インドネシア国・メラピ火山南西山麓における降雨の時空間特性

抄録

A basic analysis on the characteristics of time series fluctuation and spatial distribution of precipitation at Mt. Merapi in Indonesia is presented in this paper. In the torrid zone, precipitation is much more variable over time and space than in the temperate zone. It is important to know the relation between the deviation power and spatial scale for estimating hydrologic quantities.
First, we made a comparison between rainfall characteristics of Mt. Merapi and those of Mt. Fuji in the temperate zone, with the result that the characteristics of convective rain became clear. Next, we interpolated spatial rainfall data between five rainfall points on Mt. Merapi, and combined the spatial rainfall data obtained by the radar rain gauge system to examine the interaction between the time scale and spatial scale of precipitation. As a result, it became clear that varying the duration from 10 minutes to 1 month enhanced the spatial scale that could be represented by point rainfall data. In addition, the spatial fluctuation of precipitation for 1 month at Mt. Merapi was found to be equivalent to 1 hour at Mt. Fuji.