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Human impact on fluvial environment during the reclamation period in Tokachi Plain, Hokkaido, JAPAN.

日本北海道十胜平原开垦时期人类对河流环境的影响。

基本信息

批准号：
14580099
负责人：
YAMAGATA Kotaro
金额：
$ 2.37万
依托单位：
Joetsu University of Education
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14580099/
关键词：
Tokachi plasin Human impact wetland deposits lake deposit suspended deposit environmental radionuclide reed gene 粒度分析湖成堆積物テフラ

项目摘要

Hokkaido is a region where the main factor of production changed drastically from hunting and gathering society of Ainu to farming society of Wajin on the boundary of Meiji Restoration. Therefore, the region is an extremely important region for examining the influence of human impact to natural environment. It can be thought that the deposit of the flood plain and lakes and marshes in the downstream recorded past environmental changes occurred in the drainage area, such as large-scale deforestation and reclamation. The aim of this research is to clarify the situation of the artificial environmental destruction and its influence to the fluvial environment during the development period in Tokachi Plain.By means of detailed analysis of the floodplain and lake deposits and observation of soil profiles in the drainage basins, it was confirmed that the coarsening of the deposits and increasing of depositional speed occurred in response to the human activity in the most of river basins of sou … More thern Tokachi Plain. By the chronological investigation using 137Cs and tephra, it was confirmed that rapid sand deposition occurred in response to the postwar abrupt farmland expansion in the Toberi river basin. And we also found the evidence of frequent forest fires during early Meiji era. The main source of the coarse materials was identified as a tributary (Toberi Horonai River) by grain-size sediment-tracer technique and mineralological investigation. Furthermore, such active sediment supply from the river induced the transportation of reed rhizomes from the upper course to the wetland to form new population. The lake sediment core was taken from the lagoon (Yudou-Pond) and analyzed. As a result, it was clarified that the coarsening of the deposit began in around 1920, and depositional speed had accelerated further in 1960's. By the observation of soil profiles in the Yudou river basin, it was suggested that the reclamation of pastures is the most important cause of the soil erosions. Less

北海道是明治维新边界上由阿伊努人的狩猎采集社会向瓦津人的农耕社会发生主要生产要素急剧变化的地区。因此，该区域是研究人类活动对自然环境影响的一个极其重要的区域。可以认为，下游冲积平原和湖泊沼泽的沉积记录了流域过去发生的环境变化，如大规模的森林砍伐和开垦。摘要本研究的目的是阐明德胜平原在开发时期的人为环境破坏状况及其对河流环境的影响。通过对河漫滩和湖泊沉积物的详细分析，以及对流域土壤剖面的观测，证实了在东胜平原北部大部分河流流域，沉积物的粗化和沉积速度的加快是对人类活动的响应。通过137Cs和tephra的年代学调查，证实了在战后突发性农田扩张的影响下，Toberi河流域发生了快速的沙沉积。我们还发现了明治早期频繁发生森林火灾的证据。通过粒度示踪技术和矿物学调查，确定了粗粒物质的主要来源为一条支流（Toberi Horonai河）。此外，这种来自河流的主动输沙促使芦苇根茎从上游向湿地迁移，形成新的种群。取鱼斗湖沉积物岩心进行分析。结果表明，矿床粗化开始于1920年左右，60年代沉积速度进一步加快。通过对雨斗河流域土壤剖面的观测，认为草地开垦是造成雨斗河流域土壤侵蚀的主要原因。少