Acidity variations along hydrological processes of snow deposit, snowmelt and runoff.

酸度随积雪、融雪和径流的水文过程而变化。

基本信息

批准号：
06455002
负责人：
ISHIKAWA Nobuyoshi
金额：
$ 3.78万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

项目摘要

Assessment of the acidification and changes of the chemical contents of seasonal snow within the snowmelt process were carried out at a small watershed of the northern Hokkaido from 194 to 1996 include two snow cover seasons. Vegetations at the watershed are mixed forests of evergreen needle-leaf trees and deciduous broad-leaved trees with bamboo bush undergrowth. The surface soil is composed primarily of silt and clay, and is underlain to a depth of 3m by tuffaceous silt stone and sandstone of the Neocene. Snow samples were taken from three fixes sites : open site, forest fllor, forest canopy. Water samples were obtained from the bottom of the snow cover, from 10cm deep and from the stream. The range of pH in the dry snow was 4.7 to 5.3. These values were similar to the snow accumulated on the forest floor and the canopy. Dry snow has homogenous distributions of pH,EC and chemical constituents in the lateral direction of each layred structure. However, once melt water penetrated, the homogenous distributions were partly destroyed even in winter. During the snowmelt period pH of the snow increased and EC decreased to below 10muS/cm. pH of the melt water that percolated through 10cm deep soil accounted for 6.4 to 5.8, and those of the stream 7.1 to 6.8. The values did not change much through the snowy season. The percolated water showed high concentrations of anion compared with those of snow, but the water contained higher cation, which neutralized the anion, and pH of the water increased.

从194年到1996年，包括两个积雪季节，在北海道北部的一个小流域进行了融雪过程中季节性雪的酸化和化学含量变化的评估。流域植被为常绿针叶树和落叶阔叶树的混交林，灌木丛为竹林。表层土壤主要由粉砂和粘土组成，其下方为新近世凝灰质粉砂岩和砂岩，深度达 3m。雪样取自三个修复地点：露天地点、森林花丛、森林树冠。水样是从积雪底部 10 厘米深处和溪流中采集的。干雪的 pH 值范围为 4.7 至 5.3。这些值与森林地面和树冠上积雪相似。干雪在各层状结构的横向上具有均匀的pH、EC和化学成分分布。然而，一旦融水渗透，即使在冬季，均匀分布也会被部分破坏。融雪期间，雪的pH值升高，EC降低至10μS/cm以下。渗入10厘米深土壤的融水pH值为6.4至5.8，溪流pH值为7.1至6.8。在雪季期间这些值没有太大变化。与雪相比，渗滤水的阴离子浓度较高，但水中的阳离子含量较高，中和了阴离子，水的 pH 值升高。