Relationship between formation process of water quality and natural pH recovery, and response estimation model for water quality on acid lake

水质形成过程与自然pH恢复关系及酸性湖水质响应估计模型

• 批准号: 16510002
• 负责人: HINO Shuji
• 金额: $ 2.43万
• 依托单位: Yamagata University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16510002/
• 关键词: acid lake; carbon cycle; phosphorus limitation; formation of water quality; Lake Inawashiro; 応答応答予測モデル

Slow rise of pH value was observed in Lake Inawashiro since 1995. Until now, the cause of this phenomenon is not made clearly. Although mass of primary production with nanophytoplankton smaller than 20 μm dominated to the total amount, it was decreasing until 2003, and it is unclear that this is due to decreasing dissolved inorganic carbon or due to limiting of photon. In this study, we attempted to determine limiting factor and analysis water response model of quality in Lake Inawashiro. Ratio of carbon to nitrogen (C/P) and carbon to phosphorus (C/P) were 1±2 and 330±110 in surface layer and 5 m layer, respectively in 2004. Those in 2005 were, 8.5±1.0 and 354±82 in surface layer, and 8.7±1.1 and 324±51 in 5 m layer. As C/P ratio was so higher in both years, phosphorus is limiting factor in Lake Inawashiro. In addition, inorganic carbon was also limiting factor as pCO_2 was in low level although this lake was acid lake. Therefore, primary production was in low level as inorganic carbon and phosphorus lacking. As vertical distribution in inorganic carbon including CO_2 was did not change from surface to deep layer, supply of CO_2 from atmosphere is not important as compared with supply with inorganic carbon loading from inflowing river.

自1995年以来，在猪濑代湖观察到pH值缓慢上升。到目前为止，这种现象的原因还不清楚。虽然小于20 μm的微型浮游植物的初级生产量占主导地位，但直到2003年，它一直在下降，目前还不清楚这是由于溶解无机碳减少还是由于光子的限制。本研究试图确定稻和代湖水质的限制因子并分析水质响应模型。2004年表层和5 m层的碳氮比（C/P）和碳磷比（C/P）分别为1±2和330±110。2005年，表层平均值分别为8.5±1.0和354±82，5 m层平均值分别为8.7±1.1和324±51。由于C/P比值在这两年都很高，磷是猪种代湖的限制因子。此外，虽然该湖为酸性湖，但pCO_2仍处于较低水平，无机碳也是限制因子。无机碳、磷缺乏，初级生产力处于较低水平。由于无机碳（包括CO_2）的垂直分布从表层到深层没有变化，因此大气CO_2的供应与河流无机碳的供应相比并不重要。