河川在自然環境中為一具代表性之生態體系。因此為維護河川中棲地型態與物種的多樣性，已成為河川保育重要的ㄧ環。本文之研究區域為台灣之卑南溪與高屏溪，研究方法以二維河川棲地模式River2D為演算核心，模擬河川流況及棲地型態之變化，對台灣棲地環境型態做定量的描述；並以台灣魚類地理分區為基礎，針對卑南溪與高屏溪研究河段之台灣特有淡水魚種棲息之水域環境條件加以探討，最後對於河川型態與棲地分布情況之關係進行分析。 兩研究河段在棲地分佈結果顯示，以生態基流量為條件下，流量Q75相較於流量Q95下，棲地擁有較為多樣的環境，對水域生物來說相對為較多元且有利的生存空間。而將兩河川之模擬流量分布範圍擴大至最大流量300cms，結果顯示，卑南溪於流量40cms至流量100cms下，其四種棲地類型分布比例較為平均，棲地組成相對穩定；而高屏溪研究河段，則於流量40cms至150cms，亦有棲地組成相對穩定模擬結果。另以棲地多樣性的角度而言，卑南溪與高屏溪研究河段分別於流量60cms及30cms下，四種棲地類型之分布比例最為平均，故此兩流量下擁有較有利於魚類的繁衍與成長之水域環境。此外，對於辮狀河川之相同趨勢而言：淺瀨(Riffle)棲地面積百分比大部分皆為四種棲地中最少者；深流(Run)棲地分布其模擬結果均有隨流量增加而增加之趨勢。而就棲地分布穩定的條件，以流量100cms以內為最佳。 The river is one representative ecosystem in the natural environment. Therefore, to maintain the variety of habitat and species in the rivers becomes an important part of the river conservation. In this thesis, the research areas are Bei-nan creek and Go-pin creek in Taiwan. This study relies on a two-dimensional model, River2D, that simulates the change of the hydraulic characteristics and habitat types in the rivers, and reports quantitative description to the habitat environmental in Taiwan. Besides, the information on the Fish district of Taiwan is adapted to analyze water environment on the rivers. Finally, the relationship between the river types and habitat distribution it estimated. The results show that the ecological base streamflow as Q75 has a various ecological environments in the habitat than that as Q95. The simulation of streamflow is performed until 300cms. It is shown that given the streamflow from 40cms to 100 cms in Bei-nan creek, four kinds of habitats from an average habitat proportion condition and habitats distribute relatively stabe. While in Go-pin creek, given the streamflow from 40cms to 150cms also result in a similar conclusion. In the other way, when the streamflow being 30cms in Bei-nan creek and and 60cms in Go-pin creek, it forms the most evenly proportion in four habitat categories, which provides adequate procreation and growing up for fish under the flow. In addition, for a braided river, riffle area has least percentage of the four kinds of habitats. The run habitat area increases with the flow at simulation. The condition remains steady when streamflow is less than 100cms.
