小波複解析法之理論解析及其應用於淡水河感潮河段水位－流量率定曲線之修正

本文係研析感潮河段內水位－流量之率定關係，藉著小波理論分解、去噪及重建之功能，串聯合適之水文模式，以建立一種濾除潮汐效應後之修正流量－水位率定曲線。文中利用小波複解析法對感潮河段之紊亂水文資料進行逐層分解，分析出有感潮效應之干擾後即予以去除潮汐影響部分，再重建並組成無潮汐干擾之流量。研究中將小波複解析法串聯具有兩參數物理概念模式之瀦蓄函數法，配合參數整體性優選之洗牌複演進法，檢定出模式中之各項最佳參數，並以最小洪峰誤差之目標函數A及HEC-1所建議之目標函數B作爲模式校驗及比較之依據。本文分別以淡水河系中基隆河流域之大直橋、新店溪流域之中正橋及大漢溪流域之新海橋作爲感潮河段內之研析測站，以探討小波複解析法對去除潮汐效應之適用程度。由模擬結果顯示，複解析法確實能有效且快速地去除潮汐影響部分，並能建立感潮河系內較合適之率定曲線，臻以提供感潮河系防洪工程規劃設計之參考應用。

關鍵字

感潮河段；率定曲線；小波分析；水文模式；參數優選

並列摘要

The purpose of this paper aims at building up a rational water level-discharge rating curve of the tidal reach. By applying functions of decomposition, denoise and reconstruction of wavelet theory and combining with the adequate hydrological model, the tidal effect in the downstream reach can be eliminated and the appropriate rating curve of water level and flow discharge is thus modified. The disturbed data in the tidal reach is decomposed using the Wavelet MultiResolution Analysis (MRA). Its components from tidal effect can be eliminated, and after the reconstruction process the adjusted discharge is free from drifting with the tide. The study combines MRA with storage function method, which is the physical conceptual model with two parameters. By employing the Shuffled Complex Evolution (SCE) Algorithm, all the parameters can be optimized at one time. The optimum parameters in the model are evaluated, using either the minimum error of peak discharge as the objective function A, or the objective function proposed by HEC-1 as objective function B. The results with these two objective functions are then discussed and compared about their performances in the model. Three sites in Tanshui River System, namely, Tah-che Bridge in Keelung River Basin, Chung-cheng Bridge in Hsin-tien River Basin and Hsin-hai Bridge in Ta-han River Basin are taken as the studying sites for better understanding about the applicability of tidal effect eliminated by MRA. The simulations show that MRA can effectively filter out the tidal noise. By the model proposed, a rational and modified rating curve may be reconstructed, making it is promisingly useful as a reference for the planning and design of flood-mitigation projects in the tidal reach of a river.

並列關鍵字

Tidal reach ； Rating curve ； Wavelet analysis ； Hydrological model ； Optimization of parameters

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