新武吕溪水质监测之初步研究

Preliminary Studies on Water Quality Monitoring in Shinwulu Creek

台东县海端乡之新武吕溪,具有深潭、急濑和稳流等各种不同的河床型态,以及巨石、卵石、砾石与泥沙等底质材料,也因此新武吕溪蕴含丰富鱼类资源,但因垂钓者众多,水中生态渐渐受到破坏,为了保护珍贵的鱼类资源,海端乡公所于1999年3月公告禁止垂钓,进而开始执行溪流保育工作。因此,本研究着手调查保护区内水文及地文资料,并长期进行水质监测,调查成果如下:自2003年9月至2005年10月之pH值有降低趋势;保护区内在丰水期与枯水期期间之浊度有明显的区分;而温度的高低决定溶氧量含量,但调查结果中,温度变化不大,但溶氧量的变化却相当明显,故需再进行细部探讨;电导度与水中之溶存物质(NaCl)成反比,调查结果此现象于新武吕溪较明显。本研究之目的,希望藉由长期观测,减少仪器观测误差,而更有利于新武吕溪保护区之水质管理,并建立保护区内最佳指标值。

The Shinwulu creek in Haitu Township （Taitung County） which have kinds of different fluvial forms such as deep pools, torrents and stable flows, and bed materials such as boulders, cobble, gravel and sands. Therefore, the Shinwulu creek was contained abundant fish species. However, there were too many rodmen to keep the ecological environment. In order to protect the rare stock of fish, the Haitu agency began the nursing working to prohibit from fishing on March 1999. Hence, the researchers started to investigate the hydrological and flood information of protection, and proceeded long-term water quality monitoring. The consequences were as follows： from Sep. 2003 to Oct. 2005, the pH value was reduced; there were obvious different from dry season and raining season for turbidity; the water temperature （WT） effect by dissolved oxygen （DO）, the temperature was smooth but the DO displayed the significant variance; the proportion of electrical conductivity （EC） to the NaCl is inverse obviously in Shinwulu creek. The main purpose in this study is reducing the error of gauging observation and to offer the best management of water quality by long-term monitoring and establish the most important index of the Shinwulu creek.