Abstract
　In this paper we took a general view on the subject of the historical changes of land reclamation and disaster prevention at the Urado Bay area in Kochi prefecture. All parts of the head area around the Urado Bay have been constructed by the land reclamation at Chosogabe(1592-1595) and Yamauti (1596-1867) era. At that era severe obligations of a bank control were imposed to farmers with a village headman as the central figure. Works of disaster prevention mainly were recovery from illness of banks and channels which had been injured from a flood or a flood tide. Water disasters have been repeated for a long time. At length works of disaster prevention have been executed in a large way after big damages from the flood tide by the typhoon 7010 and from the big flood by the Typhoon 7505 and 7617 with based on the probabilistic evaluation in regard to natural forces. But necessity of disater prevention of this area is never gone indefinitely.

【キーワード】：干拓，洪水，高潮，災害，防災
Key words: reclamation, flood, storm surge, disaster, disaster prevention

*高知大学農学部
Faculty of Agriculture, Kochi University