中世都市と排水施設

抄録

This paper discusses the management and maintenance of an urban center in early medieval Japan (twelfth and thirteenth centuries), with particular reference to the drainage system in Kamakura, the political center of Japan between 1180 and 1333. As population of Kamakura grew in the thirteenth century, residents had to spread into alluvial lowland, which later became an important area for the shogunate. In the process, a well-planned drainage system was adopted, which is evident at numerous archaeological sites in present-day Kamakura City. Nonetheless, the Azumakagami, a chronicle of the Kamakura shogunate, records that many floods hit Kamakura. It has become apparent archaeologically that well-constructed drainage ditches filled up with garbage, pottery sherds, and animal bones. Historically, the Kamakura shogunate issued a decree in 1261 prohibiting the discarding of "sick people, orphans, dead bodies, as well as the carcasses of oxen, cows, and horses on and along the streets." All these indicate that the drainage system in Kamakura was not well maintained and managed by the shogunate, and it may be supposed that this poor maintenance contributed to the floods that destroyed houses and districts, as recorded in the Azumakagami. One reason why the government did not prevent people from discarding garbage in the drainage ditches may be the belief shared by the shogunate and residents of Kamakura in the power of water to wash away impurities.