台中柳川應用生態工法於魚類棲地改善之研究

Fish Habitat Improvement Research for Ecotechnology Applications in Liu Regional Drainage

施上粟(Shang-Shu Shih) ； 李鴻源(Hong-Yuan Lee) ； 胡通哲(Tung-Jer Hu)

《中華水土保持學報》 35卷3期 (2004/09) Pp. 229-239

https://doi.org/10.29417/JCSWC.200409_35(3).0004

摘要

本研究以擬似二維數值水理模式NETSTARS進行生態工法規劃設計流程之通洪能力分析，並據以作爲規劃設計生態工法的基礎。本文以台中柳川區域排水爲例，應用擬似二維數值模式NETSTARS進行柳川未整治渠道（原始渠道）之通洪能力檢討，並由模擬所得之水位高程檢討洪水位是否超越現有堤岸高度，以推估何處會發生溢堤淹水的情形。模擬結果發現，當發生2年、5年及10年洪水時，各斷面水位將高於原有護岸，有越堤的危險；而現有原始渠道斷面7～8及8～9間則會發生水躍。
本研究並利用水平二維水理模式TABS-2進行不同工法對魚類棲地面積的改善情形，模擬結果顯示，因曼寧n值提高（反應渠道中施設生態工法），將使渠道流速降低，因而渠道中低於1.2m/sec流速的面積增加約13.4%；由此可知，應用生態工法對魚類將有正面的助益，可有效提升其棲地面積。

關鍵字

生態工法 ； 水理數值模式 ； 魚類棲地

並列摘要

Following the concept of ecotechnology, NETSTARS, a quasi-two dimensional hydraulic model was used to estimate the flood capacity of Liu Regional Drainage in Taichung County. The calculated results, including water surface elevation (w.s.e.) and water velocity, were used as a basis for the ecotechnology. The design consisted of placing a number of concrete blocks, timbers and rocks on the riverbed and riverbank. The model was used to evaluate the present situation and also the proposed design. The cross-sectional w. s. e was obtained and we and evaluated if whether the river banks would be flooded by a rise in the water. The results showed that flooding occurs in all cross-sections during the 2, 5 and 10 year return period discharge. Moreover, hydraulic-jumps occurred in a number of river stretches.
The effects of this applied ecotechnology were investigated and compared with the original method. It was found that the fish habitat increased significantly, when the ecotechnology aimed at decreasing water velocity was used. The ecotechnology was reflected by an increased Manning's n. The potential fish habitat, in which the flow velocity is lower than 1.2m/s, increased by around 13.4%. We conclude that applied ecotechnology can improve fish habitat potential.

並列關鍵字

ecotechnology ； hydraulic numerical model ； fish habitat