The historic kernel of Dhaka, commonly called 'Old Dhaka', retains the traditional features it has inherited from a long history of urbanization influenced by various cultural phases, sometimes hostile to its natural process of evolution. Local culture and the way of life had always been a unique modifier to absorb or adapt that is new, in its folds. A series of superimposed or juxtaposed layers of interventions due to these phases, sometimes beyond recognition, when unfolded, reveal an epitome deep beneath. This epitome shows clues to a hidden order that gives a distinctive texture to indigenous settlement morphology. In order to understand the spatial structure of Old Dhaka or to predict its future, it is essential to understand the process and context of its transformation. This present research sets out to investigate the process of the spatial transformation of Old Dhaka through analysis and synthesis of the socio-physical interaction.

It has been observed that, in contrast to total Dhaka city the older areas still retain their traditional life styles. One of the probable reasons may be the social interaction of community with the neighbors, relatives and friends within neighborhood areas. Another significant reason may be the physical structure of the built form as well as urban spaces of local areas that persists the traditional qualities of articulation. Therefore, it seems imperative to understand the socio-spatial organization of such urban areas. Hence, the morphological features of man made space at local level could be lawfully determined by social process with physical intervention.

Since study of the whole of the Old Dhaka is beyond the sphere of the available time frame of research. An attempt had been made to pick up an area providing scope for studying urban structure of Old Dhaka and processes of transformation. Assuming that socio-cultural and spatial aspects of land use do not significantly differ from place to place within Old Dhaka, the Pre-Mughal boundary, the area inside the Dholai Khal (canal), the oldest part of Old Dhaka is chosen for this study.

The present research intended to explore the origin and development of indigenous city form with particular emphasis on Old Dhaka through an orderly comparison of its historical, social and morphological growth pattern. Moreover, spatial structure of historically and culturally eminent local areas is thoroughly observed within the overall nexus of organically generated old society. Hence, the main objective of this present research sets out to understand the urban morphology of Old Dhaka and the forces that had acted here to produce it. Then finally analyze the socio-physical qualities and internal spatial structure of these areas and their transformation that makes the Old Dhaka vibrant and impulsive even at present.

There is a dynamic relationship between the human settlement and process of transformation and their response to each other. Like other cities with colonial influence, Old Dhaka consists of a patchwork of different areas are layers from different periods. How to describe this kind of mosaic situation in this context is a major challenge of this study. The image of Old Dhaka and public perception within or outside this area still continues and we have to understand the key elements behind this. What factors produces the image and spatial essence of Old Dhaka, remains the key question.

This research simultaneously draws out the emerging of discourses discussing complex system throughout several discipline and grounds the theoretical framework in the Pre-Mughal area of Old Dhaka with the dynamics of the evolution and transformation of the spatial structure as main focus, with an emphasis on socio-physical interaction. The theoretical framework and reading of the Pre-Mughal area of Old Dhaka as complex system and grounded theory as the research approach. More specific research detects the dynamics between socio-physical interaction and the consequent transformation of the spatial structure.

The analysis is conducted in three steps; the first step is to review and synthesize the theories in the study of spatial and social structure of cities; the second step is to identify the evolution and change in historical, social, cultural, political aspects in relation to the spatial structure of Dhaka; the third step is to identify the characters of the spatial structure and transformation of the Pre-Mughal area of Old Dhaka during last one hundred years.

The formation of the study has been divided into seven chapters. The initial chapter defines the problem and background of the study followed by the research question, objective with specific aim and description of methodology to examine the socio-spatial structure of the Pre-Mughal area of Old Dhaka. The next three chapters mainly deal with the three broader issues that are listed below respectively.

a. Review and synthesis of literature in the study of spatial and social structure of cities

b. The study of historical and morphological evolution of Old Dhaka as indigenous organic development over the period of four hundred years.

c. Comparative study of the social structure and spatial formation of urban Dhaka

The second chapter reviews the thoughts and ideas present in the field of socio-spatial study of cities. This chapter tries to focus on the existing theories and concepts of different researchers to understand the background and possibilities of this research.

After the theoretical review and synthesis of the literature, the third chapter is considered as a preamble to the city of Dhaka. It discusses the brief history of this city and dynamics of the physical growth and the spatial structure of Dhaka city over last four hundred years. This part of the research tries to pinpoint how the cumulative process of growth and consolidation has influenced the spatial structure of Dhaka. This section extracts mainly on the historical, political and morphological pattern of development that has been categorized into six major phases and how the theoretical interpretations of organic development intermingle with the historical development of old city. In the fourth chapter, the social structure and spatial formation of Dhaka over four hundred years has been discussed from a socio-cultural perspective.

The analytical finding of the empirical research is compiled here in two chapters. Among them chapter five discusses the dynamics of the physical growth and the spatial structure of the Pre-Mughal area of Old Dhaka over last century with the help of available cartographic maps at four different stages from 1859 to 2010. This part of the research has presented the field survey findings on the spatial structure and analyzed the extent of transformation. It finally introduces the areas which are selected from different phases of growth for the detail investigation to understand the socio-physical interactions.

The sixth chapter deals with the spatial structure of the selected areas in Old Dhaka. This chapter tries to identify different physical units of this area having a distinct social as well as spatial attribute; and also intends to investigate their particular relationship to one another. It is actually a search for a morphological order of neighborhood areas within the urban structure. In doing so, it also tries to examine the existence of historic neighborhood within the existing fabric. It also focuses on the social aspects associated with the perceived spatial organization. It tries to ascertain the social structure and spatial behavior pattern of the urban mosaic and its significance.

The last of the seven chapters tries to provide a holistic view of the study. it sets out to delineate the generalizations achieved through this research endeavor about the socio-spatial structure of the Pre-Mughal area of Old Dhaka, and to relate them to more general observations about the organic city form and the continuations and changes in the spatial logic of these underlying social processes.

Thus through a systematic unfolding of the social as well as spatial structure of local areas, this thesis tries to find the generic characteristics of the organic morphology of Old Dhaka. It is believed that this study would create an understanding, so that urban design approaches might take a greater influence from the phenomena created in the organic areas.

本論文は、バングラデシュの首都ダッカの旧市街地であるプレムガール地区を対象に、詳細な都市形成史分析を行い、その都市構造とその変遷を詳細に明らかにすることを目的としている。

従来、ダッカの都市形成に関しては、地図資料の制約からごく限られた一時資料を基に部分的な野外調査をもとにテーマを絞った分析がおこなわれているに過ぎなかった。これに対して、本論文では、プレムガール地区について悉皆的な踏査を実施し、詳細な地図資料を作成することを初めて実施し、その成果をもとに、ダッカ旧市街地の空間構造の主要な特質を明らかにし、その変遷がどのようなプロセスによっておこなわれてきたのか、に関して、主として近代100年の歴史をもとに実証的に明らかにすることを具体的な目的としている。

論文は7つの章から成っている。

第1章において、研究の目的・方法を明らかにするとともに、本論文で用いる主要概念の定義をおこない、本論文の構成を示している。

第2章では、都市の空間構造と社会構造の関係に関する既往研究をとりまとめている。

第3章は、ダッカの都市全体に関して、その物理的な発展過程を明らかにしている。都市発展の時期区分をプレムガール期、ムガール期、東インド会社期、英国支配期、パキスタン支配期、バングラデシュ独立期に分けて整理をしているほか、都市の形態学的分析、地形分析、空間分析などの各種手法によって、都市形成を多面的に論じている。

第4章は、同じくダッカの旧市街地全体を対象に社会構造の変化を中心に論じている。特にプレムガール期のヒンドゥー教、ムガール期のイスラム教、英国植民地時代のキリスト教という宗教上のコミュニティを軸に社会構造を捉えている。

第5章と第6章は、いずれもダッカの旧市街を対象に実地踏査をもとにした一次資料をもとに分析をおこなっており、本論文の中核をなす部分である。うち第5章は、第4章と同様の地区を対象に、物理的空間の構成要素分析とその変遷を明らかにしている。依拠している地図は1859年、1912年、1970年、及び2006年のものであり、これらを統一的な図面様式に転換し、現地調査によって修正を加えたものをベースとしている。建物用途別図や建物階数別図、建物建設時代別図などは悉皆調査によって新たに得られたデータをもとにしている。その結果、ダッカ旧市街の都市化のメカニズムが詳細に明らかにされた。

第6章は、ダッカ旧市街地の内部に関して、地区レベルでの変遷を調査した章である。文化的背景によって地区区分をおこない、主として宗教コミュニティによって4つの地区を選択して、詳細な個別プロットごとの建物空間に関する実態調査及びヒアリング調査をおこなっている。その結果、宗教的な背景によってその後の都市開発の形態に明確な差異が見られることを明らかにしている。

第7章は、これまでの成果をまとめ、地区レベルでの文化的同質性・異質性によって地区の境界領域の変遷に明確な差異がみとめられること、社会的な地区構造と空間的な地区構造とが相互に影響し合う状況を詳細に明らかにしている。

以上、本論文は、ダッカ旧市街地の歴史地図情報を駆使しつつ、実地踏査によって得られた一次資料を利用することによって、地域の空間特性がいかにして形成されてきたのか、そこに社会的特製がいかに相互的に影響を及ぼしあってきたかを詳細に明らかにしている。これらの作業はこれまでダッカに関しておこなわれたことがない、バングラデシュにおける先駆的研究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。