二維河流棲地變遷模式之研究

A Two-Dimensional Numerical Model for River Habitat Transition

陳金諾(Ching-Nuo Chen) ； 蔡智恆(Chih-Heng Tsai) ； 蔡長泰(Chang-Tai Tsai)

《中國土木水利工程學刊》 20卷3期 (2008/09) Pp. 341-355

https://doi.org/10.6652/JoCICHE.200809_20(3).0006

摘要

近年來國人逐漸重視河流環境問題，更體認環境保育與生態平衡的重要性，因此對已開發利用或因人為整治以致生態功能下降之河溪，進行生態保育及復育工作，達成溪流復育的目標。規劃河溪復育計畫，或減少河流整治對生物棲地的不利影響，均須先針對河道棲地進行瞭解評估。因此本文發展二維河流棲地變遷模式，以大里溪為研究對象，進行豐枯水期平均流量及各重現期洪水流量演算。在豐枯水期平均流量下，權重可使用棲地面積大致發生於河道主深槽；而大里溪發生洪水時，無論洪漲或洪退，適合度因子在洪水平原皆較大，洪峰發生時刻主深槽甚至完全沒有權重可使用棲地面積。

關鍵字

河流棲地 ； 棲地變遷 ； 二維數值模式

並列摘要

In recent decades, the issue of river environment has brought into extensive focus, and the importance of environmental protection and ecological balance has also been recognized. The ecological capability in the river decreases due to human activity or dredging. Hence, ecological protection and restoration are undertaken in order to attain the purpose of river restoration. For planning the project of river restoration or reducing the contrarious effect of habitat caused by dredging, river habitats must be evaluated in advance. In this study, a river habitat transition model was developed. The Tali River is chosen as an illustration example. The numerical calculation was performed for different average discharges of low flow rate (dry and rainy periods) and flood for each return period. The value of combined suitability factor (CSF) and the main distribution of weighted usable area (WUA) were found in the main channel for average discharge of both dry and rainy periods. The value of combined suitability factor in the floodplain is greater regardless of the situation of either flood rising or flood recessing. There was no weighted usable area at the time of peak flood in the main channel.

並列關鍵字

river habitat ； habitat transition ； two-dimensional numerical model