| 摘要: |
| 南仁湖区位于台湾省屏东县满州乡境内,是一个封闭且独立的盆地,土壤属于洪积层发良之红壤,是经过强烈淋洗后的风化产物。成分以粘土矿物为主,低价元素皆在风化过程中大量流失,呈强酸性反应(pH值为3.65-5.30)。淋洗出的土壤渗滤水pH值介於5.O左右,碱度几乎全在0.020 m mol(+)/L以下,没有提供大量碱度到湖水中,和-般沉积岩区土壤渗滤水不同。湖水中的叶绿素a含量大多数在10μg/L之上,属于富营养化的水域;碱度大部分在O.20 m mol(+)/L以下,属为对酸敏感到极敏感湖之列;磷含量已多在20μg/L以上,在分类上亦属于富营养阶段;氮和磷的比值相当低,因此氮成为水中浮游生物的主要生长限制元素;其他主要离子的来源受控于当地环境和雨水及海水飞沫的影响。为了解影响湖水化学组成的主要因素,作者收集南仁湖区的雨水、土壤渗滤水和湖水,以求了解其各别的离子含量及变化;同时还测量湖水流出量,并收集相关气象资料,企图计算出各种离子在集水区中的收支情况。经过实验及计算,估计雨水在1989年输入大约167×103mol(+)的离子,占年度总输入量的6%左右,其余则来自陆地;大约577×103mol(+)的主要离子从出水口流出南仁湖,约占总输入量的19%,其余的离子累积于湖盆中。显见陆源水的化学物质含量是影响南仁湖水质及化学组成的主要因素。水中有机质以33.7-52.9mg/cm2·a的速率累积于南仁湖沉积物中,沉积物的总累积速率为581-911mg/cm2·a。 |
| 关键词: 垦丁国家公园 南仁湖 地球化学 酸雨 沉积率 离子平衡 |
| DOI：10.18307/1993.0107 |
| 分类号: |
| 基金项目: |
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| Geochemistry of the nanren lake in the rending national park |
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C-T A. Chen, J. C. Chen, Q. S. Wong
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Institute of Marine Geology, National Sun Yat-sen Univ., Kaohsiung Taiwan
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| Abstract: |
| The Nanran Lake is located in a closed basin at Manchou, Pintonv southern Taiwan. Soil in this area is the pleistocene red loam, a product of severe weathering. Clay is the major component in the soil. Most of the low valence elements have been leached out during weathering, resulting in very low pH values (pH 3.63-5-30). The infiltration water collected is about 5.00 in pH. Very little alkalinity in the lake waters is supplied from land. Chlorophyll a concentrations in the lake are mostly above 10 μg/L and suggest eutrophication. Most alkalinity concentrations are below 0.2 m mol(+)/L and the waters are sensitive or very sensitive to acid precipitation. Most phosphorus concentrations are higher than 20 μg/L, also indicating eutrophication. Low N/P reveal that nitrogen is the major limiting factor to the phytoplankton growth. The major element concentrations in the lake are controlled by the land and by the sea salt spray. In order to understand the major factors affecting the compositions of the lake water, rain water, infiltration water and lake waters were collected and analyzed for evaluation the ion contents and their relative ratios. Outflow from the lake was also measured, and the related meteorological data collected. The ion budget of the lake was established using the above data. Input from the rain was estimated to be 167×103 equivalents, only about 6 percent of the total input to the lake. The other 94 percent are from the land. About 577×103 equivalents, or 19 percent of the total input, is lost from the lake in the outflowing water. The rest accumulates in the lake and affects the composition of the lake water. Assuming that the excess 210Pb is diluted by the organic matter in the water column, the authors estimated the accumulation rate of the organic matter between 33.7-52.9mg/cm2·a and that of the bulk sediments 581-911mg/cm2·a. |
| Key words: Kending national park Nanren Lake geochemistry acid rain sedimentation rate ion budget |
