Influence of acid snowmelt on the chemistry of stream water in the forest watersheds of the cold and snowy region, Japan

酸性融雪对日本寒冷多雪地区森林流域溪流水化学的影响

• 批准号: 07660177
• 负责人: SATOH Fuyuki
• 金额: $ 1.34万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07660177/
• 关键词: snowmelt; ionic composition; streamwater; acid shock; forest watershed; forest influence; cold snowy region; middle latitude; 融雪期; 化学組成; 酸性融雪水; 酸性雪; 選択的溶出; 水資源

A series of observation was carried out to investigate the occurrence of acid snowmelt and its influence on the in the forest watersheds of northen Hokkaido. The results are as follows :1. The chemical composition of the snowpack of the watershed in mountain area was strongly affected by the presence of forest and had little relation with altitude. The snowpack on open area was acidic. On the other hand, those in forests showed lower acidity and higher ionic concentrations. These findings indicate that forests not only buffer the acidity of snowpack but also have an effect on trapping dry deposits.2. The pH of initial snowmelt was less than 4.0 and then rapidly increased as the progression of melting. A Continuous elution of ionic species was observed from the snowpack during the thaw period. Approximately 70% of H^+ eluted out during the thaw was lost with the first 20% of meltwater (chemical fractionation) , which indicated the strong release of acid in the beginning of the thaw.3. Although strong release of acid was evident for the meltwater, the decrease of pH was obscure in the streamwater of forest watersheds. Following reasons were considered : the meltwater penetrated into the deeper part in case of the watersheds of the rocks in tertiary period ; the streamwater had high HCO_3^- concentration in case of the watersheds of serpentine rocks. In addition, it was also possible that the forest on the watersheds decreased the acidity of the snowpack.4. As for Ca^<2+>, Mg^<2+> and HCO_3^-, their output from the watershed exceeded their input from the snowpack, which indicated they were supplied, to some extent, from the inside of the watersheds via biogeochemical processes. The respiration of microorganisms acted an important role for the generation of HCO_3^- Which was dominant proton source inside the watersheds after the thaw period.

对北海道北部森林流域酸性融雪的发生及其影响进行了一系列观测。研究结果如下：1。山区小流域积雪化学成分受森林影响较大，与海拔关系不大。空地上的积雪呈酸性。另一方面，森林中的土壤表现出较低的酸度和较高的离子浓度。这些发现表明，森林不仅可以缓冲积雪的酸性，而且还具有捕获干沉积物的作用。初始融雪的pH值小于4.0，随着融雪的进行，pH值迅速增大。在解冻期间，从积雪中观察到离子种类的连续洗脱。在解冻过程中，大约70%的H^+随着前20%的融水（化学分馏）而消失，这表明在解冻开始时酸的强烈释放。虽然森林流域的融水有明显的强酸性释放，但其pH值的下降并不明显。考虑了以下原因：在第三纪岩石流域，融水渗透到较深的部分；蛇形岩流域的河水HCO_3^-浓度较高。此外，流域上的森林也可能降低了积雪的酸度。Ca^<2+>、Mg^<2+>和HCO_3^-从流域输出超过积雪输入，说明它们在一定程度上是通过生物地球化学过程从流域内部供给的。解冻期后，微生物的呼吸作用对HCO_3^-的生成起着重要作用，HCO_3^-是流域内主要的质子源。

项目成果

佐藤 冬樹: "北海道北部における積雪底面融雪水のイオン組成" 北海道大学演習林研究報告. 54. 175-187 (1997)

佐藤冬树：“北海道北部积雪底部融雪水的离子成分”北海道大学实验森林研究报告54。175-187（1997）。

佐藤冬樹: "北海道北部の新雪に含まれる化学成分の空間変動 -選択的溶出とNH4+沈着の影響-" 北海道大学演習林研究報告. 53・2. 205-218 (1996)

佐藤冬树：“北海道北部新雪化学成分的空间变化——选择性洗脱和NH4+沉积的影响”北海道大学实验森林研究报告53・2（1996）。

佐藤冬樹: "寒冷積雪地における酸性雪の融雪水組成" 日本林学会大会論文集. 106. 157-158 (1996)

Fuyuki Sato：“寒冷多雪地区酸性雪的融雪水成分”日本林学会会议记录106。157-158（1996）。

佐藤 冬樹: "北海道における酸性雪" 雪氷. 58(印刷中). (1996)

佐藤冬树：《北海道的酸雪》《雪与冰》（1996 年）。

佐藤 冬樹: "北海道北部山地の積雪の科学組成-森林の影響と流域物質収支解明への予備調査-" 北海道大学演習林研究報告. 53. 219-234 (1996)

佐藤冬树：“北海道北部山区积雪的科学组成——阐明森林和流域质量平衡影响的初步调查——”北海道大学实验森林研究报告53。219-234（1996）。