内水災害に関する諸問題について

Abstract

The aspect of submersion damage in the low-lying districts where towns, cities andagricultural lands and so on are extended, now seems to be serious stage in Japan. In thispaper, the factors which cause such disasters were discussed from engineering standpoint.It was pointed that the three natural factors which cause the submersion disaster arethe trend of concentration of heavy rain, the lower height of urban land compared with floodlevel and the subsidence of ground.As the cultural factors, the historical inevitability for the development of lowland, thedevelopment of water works for the utilization of water and the prevention of flood damage, and the high growth of various industries and so on delicately influence to such disasters.In order to find the rational approaches to prevent or mitigate such disasters, the essen-tiality of basic research program was emphasized and the main research subjects were shownas follows. (1) Hydrological (hydrologic-statistical) study on rainfall and flood. (2) Studyon hydraulics of surface flow on lowland district. (3) Study on special sediment hydraulics.(4) Study on behaviour of ground water and its controll. (5) Synthetical study on rationalapproaches of prevention or mitigation for submersion damage in low-lying districts.