Contenu du sommaire : Villes et fleuves au Japon et en France

This paper examines the natural features of Japanese rivers and analyses the qualitative changes produced by hydraulic works and increasing pollution. These changes which began with the Meiji era, increased notably during the period of rapid urbanisation following the Second World War. The author also refers to urban hydraulic works and the related spatial segregation between man and water.

Relations between cities and rivers act on three levels. The first one involves floods containment or an increasing management of river courses. The second one leads to the transfer of economic activities out of cities centers except for recreational pursuits such as boating and yachting. The third level involves using waterfronts for building embankments devoted to roads and car parks. Nowadays however, the trend is to an improvement of urban waterfronts to create attracting

Japanese rivers are small but numerous. The towns that were naturally formed at their mouths are nowadays the country's largest cities . The general aim, therefore, of analysing Japanese cities and rivers is to consider coastal cities. The Edo (Tokyo) and Sumida (Tone-gawa/Ara-kawa) are representative cases by which it is possible to study the role of rivers in development of cities in relation to natural, human, social and economic change.

At Tokyo the small rivers of the western terraces contrast with their larger counterparts and canals of the lower part of the city in the east. The first are illustrated by the No-gawa and the second by the Sumida. Their respective development patterns are outlined as well as the manner in which the local society, ranging from ordinary citizens (the case essentially of the No-gawa) to leading decision makers (the case essentially fo the Sumida), has sought to improve the quality of the landscape and ecological conditions after years of neglect.

Over the last century the image of the Sumida has already been modified twice, while a third change is currently taking place. Prior to the Meiji era the river acted not only as a communication axis and red light district, but also as a recreational area and sacred zone. With the opening up of Japan, it developed as one of Tokyo's industrial districts, also becoming a cosmopolitan but marginalised area. With rapid growth this marginalisation was accentuated, with the "razor blade embankment" and motorways cutting off the river and its banks from the city. The present phase of change, which began in 1980, is marked by the wish to rediscover certain riverscape values : a redeveloped waterfront, the razor blade embankment demolished and new bridges built. Even the temples of the river banks are again pilgrims.

Archetypal forms of riverscapes in Japan, prior to the 19th century, are studied using illustrated documents of "famous places". Themes dealt with include the manner in which water and land surfaces are landscaped, the osmosis between land and water, and the importance of landscape in river bank festivities. In Japan the areas linked to such activities represent the most appropriate places for the "fûryû" style of life, cherished by the Japanese.

The city of Hiroshima is built on the Ota-gawa delta. Such a site appears inhospitable but it nevertheless allowed land to be developed through flood protection works, drainage and the suply of water. As a result a close symbiosis exists between the city and the river, although during the High Growth period this was somewhat forgotten, only to be rediscovered recently through a municipal policy of improving amenities.

The rivers running through Lyon, Rhône and mainly Saône, assumed in former ages a leading part in the urban activities, before they have been separated of the urban net by erection of dams. Their interest and the value of rivers as a label of the city are now recognized in the so called "Blue Plan" of urbanization : dams are designed, gardens and mall are built, river piers managed. Upstream of Lyon, a large semi-wild space will be also protected.