利用台灣生態水文指標推估魚類生態特性

Abstract

生態群落在河川流態中，長時間的演化下已漸趨穩定，但隨著生物棲息環境的開發和水資源規劃與管理的影響下，不僅對於棲息地中物質能量的傳導造成影響，更會阻隔生物迴游的空間，亦同時改變河川流態的穩定性；因此河川流態特性及流量變化與河川生態系統的關係是相當錯綜複雜，如何量化及建立反應關係，定義對河川生態系統較佳的河川流態，將生態水文關係具體的化為生態需求目標等，為目前所遇到之難題，本研究將分別朝向全台流態特性和魚類生態特性兩個方向作探討，考量以日流量轉換之台灣生態水文指標作為河川流態特性指標，生物採樣資料以生物多樣性指標量化作為河川流態中生物群落分佈的依據，從複雜的「台灣生態水文指標-生物群落分佈」關係中歸納兩者間之特性，依據流態資料與魚類採樣資料之分類結果，各集群間皆有地文分佈的特性，在兩資料之中游區域的歧異度與均勻度指標值皆為三類中最佳，且流態特性趨勢變化亦相似，故流域中游之流態特性與生態特性之相關性高，期望藉由此結果提供未來水庫管理或水利規劃等單位，在研究作水資源控制操作時的參考資訊，在颱洪時期更可藉於此控制洪水排放量，以恢復或改變河川流量的變化來維護或提升生物群落的多樣性。

The ecological community in river flow regime has become stable via long-term evolution. However the transportation of sustenance and the stability of river flow regime have changed due to exploitation of species habitats and water resources management. The relationship between river flow regime and river ecosystem is very complicated. The most important task at present is to develop ecological flow regimes by taking the interaction and relationship between flow regimes and river ecosystems into account. In this study, derivation of the characteristic relationship between “TEIS-Community Distribution” from taking TEIS(Taiwan Eco-hydrological Indicator System) conversed from daily flows as the index of river flow regimes and fish sampling data as the index of community distribution is the main research objective. According to the classification results of river flow regimes and fish sampling data, it shows that there exist physiographic relationships among fish communities. Furthermore, midstream possesses the best indices of diversity and uniformity with similar trend changes of flow regimes, compared to upstream and downstream. Therefore, the flow regime and ecological characteristics in midstream show high correlation. These research results can be applied to reservoir management, water resources management, flood management for discharge capacity during typhoon periods, and river flow restoration for sustaining ecological diversity.