矢ケ﨑太洋, 吉次 翼
地理空間 7(2) 221-232 2014年 査読有り
東日本大震災による被害の大半は低地部における津波災害であり,被災市町村の行政や住民は,将来の津波に備えて集団移転やかさ上げによる住宅再建に取り組んでいる。本研究では,こうした住宅再建の動きに着目し,岩手県陸前高田市を対象地域として,震災以前と復興過程,復興事業完了後の3期に区分し,現地調査の結果を踏まえて都市復興に伴う都市の再編成について考察を行った。津波被害を受けた陸前高田市中心部は低地部に立地し,チリ津波以降に形成された。被災した公共施設・商業施設等は,仮設形態で周辺の丘陵地帯に分散立地し,住宅は集団移転団地・災害公営住宅を除き,拡散立地していることが明らかになった。陸前高田市による復興計画では公共施設・商業施設は中心部のかさ上げ地区へ,住宅は集団移転先等へコンパクトに集積する計画である一方,自主再建住宅が分散立地することで震災前より低密度分散化する可能性が示唆された。The tsunami caused by the Great East Japan Earthquake on March 11, 2011, devastated the Sanriku's coastal areas of northeastern Japan. Since then, local governments and residents have engaged in reconstruction. In order to prevent and reduce possible future tsunami damage, it is important to raise the ground in the once area damaged by tsunami and to relocate to higher ground. This study attempts to analyze the changes occurring in affected urban spaces during the process of reconstruction. Taking up the example of Rikuzentakata, Iwate Prefecture, the characteristics of location tendency of the housing reconstruction urban spaces are analyzed in the pre-earthquake period, the reconstruction period immediately after the earthquake, and the post-reconstruction period. In the pre-earthquake period, Central Business District (CBD) was located in the coastal lowland, which was protected by the black-pine forest on the coast and the tide embankment that was constructed after the Chilean Tsunami of 1960. In the reconstruction period, the city offices, public facilities, and stores were all temporarily relocated to hastily-constructed buildings located on higher ground that was unaffected by the tsunami disaster. The residents who lost houses chose to settle in temporary shelters or to rebuild their houses independently on high ground. Consequently, new urban areas became dispersed outside the area damaged by tsunami in contrast to the compact urban area developed in the coastal lowland prior to the great earthquake. The official reconstruction plan of Rikuzentakata aims to recreate a compact city by rebuilding CBD on the raised ground once flooded by the tsunami. On the other hand, independendently-reconstructed houses, public housing to be built by the city and prefecture governments, as well as collective, high-ground relocation projects are all scattered in the municipal area. It is predicted that the future urban space of Rikuzentakata will be constituted by dispersed housing.