| 摘要: |
| 本文对位于台湾南部两个次高海拔湖泊——大鬼湖及万山神池进行研究。并试图探讨此二无明显进、出水口之封闭型湖泊中,水体溶解氧垂直分布出现极大值之成因。此二次高海拔湖泊地处偏远、人烟罕至,因此较不受人为干扰,为研究湖泊水体中种种自然作用的良好对象。大鬼湖平均水深约14.8m,最深处约40m,除冬季外,水体均有分层现象。1988年夏季资料显示,水深16m以下水体趋于无氧状态,且于水深8~10m处有溶氧极大值(约7mg/L)出现。但于相同深度,pH或溶氧饱和值却无极大值出现,且于此深度以上的溶氧饱和值,均接近当地的大气饱和值(约78%)。经各种资料推断,此极大值的成因,除水团乃于春季时留下高溶氧值之外,应综合了季节增温效应下使表水向下混合的物理作用(尤其是山区明显的日、夜温差所引起的表水冷却向下混合作用,且其混合深度随著季节增温而逐渐变浅)、消耗溶解氧的生物作用及温跃层存在等影响因素,而非单纯的物理或生物作用所造成。1991年4月万山神池观测资料显示,湖水平均深度约8m,最深可达14m。其溶解氧饱和程度分布在80%~104%之间,表水接近当地饱和值(78%),而于1.5m处往下增加,于2m处有溶解氧及饱和程度极大值,比当时大气饱合值高约20%,此极大值深度与叶绿素a极大值深度相吻合,主要由生物之光合作 |
| 关键词: 大鬼湖 万山神池 溶解氧 溶解氧极大值 pH值 |
| DOI：10.18307/1995.0108 |
| 分类号: |
| 基金项目: |
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| Formation of dissolved oxygen maximum in lakes |
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C. T. A. Chen, J. K. Wann, B. J. Wang
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Institute of Marine Geulogy.National Hun Yal-sun Uniw., Kaushinng, Taiman
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| Abstract: |
| This study elucidates the main cause for the dissolved oxygen maximum of the Great Ghost Lake and Wannsan Divine Lake, both belonging to the best preserved natural lakes in Taiwan, with little pollution because of high elevation and isolation. There are also deep natural lakes, suitable for study of chemical, physical, and biological processes under natural, undisturbed conditions. The average depth of the Great Ghost Lake is about 14.8 m, the max. depth is about 40m and the water body is stratified annually except in winter, Based on the data collected in summer (1988), the oxygen content was about 6 mg/L at surface and was sharply reduced between 10 m and 16 m, and became anoxic below 16 m. There was an oxygen maximum of about 7 mg/L (close to saturation) at 8~10 m. The maximum was mainly controlled by physical processes driven by surface cooling accompanied, with oxygen influx during the previous seasons. The subsurface remnant cooler water with high oxygen content remained steady while the surface layer warmed. Below the maximum oxygen, the oxygen content was sharply reduced because of mixing with anoxic water below. Photosynthesis did not play a major role and there was not a pH maximum at the oxygen maximum. The average depth of Wannsan Divine Lake is about 8m and about 1 dm in maximum depth. The saturation of oxygen ranged between 80%~10d%. The surface water, at 80%, was close to the saturation value of 78%, and the oxygen content increased with depth below 1.5m. There was a maximum of oxygen saturation, about 20% higher than the solubility, at 2 m. Contrary to the phenomena found in the Great Ghost Lake, the maximum at Wannsan Divine Lake was mainly caused by photosynthesis and was acconipanied by a pH maximum. |
| Key words: Dissolved oxygen oxygen maximum pH the Great Ghost Lake Wannsan Divine Lake |
