| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2001: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2000: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Research Abstract |
A new theory of "WEVELET ANALYSIS", proposed in the early 1980's by J. Morlet is rapidly expanding its application fields, especially to signal processing, information communication and compression of image data. While the convential method of random data analysis, spectrum, is the resolution method of data only in terms of frequency for entire time domain, the new method of wavelet analyzes data in both frequency and time domain. In this research, we have tried to extend the applicability of the method to hydraulic engineering and hydrology.
(1) Hydrology and Hydrometeorology : Hydrological and hydrometeorological time series, such as rainfalls, temperature, and streamflows repeating the seasonal variation, show the annual changes of the patterns. The wavelet analysis has been applied to elucidate these characteristics.
(2) Remote Sensing Data Analysis : Vegetation has the effect of climate mitigation. Two large forest areas in metropolitan area have been analyzed in terms of NDVl (Normalized Difference Vegetation Index) and GST (ground surface temperature). A wide scatter of points in the scatter diagram between NDVI and GST can be explained by the size of forested and urbanized area determined by the 2-dimensional wavelet analysis.
(3) Turbulence Structure of Canopy Flow : Honami phenomenon is interesting not only from the view point of fluid mechanics but also from a practical view of environment and food production, since the plant waving may contribute considerably to accelerate the exchange of momentum, matter (CO_2 and O_2) and heat. The wavelet analysis of 3-dimensional numerical simulation of the turbulent canopy flow shows the temporal change of the flow structure.
(4) Removal of Measurement Error : Noise signals which cause serious error especially in inverse estimation problems are removed by the technique, detecting meaningless higher frequency white noise and impulse signals.
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