淡水河系之水理與水質模擬

A Hydrodynamic and Water Quality Model for Danshuei River System

吳啟瑞(Chi-Ray Wu)

指導教授 ： 許銘熙

國立臺灣大學/生物資源暨農學院/生物環境系統工程學研究所/博士(2006年)

https://doi.org/10.6342/NTU.2006.02680

摘要

台灣地區四面環海，河川大多坡陡流急，最終都注入到海洋中。河川下游河口區及感潮河段為河川與海洋間之水與物質傳輸交換必經之通道。河口區承接上游集水區之污染源，造成水質與生態的污染與危害問題。對於此一現象，必須先瞭解該河段之水理水質狀況，並模擬污染物質在水體中之傳輸與交換過程，以對河口生態環境作最妥善之規劃與安排。
本研究主要針對台灣最大之感潮河川淡水河系進行研究，探討河口地區之重要水理現象，並充分瞭解其水理特性，因此必須藉助適當之水動力數值模式進行模擬。本研究發展一網狀感潮河系數值模式，以處理淡水河系匯分流之複雜流況，並可依需求單獨調整單一河道間距，以進行區域內之細部模擬。模式發展完成後，本研究設計了幾種測試方案，驗證擴充前與擴充後模式整體之合理性與正確性。
發展模式之前為瞭解淡水河系特性，本研究於民國91~93年期間於淡水河系進行長期性的現場量測，量測項目包括鹽分濃度、水溫、懸浮顆粒濃度、葉綠素濃度及溶氧濃度，其分析結果可協助掌握淡水河系水理水質特性，實測值亦可協助做為發展模式時參數驗證之用。

關鍵字

淡水河系 ； 匯分流流況 ； 水理與水質模擬 ； 現場量測

並列摘要

Taiwan is an island which the discharge in most rivers flowing enters the ocean. The tidal river is the way of substantial exchange between river and ocean. Fresh water polluted by point and non-point sources from drainage areas concentrated in the tidal river and induced environment and ecology problems. The field surveys on Tanshui River were conducted to investigate the hydraulic and water quality in the processes of substantial exchange of the tidal river.
Tanshui River, the largest tidal river in Taiwan, is the study site in this study. A hydraulic and water quality numerical model for Tanshui River, which consists of tributaries, division channel and confluences, has been developed to simulate the detailed variation of the hydraulic and water quality. Several study cases were examined to verify the rationality and accuracy. The result shows that the proposed model can be used to simulate the hydraulic and water quality for the tidal river.
The field surveys including salt, temperature, suspended solids, chlorophyll and dissolved oxygen on Tanshui River were carried out from 2002 to 2004. Those field data were used for model calibration and verification. It reveals that the simulation results of the hydraulic and water quality were good agreement with observed values. The present model can provide satisfactory and reliable results of hydraulic and water quality for the tidal river.

並列關鍵字

Tanshui River ； division channel and confluences ； hydraulic and water quality ； field surveys

參考文獻

曾耀彬，「網狀感潮河系水動力模式之發展與應用」，碩士論文，國立台灣大學生物環境系統工程研究所 (2004)。

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