical grid, which would allow the evaluation of the degree of multifunctionality of the different spaces that compose a city, applicable to the subject of our work which is the new cities in particular.

11The second part deals with the problem that is on the current agenda in Algeria: the state of the new cities and the search for an alternative sustainable urban planning with an optimal and multifunctional occupation of spaces. These models could help to overcome the dominance of collective housing and the lack of transport modes and services. This part is based on field study, the author's on-site visits and interviews with the managers in charge of our case study: the new city of Sidi Abdellah in Algiers. These interviews were followed by a survey of 100 of the inhabitants of the new city to confirm the initial results; several questions were based on the information needed to our study i.e.: the existence of functions, their nature, their diversity and the degree of multifunctionality as seen by users.

12The last part assesses the degree of multifunctionality in the urban spaces that compose the new city of Sidi Abdellah, a city where construction work is the most advanced among the new Algerian cities. We have chosen the neighborhood scale as the basic scale for this study and we have assessed the concept of "multifunctional land use (MLU)" for each urban area, in order to have a complete mapping of the city and its degree of multifunctionality. This choice follows the urbanistic approach of the designers who adopt the logic of fragmentation of the city into "urban islands" (as described in the report of its presentation). They define each section of land that primarily groups a function with housing, complementary services and natural spaces. The data processing was elaborated using Geographic Information Systems GIS (with the ARC GIS 10.2 software) on the basis of four significant criteria selected after study. These criteria are: types of activities, ways and degree of multifunctionality and the time (duration) of occupation of the spaces by its users.

13Finally, we have to explain the reason why we have added the survey (the subjective evaluation) to our result’s study (the objective evaluation); the approach used for the assessment could be purely mathematical using modeling (Stürck and Verburg, 2017) but this will deeply marginalize the needs and expectations of new cities residents, the urban forms are linked and influenced by the social practices and perceptions of users in all their complexity (Dris, 2005).

Multifunctionality of urban spaces

14The concept of mixed and compact city appeared with "the smart growth" in the United States in the early 1990s (Handy, 2005); the first scientific publications about it appeared in 1998 (Downs, 2005). It emphasizes the diversity of urban uses and functions with the creation of a favorable environment for pedestrians. It has been preceded since the 1980s by the "neotraditional urbanism" movement, which later became "new urbanism" with a more fashionable name (Picon and Orillard, 2012), encouraging a return to the principles of traditional urbanism, a diversity of functions and activities in a city and their proximity (Dupuis, 2017).

15The concept of multifunctional use of space had an impact in the Netherlands first and then with a German evolution (Brandt and Vejre, 2004; Mander et al., 2007), it became the "urban multifunctional land use (MLU)" or the concept of multifunctional use of urban spaces (Vereijken, 2001). It was inspired in geography and urbanism by the field of agriculture (Brandt and Vejre, 2004; Fry, 2001) where it was widely applied to increase production with a rational, diversified and annual use of agricultural land (Dufour et al., 2007). It encourages a compact city model with diverse functions, especially with a synergy between the proposed functions (De Groot et al., 2004).

16The MLU implies the combination of high densities, compact cities, mixed zones with pedestrian or bicycle traffic, with the creation of synergy between the different functions injected (Van Broekhoven and Vernay, 2018): "It is said that a land-use pattern becomes more multifunctional when, in the area considered, the number of functions, the degree of interweaving or spatial heterogeneity increases" (Rodenburg and Njikmp, 2004).

17The MLU provides a sustainable environment by taken into account the economic, social and environmental objectives (Grant, 2002). This close relationship between sustainability and the compact and diverse urban form (Emelianoff, 1999) drives the Algerian planners to introduce compactness, mixed land use and the function integration (the multifunctionality) to the urban schemes of new cities (Bekkouche, 2014) and adapt the city to Algerian cultural values and social behavior changes (Grant, 2002).

18The papers published in the database "Web of science" on the theme of "multifunctional land use" as a keyword reach 841 articles from 1975 to 2020 in all fields. We obtain a total of 294 articles about this concept when refining the search in the following fields: environmental sciences, geography, urban studies, sustainable ecology, regional urban planning and architecture. The search was not exclusively based on Web of science but also Google Scholar and the website of Strasbourg university library (bu.unistra) which also gives access to the defended theses (using the platform theses.fr).

19The multifunctionality of spaces has partially in common some elements with what some French urban planners call "circular urbanism": an urban planning inspired by the circular economy, in analogy to the human metabolism. It is an urban planning based on recycling and reusing urban spaces and permanently rebuilding the city on itself (Grisot, 2020); thus avoiding the risks caused by the urbanization of agricultural land and urban sprawl, but also the high development costs of a dispersed city, compared to an economically dense city (Grisot, 2020). In sum, circular urban planning promotes the reuse of vacant and wasteland spaces by assigning them other functions. In the case of the MLU, it encourages assigning functions other than the main function to urban spaces even if they are still functional, thus increasing their duration and occupation level (their "life cycle" according to Grisot) in order to avoid more construction, more land consumption and therefore more sprawl.

20The papers about MLU have been published most often in ecology, landscape and planning journals (focus will be on the latter); these publications are quite recent. Since 2009, publications on this concept have multiplied in Germany and the Netherlands, followed by Australia and the United Kingdom. Empirical studies came after from the United States and Western European countries.

21This interest in multifunctionality can be explained by the fact that these countries have already experienced several transitional phases in their urban planning since industrialization and the image of their cities have been transformed with the acceleration of motorization. On the other hand, this concept is little known in the countries of Eastern Europe and Africa, particularly in Algeria, which have so far experienced partially (or implicitly) the damaging consequences of urban sprawl and fragmentation in their large cities (Keeton and Nijhuis, 2019). For this reason, research in this field is significant in Algeria to avoid what industrialized countries have already experienced since the early 1960s, by moving towards a more sustainable, softer, more energy-and space-efficient urban planning according to its own context.

22The correlation scheme (Figure 01) has been established with the key-words cited in the 294 previous scientific productions. The Vosviewer software brings them together to study the relationships of strength and importance related to the MLU. The writing in large format characters reflects the importance of the theme and the colors as well (red being for the most important relationships, followed by green, blue, yellow and last the blue for the weak relationships).

23We can see the close relationship between this concept and sustainability (ecosystem services, multifunctional landscapes, governance and green infrastructure) on one hand and the mixed and intensive use of spaces on the other hand. From this; we can deduce that one of the primary objectives of sustainable urban planning is to achieve an optimal functional mix of spaces in any city (see the link with city, cities, urbanization and urban planning).

24It also shows that the strongest relationship exists between this notion and land use, which explains the capacity of multifunctionality to be applied in different fields of research concerning the exploitation of space (urban planning, geography, agriculture, etc.).

Assessment parameters of multifunctionality

25Multifunctionality can be defined as a combination of different functions in the same area (or space). It is recognized that some spatial functions can be merged to save energy and space, and to be more respectful of the environment (Rodenburg et al., 2003). The concept aims to maximize the use of a single space and increase its occupation time; reduces urban sprawl and car dependence and long travels.

26There are two types of classification (according to Remesar and Costa, 2004): the dominant urban functions or the main functions dominating an urban area and the located urban functions or the specific functions that complete the dominant functions.

27According to Dieleman and Wegener (2004), the concept is directly related to the compactness of a city and its degree of urban sprawl. Batty et al. (2003) define it as a relative concept, complicated to realize in practice and in theory; its estimation is easier for the periphery: because of its dispersion and spread, where the functions (generally the only function) of a space are more easily identified than for the center, which is a compact space diversified in alternating functions, and therefore difficult to recognize. They also link it to density: if the density is low, the functions are dispersed; if it is high, this implies a grouping of activities in the same space and/or at the same time, although this explanation knows an exception if the density of land use is increased by the housing function and the latter evolves in height.

28Multifunctionality has also affected green spaces in cities to deliver useful products; participate for leisure and recreation and provide an aesthetic environment; all in the same time (Van Leeuwen et al., 2010).

29On the basis of these definitions and the research carried out, it is estimated that multifunctionality includes the concept of multifunctional use of space, social and functional mixity, compactness, density and diversity.

30Contemporary researchers study the multifunctionality as a solution to the problems of zoning and spatial segregation (Brandt and Vejre, 20004) and demand the coordination of all implied actors (Van Broekhoven et al., 2015).

31Recently, multifunctionality has inspired planners in sustainable urban planning because it breaks with modern-style zoning that causes urban sprawl (Jacobs, 1961). This concept has other benefits as well:

• It reduces the need for new construction, increases the density of urban areas, and leads to more economically and socially dynamic cities, unlike dormitory towns or old centers that currently empty out in the evening of their users (Batty et al. 2003).

• It also contributes to the reduction of commuting migrations (by car or public transport) (Le Néchet, 2012), to the overconsumption of space and thus has economic, social and environmental advantages.

• It is also linked to users and promotes a social and intergenerational mix with maximum optimization of the duration and occupancy rate of spaces, which sometimes leads to the use of vacant space for other functions but requires synergy between the proposed functions (Ghafouri, 2016). The most representative example is the use of school classrooms and playgrounds outside their main use, during summer vacations for exhibitions, sports activities or the reuse of offices for other purposes beyond working hours and on weekends.

32The current lifestyle - with working women, more travel and smaller households compared to traditional family units (Dupuis, 2017) - will continue to spread and it is important to create comprehensive programs of attractive housing, facilities (especially commercial) and services and to create a spatial equilibrium (De Groot and al., 2004). This partly justifies a return to the neighborhood as a basic unit in the desired city model (Dieleman and Wegener, 2004).

33In sum, the MLU can be part of a sustainable city model because it implies a return to a dense, mixed and nearby city. It can therefore be considered spatially as an essential component of sustainable urban planning. It is about raising the parameters that allow us to assess the degree of multifunctionality in a new city in order to contribute to the construction of a new city model that is multifunctional and therefore part of the sustainable model.

34The previous literature review on the MLU and its analytical reading allowed a decomposition of indicators of the multifunctionality of urban spaces. Based on the criteria selected for their relevance and their close link with the concept and its application to new cities, we have attempted to present them in the following table while trying to classify them into categories (Table 01).

35From each paper, we extract the parameters that can assess MLU in the Algerian new cities (according to the context), the parameters that can provide us a maximum of information to find out the nature and the degree of MLU in Sidi Abdellah.

Table 1: Table of criteria (parameters) for the evaluation of urban multifunctionality

Assessment categories	Reference	Evaluation Criteria	Aspects of analysis
Scale	A. Ghafouri, 2016	Small scale	We study the space in the architectural scale; it can be the housing, a grouping of buildings or constructions generally.
		Medium scale	It is the scale of a district or grouping of several districts.
		Large scale	The scale of the city in this case so we can therefore judge whether a city is mono or multifunctional.
Type of activities	Jan Gehl, 2010and Jane Jacobs, 1961	Necessary activities	Housing, industry (factories, companies), gardens and parks, playgrounds, shops, hospitals, restaurants, schools, education, mobility (any transportation infrastructure).
		Secondary activities	Administrations public equipment and services (agencies, banks...)....etc.
		Complementary activities	Cultural public equipment (Museums, cinemas, theaters), sports (gyms, swimming pools), touristic equipment (hotels) and security...etc.
		Housing diversity	- Individual, - Semi collective, - Collective housing.
Type of environment	Batty and al., 2003	Central	Old town centers.
		Residential	Exclusive residence function.
		Mono-environnement	Dominant function.
		Combined	Forwarding and mixed zone.
Ways of multifunctionality	Priemus et al., 2004	By interweaving	Several functions in several spaces.
		By spatial heterogeneity	Occasional extra functions (during weekends and vacations for offices and schools, etc.)
		By diversity	Several functions in one space.
Degree of multifunctionality	Souidi, 2018	Monofunctional	Only one space, one function, one type of users and rarely occupied.
		Functional	One space, one function, more users and more occupation over time.
		Mixed	More than one function, more users and more occupation over time.
		Multifunctional	Necessary and complementary functions in a single space, constantly occupied by all types of users.
Specific features	Gahfouri, 2016	Space	Additional details about the space in consideration that contribute to our study (small or large, open or closed, public or private).
		Time	Daily, nightly, weekly, seasonal, annual...etc.
		Function	Additional details on the functions involved (such as frequency or rhythm and links between functions).
		Users	- Social classes (underprivileged, poor, average, rich), - Age groups (children, young, old), - Gender (male, female), - Family composition (singles, young couple, small family, large family).

Source: Author, 2020

36In the end of this part, we should point out that the matrix includes as many assessment criteria as possible but that the case study is also taken into account in parallel to its elaboration (which is the new Algerian city and Sidi Abdellah precisely). It is possible, however, that these indicators may vary in order to use the same matrix in the analysis and assessment of multifunctionality in other new cities while respecting the general context of reception and the specific criteria of the city itself; it is then essential to set up indicators that are compatible to each case.

37Due to the lack of information collected and the resources needed to carry out the evaluation process, we have selected only four parameters for the evaluation: type of activities, type of multifunctionality, degree of multifunctionality and time occupation. These are the parameters that provide important and useful information to create our databases for mapping. The questions of the survey were made according to the specific features so we can have additional information for the creation of our GIS database. We finally excluded the scale parameters; the type of environment and the specific details about the space due to their minor impact (significance) for this study.

Case study in Algeria: the new city of Sidi Abdellah

38New cities in Algeria are defined as a new creation generally, based on one or more existing housing centers, decided by executive decree after their nomination to the national land use planning scheme SNAT (the most recent revised version is from 2010 to 2030). They are managed by a public institution called the "new city organization" (EPIC in French) responsible for directing the study and implementation actions and carrying out infrastructure and equipment operations on behalf of the state (SNAT, 2010). They are intended to relieve congestion and control the uncontrolled urban sprawl in the metropolis and should serve as centers of social, economic and human balance, through employment, housing and equipment opportunities.

39They are subdivided into three categories according to their geographical location and according to the objectives relating to the characteristics of each geographical area of the Algerian territory.

40Sidi Abdellah is considered as one of the first new cities in Algeria and the most promising in terms of sustainable development. Unlike the other cities where work has been interrupted for years and has recently restarted, the construction of housing programs in Sidi Abdellah continues with some basic equipment and infrastructure: Was this the objective in the creation of the new city of Sidi Abdellah? How is the social and functional mixity in Sidi Abdellah planned in the development of infrastructure at the national level and housing units at the neighborhood level? The main question in this paper is the following: Is there really a multifunctionality of urban spaces in this new city? Can we say that the sustainable (or at least multifunctional) new city model has been concretely applied to Sidi Abdellah since the revision of the SNAT in 2010 and the projects resumption in accordance with the new laws? Has the new city public organization explicitly integrated the concept of multifunctionality as one of the tools of sustainable development?

Presentation and situation of Sidi Abdellah

41The new city of Sidi Abdellah was created in 2004 by the law decree number 04-275 which contained its basic functions, objectives, future population and its general program with a public institution as the managing organization of the new city (EPIC VNSA). Sidi Abdellah extends over an area of 7000 hectares (only 3000 hectares can be urbanized and constructed, surrounded by 4000 hectares of natural spaces as a protection area), located in 25 kilometers far from the capital Algiers, in the south-western periphery.

42In terms of accessibility, Sidi Abdellah is close to the railway line of Zéralda with two peripheral roads North and West. The road network is also classified into four categories: main roads (bypasses and national roads), secondary roads, service roads, and neighborhood roads (see Figure 02).

45In addition to compactness, its development should in theory be based on the creation of "integrated neighborhoods": the definition of their purpose or content is ambiguous in the report (Mission B, 2010, Part 2:13, 34-36), but a deeper reading reveals that the main purpose of an integrated equipment, neighborhood or center is to provide a secondary function backed up by the basic function.

46The speech of the report says a lot and proves to be very ambitious, but if we compare it briefly with the projects underway at VNSA, we can quickly realize that sustainability is reduced to the environmental aspect and that multifunctionality is here reduced to functional (and/or probably social) mix. This will be discussed in the last part of this article.

Sidi Abdellah: Discourse vs. Reality

47Jean Jacques Deluz, the Swiss architect who lived and died in Algeria in 2009, was the first architect designer of the project of Sidi Abdellah since 1997 when the Algerian government wanted to realize new cities around the big Algerian cities. He mentioned in one of his interviews (Deluz, 2007) that the collective housing took the major part in Sidi Abdellah. It is a reality in all the other new cities; the area of the city is very large and the neighborhoods realized were identical to each other, their inhabitants went to work far from the city and were not present during the day, they come back for the evening, that’s why many journalists and researchers describe Sidi Abdellah as a dormitory town. The Algerian authorities justify this by a constant urgency to rehouse the middle and underprivileged classes (See figure 03).

48We made several visits to the new town of Sidi Abdellah where we raised some preliminary remarks as an architect and urban planner. We also visited the public institution of the new city (EPIC VNSA) to discuss with the professionals who have worked and are still working on the ongoing projects of this town. Thus, based on press articles, our own visits and meetings within the organization planners, we make the following observations:

• It turns out that the new city so much dreamed of by Deluz and designed by Algerian architects as a high-performance technological center is in reality just a dormitory town where all the apartment buildings and blocks look the same, where a new inhabitant, an illiterate elderly person or a small child can get lost looking for their own home. Sidi Abdellah is even described in the Algerian and international press as “urban chaos” (Bozonnet, 2017).

• The installation of most of the inhabitants in their homes was carried out despite the unfinished infrastructure work; it was justified by the authorities by the constant urgency of rehousing the middle and underprivileged classes, but also of allocating housing to young households before the completion of the road works and the construction of the infrastructure accompanying the housing.

49As urban planners, we had made many visits to the city of Sidi Abdellah where we raised some problems. We also went to the managers of the organization of the new city for some interviews. On the basis of the literature and documents collected, the information we got from the visits and the interviews, we could create and establish the maps below to assess the parameters of multifunctionality selected and named previously: types of activities, ways and degree of multifunctionality and the occupation time by the users.

50In order to support our study results and have a wider view on the user’s situation and their daily life, we conducted a survey for 100 persons (first, the survey was shared online because of the pandemic of Covid-19 and completed then in the new city). The questions focused on the last two specific features of the table above (Function and time) to complete the information for the data collected before. These two parameters where excluded from the assessment because we could not have more details until we completed the survey and had enough answers.

Results and discussion

51To answer the initial question: Is the city of Sidi Abdellah a multifunctional new city? And to check the relevance of the remarks and observations presented earlier, we proceeded first to create the map of Sidi Abdellah using the GIS that did not exist before and then we joined to it a database created from the information collected on this city and on the functions assigned to its spaces. Here is the thematic cartographic representation of the results of our study, which we will present as follows:

The objective evaluation (GIS data processing):

52Figure 04 is the map “types of activities”: Among necessary, secondary and complementary activities: The thematic cartographic analysis of the "types of activities" criterion in this map reveals some balance of functions in some neighborhoods of the new city, but there are also neighborhoods with completely empty zones without any function. The planners explain this by the incomplete projects of the new city (especially in the north-eastern neighborhoods). For this reason, the north-western and southern parts are the most structured in terms of function assignment (balance between housing, services and recreation areas). We also note that the activities (functions) at high risk are located far from the residential neighborhoods and high-traffic areas.

53Map of ways of multifunctionality in figure 05 (interweaving, spatial heterogeneity or diversity): In this same framework, for the study of the indicator "multifunctionality ways" represented in the map above, the presence of empty fields (grounds) is noticed. We also found that there is no area with the criterion of spatial heterogeneity which means no area accommodates additional activities outside the time of occupation by its main function, no area is arranged to accommodate another function during weekends or vacations, for example. Spaces with functional diversity are very rare; mono-functionality is dominant in almost all the districts of Sidi Abdellah.

54Map of the degree of multifunctionality (figure 06) ranging from monofunctional space (represented by the sign 0), functional space represented by (the sign 1), mixed space represented by (the sign 2) to multifunctional space (the sign 3): This map shows that monofunctional spaces are largely the empty lands and the rest are equipments (facilities) that contain a single dominant function or a district with exclusive residential use, most often collective. It is the latter type of space that occupies most part of the new city, followed by functional spaces. The central northern part of the new city enjoys mixed urban spaces in its design, as do the neighborhoods to the northwest. On the other hand, there is no space that can be qualified as multifunctional based on the definition given earlier in the table of analysis criteria.

55On the map (figure 7) we have opted for a gradual numerical representation of the time occupation of the new town: we have therefore represented empty spaces and unoccupied land by the sign (0), spaces occupied during the day (or night) only as offices as workplaces or throughout the day (day and night) by the sign (1), those occupied by users during the week (or weekdays except weekends) will be represented by the sign (2), spaces occupied in season will be mentioned by the sign (3) and those whose occupation time is annual by the sign (4), i.e. they are spaces totally occupied by users throughout the year.

56In the map "time of occupation", we can clearly deduce that most of the urban spaces of the new city are very little or not at all occupied, the most occupied urban spaces throughout the year in Sidi Abdellah are the houses. This does not mean that the city is permanently occupied by its users as the majority of these spaces are occupied throughout the year but only in the evening or at night: they are therefore unoccupied during the rest of the day and/or the year. The other types of spaces have been previously designed for partial occupation and the developers do not consider the idea of occupying a space with an additional occasional function: Sidi Abdellah cannot therefore be considered as a city with a high occupancy rate.

57The figure below confirms the time occupation results on the last map where we can find many unoccupied places by users: empty places, stores and playgrounds during the morning time.

The subjective evaluation (the survey):

58The answers collected from the survey showed that the inhabitants occupied the new city recently (for a maximum of four years) with an average household composition and an average age range. The results show that the employed persons suffer from a daily long distance job-house trips (30-40 km); they travel also for others occasional purposes like medical care or sport activities.

59These families are from the middle and lower classes; they cannot even afford week ends far from the new city (some of them told us that they struggle to go see their families and friends in holidays because of the lack of public transportation).

60Sidi Abdellah is not an attractive city; the main function proposed for the users is the housing. The persons interviewed confirm that they need more than the activities currently available: more public and leisure spaces, doctors and pharmacies, sport facilities (gym and pools especially the teenagers) and different types of shops and markets.

61This survey confirms the absence of functional diversity; the domination of collective housing and the lack of necessary functions for the daily life of Sidi Abdellah’s inhabitants; it shows an important imbalance in the distribution of functions and activities.

Conclusion

62This work studied and assessed the multifunctional use of urban spaces in the new city of Sidi Abdellah in Algeria. The scale and aspects used in this study and presented in the previous table can be applied to any other new city.

63It seems clear that the application of MLU has limits and that urban multifunctionality is relative: we should instead think of a synchronization and a synergy between permanent functions and secondary or "integrated" functions in a single space, even if these are in different timeslots, in order to ensure a smooth transition between uses (Grisot, 2020) and favor the small and medium scale, i.e., the neighborhood scale (Batty et al, 2003) for a multifunctionality by “sections”, contextualized in the entities that make up the city.

64As mentioned above, the lack of coherence between the decisions of the elected representatives on the one hand and the ambitions of the urban planners towards a more sustainable and multifunctional urban planning on the other hand, is always apparent in the new development areas in different countries of the world and particularly in Algeria. City planners claim to have taken into account the principle of compactness, whereas in reality, development is planned on the outskirts of the new city, away from the center. We deduce that this principle has not been respected and that the city runs the risk later on of sprawl on its perimeter of protection and the natural spaces that make it up to connect them to the closer existing districts, thus neglecting the central spaces.

65The reports also show that they have taken into consideration the objective of making the new city "sustainable". However, the achievements are very far from sustainability in Sidi Abdellah, and this name cannot be attributed to it at present. Therefore, the requirements of sustainability are among the priorities because it is a question of meeting the needs of current and future generations in an equal and respectful manner of the land and natural resources.

66Neighborhoods with a predominance of individual housing (especially those existing before the creation of the new city in Zaatria, Rahmania and Maalema) are equipped with basic infrastructures: mini-markets or doctor’s offices on the first floor of individual houses, unlike neighborhoods with a collective housing character where local facilities have not yet been established. Except that the inhabitants of these neighborhoods have sometimes consumed spaces that are supposed to be natural or leisure spaces and on which houses or buildings are built for economic investment purposes only.

67The new city public organization EPIC VNSA should consider the integration of several functions in the same facilities and neighborhoods for more multifunctionality. Yet, we find very few multifunctional or "integrated" achievements in Sidi Abdellah. The alternative would be to think about the concept of a mixed island for the neighborhoods that are not yet built and an alternating use of vacant spaces for those which are already built. Our results allow us to conclude that the mixed use concept was very quickly dismissed from the implementation principles during the construction phase.

68Algerian new towns are certainly a strategic project, but it is at the level of decision-makers and planners (or developers) that the change should be made in planning policy and the adoption of more circular and sustainable urban planning. The notion of citizen participation is marginalized in the realization of a project in Algeria. The adoption of "sustainable" concepts for development, first of all the multifunctionality of urban spaces and its substitution to spatial zoning, should be encouraged beyond the official discourse. This would be the beginning of a change towards a more human urban planning and a sustainable alternative to urban sprawl.

69Improving the MLU in the Algerian new cities will improve the life-style of the inhabitants by providing them with the required complementary infrastructure according to their needs. It will also reduce the car travel by balancing the job-housing trips of the inhabitants; increase the dependence of new cities and re-balance the metropolitan cities territory.

Appendix: Results of the survey made with 100 persons in Sidi Abdellah (fig. 9)