Precise interpretation of Induced Polarization (IP) structure in groundwater flow system by tank experiments

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K04631
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22040:Hydroengineering-related
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Komori Shogo 国立研究開発法人産業技術総合研究所, 地質調査総合センター, 主任研究員 (60611192)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: IP法電気探査 / 地下水資源 / 水槽モデル実験 / 粘土鉱物 / 水飽和度

Outline of Final Research Achievements

In order to improve the understanding of the state of groundwater resources, we are improving the structural interpretation of resistivity and induced polarization(IP) distributions obtained by the IP survey. In order to interpret the subsurface structure obtained in the field survey, we have constructed a tank model experimental apparatus that can measure complex resistivity in a wide bandwidth from 0.01 Hz to 1 kHz, which is about 1/100 of the scale of the field survey, and are conducting experiments to simulate the complexity of the subsurface structure. In parallel with this, an IP survey was conducted in a groundwater flow field in Japan, and somewhat complex subsurface resistivity and IP distributions were obtained. Further detailed waveform analysis and tank experiments are underway to interpret this both qualitatively and quantitatively.

Free Research Field

IP法電気探査による地下構造探査

Academic Significance and Societal Importance of the Research Achievements

気候変動・地下水汚染リスクへの備えという観点から、地下水資源の保全意識は近年国際的に高まっており、地下水資源量把握のための高精度な地下可視化技術の開発が求められている。IP効果を利用した探査は、粘土粒子の多寡や不飽和状態に感度を持つため地下水資源の賦存状態の把握に有効と考えられているが、一般に複雑な形状を持つ地下比抵抗・IP特性分布を定性的・定量的に解釈することは難しい。本研究はその複雑性を模擬した水槽モデル実験の結果を地下構造解釈に適用するというアプローチであり、フィールド調査・水槽実験双方の結果を整合的に説明可能な構造解釈を行うことで、解釈の精度を向上させることが可能になると期待される。