Soil sampling optimization for complex topography in mountainous, upland and hilly area of Japan

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06155
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 40010:Forest science-related
• Research Institution: Forest Research and Management Organization
• Principal Investigator: Yamashita Naoyuki 国立研究開発法人森林研究・整備機構, 森林総合研究所, 主任研究員 等 (30537345)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 森林土壌 / 広域評価 / マッピング / 土層厚 / 実験計画法

Outline of Final Research Achievements

The digital soil mapping (DSM) is rapidly developing due to the progress of AI. However, there is limited information on methodology for appropriate sampling for DSM, and there is insufficient evidence and assessment against traditional approach, especially in Japanese mountainous areas with complex topography. In this study, we applied for the first time a sampling method that considers various geospatial information available prior to the survey (e.g., slope and slope location) to appropriate sampling in a Japanese mountainous area and assessed the performance of this method. The results showed a clear advantage over traditional approach, especially useful for mapping soil properties at regional scale and with fewer sampling points.

Free Research Field

森林土壌

Academic Significance and Societal Importance of the Research Achievements

土壌特性値のマッピングを最適化するサンプリング手法の開発は平野部や農地が多くを占める欧州を中心に発展してきた。日本の山地のように非常に複雑な地形上で手法の開発・検証を行った例はほとんどなく、学術的な意義が大きい。市町村・全国スケールにおける森林生態系サービスの空間評価の必要性は年々高まっており、本手法を活用した精度の高い土壌空間情報は、適切な炭素管理や防災機能評価等の行政ニーズに大きく貢献する。また、土壌調査を効率化できるため、様々な事業においてコスト削減の効果が期待できる。