抄録
The natural conditions of Kagoshima in the southern Kyushu are characterized by the properties from the great volcanic products “Shirasu” in topographic and geological aspects and from the typhoon hitting area with heavy rainfall in meteorological features. Consequently, slope-failures, floods and high tides frequently occur during storms or heavy rainfalls, and bring about a great many of subversive disasters which inflict serious damage on inhabitants and others. The main purpose in this paper is to present a basic concept on the prevention and the decrease of disasters from the standpoint of damage sufferer and to contribute to a countermeasure against disasters, analyzing the descriptions of disaster records from 1946 to 1980. The amount of precipitation and the history of land use are adopted as the parameters of natural factor and anthropogeny factor respectively, and damage index is defined in order to investigate the historical change and the correlation of disasters.
Type, frequency of occurrence and scale of damages caused by disasters show a change with the transition of these parameters. For instance, the loss of human lives caused by slope-failures have the tendency of increase since the 1960's in spite of the uniform condition in precipitation.
Also, some relationships between damage value and condition of precipitation ar ascertained. The relationships between the annual damage value, H, the annual amount of precipitation, R, and the number of day of precipitation over 100 mm/day from April to October, T, are given by
H=a exp (bR) and H=cTdwhere, a, b, c and d are coefficients depended on the occurrence condition of damages.
