Evaluation of sediment discharge based on decennary landslide change for after heavy rainfalls

2015 Fiscal Year Final Research Report

• Project/Area Number: 26870830
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Forest science; Natural disaster / Disaster prevention science
• Research Institution: Hokkaido Research Organization
• Principal Investigator: Koshimizu Ken'ichi 地方独立行政法人北海道立総合研究機構, その他部局等, 研究員 (30636171)
• Research Collaborator: UCHIDA Taro 国土技術政策総合研究所, その他部局等, 研究員 (60370780) ; ISHIMARU Satoshi 地方独立行政法人北海道立総合研究機構, その他部局等, 研究員 (50446366)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 大規模土砂生産後 / 拡大崩壊 / 崩壊土砂 / 流出土砂 / GIS / 流域土砂管理

Outline of Final Research Achievements

For integrated catchment-scale sediment managements after heavy rainfalls, we investigated for both aspects as follows: 1)the sediment yield by the expanded landslides compare with the sediment yield by the newly landslides. 2)after a heavy rainfall, the volume of sediment runoff from landslide deposit caused by a heavy rainfall on hillslope area. As a result, we found that the sediment yield by the expanded landslides was larger than the sediment yield by the newly landslides. In addition, we confirmed that the volume of sediment runoff from original landslide deposit on hillslope area was quite few compared with the volume of original landslide deposit on it. In other words, original landslide deposit still remained on hillslope area.
Therefore, in the case of integrated catchment-scale sediment managements after heavy rainfalls, we can be explained that it was necessary to focus on the sediment yield by the expanded landslides as well as remained landslide deposit on hillslope area.

Free Research Field

砂防学