Precipitation and hydrological characteristic of subtropical forest in Okinawa Main Island

抄録

Time series analysis and forecasting has become a major tool in different applications in hydrology and environmental management fields. In this study, hydrological characteristics include precipitation, river flow and water level of the subtropical Yambaru forest was examined. The 10 years of hydrological data from 10 sites obtained from AMeDAS (Automated Meteorological Data Acquisition System) was analysed. Water level and river flow showed a comparable trend by years, peak in June due to the East Asian rainy season. Time series analysis and forecasting using ARIMA (Autoregressive Integrated Moving Average) model was employed to predict monthly rainfall for upcoming years. An intervention time series analysis could be used to forecast peak value of rainfall data and it could help decision makers to establish priorities in managing water demand in Okinawa Island.