(本文) This cityscape identity is formed based on a certain political, economical, and social circumstance within a specific place and time, so that the cityscape identity of one city is different from that of another city. Various tangible and intangible components of cityscape-from physical elements such as buildings, open spaces, and spatial structure, to socio-cultural elements such as people, activities, and the interactions among them-enable us to associate a representative image with each city. Cityscape identity is generated when a place is discerned by such elements, and it becomes the measure by which people come to recognize a city as "the city."

With the advent of the localization era followed by economic stability, many local cities and towns in Japan have recognized the significance of cityscape management and cityscape planning as a means for developing their own city identities, which creates an economical advantage over other cities and thereby safeguards the city's competitiveness in the long run . In particular, in order to support and improve the quality of life of citizens as well as to promote city competition in manifold ways, cityscape management is an indispensable strategy that enables planners to discover and foster a desirable identity for a city. Moreover, cityscape management views the city's future identity multi-dimensionally from various perspectives, compared to urban planning systems such as land uses, circulation systems, and district plans, which are confined to only two-dimensional matters. In this context, each local government in Japan has begun to give priority to cityscape management plans and policies and tried to discover-reorganize-visualize distinctive cityscape features, cityscape identity.

The boom of establishing a unique cityscape management system in local cities from the late 1970s to the early 1990s, which had been-some cities have still been-mainly drawn by the National Government of Japan, indicates general concern about city identity management through the lens of cityscape management. Under these social circumstances, local cities in Japan have devoted themselves to introducing adequate cityscape management systems, and some of them have been very successful in dealing with their own cityscape identity, while others have not. That is because the latter failed to understand the essential qualities based on their own historical background and the present condition through a holistic approach.

Thus, it is necessary for cities to adopt appropriate cityscape identity management systems by considering and expressing their own urban context and to beware of the transformation of agreed unification into uniformity. The first thing to do, therefore, is to understand the basis of a city by trying to understand it from various perspectives, from the development of human culture to the use of land, while clarifying the concepts related to cityscape identity management in parallel, which is helpful for setting the direction in introducing cityscape identity management tools. The following chapter will briefly mention general definitions and interpretations of the terms used in the study and suggest new definitions necessary to proceed in this study.

The major premise for all these works was that the cityscape of every city has been and would be changed, under the influence of each management system and any effort to manage it, and the best way to manage cityscapes while considering their unique characteristics could be found. The objective for the current study was therefore to determine the most appropriate cityscape identity management system and evaluate its significance as a way to help establish unique management systems for each ward and city in metropolitan Tokyo. As for this, the exact meaning and confine the range of terminologies used in further study was clarified first, and then the management systems and activities concerning cityscape identity in the cities of Tokyo, where the local government plays a major role in cityscape management was analyzed. Also, it was investigated whether and how management tools have been adapted to the cityscapes and how they affect each city. After providing a theoretical foundation and explicating the mechanisms of cityscape management systems in each city, their effectiveness between cities and evaluate them was evaluated, so as to suggest the most appropriate cityscape identity management system for each city, which was the ultimate goal of this study. In this way, the present research concentrated on the appropriateness and effectiveness of management techniques, which fit a particular context, holding the potential for devising new approaches.

As one of the fastest growing cities having a great potential to be completely changed with new and creative cityscapes and the most historic old capitals exhibiting in various historical cityscapes at the same time in Japan, the 23 ward area of the Tokyo Metropolitan City clearly was chosen as the study area of this study; These abundance and diversity of cityscape identities which can be easily damaged if there is no proper management system. Also, 23 wards of the Tokyo Metropolitan City has established and implemented the most representative local cityscape management systems; with the Local Government Law established, each local city including the 23 wards has developed its own cityscape management system independently since the 1980s, and each system of these individual 23 wards can be representative of the rest of the local-level cities of Japan. Furthermore, because it has been about one to two decades since local cities of Tokyo introduced cityscape management systems, and some of them are preparing to revise the existing system or introduce a new one, it is the proper time to evaluate their performance so far.

As the methodology, this study first reviewed pertinent studies such as existing research related to the general concept of cityscape/landscape, the development process of cityscape identity, the cityscape management system, and the conservation activities related to historic landscapes; legal documents such as laws and ordinances about cityscape/landscape, minutes recorded at the Cityscape Council meetings; urban planning documents such as design guidelines of cityscape/landscape for each ward; and all the records of relevant undertaken projects and citizen activities such as project brochures, pamphlets, newsletters, and the web pages of each ward. Moreover, in-depth interviews with officials in charge of cityscape management in each ward will be performed. This work then focused on the classification process of cityscape management systems according to the characteristic and function drawn by the previous review, so as to elucidate the differences between wards and evaluate the appropriateness.

Focusing on how the recognition of cityscape management has emerged and expanded to the establishment of a cityscape management system at the national level, Chapter Two reviewed several relevant systems used by the Japanese national government in the city planning fields that have affected cityscape management activities, as well as the cityscape management systems themselves. Interestingly, the management of the cityscape has been addressed under the Law as an obligation of the government, and various city planning systems control it with detailed guidelines and regulations. Moreover, it was found that a paradigm shift from prioritizing the quantitative aspects of city planning to considering the qualitative aspects together has raised awareness about the importance of cityscape management from recent days.

Based on the previous review, further research about the development of the cityscape management system at the regional and local levels was carried out to understand how substantially the national-level systems are reflected and implemented in the sub-level's systems, by examining the cases of the Tokyo Metropolitan Government and the 23 special wards of the TMG in the next chapters; the cityscape management system of the Tokyo Metropolitan Government which has been changing from comprehensive approaches to individual and specific approaches with stress placed on each ward's independent role was reviewed in Chapter Three. Chapter Four took a closer look at the cityscape characteristics of each ward through its formation process by focusing on three main factors that comprised the cityscape of the 23 wards to derive the cityscape identity of each ward. It was found that the various influencing factors have played an important role in keeping or changing the original cityscape and creating its identity, and based on this historical background and circumstance of each ward, Chapters 5 and 6 analyzed the cityscape management system of the 23 wards; first, the 23 wards were divided into two groups first. One is a group of eight wards implementing cityscape management systems on the legal basis of their own, such as a cityscape ordinance, cityscape plans and guidelines, or a preliminary notification system concerning only the ward's own cityscape, which were introduced independently of those of the upper organization, Tokyo Metropolitan Government. The other is a group of the remaining fifteen wards controlling cityscapes under the urban planning systems of their own or adopting Tokyo's cityscape ordinance or cityscape planning as a legal basis.

In Chapter Five, eight wards implementing cityscape management systems based on their own legal management tools was analyzed such as Bunkyo ward, Chiyoda ward, Kita ward, Koto ward, Setagaya ward, Taito ward and Toshima ward, concerning the introduction time of the cityscape management systems including the cityscape ordinance and its background, and the implementation circumstance of each management tool including the method of area division, the range of objects being managed, and the kinds of objects that require notification to the ward office. The systems reviewed was categorized into three groups, legal systems such as cityscape ordinances and cityscape planning, devices for implementing or supporting those legal systems such as a pre-notification system or pre-counseling on new building development, and tools related to publicity activities and the encouragement of citizen participation. Finally, a further look at the deficiencies or difficulties encountered so far in implementing the cityscape management system was carried out, through interviews with officials in charge of each ward. This review found that the 8 wards with their own cityscape ordinances and planning systems, have developed the basic tools in their own ways while implementing cityscape management systems based on similar principles and methods.

Lastly, Chapter Six reviewed 15 wards with indirect cityscape management systems, in order to clarify their characteristics and draw some implications about other Japanese cities in similar conditions. The 15 wards was first categorized into five groups, which are the wards managing the cityscape through the District Planning, the wards managing the cityscape through the active participation of citizens, the wards managing the cityscape using mixed methods, the wards managing only the limited district's cityscape, and the wards without any special systems for managing the cityscape. Each group was investigated through pertinent materials and in-depth interviews with officials in charge, focusing on the main cityscape management tool, contents and details of the coverage of each tool, through examining with what system and how the ward manages the cityscape by which department of the ward, citizens' interest and participation and any educational activities to attract people's attention to cityscape management and involve them in the process, other relevant particulars that should be mentioned, and deficiencies and solutions. This review found that the wards that had not established an exclusive cityscape management system and certainly had implemented fewer cityscape management tools using the word 'cityscape' in their title, from just one tool to a maximum of seven tools, which amounted to half the number found in the wards with exclusive cityscape management systems reviewed in Chapter Five. However, the specifics of each ward varied in actuality; not only were there wards giving low priority to cityscape management, but also there were wards actively utilizing other tools in managing their cityscapes in practice, even some that did not realize that those activities could be considered formal and official "cityscape management." Nonetheless, it is certain that citizens' awareness of cityscape management still has an important role in cityscape management with or without a formal system, and thus the significance of educational activities about cityscape management can never be overstressed. Consequently, the most ideal cityscape management system, in terms of its feasibility as implemented by both the executer - the ward - and citizens directly concerned with their surrounding cityscape, was found in wards where the ward and its citizens together were greatly concerned about the surrounding cityscape and the management of its identity, and therefore cooperated with each other, thus facilitating the realization of an effective cityscape management system.

本論文は東京23区すべてを事例として、景観管理システムのあり方および運用実態の詳細な調査分析を通して、景観管理政策の意義と手法を総合的に検証し、その望ましい姿へ向けての提言を行うことを目的としている。

論文は研究の背景・目的および展開方法を述べた第1部と、日本における景観管理システムのこれまでの発展を概観した第2部、そして景観管理システムの実際を23区を事例として比較検討を行った第3部とから成っている。

第1部は導入部である。第2部はさらに日本における景観の保全と整備とに関する意識がどのように生まれ、現在に至っているかという歴史的発展過程を明らかにした第2章と23区の景観管理政策に大きな影響を与えてきた東京十景観管理システムおよび他の都市計画上の景観関連の主要施策の展開を跡づける第3章とから成っている。

本論文の中心となる第3部では、まず、第4章において、景観管理システムとして独立した景観条例を有している文京・千代田・北・江東・世田谷・新宿・台東・豊島の8区を取り上げ、それぞれの景観管理システムの特徴を相互に比較し、地形や歴史などをもとに各区の特性に合わせた景観管理のシステムの評価と問題点の指摘を行っている。

とりわけ、景観条例による規制の内容や目的は類似しているものの、各区における運用実態に大きな隔たりがあり、細かな規制手段の用い方や開発圧力の大きさなどがその要因としてあることを考察している。

続く第3部第5章においては、景観条例をもたないため従来は景観行政に熱心でないとして調査分析の対象となりにくかったその他の15区を対象として分析を行っている。これらの区を地区計画を中心に景観施策を展開している区(足立・中央・目黒・太田)、区民参加によるソフト施策を中心に景観施策を展開している区(荒川・港・中野・杉並・墨田)、両者の混合施策を実施している区(板橋・練馬)、特定地域に施策を集中させている区(江戸川・葛飾)、その他の区(渋谷・品川)という5分類を行い、それぞれに分析を行うとともに相互の行政スタイル間の比較を行っている。

特に地区計画主体の施策を展開している区は大規模開発など、景観上の大きな変化が予測される区が多く、対象地に対しては詳細なアプローチをしているものの、区全体に対する景観管理上の将来像を描くということに関しては不十分である。一方、区民主体のまちづくりによって景観施策を実施していくことを計画している区では、住民参加の格段内において多様な意識付けのプログラムが用意されている場合が多く、景観はその活動の一部として役割を果たしているという位置づけにあることがわかった。

また、特定地区に限定した景観管理システムを実施している区においては、ガイドラインや事前協議の仕組み等、景観条例の枠組みとは多くが類似しているものの、行政の施策が区にとってシンボリックな目玉地区に集中する傾向がある。部分を優先し、全体像は部分の蓄積の上に次第に拡がっていくという方法論は、景観計画策定による全体像の把握を推奨している景観法の仕組みと対照的である。

全般に第5章で扱われている区においては、景観と他の施策とが融合的に実施されている点がもっとも大きく異なっており、たとえば居住環境整備のような総合施策としてより高次の概念の中に現行の景観管理システムを位置づけ、説明していかなければならない。

以上、本論文は、従来悉皆的に調査することがなされなかった23区すべてについて景観管理システムとその異同を明らかにすることによって、各地方自治体の個性や事情に応じた複数の奥行きのある景観管理施策が実施可能であり、現に23区では様々に実施されていることを実証的に明らかにしている。さらに景観管理施策がよりおおきな行政目標の中に効果的に位置づけられることが効果的であるといった戦略を示唆している。これらの分析を通じて、総合的な政策目標とその中での景観管理施策の今後の可能性を示し、各自治体の今後の景観施策の方向性についてきわめて有効な提言を行っているものとして高く評価することができる。

よって本論文は博士(工学)の学位申請論文として合格と認められる。