Primary purpose of this study is to define the procedures through which the infrastructure of natural environment is promoted in the restoration process of suburban new towns by clarifying the relationship between regional hydrological system, represented mostly by surface drainage pattern in watersheds, and the open space system. A case study at Senri New Town in Osaka Prefecture was conducted in terms of (1) location of irrigation ponds and hydrological pattern in the area before the development and their changes, (2) cross regulating relationship between surface drainage pattern and physical planning for land formation, road/street and parks/open spaces after the development, and (3) structure of hydrological system as an infrastructure of natural environment for the open space system. Internal and external conditions influenced the development were also examined, and it is concluded that by reflecting those conditions to the physical planning and design of land formation, road / street network, and surface drainage pattern, the infrastructural framework of natural environment which underlies the open space system in the new town was activated.

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過去4年間のDXN常時監視において, 環境基準を超過している神崎川水域における河川水質及び底質中のダイオキシン類 (DXN) の濃度分布について調査するとともに, 上流から下流にかけての地点における濃度変動や組成の変化について明らかにした。河川水中のDXN濃度は, 中流部でやや高いが, 下流地点では減少し, 濃度変動も小さかった。また, 水質及び底質濃度の高い中流部の地点において, 底質の巻き上げが水質に大きく影響を与えていることが確認された。
中流部における河川水の溶存態及び懸濁態DXN濃度の割合は, 5～8塩素化のPCDD/PCDFsで懸濁態DXNが90%以上を占めたが, 4塩素化PCDD/PCDFs及び4～5塩素化Co-PCBsの溶存態の割合は約20%程度とやや大きかった。
下流部底質中のCo-PCBs濃度は, 中流部の10倍程度高濃度であった。また, 含水率 (50～60%) , 強熱減量, 硫化物濃度の高いシルト分が主成分の底質に高濃度のDXNが検出された。

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Primary purpose of this study was to examine the process of landform transformation for the new town development in the suburban hilly topographical areas, and the concepts and ideas of physical planning and design in its background as well. A case study was conducted in Senri New Town that extends across the area of Suita City and Toyonaka City, Osaka Prefecture. Based on the information found in graphical plans and project reports, and following three steps of project level, i.e. project planning for the entire area, planning of each individual area and layout design of each residential block, how the original topography was integrated into the landform and landscape planning was closely traced. Although the topographical features was given a higher priority on the level of project planning and numerous methods to adopt topography to landform design were employed, those have been dismissed in the later steps of project due mostly to time constrains and innovations in civil engineering technology. On the other hand, substantial endeavors were given to planning and designing prominent residential environment by integrating topographical features on the level of developing each residential block

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