Temporal and spatial characteristics of rainfall on the southwest slope of Mt. Merapi in Indonesia

Abstract

A basic analysis of the characteristics of the time series fluctuation and the spatial distribution of rainfall on Mt. Merapi in Indonesia and Mt. Fuji in Japan is presented in this report. In the for rid zone, precipitation is much more variable over time and space than in the temperate zone. Therefore, it is important to know the relation between deviation power and spatial scale when es timating hydrologic quantity in the torrid zone.
The rainfall characteristics of Mt. Merapi were compared with those of Mt. Fuji to clarify the difference in precipitation between the two climatic zones. Next, spatial rainfall data for Mt. Merapi was interpolated among five ground rainfall stations and linked with the spatial data obtained by the radar rain gauge system to estimate the interaction between the time scale and spatial scale of precipitation. As a result, it became clear that varying the time scale from 1 hour to 1 month enhanced the spatial scale that could be represented by point rainfall data. In addition, the spatial fluctuation of rainfall for 1 month on Mt. Merapi was found to be equivalent to 1 hour on Mt. Fuji.