| Summary: | 碩士 === 國立中興大學 === 水土保持學系 === 91 === The purpose of this study is to carry out time series analysis of the cycle fluctuation and secular trend of rainfall and groundwater table. Cross correlation function analysis of rainfall and groundwater table are performed to calculate the lag time. Time series of groundwater table are analyzed by stochastic method and their ARIMA (p,d,q) models are built. Beinan river basin in Taitung region of eastern Taiwan is selected as the study area. There is no reservoir in Taitung region, and people are dependant on surface flow and groundwater for water use.
Therefore, understanding of groundwater characteristic is important for water resource planning and managened in Taitung region. Time series analysis of rainfall and groundwater table should be useful in surface water and groundwater in eastern Taiwan.
Firstly rainfall and groundwater table data are compiled. Season analysis, spectral density analysis and moving average are performed to check periodicity and secular trend of rainfall and groundwater tables.
Finally groundwater table data are used to build stochastic ARIMA(p,d,q) models.
The results show that the secular trend of rainfall increase and the secular trend of groundwater decrease gradually from January 1988 to December 2000. The rainfall and groundwater table appear to have some correlation. Rainfall apparently is the leading factor that affects groundwater table variations. The results of this study indicate that it is feasible to use ARIMA(p,d,q)model to project groundwater table.
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