Gustavo Girão
email: girao@imd.ufrn.br

Flávio Rech Wagner

Managing Cache Memory Resources in Adaptive Many-core Systems

Keywords: Many-core, Resource Management, Adaptable Memory Hierarchy, Network-on-Chip

In the last decades, the increasing amount of resources in embedded systems has been leading them to the point where an efficient management of these resources is mandatory, especially for the memory subsystem. Current MPSoCs have more than one application running concurrently. Hence, it is important to identify the memory needs of these applications and provide them accordingly. In this work we propose the use of a cluster-based, resource-aware approach to provide this efficient environment. The solution proposed here improves the overall performance of these systems by aggregating memory resources in clusters and redistributing these resources among applications based on a fairness criterion. For this memory clustering proposal, we use the information of external memory access-es as an estimate of the amount of memory required by each application. T Experimental results show that, depending on how the redistribution of memory resources among application occurs, the overall system can improve performance up to 18% and the energy savings can reach up to 20%.

Introduction

The memory resources in many-core systems must be even more abundant than processing elements. As a classical and perennial bottleneck of computer systems, the memory resources must be managed with the outmost efficiency in order to provide decent performance.

The aggregation of resources as well as their efficient distribution among concurrent applications may lead to substantial gains for the overall system. It is a well-known fact that applications may have different needs of processing and memory requirements. Processing requirements refer to the needs of the application to execute its code faster, for instance using TLP (Thread Level Parallelism) and ILP (Instruction Level Parallelism) techniques. As a usual solution, processing demands must be addressed by assigning more processor elements (e.g. cores or specialized hardware) and/or more time slices to applications. On the other hand, certain applications manipulate considerably higher amounts of data and, therefore, the use of more memory resources (e.g. L1/L2 caches) would increase their efficiency. Figure 1 shows the memory demands of applications from the SPEC benchmark [START_REF] Jaleel | Memory characterization of workloads using instrumentation-driven simulation -a pin-based memory characterization of the spec cpu2000 and spec cpu2006 benchmark suites[END_REF]. For these applications, it is possible to see that the amount of memory access instructions (read or write) can range from 30% to 70% of all instructions. It is clear that an efficient memory resource distribution system, in an environment that can run several applications like those, can be advantageous. In this work, we explore various aspects of a memory resource management approach in an NoC-based MPSoC platform used as case study. First, we introduce a mechanism that is able to assign each L2 memory bank in the system to the exclusive use of a given application (and its respective tasks). This mechanism is based on dynamically changeable association tables present in every L1 cache, which indicate the L2 cache banks assigned to the application, their memory address range, and their NoC addresses. Second, we establish a mechanism to redistribute the L2 cache banks among the applications. Experimental results show that an overall system improvement can be reached at the expense of the performance of some individual applications. The key observation is that some applications have more impact on the overall system execution than others, and, consequently, reducing the memory latency of these critical applications can lead to performance gains. Results show that the overall execution time decreases up to 18% and energy savings reach up to 20% in the best case.

The remaining of this paper is organized as follows. The next section presents the baseline architecture considered in this work and the Memory Clustering mechanism itself, including the redistribution approach and redistribution mapping. Section 3 exposes the experimental setup, while Section 4 presents the results. Related work is discussed in Section 5, and, finally, in Section 6 conclusions are drawn and future work is outlined.

Memory Clustering

Let us consider the baseline architecture for this mechanism as an NoC-based MPSoC whose nodes are as presented in Figure 2. In this case, the memory subsystem is homogeneous and composed of local private L1 caches and distributed shared L2 caches. Inside each of the four nodes in the corners, there is also an external memory controller, which has a very important role in this approach.

The key idea of this methodology, called Memory Clustering, is to assign the L2 memory blocks according to the needs of each application. The intuition here is that reserving more memory resources to applications that deal with more data will lead to a faster execution overall.

It is important to notice that, as the goal is to improve the overall performance and energy savings, the Memory Clustering approach must act on the address spaces of all applications (through the L2 caches) instead of simply redistributing the L1 cache resources, which apply only to the address space of the application currently running in the processor to which each L1 is attached.

The mechanism proposed in this work is a cluster-based resource-aware approach for the memory subsystem. In a previous work [START_REF] Girão | Exploring resource mapping policies for dynamic clustering on NoC-based MPSoCs[END_REF], this cluster-based approach for resource management has been introduced. However, only processing resources have been considered. In this paper we consider a cluster as an aggregation of physical resources (more specifically, L2 caches) delegated to an application. More than one application may be running in the system, and each one has its own set of resources. Due to the importance of the memory subsystem to the overall system performance, it is desirable to reduce memory latency for data-intensive applications. The proposed process for redistributing memory resources occurs as follows. Since the beginning of the execution, the memory controllers count the number of external memory accesses made by each application cluster (each application cluster being the aggregation of resources initially assigned to each application, as shown in Figure 2). At some point during the system execution, these memory controllers (located in the corners of the MPSoC, as presented in Figure 2) use these statistics to define which application has more cache misses. A synchronization step is performed when one of these memory controllers (henceforth known as master controller) receives messages from the other controllers informing the number of cache misses of the various applications. After that, this master controller uses some redistribution policy (to be detailed in the next sections) to establish how many memory resources (L2 memory banks) each application cluster should have. This number of L2 memory banks allocated to each cluster will be proportional to the percentage of cache misses from the corresponding application. This strategy is an attempt to reproduce, at runtime, the knowledge presented in Figure 4, which shows, for a system concurrently running four applications, the amount of memory accesses extracted from an application profile at design time.

In order to redistribute memory resources, this approach takes advantage of a previously introduced directory-based cache coherence mechanism [START_REF] Girão | Cache coherency communication cost in a NoCbased MPSoC platform[END_REF]. This mechanism uses a small table called ATA table on each cache in the system, which relates an address range to the memory module in the system that may have blocks that belong to such range. This means that each cache memory only perceives a certain amount of physical memory modules in the system, depending on the memory address range of its current memory blocks.

As explained before, at the beginning of the execution each application cluster has its own set of L2 caches and all L1 caches in this cluster have an ATA table that indicates which range of addresses is possibly available in each L2. Each L2 cache controller also knows which addresses should be placed in its own memory.

Let us assume a small scenario of only four L2 caches for an application. As presented in Figure 3, each cache bank can have a certain contiguous range of addresses from the external memory address space. On the left side of the figure, there is a representation of the ATA table of L1 caches in the cluster assigned to this particular application, where each line corresponds to the range of addresses assigned to each node of the cluster. After the synchronization step, as illustrated in Figure 3, the master controller may reach to the conclusion that this cluster needs four additional memory banks. After choosing which memory banks in the system shall be aggregated to this cluster (the dashed L2 cache banks represent these recently added resources), the ATA tables must be updated. On the bottom-right side of Figure 3, the new ATA table is illustrated. It is important to notice that the addresses from the application address space are equally divided among the L2 cache banks.

Redistribution Policies and Mapping

Once established how the number of L2 caches associated to each L1 cache can be modified, the next decision in the memory clustering mechanism regards the moment when resources (in this case, L2 caches) are taken/given from/to a cluster, thus creating a resizable cluster. Two main approaches are presented here: Pre-defined Distribution and On-demand Distribution

The Pre-defined distribution is the model used as baseline for the experimental results. The idea is, based on a design time profiling of the application, to establish beforehand the number of L2 memory modules that each application should have. This distribution takes into account the amount of input data for each application. Since external memory accesses can be very costly, the goal here is to minimize this situation by giving more cache memory space for the most data-intensive applications. This is a static offline approach and is used only to establish how good the second approach is. The graph on Figure 4 presents the amount of memory accesses for each application used in the experiments and for each scenario with different MPSoC sizes (number of nodes). The memory resources (in this case, L2 cache memory banks) can be divided among the applications proportionally to the amount of data that each one handles. However, this information depends on profilling and it may not always be available. Therefore, some runtime approach should be considered. In the Ondemand distribution, all clusters initially use the same amount of L2 caches.

After a certain amount of cycles, the external memory cache controllers (located on the corners of the MPSoC) exchange information, and, based on the number of external memory accesses, the master controller defines which clusters need more memory nodes. The master memory controller then redefines the ATA tables of L1 caches (potentially, all of them), thus redistributing the memory resources in the system.

The biggest question here is how we define the time instant at which the memory controllers must take action to redistribute resources. In this paper we will call this instant in the execution a redistribution point. Intuitively, this point must not happen too soon along the overall system execution, because the clustering mechanism needs values that characterize the memory demands for each application and are statistically significant. On the other hand, by doing it too late in the execution time, the pattern will be well defined, but it may be too late to overcome the overhead caused by the redistribution itself. Therefore, some trade-off should be considered in this approach.

By giving more L2 memory banks to some applications, there is no alternative but to take these resources away from other applications. The hope is to efficiently take the correct amount of L2 caches from applications that need them less and give them to applications that need them most. The aspect to be explored is which L2 caches shall be taken away at the moment of the redistribution.

The policy used in this case is to gather new resources that are closer to the resources originally allocated to the application. In this policy, it is reasonable for the applications to exchange resources placed on the edge of their clusters. That condition has the goal of keeping the resources close together, thus avoiding cluster fragmentation. The master memory controller starts by assigning the new resources to the cluster with more memory needs. Next, this process is repeated with the second cluster with more memory needs. This process goes on, with each cluster taking turns on the resource assignment, until the number of resources to be redistributed is reached.

Experimental Setup and Results

The experiments consider four applications: a matrix multiplication, a motion estimation algorithm, a Mergesort algorithm, and a JPEG encoder.

Considering the data inputs for the applications described above, Figure 5 represents their communication workload regarding different numbers of processors. Based on this chart, it is expected that the Motion Estimation algorithm will generate a larger amount of data exchanges. This shows that the benchmarks used here are capable of generating significant amount of communication traffic. This would make an efficient memory hierarchy even more required in order to avoid unnecessary memory requests.

Experiments evaluate two characteristics: performance, measured by the total execution time of each application, and the overall dynamic energy spent, including processors, network, and memories. For the energy of the processors, a cycle-accurate power simulator [START_REF] Chen | Power compiler: a gate-level power optimization and synthesis system[END_REF] is used. For the network (including buffers, arbiter, crossbar, and links), the Orion library [START_REF] Kahng | ORION 2.0: A Power-Area Simulator for Interconnection Networks[END_REF] is applied, and for the memory and caches the Cacti tool [START_REF] Wilton | CACTI: an enhanced cache access and cycle time model[END_REF] is used.

All experiments were performed in a SystemC cycle-accurate MPSoC virtual platform that can instantiate architectural components as illustrated in Figure 2. Due to their smaller size, this virtual platform uses MIPS processors as cores implementing MIPS I ISA. The configuration used in all experiments in this platform is presented in Table I.

The remainder of this section presents results regarding the memory clustering experiments using the Pre-defined and On-demand Distribution policies. In this second policy the experiments were performed using four distinct redistribution points. Goal of these experiments is to find the best moment during the execution of applications to perform a memory redistribution, in a way that, after this point, the system can have an overall performance boost. The ideal time point at which the redistribution of the memory subsystem must be performed depends on each scenario, considering number of cores, number of L2 caches, execution time of all applications, etc. Since we are dealing with different MPSoC sizes, the overall execution time can vary drastically. Therefore, the redistribution points for the four experiments were defined at 10%, 25%, 50% and 75% of the overall execution time in each case, such that we can explore the impact of different values for this parameter. Figure 6 presents the performance and energy results using the Pre-defined Distribution. One can notice that the applications with higher input data (Motion Estimation and Matrix Multiplication) have large benefits, as opposed to the JPEG and Mergesort applications. These last two applications actually present a drop in performance, down to 22%. However, there has been an increase in the overall system performance (i.e. the amount of time to execute all applications) of 34% in the best case. As for the energy results, they present a very similar pattern when compared to the performance results, reaching up to 40% of savings. These performance and energy improvements happen because the larger applications have higher impact on the system. Obviously, due to the overhead discussed previously, these numbers are virtually impossible to achieve in practice. However, they give a good basis for understanding how good this approach can be.

Table II presents the results of the On-demand Distribution policy considering redistribution points of 10%, 25%, 50% and 75% of system execution time. By the results of overall performance it is possible to see that the best results occur when a redistribution point of 50% is used. This means that the execution at this point is enough to obtain a reasonable distribution of memory resources in the system. When this redistribution point occurs too early, as in the case of 10%, it almost does not affect the performance of the system. This seems to be due to the fact that this short amount of execution time is not enough to characterize memory demands of all applications correctly. Experiments with later redistribution points do not present the best results as well. There are two explanations for this behavior. First, when leaving the redistribution to occur that late in the system, the applications that needed more memory resources were not prioritized for the most part of their execution. This would have a considerable impact on the overall performance. Second, at 75% of execution time, there is not much time left to compensate the overhead caused by the memory redistribution itself. 3% 2% 1% 18% 12% 7% 23% 20% 16% -5% -3% -2% Matrix Multipl. 3% 2% 2% 11% 7% 5% 17% 14% 10% -3% -2% -1% JPEG -4% -5% -6% -3% -8% -10% -9% -14% -20% -2% -1% -1% Mergesort -2% -3% -5% -3% -6% -7% -2% -5% -8% -3% -2% -1% Overall 1.2% 0.1% -0.6% 12% 6% 3% 18% 14% 11% -3.5% -2.3% -1.4%

Table III presents the energy results for the On-demand Distribution. As in the case of the Pre-defined Distribution, the energy results follow a similar pattern when compared to the performance results. There are slightly higher energy savings than performance gains, probably due to the higher energy costs of accessing the external memory if com-pared to the time access penalty. Conversely, the penalty using a redistribution point at 75% of execution is higher. JPEG -5% -6% -7% -3% -8% -9% -9% -15% -22% -3% -2% -3% Mergesort -2% -4% -6% -4% -7% -6% -3% -8% -10% -4% -3% -1% Overall 2% 0.6% -0.2% 13% 9% 4% 22% 18% 13% -5.6% -3.7% -2.3%

Related Work

Even though no approaches using dynamic cluster-based approaches for managing memory resources were found in the literature, some works propose resource management techniques that could be extended to the memory subsystem. In this section we present some of these works. Qureshi et al. [START_REF] Qureshi | Utility-based partitioning of shared caches[END_REF] present a redistribution mechanism in an L1 private/L2 shared cache architecture. In this mechanism, the evicted lines from one cache (called spiller) can be allocated in another cache (called receiver) in the system through a snooping mechanism. This is an approach with the goal of extending the size for one cache (the spiller) and to make the data stay inside the chip longer. This approach considers a single address space and several threads from the same application while ours is a global approach.

Recent works propose a paradigm of multicore programming called Invasive Computing [START_REF] Teich | Invasive Computing: An Overview[END_REF][START_REF] Henkel | Invasive manycore architectures[END_REF][START_REF] Kobbe | DistRM: Distributed resource management for on-chip manycore systems[END_REF]. The proposal is to take advantage of a large many-core processor in the best possible way. The idea leverages on malleable applications where the degree of parallelism can change on the fly. At the application level, the programmer uses functions that trigger the invasion process. When an application sends an invade request, a distributed resource manager evaluates the request based on the amount of resources required and the estimated speed-up per core. This Invasive Computing works at different levels of abstraction, and, therefore, the programmer must have some notion of the methodology. In the case of the Memory Clustering approach proposed in this paper, all mechanisms are transparent to the programmer.

Conclusion

In this paper we introduce the con-cept of Memory Clustering. Since some applications have more memory needs than others, the key idea of this mechanism is to reserve more memory resources (in fact L2 caches) for the more timeconsuming applications, taking them away from other applications that do not need them as much. Overall results presented show that, depending on the time point where the redistribution of memory resources occurs, there is room for performance and energy gains for the system as a whole.

In the future, we intend to investigate other methods to determine the right moment for the memory redistribution. In the experiments presented here, the best time points for the redistribution (25% and 50% of the overall system execution time) have been identified for specific experiments. Therefore, in a situation where there is no previous knowledge of the applications, the best redistribution point can be different from those values. In the future, we will investigate further the cache misses before and after the redistribution points, in order to better characterize causes of the initial performance loss and effects of the memory redistribution.

Fig. 1 .

 1 Fig. 1. Memory requirements from SPEC. [1]

Fig. 2 .

 2 Fig. 2. Example of data space for a set of applications.

Fig. 3 .

 3 Fig. 3. ATA table and MPSoC before and after resource distribution.

Fig. 4 .

 4 Fig. 4. Pre-defined distribution.

Fig. 5 .

 5 Fig. 5. Communication Workload.

Fig. 6 .

 6 Fig. 6. Pre-defined Distribution performance and energy results.

Table 1 .

 1 Configuration of the Virtual Platform.

	Number of Processors	16; 32; 64
	Number of L2 caches	16; 32; 64
	Total Number of Initial Tasks per Application	32
	L1 Cache Size	8192 bytes
	Block Size	32 bytes

Table 2 .

 2 Performance Results for on-demand Distribution.

	Redistrib. pts	10%		25%	50%			75%
	No. of Cores	16 32	64	16 32 64	16 32	64	16	32	64
	Motion Est.

Table 3 .

 3 Energy Results for on-demand Distribution.

	Redistrib. pts	10%		25%	50%			75%
	No. of Cores	16 32	64	16 32 64 16 32	64	16	32	64
	Motion Est.	4% 1% 1% 20% 19% 8% 25% 23% 18% -7% -4% -3%
	Matrix Multipl. 5% 3% 2% 12% 7% 7% 21% 19% 12% -6% -4% -2%


Author Cheikh

Tidiane Lo

Heritage Making and Urban Memories: An Ethnographic Study of the City of St-Louis in Senegal

Keywords: Colonial heritage, Collective identity, Memory dispute, Urban dynamics Patrimoine colonial, identitié collective, mémoire conflictuelle, dynamique urbaine

In light of local community's involvement and urban dynamics, this paper sheds light on the cultural management of St-Louis Island, a former French colonial settlement. This ethnographic study comes from a field project undertaken since 2014. Put on the Unesco World Heritage List (WHL) in 2000, St-Louis has undergone deep demographic and urban changes, unfavorable to the colonial architecture, which is at the core of the heritage safeguarding initiative, and to the local inhabitants, tourists and visitors. This series of problems facing the preservation programme could be explained and resolved if issues of memory and community involvment were taken more seriously, rather than letting bureaucratic concern to protect the built heritage prevail. We argue that there is a discrepancy between the need of memory affirmation, community identity politics, and the selection of the colonial legacy as embodied in the architectural fabric of ancient buildings. If this discordance is taken into account, conflicts and memory disputes besetting the preservation project could be conciliated by according greater attention to the current needs of local communities and the stake of preserving the colonial remnants.

INTRODUCTION

This paper offers an ethnographic study of heritage experiences, what I call "heritage ontology", at the community level in St-Louis, Senegal. By ontology, I mean the lived experiences of a textual or abstract reality. Heritage, being constructed through discourse and text, nevertheless, exerts its effects on people and generates responses from them. This paper seeks to answer the following questions: why and how does the colonial legacy manifest itself in St-Louis? To what extent do postcolonial people's aspirations for modernity, in light of/despite the existing poverty, facilitate or hinder heritage conservation policies? Moving from a less epistemological approach to a more ontological consideration of heritage, this study participates in the debates around the legitimacy of preserving colonial legacies in an ex-colony. It unravels the multivocality of heritage ontologies characteristic of heritage sites in general, and postcolonial contexts, in particular.

My focus on multivocality attends to visitors, discourses, memories, nostalgia, and how they shape heritage dynamics in a postcolonial context [START_REF] Sinou | Le patrimoine architectural et urbain en Afrique. Un état des liens à l'échelle continentale[END_REF][START_REF] Ouallet | Mémoires urbaines et potentialités patrimoniales à Addis-Abeba[END_REF]Dimesie, 2013;Konate, 2012). All that is outlined above boils down to showing processes of heritage inscription, interpretation, and conservation. I will argue that there is a much more complex interaction around listed heritage than usually defined and idealised in official heritage narratives of governments and specialised institutions like Unesco. Despite official attempts at codifying heritage, it escapes bureaucratic control, and becomes a performative tool in the hands of actors, and stakeholders, who subjectivise how they choose to engage with it, rendering the heritage futures unpredictable and evasive. The values local people attach to heritage are often different from, although not necessarily less important than, values ascribed by historians, archeologists, government officials, and tourism developers. I suggest that an understanding of this performative quality of heritage, its diffuseness, is needed to alleviate less favored communities who are often left behind by institutional measures, but also to constantly redirect pre-conceived policy towards aspects outside the bureaucratic loop.

METHODOLOGY

This study is based on fieldwork sessions held in different periods of the year, from 2014 to 2016. Narratives, archives, newspapers, and direct participant observation facilitated the data collection. Arguably, doing fieldwork in a place you are familiar with, where you have spent some time to get acquainted with the physical layout, the language, as well as the cultural norms of the people, is an asset for the ethnographer. One should, however, acknowlegde that problems of inconscious biases and excess of subjective projections may often impinge on the final analysis. St Louis is my second home. I have spent five years as an undergraduate and graduate student, shopping in its markets, visiting its most attractive places, fostering friendships with some local inhabitants. I cashed in on this pre-knowledge as a form of social capital to speed up or short-circuit one classical ethnographic phase: the period of establishing rapport. I had still to refer to new individuals and groups, in the bureaucratic apparatuses or ordinary spaces. But, it was quite an easy move, with few exceptions.

SPATIAL SETTING

Located in the North-West of Senegal, the colonial town of St-Louis is an island divided into three strands of land by a river that runs into the Atlantic Ocean. During the colonial period, St-Louis played a considerable role in the exertion of the colonial power over religious and political leaders of Senegal and from the broader Occidental French Africa 1 . With independence, the colonial buildings that housed offices and served as dwellings for colonial administrators and officers were gradually conceded to local authorities and the ruling elite. After the 1 Translated from French, Afrique occidentale française. complete transfer of the capital from St-Louis to Dakar in 1960, a considerable number of local indigenous people appropriated those historic buildings due to the rampant urbanisation and population growth. In view of its historic importance, both within West Africa and for France, Unesco listed the whole island as world heritage site under the title of Outstanding Universal Value in 2000. Through commerce, slave trades, and racial mixing, the island had become a cosmopolitan space since the 17th century (Konate, 2012;Samb, 1998).

RESEARCH FINDINGS

Since the 1970s, local authorities, and actors interested in the built heritage have been raising people's awareness about the alarming proportions of the colonial architectural destruction (around 20% of the buildings falling apart, 30% needing serious repair). After its inscription on the WHL, the municipality, in partnership with State's agencies, international cooperations, such as French Development Aid Programmes (DAP), the French local Architecture School, efforts were made to establish a conservation database to help inhabitants respect heritage preservation instructions.

A report published in 1973 by the Ministry for Urbanism and Habitation signals serious concerns from local authorities regarding the built legacies' increased degradation in St-Louis (Toulier, 2003). It outlines a set of restoration plans envisaged by the national government, in partnership with local institutions, for the island of St-Louis. Unlike what occurred in many parts of independent Africa, the Senegalese young nation did not display tremendous aversion toward the colonial iconography and edifices, under the presidency of Leopold Sedar Senghor . His vision and philosophy partly explain the attachment and peaceful relation that characterised French and Senegalese nations, including his contribution to the creation of the Francophonie (an international organisation uniting French-speaking countries around the world) in 1970. With this regard, Boucoum and Toulier write: "after independence, the first President Leopold Sedar Senghor, with the movement of Negritude, developed a culturally-oriented vision for the Senegalese heritage, without breaking off with the Francophonie" (2013: 9). In this context of diplomatic relationship, Senegalese ruling elites, mostly educated in French schools and universities, seemed to be favorable and tolerant with respect to colonial symbols left by France (Marshall, 2008).

One of the most active institutions that claim credit for the preservation efforts is the Center of Research and Documentation (CRDS, ex-Institut français d'Afrique noire/IFAN). During the colonial period, it acted as a museum and an archive for Senegal and Mauritania. Miss Fall, the current Director, shared her version of early initiatives undertaken by the cultural institution since the 1970s. According to Fall, the CRDS was primarily oriented to the collection and valorisation of popular artefacts. In 1995, it was decided to reframe its mission statement to focus on architectural and heritage preservation (see the "St-Louis Machine" conservation project; funded by French cooperation and inventorying industrial remains and infrastructures such as bridges, water supply plants, towers…). In 1998, the municipal authority of St-Louis held several general assemblies on various sectors, including tourism, leading to plans, with the CRDS, for the revalorisation of the island. The top priorities, the Director identified, were all elements of tangible heritage.

I investigate how gentrification, as derived from the heritage added value, operates in St-Louis, bearing in mind that there are context-specific aspects that would merit further scrutiny. Gentrification is associated with the rise of price in real estate after the island's inscription on the WHL, together with mainy homeless families that turn into backstreet squatters of abandoned colonial houses. It is hard for an ethnographer to fathom whether a particular family is illegally occupying a given house as squatters because it is a matter of dignity to reveal that. The only way I could learn about this has been from narratives of long-term residents who possess sufficient knowledge about histories of houses and who owns what.

Relying on these secondhand accounts, I found that several families today on the island moved to abandoned ancient colonial houses as a temporary shelter. This phenomenon seems to have increased since the island's inscription because real estate value has tripled according to Sow, a heritage scholar at the local university whom I interviewed in 2014. Based on the definition I quoted above, gentrification is associated with man-led activities. However, natural factors also contributed to moving people out of their homes or compel them to construct in height. It is the case for example in the Langue de Barbarie, one of the buffer zones of the heritage, a strand of land on the Northern side of the main island which is today threatened with disappearance because the water is advancing inwardly. Due to the shrinking of the land, many people had to move out of their original homes into uninhabited houses on the main island, while more economically powerful fishermen build four-story houses, transgressing the height limit of heritage restrictions.

Cases of squattering is recurrent. Mrs. Camara, a mixed race female entrepreneur, who left her native country France in 2007 to settle in St-Louis, has created a Facebook page, "Entr'vue"2 . She once posted a photo of a low-income family that lives as squatters in a derelict house on the brink of downfall. She commented the picture: "a family has been occupying the lieu for some months because they did not have a place for shelter. In spite of some individuals' calls for help, the horizon is becoming more and more bleak for this family who kneels, haplessly and lost, in this abyss of death" (Camara, 2015). A father experiencing similar things expresses his situation in a way that captures the prevalent mood of these desperate family squatters: "We want to move, but we don't have means. No authority has come to see us".

How does this affect the heritage conservation policy? If it is clear that there exist several families who illegally inhabit derelict colonial houses in need of repair, how can they renovate something on which they cannot claim ownership? I met Mr. Gueye, a native of St-Louis who works in Dakar, whose family is still living in St-Louis. Through our conversation, he learned that I was studying heritage issues in his native town. Of the ideas he shared with me, one stood out. Many living on the island without legal papers to prove ownership of their homes are actually descendants of people who used to work with the white colonial owner; they took over the house after the employer died or moved back to France after the Senegalese independence in 1960. These types of occupants are hesitant to invest money in rebuilding their houses for fear of a possible return of the original owner, as it already happened.

So beyond the romanticisation of heritage, as it transpires through some people's narratives, the communities' experience of the impact of heritage policies are not always rose and positive. Heritage authorities and experts have emphasised the need to uphold the heritage list, which they characterise as a gift, a recognition to be preserved, yet some of them seem to ignore or downplay why communities are not responding to their invitation. Part of the reasons for this inefficiency springs from a simplification of the socio-cultural realities determining people's rapport and relationship with heritage site.

There are also cases of successful renovation. Yves Lamour, a French who settled on the island, bought old colonial buildings with a view to restoring them. For him, St-Louis "is a bit of French patrimony on an African soil". When interviewed by a journalist (2012), he said: "les gens s'aperçoivent du patrimoine. Le classement de l'Unesco a fait du bien. Donc, les gens s'en rendent compte. Il faut attacher de l'importance à la réfection des balcons et des façades en particulier"3 . As the journalist puts it, Lamour's goal has been to "awaken the slumbering French colonial heritage of St Louis". His discourse is tinted with a certain patriotism, a duty to enliven his bygone ancestors' legacy on the African continent.

Jean-Jacques Bancal, metis of white French and black African parents, emphasised that cultural blending, double-identity animate him. He aspire to restore at least 20% of the built legacies, estimated to 500 buildings and monuments, as well as other mobile materials that index colonial past: "je suis très lié à St-Louis car elle fait partie de mes racines"4 . One of the striking efforts he undertook in 2006 was his purchase of the ship Bou el Mogdad, which ensured the transit of goods, mails, and people between St-Louis and other coastal towns along River Senegal from 1950 to 1970.

Alternative forms of preservation are noticed through festivals, open-door events, and aware campaigns conducted by youths association. The Fanal Festival and the International Jazz Festival are unique platforms appropriated by communities to express their identities and refresh their memories to come to terms with their sense of belonging in the heritage space.

DISCUSSION AND CONCLUSION

Far-fetched comparisons may not help us resolve the puzzle of heritage conservation in St-Louis, but I tend to believe that there are common problems besetting tangible heritage management worldwide, particularly in postcolonial developing countries in Africa. And such commonalities can be sources from which to learn to better comprehend local issues. Colonial heritage, generally found in urban settings, confront several obstacles linked with poverty, urban expansion, rural exodus, and gentrification. The lifestyle of first inhabitants often differ from newcomers who left rural areas to settle in postcolonial heritage sites, and this creates a discordance of value between heritage experts, stakeholders, and those incoming communities.

In St-Louis newcomers invade urban centres with more acute economic preoccupation than the preservation of heritage, leading to a serious neglect of the conservation guidelines. In addition to this discrepancy of value, poverty, and precarious ownership, lack of involvement of communities plays out in the degradation of the lived environment as well. Indifference to heritage preservation needs stems also from "a lasting legacy of colonialism" (Pwiti & Ndoro, 1999). Many inhabitants do not see the value of preserving the remenants of an oppressive colonial system, considering its symbols as againts national glory. This memory resistance is much visible among certain local scholars in St-Louis (Diarra, 2012). For these reasons, as Low argues, "understanding the cultural dynamics of a place so that specific individuals and their histories and values are sustained at or near the heritage site, across generation, and overtime" ( 2003) is crucial to ensure a more sustainable and integrated management of heritage sites. This presentation on the social life of heritage helped us to unpack the complexities of urbanisation, interpretative frameworks, memories, and power relations on the ground [START_REF] Ch | The politics of heritage management in Mali: from Unesco to Djenné[END_REF][START_REF] Turgeon | Patrimoines métissés : contextes coloniaux et postcoloniaux[END_REF]. Postcolonial urban logics, characterised by hybridity, obscures the heritage policy founded upon the dual colonial urban planning of centre vs periphery. Most communities, grappling with poverty, family disputes, and informal economies, argue, reject, or simply ignore top-down conservation regulation. Also, the unwarranted ownership of most dwellers renders the heritage policy implementation daunting for heritage bureaucracy, besides being undercut by political abuses, lack of technical expertise to carry out its mission adequately. The selected colonial heritage display, dominant in official discourse, becomes thus overshadowed by unharnessed everyday practices and gentrification.

www.facebook.com/entrevuesaintlouis

"People can see the heritage. The UNESCO's classification has been good. So, people have realised that. We need to give importance to balconies and, more precisely, to facades" [online: www.youtube. com/watch?v=irhaKx1jvSU&hd=1].

"I am very attached to Saint Louis, for it is part of my roots", interview by Rosen Le Roux (12/2011) [online: www.saintlouisdusenegal.com/jjbancal2011.php].

THE AUTHOR Cheikh Tidiane Lo

Indiana University-Bloomington Departement of African Studies chelo@indiana.edu


Gloria Author

Lanci

Mots Clés

Translating Cities: Urban Spaces in Contemporary Art Maps

Keywords: Contemporary Art, Cartography, Urban Spaces, Liverpool espaces urbaines, Liverpool

This paper will present a project that investigates how cities are perceived and represented in contemporary art maps. The research approaches current mapping practices through interviews with artists, enquiring how they apprehend, process and re-create urban spaces. Our focus is on the performative dimensions of art maps rather than their representational aspects, and their capacity to re-shape territories along imaginary geographies. We will discuss the map as practice that can unfold personal and collective narratives, contestation and play. Four art maps produced for the city of Liverpool after 2008 will illustrate our discussion of how contemporary art works can be related to traditional and non-traditional cartographies and how they contribute to engage on new ways of understanding, experiencing and imagining cities.

INTRODUCTION

Cities have been subject to mapping throughout history in the most diverse ways, from the early clay tablets and rock engravings, to the intricate printings of the Renaissance and the current hyperreal digital visualisations. Beyond documental purposes urban maps are embedded with human culture -they are manifestations of ideologies and societies, technology and power. They also have a long association with the planning and design of cities and utopian visions of urban life.

However, no matter how diverse in techniques, materials used and information gathered, the topographical perspective "from above" has been paramount in representing cities in the form of diagrams, panoramas, bird's eye views and urban plans. The technological advances of the 20th century in aerial photography, satellite imagery and remote sensing only reinforced this surveying approach to cartography, where a map is a synonym of accurate visual representation of the land.

The understanding of map as an objective device for representing reality, disconnected from historical and cultural frameworks, and of mapping being a scientific and political neutral practice, has been questioned in the past decades among academics and artists alike [START_REF] Cosgrove | Maps, Mapping, Modernity: Art and Cartography in the Twentieth Century[END_REF]. Considering a creative practice mapping has the potential to "uncovering realities" [START_REF] Corner | The Agency of Mapping: Speculation, Critique and Invention[END_REF] and on this capacity relies its imaginative power: it creates multiple narratives of historical events and physical features, of cultural traits and economic conditions. Artists are thus lured to maps as they see their prospective visual qualities to communicate, to tell stories and to explore space in creative ways.

INFLUENCES IN CONTEMPORARY ART MAPS

The contemporary1 art practices of mapping are very linked to a legacy of previous art movements that, especially in the case of representing urban spaces, can be traced back to the 19th century and the Baudelairian figure of the flâneur, roaming the streets of Paris. The Surrealism and Dada movements of the 1910s and 1920s, the Lettrism of Isidore Isou in the mid-1940s, the COBRA movement of late 1940s and the Situationist International founded in the late 1950s were foundational art movements and groups that influenced a whole generation of artists that incorporated cartography in their practices.

The Land Art and Conceptual movements that followed in the 1960s and 1970s included then emergent artists as Jasper Johnson and Yoko Ono who engaged in creating map pieces. Robert Smithson, Richard Long, and Christo and Jeanne-Claude, to name few, became internationally recognised as "earth artists" who took landscape and the Earth's surface as raw material to produce art works and interventions. As maps and map-making became ubiquitous towards the 1980s and 1990s, featuring across different media, so in the art world we observe a growing interest in the field, with art curators and institutions giving "map artists" more visibility and opportunities for exhibition [START_REF] Wood | Map art[END_REF][START_REF] Watson | Mapping and contemporary art[END_REF].

In parallel with these art movements, intellectuals engaged in debates around society and territories were shifting their attention to cartography as a way to better understand relations of power. The work of the geographer William Bunge in the 1960s and 1970s, mapping disadvantaged neighbourhoods in Detroit, is exemplary of what later was recognised as a "counter mapping" or "radical cartography" which also inspired artists in practices that combined aesthetic defiance and activism (Mogel & Bhagat, 2008).

New digital technologies developed from the 1970s onwards by artists and academics likewise converge in the exploration of the map as aesthetic and informative medium to questioning, using technology to their purposes of experiment, creativeness. The novelty of these art, research and technological practices founded in the mid-20th century is the engagement "from below" with the urban space, against the traditional detached view that homogenise perceptions.

MAPPING LIVERPOOL: AN ANALYSIS IN FOUR ART MAPS

Liverpool is a city with a wealthy past, once regarded the second city of Empire, after London, by early 20th century. Having its main economic activity concentrated around the port, the city was badly affected by the bombings during the Second World War and the decline of the British manufacturing industry from the 1960s onwards. There was a sharp decrease in population, a rising number of derelict buildings and an atmosphere of complete defeat by the 1980s, when local authorities were eligible for applying for external funding, mostly from the European Union, as it was considered one of the poorest urban areas in the continent [START_REF] Ch | City of change and challenge. Urban planning and regeneration in Liverpool[END_REF].

In 2008 the city of Liverpool was about to stage the European Capital of Culture year and a map previously commissioned in 2005 was ready to be exhibited to the public. Ben Johnson's Liverpool Cityscape (fig. 1) is a large painting that depicts a classical bird's eye view of Liverpool city centre, its most iconic buildings and its surroundings. During three years, the artist and five assistants worked full time in the studio, along forty-three people who collaborated intermittently; more than three thousand photographs were taken, almost twenty-three stencils were used and seven hundred individual colours mixed (Bukantas, 2008). The production process is mostly based in photographic documentation taken by the artist in the city, which were then used for creating computer-generated drawings from what stencils were produced to apply the painting on the canvas. This intriguing work seems to have two distinctive natures: a very formal one, where the production process is committed to detail and perfection, and a fantasy-like one. Ben comments: "What I'm painting is perhaps a fantasy of the city. It is a city seen at a great distance.

[…] There are no people, there are no cars. There is an invitation for somebody to enter that dreamlike world and inhabit it" 2 .

After three years, the painting moved from artist's studio in London to be finished at the Walker Art Gallery in Liverpool, under public view. According to the artist "it was always my intention to finish it in public so that people could see that the work didn't come out of an ivory tower; it's actually made by very ordinary people" 2 . In 2011 the painting was moved to the Museum of Liverpool where it is in permanent exhibition. hand-drawn map made during six months. From his own account during his initial visit to the city, he fell in love with a woman from Liverpool and this chance meeting led him to further explore the local history and people, resulting in a map "far larger and more detailed than was initially planned"3 .

The map is a product of the first-hand experience of the artist in the city, web-based research and historical maps and books. Public figures, historical events, folklore, built infrastructure, pubs, football stadia and green spaces were placed accurately, using an up-to-date Ordnance Survey map as cartographic base. "I began to translate Liverpool's character on to paper, its quirks, idiosyncrasies and its stereotypes into a celebration of the masonry and hearts of Liverpool" 3 .

The detail and array of information is vast and displayed in what may appear as a cacophony of notations but looking closer the map reveals more of its structure. It depicts a choice for the picturesque and curious, political commentary and humour. The extensive legend located at the top right corner of the map is suggestive of the mix of historical and geographical survey, anecdotal facts and personal observation of the urban landscape. Thus among pictograms for "museum", "hospital" and "supermarket" we find "questionable fact (Wikipedia)" "public hangings took place here" and "reference to boobs or fit women". The map is in permanent exhibition at the Bluecoat Art Centre in Liverpool. The Map of Liverpool (fig. 3) started with a national competition launched in June 2008 asking for a cultural map of Liverpool to celebrate its European Capital of Culture year. The map would be placed in the new Museum of Liverpool and integrate its permanent collection. Inge Panneels and Jeffrey Sarmiento, artists both based at the National Glass Centre in Sunderland, won the competition proposing a large sculpture, to stand two metres high, constructed from stacks of fused sheet glass. This technique would allow representing a "multi-layered snapshot of Liverpool in 2008", which the artists describe as "a true team effort" that received many contributions its concept, development and production [START_REF] Davis | Layers of Liverpool: mapping a sense of place. The story of the Liverpool Map[END_REF].

At first glance, the Map of Liverpool has the look of a "traditional" map but deeper inspection reveals the many layers within its geography. The information inscribed on the map was gathered by public survey conducted by a local newspaper in Liverpool and is a result of the public's choices on the most representative people and places of the city.

TRANSLATING CITIES: SOME REFLECTIONS

On conducting this project, interviewing artists and analysing their practices, we have oriented our enquiry towards the performative dimensions of art maps rather than their representational aspects. When analysing the Liverpool maps we face a group of works that utilise different techniques, styles and materials while all being products of similar cultural and historical circumstances. We also want to emphasise in each work the different aspects of the map as an artefact and the map as process (mapping).

Ben Johnson's painting, and Panneels and Sarmiento's glass sculpture, are both commissioned works, chosen by a board of sponsors and local representatives of government and civil societies in Liverpool to celebrate the Cultural Capital year. Johnson's cityscape is an architectural compendium of the city and its iconic buildings -the two cathedrals, the three graces and the Museum of Liverpool are in much evidence, surrounded by other ordinary buildings. The public somehow participated in the process as observers but did not have a concrete influence on the final work. The map/panorama can be considered as a view "from above", despised as "traditional" or even "authoritarian" in the art movements commented previously in this paper. Panneels and Sarmiento's map, on the other hand, seems to result from a more participatory and collaborative practice, between the artists themselves and between the artists and the public -even though this last was a mediate relation, via the survey collected by the commissioners.

Stephen Walter's drawing and Brian Mackern's digital installation are individual enterprises, where resourced historical documentation in old maps, photographs and history books (also used in Johnson's and Panneels-Sarmiento research) is complemented by direct experience within the urban environment. Story telling is a central theme in both maps, and historical perspective (more evident in Mackern's work) is explicit in many references to dates and personalities.

Although approaching the same city, the maps are very different in terms of the actual territory covered: Johnson's and Mackern's works focus on the city centre; they are cropped views of Liverpool. Walter's goes as far as the urban landscape ends and the rural begins, making sure the entirety of the urbanised area is included. Panneels-Sarmiento's map has a city-region view as it includes the Wirral and further surroundings.

The artists interviewed mentioned the expectations that maps induce in people, the importance that maps reflect peoples' places and histories and that somehow they want to be able to recognise themselves in the artwork, to identify, to use the map as a mirror for identity. The artists reported having personal experiences of engagement with the place and the people of Liverpool, even if they were not in direct contact with them. In this sense, the Liverpool maps are successful in transposing the geographical boundaries and enacting more subjective values. Perceptions like a sense of pride for the city and its people, a common attitude of resilience and defiance facing economic and social struggles, associated with a welcoming and friendly approach to strangers, were the main characteristics that these "outsider" artists mentioned in relation to local inhabitants and that in many ways were impressed in the art works produced.

Figure 1 .

 1 Figure 1. Liverpool Cityscape by Ben Johnson

Figure 2 .

 2 Figure 2. Liverpool 2008-09 by Stephen Walter. Full map (left) and detail (right)

Figure 3 .

 3 Figure 3. The Map of Liverpool by Inge Panneels and Jeffrey Sarmiento, as exhibited in the Museum of Liverpool

Figure 4 .

 4 Figure 4. This too shall pass by Brian Mackern (screenshot)

This project considered the production of living artists.

See stephenwalter.co.uk/the-maps accessed 31/03/17.

THE AUTHOR

Gloria Lanci

University of Liverpool CAVA Research Centre/School of the Arts gloria.lanci@liverpool.ac.uk


Andreas Author

Faludi

Beyond Territorialism: Europe as an Archipelago

Keywords: Territorialism, Territoriality, Neo-medievalism RÉSUMÉ Territorialisme, territorialité, néo-médiévalisme

Under territorialism (Scholten, 2000), space is divided into territories over which states exercise territoriality (Sack, 1968). What territoriality the European Union (EU) exercises depends on whether it is intergovernmental or supranational. In either case, the representation of its territories is based on the map of member states. Under the intergovernmental view, their borders will be prominently present. A supranational representation might not even feature internal borders. The real challenge is to figure out how to represent territories under alternative views of the EU. Recognising that traditional statehood is breaking down -that we experience "the end of territories" (Badie, 1995)-such views see the EU as an "unusual polity" (Nugent, 2010). Of such views, the one of the EU as a "neo-medieval empire" (Zielonka, 2014) particularly challenges notions of the spatial representation of its territories. I propose to represent states as islands in a sea of overlapping functional relations.

TERRITORIALISM, THE STATE AND THE EUROPEAN UNION

 Scholte (2000: 46)argues that the "proliferation and spread of supraterritorial [...] connections brings an end to what could be called 'territorialism', that is, a situation where social geography is entirely territorial". However, he continues, territory no longer constitutes the whole of our geography, a view which has far-reaching significance for what is called territorialism. After all, the latter "implies that macro social space is wholly organised in terms of units such as districts, towns, provinces, countries and regions. In times of statist territorialism more particularly, countries have held pride of place above the other kinds of territorial realms" (ibid.: 47). Under state territorialism so defined, space is divided into territories over which one each exercises territoriality. Sack (1968: 19) defines territoriality as "the attempt [...] to affect, influence, or control people, phenomena, and relationships, by delimiting and asserting control over a geographical area".

Meaning that the state is geographically based and bound, territoriality is one of the essential elements of statehood. Nugent (2010: 421) adds two others: Sovereignty, meaning that the state is above all other associations and groups within its geographic area and that its jurisdiction extends to the whole population of the area, and legitimacy, meaning that the authority of the state is widely recognised, both internally and externally. The latter refers to international relations theory recognising the state's monopoly of governance, both as regards public decision-making as well as enforcement. However, under European integration, these characteristics of a state come under scrutiny. The focus here is on territoriality. Does the European Union exercise at least some of territoriality?

The answer depends on whether the Union is considered as an intergovernmental or a supranational formation. If intergovernmental, then territoriality would seem to be exclusively for member states. In fact, the Union might not be considered to have a territory at all; only member states would.

By definition, it being supranational would mean that the state's monopoly of governance is broken. Elements of public decision-making as well as enforcement of territorial control shift to the level of the Union. The Union would thus have a territory of its own. In either case, the representation of the European Union territory -or what goes for it-would feature the map of member states. Under the intergovernmental view, giving primacy to member states, their borders would be prominently present. Taken to its logical conclusion, a supranational representation might not even feature internal borders. After all, the European Union would be considered to have legal personality of its own.

TRANSCENDING TRADITIONAL STATEHOOD

The real challenge is to figure out how to represent the territories of the European Union under alternative views, neither intergovernmental nor supranational, which do exist. Nuggent accepts that the situation is changing, requiring such alternative views: "[The] realities of traditional statehood are breaking down in the modern world, most particularly under the pressures of international interdependence. So, for example, no modern state can now be regarded as being fully sovereign in a de facto sense, and the EU member states cannot even claim that they are fully sovereign in the de jure sense" (2010: 421-422). Recognising that traditional statehood is breaking down -that we experience "the end of territories" [START_REF] Badie | La fin des territoires[END_REF]-such views see the EU as an "unusual polity" (ibid.: 437). Of such views of the EU as a "neo-medieval empire" [START_REF] Zielonka | Is the EU Doomed?[END_REF] particularly challenges notions of the spatial representation of its territories. Zielonka himself is less concerned with space. Referring to the present, he invokes Barbara Tuchman when she writes about situations in which nations going to war as the "march of folly". Every attempt to make the Union a proper federation would thus be counterproductive. The strategy should rather be one of "creating more 'Europes' and not more Europe, meaning a single integrated continent" (ibid.: 48) The Union itself will survive, if at all, only in a weakened form. Cities, regions and non-governmental organisations will become stronger, making state borders fuzzier, thereby even further dividing loyalties. Invoking Saskia Sassen, Zielonka sees agglomerations and "global cities" filling the political and administrative vacuum left from the loss of power at national level. "Modern cities operate transnationally 313 through a variety of trans-border networks, often ignoring traditional interstate diplomacy. Their inhabitants are also transnational.... They are actors from a different, super-modern universe" (ibid.: 90). In fact, they sometimes work like the medieval Hanseatic League.

Zielonka envisages such diverse and decentralised networks, for instance for transport, energy, migration, tourism and sport. These could prove to be more effective and efficient than any attempt to bring all of them under one jurisdiction.

Importantly, he nowhere suggests a return to the rule of nation states. National sovereignty is meaningful only where national borders coincide with market transaction fringes, military frontiers and migration trails. Relying on the revival of the nation state is thus not the answer; networks are. Rather, instead of a return to a "Westphalian" order based on the recognition of state sovereignty, Zielonka foresees a new medieval order. What this means is the exercise of authorities resembling the medieval mode, with divided sovereignty, differentiated arrangements and multiple identities. Rather than continuing to rely on fixed and hard borderlines, the future will bring fuzzy borders. Rather than central redistribution, there will be several types of solidarity. Rather than imposing rules, the future is one of bargaining, flexible arrangements and incentives. It is in this respect, and only in this, that Zielonka invokes the Middle Ages as a model.

REPRESENTING THE NEO-MEDIEVAL EMPIRE

How to represent this spatially? To start with, I propose to represent states as islands. Taking account of the international dependences addressed by Nugent and Zielonka, we can conceptualise the islands as forming an archipelago. The surrounding sea are the overlapping functional relations. That this is so should have implications on how states perceive themselves. A discourse of frontiers as barriers, to be crossed only at the pleasure of responsible authorities no longer fits. Islands must interact with the seas lapping their shores. Those seas form endless fields of opportunities to which the Freedom of the Seas guarantees seafarers access. Indeed, Europe deserves better than being forced into the straightjacket of thinking of states and of their territories only in terms of containers. Europe as an archipelago comes down to viewing the space of the Union differently. It is the same with spatial planning. It may concern whether the islanders succeed in developing their lands purposefully and in integrated fashion. Importantly though, planning would also be about them managing their relations with the surrounding sea and with the other islands, including those far behind the horizon. Indeed, the sea forms an endless field of opportunity, certainly for the more daring seafarers.

Perhaps an even starker metaphor would be to represent states, not as islands but as ice floats. Sometimes, ice floats coalesce into larger ones. In the fullness of time, some disappear as, indeed, states disappear. There is nothing eternal about them. States are historic constructs and as such can be undone. However, for as long as they last, which, depending on their makeup, can be long, they provide a base.

To pursue yet another line of thought, maybe, we should see Europe as a cloud. The institutions of the Union do not fit into a box, not even a large one. The spaces they cover overlap, creating an apparently disorderly pattern: the Union itself; the European Economic Area; the Schengen Area including amongst others Switzerland; the Euro zone, but note that non-members Montenegro and Kosovo and mini-states not otherwise involved like the Vatican also use the euro. There is also the Customs Union including Turkey. Likewise, some Cooperation Areas under INTERREG transcend EU's external borders, and so do macro-regions. In addition, there is the EU's Neighbourhood Policy, Maritime Spatial Planning and the Mediterranean Union. There are also various association treaties and the relation with African countries under the so-called Lomé Accord and, not to forget, French, and thus EU territories in the Caribbean, the Indian Ocean and the Pacific, including the tiny Island Europa in the Madagascar Channel. A cloud indeed.

CHALLENGING PLANNERS

Whichever metaphor one wishes to pursue, the planners' calling is to conceptualise spatial or territorial relations fitting the space of the Union as it really is, and not what territorialism tells it should be like. As metaphors, the archipelago, the Arctic sea with ice floats on it and the cloud, all conjure up a -realistic-picture of the very complexity, not to say disorderliness with which, in so doing, they have to cope. However, there is no more order to be had in today's and tomorrow's world. Attempt to impose one overall order will end in failure. What planners can do, however, is proposing strategic spatial visions to help coping with the interrelations between the constitutive elements of the Union and, since the Union is not a finished product, it means to prepare for change. Indeed, just as the shape of clouds is fluid, so is the EU: It is, and remains, in flux. At best, planning can help with rendering the process smoother. As, indeed, with Zielonka's neo-medieval vision of Europe, this sceptical view of their role may be disturbing, not in the last instance for planners with their love for order. Coping with permanent disorderliness stretches the imagination and ability to cope. So do all the challenges that Europe faces.

THE AUTHOR

Andreas Faludi

Delft University of Technology a.k.f.faludi@tudelft.nl