https://scholars.lib.ntu.edu.tw/handle/123456789/169112
Title: | 利用小波理論建立水文系統的時間和空間尺度參數化方法(I) Development of a Methodology for Parameterization of Time scale and Space scale in Hydrological Systems Based on Wavelet Theory (I) |
Authors: | 徐年盛 | Keywords: | 異質性;非定常性;小波母函數;小波能譜;尺度效應;heterogeneous;nonstationary;kernel function;wavelet spectrum;scale effects | Issue Date: | 2003 | Publisher: | 臺北市:國立臺灣大學土木工程學系暨研究所 | Abstract: | 對於異質性地下水系統而言,介質的異 質性和空間變異性是地質層本身固有的特 徵,它導致滲透性能的空間變異性而直接影 響地下水流動和污染物傳輸過程。因此,如 何將模擬地區的地質參數適切的描述,是模 擬結果準確與否的關鍵因素之所在。本研究 從探討物理模式中參數的尺度效應,建立一 套小波理論為基礎的分析方法,用以將異質 性地下水系統之參數的尺度量化,研究中首 先利用小波母函數,建立一維異質性地下水 系統水力傳導係數與壓力水頭之小波能譜理 論關係。其次,利用人工產生之非定常性水 力傳導係數場,以正向問題方法,分析與比 對實際能譜和小波分析建立能譜之間的對應 關係;以及探討尺度效應與異質性地下水系 統小波能譜的關係。本研究已完成建構一個 可以同時處理定常性和非定常性地水問題的 通式化方法的理論推演,數值實例驗證部分 初步結果顯示小波分析理論所建構尺度化分 析方法,可以辨識地層中的不連續現象(如斷 層)及非定常性(異質性)行為。 For the heterogeneous subsurface system, the heterogeneity and the spatial variability are the intrinsic properties of porous media which affects the water and pollutant transport process directly. A key factor of simulating results depends on whether the parameters of the subsurface system were parameterized properly or not. In this study, a wavelet based analysis is applied to evaluate the scale effects of parameters and to develop a quantitative method of parameter scales. First, the wavelet kernel function is used to derive the theoretical relationship between the wavelet spectrum of piezometric head and hydraulic conductivity in a one-dimensional heterogeneous system. Furthermore, by solving forward problem, the relationship between the wavelet spectrum energy of nonstationary hydraulic conductivity field that is generated artificially and the actual energy is analyzed. Finally, the scale effects that contribute to wavelet spectrum energy in the heterogeneous groundwater system are investigated. A general theoretical solution for tackling both stationary and nonstationary process was developed. The numerical examples showed that wavelet-based approach was able to identify both discontinuity and pattern of heterogeneous for the nonstationary hydraulic conductivity of subsurface groundwater system. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/2829 | Other Identifiers: | 912313B002325 | Rights: | 國立臺灣大學土木工程學系暨研究所 |
Appears in Collections: | 土木工程學系 |
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912313B002325.pdf | 465.98 kB | Adobe PDF | View/Open |
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