Discharge of suspended solids and radiocesium from a forested watershed before and after line thinning

2016 Fiscal Year Final Research Report

• Project/Area Number: 26450214
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Forest science
• Research Institution: Forestry and Forest Products Research Institute
• Principal Investigator: Shinomiya Yoshiki 国立研究開発法人森林総合研究所, 東北支所, グループ長 (20353716)
• Co-Investigator(Renkei-kenkyūsha): TSURITA Tatsuya 国立研究開発法人森林総合研究所, 立地環境研究領域, 主任研究員 (30353775) ; SHICHI Koji 国立研究開発法人森林総合研究所, 立地環境研究領域, 主任研究員 (10353715)
• Research Collaborator: OHNUKI Yasuhiro ; TSUBOYAMA Yoshio ; SAWANO Shinji ; ITOH Yuko
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 森林 / 放射性セシウム / 懸濁物質 / 間伐

Outline of Final Research Achievements

We investigated discharge of suspended solids (SS) and radiocesium (Cs-137) from a planted forest watershed before and after line thinning. Some of SS concentrations were higher after thinning than before thinning. We found that thinning had an influence on the SS discharge. We investigated the Cs-137 concentrations of SS from February 2012 to June 2016. Cs-137 concentrations in SS were not related to thinning and dropped during large storms. With the exception of large storms, Cs-137 concentrations in SS did not increase during or after thinning but decreased gradually. Immediately after thinning, SS discharges increased but Cs-137 concentrations in SS decreased in flood events. Therefore, Cs-137 export from the forested watershed did not increase sharply according to thinning. Also, for smaller areas of bare land, SS discharges and Cs-137 exports would decrease.

Free Research Field

森林水文学