1.College of Geosciences,Guilin university of technology,Guilin 541004;2.State Key Laboratory of Soi l& Sustainable Agriculture Institute of Soil Science,Chinese Academy of Sciences, Nanjing 210008China;3.Guilin university of technology Guilin 541004 China
Supported by the National Natural Science Foundation of China（Nos.42077012, 41771263）；Jinggang Shan Agricultural Hi-tech District Project (No.20222-051261-1)
【Objective】 Soil moisture movement is the main driving force of the material and energy transport in soil. However, the paths of soil moisture in soils are complex and difficult to comprehend. This is especially true in the red soil region with abundant rainfall and diverse land use types.【Method】With the help of an electrical resistivity tomography (ERT), soil moisture infiltration processes in the vadose zone were captured for the forest land and farmland of the red soil from Quaternary red clay.【Result】 The results showed that in the red soil region, ERT could realize the visualization of the soil moisture infiltration process in the soil profile of the red soil. There was a highly significant correlation (P < 0.01) between the resistivity measured by ERT and the soil moisture measured by the oven drying method. The linear coefficients of determination between them were 0.72 for forest land and 0.53 for farmland. Land use types affected the mode and depth of soil moisture infiltration. With a 2-cm water head height and 100-L water injection volume, the infiltration depth of forest land was more than 80 cm, much deeper than that of farmland (50 cm). With the continued injection of water for 200 min, the infiltration depth of the two land uses exceeded 150 cm and a preferential flow phenomenon was observed during the infiltration process. However, the preferential flow of forest land was more developed than that of farmland. The preferential flow of forest land moves down rapidly through macropores formed by plant roots and soil animal activities while the preferential flow observed in farmland moved to the deep layer intermittently mostly in the way of the finger flow. In addition, the forest land was dominated by vertical infiltration with weak horizontal flow while the horizontal movement in farmland was stronger.【Conclusion】Under the influences of disadvantageous factors such as complex soil layers, high background water content and high soil clay content, ERT technology still could successfully capture the occurrence and development processes of preferential flow in red soil area.
TIAN Yuan, ZHONG Xuemei, PENG Xinhua, WANG Yaji, GAO Lei. Inversion of Water Infiltration Processes in the Profile of Red Soil Based on ERT Technology[J]. Acta Pedologica Sinica,2024,61(3).Copy