Determination of Ecological Base flow Subject to Optimization of Water Supply

• Main Authors: Chung-Hsiang Chiang, 江仲翔
• Other Authors: 徐年盛
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/95741230909294425879

碩士 === 國立臺灣大學 === 土木工程學研究所 === 96 === This research considers optimization of supplying water system and RHABSIM (hydraulic and habitat Model) to determine the ecological base flow of rivers. The ecological base flow is calculated according to basin area in the past, not analyzed by the factors in historic flow, hydraulic and habitat. Therefore this research combines the optimization of supplying water system and RHABSIM Model, in order to understand the impact of ecological base flow on habitat for species in the river. Moreover, it comes out with optimization of ecological base flow in supplying water system. The First step of the methodology includes the following procedures:(1) To set up the threshold of the ecological base flow of rivers and creeks;(2) To optimize supplying water system in full-time horizon with a time step of 10 days; and(3) To compute the daily flow in the river reach to be considered after optimizing supplying water system. The second step of the methodology includes the following procedures:(1) To input all sections data to RHABSIM model in order to obtain the relationship between water levels, discharge and velocities under all circumstances; and(2) To compute WUA and PUA in all condition by using the suitability curves of depth and velocity of the species to be considered. The final step of the methodology includes the following procedures:(1) To calculate the Average WUA and Average PUA in the daily flow after optimizing supplying water system;(2) To compare the SI and PUA when setting up the threshold of the ecological base flow; and(3) To determine the value of ecological base flow between SI and PUA by Trade-Off method. The method in this research is applied to Tao-Qian creek Hsinchu and Acrossocgeilus paradoxus. And the value of the ecological base flow of supplying water system turns out to be 3.75cms which is of great use between water supplying and ecology.