Landscape is a social product, created in mutual relations between humans and natural phenomena. Therefore, it is desirable to analyze landscape on the basis of mutual relations which happen between humans and natural phenomena. In analyzing the historical landscape which should be done for a certain period of the past, it is also desirable to approach it through environments, ideas, and senses that people experienced at that time. However, most landscape studies have been conducted not on the basis of past environments, or ideas or concepts of the past people, but on the basis of those of the present people. The landscape of Hahoe Village which is a riverside village is also a social product that resulted from human relations with natural phenomena and powers.

The residential areas had been shaped for a long time to adapt to natural disasters. Humans came to distinguish between dangerous and safe areas through long experiences and chose safe areas to reduce flood damages. Humans didn't keep river water from overflowing but they just lived in a safe place. Due to population growth via modernization, however, humans began to live in dangerous areas that hadn't been populated before. Ways of preventing floods in modern times are quite different from those of the old days. Civil engineering works after modernization were heavily undertook for flood control in areas prone to floods to keep river water from overflowing. The modern public works for flood control have played an important role of defending residential areas from floods. Also, natural levees were reinforced with artificial levees via modern public works for flood control and as a result back marshes were changed to farmlands. And, it brought a positive result in enhancing agricultural production capabilities.

And, the works led people to recognize the river not as a threat but as a natural landscape, or an ecological space. But, consequently, these led to side effects that changed the historical landscape in a moment. These include not only a simple landscape change of a river itself but also changes in the residential environment around the river.

In this context, this study has two purposes as follows:

■ To clarify residential environment features in Hahoe Village (houses' location, infrastructures' location, and public spaces' location etc.) from the viewpoint of flood disasters.

■ To clarify how the landscape of Hahoe Village was changed due to modern civil engineering works (for flood control).

It is very important to understand and study landscape in historical context with the ideas of those days. In this dissertation, I will clarify how floods in the Nakdonggang River exerted influence on the formation of Hahoe Village in the past and how the village was changed in its structure due to the modern civil engineering works, undertaken for flood control using hydraulic model analysis.

This dissertation is composed of 5 chapters in total. The 1st chapter as an introduction part includes background and purpose of study, hypothesis of study, scope of study, Framework of dissertation, and site suitability. The 2nd chapter includes the fundamental and absolutely necessary knowledge to understand this study. In this chapter, the detailed explanation of the contents how Hahoe Village came to be born, how the village was developed, and how it declined was included. And, the specific spatial features of Hahoe Village, which is well known to people, were discussed. Namely, the fact that the yangban's residential area and the common people's residential area are divided in Hahoe Village is well explaining. And, the basic knowledge of Feng Shui is concluded in this chapter too. Thus, the mean of Gi氣 and landscape form形局 in Feng Shui, and Feng Shui stories believed in Hahoe Village was described.

The 3rd chapter is the chapter to prove the first hypothesis of this dissertation that "Flood experiences for a long time before modernization exerted influence on the landscape formation of a riverside village such as spatial structure, spatial hierarchy, and land use". First the analysis methods used in this research are introduced minutely in this chapter. And, a lot of floods had occurred in Hahoe Village before modernization, which is different from what we have known, but the research result that the flood damages were minimized due to the effect of residential environment features which had been formed by flood experiences is described. And, how Feng Shui was formed by the experiences of floods and what the social mean and function of Feng Shui was discussed from the flood disaster prevention point of view.

The 4th Chapter is the chapter to prove the second hypothesis of this dissertation that "Civil engineering works after modernization including flood control projects made people free from flood disasters but landscape structure in a village was suddenly changed by the works". In this chapter, the modern civil engineering works for flood control on the Nakdonggang River after modernization was organized. As the result, how the landscape of Haheo has been changed was explained concretely.

The 5th Chapter is the conclusion chapter. The research results of this dissertation were organized and what the significance of this research was is described in this chapter.

本論文は,韓国慶尚北道安東市に位置し,韓国の伝統的形態と景観を残す河回村を対象にして,その空間構造と景観の特徴を河川の氾濫との関係から読み解くとともに,近代以降の治水をはじめとする土木事業が村の景観に及ぼした変化を論じたものである.

河回村の起源は14世紀にさかのぼる.洛東江が大きく蛇行して形成している洲状の平たい地形上に立地し,村の三面を川に,また背景を山並みに囲まれている.河回村は,韓国では風水の観点からもっとも理想的な環境の村として著名であり,伝統的建造物群保存地区として,歴史的家並みが良好な状態で保存されてきた.2010年7月にはユネスコの世界遺産リストに登録されている.したがって,河回村に関する既往の調査研究は豊富であるが,そのほとんどが歴史学的,民俗学的および建築史学的アプローチに限定されており,河川との関係,とくに洪水が村の空間構造や土地利用にどのように影響を及ぼして現在の景観を形成しているか,という河川工学的観点からのアプローチは皆無である.さらに,近代以降の村の景観の変容を土木事業との関連から論じる土木史学的アプローチによる研究もまた例がない.

本論文は,5章から構成されている.

第1章は序論として,河川(洪水)との関係から韓国の伝統集落の景観を扱うことの意義,ケースとして河回村を扱うことの理由が述べられている.そして,河川の洪水に対する対処が村の空間構造や土地利用に影響を及ぼしているのではないか,また洛東江流域に治水土木事業が施された近代以降は,それにしたがって村の景観も相応に変容しているはずではないか,という本論文が立脚する立場が示されている.

第2章では,河回村に関する基本的な情報,および村に関して一般に知られている既往の知見が整理されている.とくに,河回村に関する一般的な風水的解釈が紹介され,河回村は風水がきわめて優れているために過去大規模な洪水被害をほとんど受けていない,という誤った迷信が存在することを指摘している.また,17世紀初頭に両班(韓国における貴族階級)が居をかまえて以降村が発展していく経緯の概略,および両班の居住区域と一般階級の居住区域が明快に区分された村の空間構造の特徴を,既往の知見に基づいて整理している.

第3章は,氾濫解析による洪水シミュレーションと,その結果に基づく村の空間構造の分析考察にあてられている.汎用氾濫解析ソフトHec-GeoRASを用いて,50年,100年,200年確率洪水の各シミュレーションを行い,その結果を古文書の記録と照合して,主に次の三点を考察している.第一に,ほぼ200年確率の規模に相当する1605年の洪水の直後に建設された両班の住宅より標高の高い場所に他の両班が居をかまえるようになり,その結果村の中心部に両班の居住区域が形成されたと考えられること,第二に,村の対岸に築かれた四箇所の「亭」(休息のための東屋)は,いずれも一様に50年確率の洪水による水位よりやや上方に位置しており,浸水被害を受けにくい場所が選ばれていた可能性があること,第三に,やはり川の対岸の岸壁に刻まれた「凌波臺」という碑の位置が,ちょうど村の一般居住区域が浸水しはじめる標高とほぼ同じであり,したがって浸水被害を避ける祈願のような意味合いがあった可能性があること,を論じている.

第4章では,近代以後の河回村および周辺における土木事業が,村の景観を変容させてきた事実とその経緯を,史料および地形図に基づいて述べている.とくに,築堤により河川と村が空間的に分断されたこと,かつて村の中心部を通り橋で対岸へ通じていた街道筋が下流側への橋の新設により廃止され,以来村は川に三方を囲まれ孤立した形になったことなど,実際には近代以降の景観の変容が大きいものであったことが指摘されている.

最後に第5章は,結論として総括を行うとともに今後の研究の発展の方向性と課題を述べている.

本論文は,氾濫解析という河川工学的手法を用いて,伝統的集落の景観の分析を試みている点がユニークであり,また,近代以降の村内および周辺の土木事業が村の景観の変容に少なからず影響を与えてきた事実を指摘した点にも意義が認められる.しかし,本論文のもっとも重要な学術的成果は,歴史学・民俗学・建築史学的観点もしくは方法論に拠ることが一般的な韓国の伝統集落に関する調査研究の現状にあって,河川工学・土木史学的アプローチによる方法論の可能性を示したことにある.このことにより,単に歴史的な建築様式・生活様式といった観点だけでなく,集落と河川との関係性,村周辺を含めた全体の景観とその変容の仕方など,より包括的観点から伝統的集落の歴史的価値の本質や保全継承のありかたを考察する視野を提供するものであり,社会基盤学および工学に対する寄与は大きい.

よって本論文は,博士(工学)の学位請求論文として合格と認められる.

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