AUTHOR=Wang Jun , Gong Qinghua , Yuan Shaoxiong , Chen Jun 

TITLE=Combining soil macropore flow with formation mechanism to the development of shallow landslide warning threshold in South China

JOURNAL=Frontiers in Earth Science

VOLUME=Volume 10 - 2022

YEAR=2023

URL=https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2022.1048427

DOI=10.3389/feart.2022.1048427

ISSN=2296-6463

ABSTRACT=Due to the particularity of granites weathering soil and typhoon rainstorm condition in South China, existing shallow landslides early warning model cannot be well applied to those areas. This study developed a shallow landslide mechanism model considering the effect of soil macropores flow and put forward a method for determining the rainfall threshold of shallow landslides early warning in South China. First, we studied the special macropore flow hydrological effect and proposed the formation mechanism model of shallow landslide by introducing the macropore coefficient of granite residual soil. Then, we calculated the rainfall threshold of each slope unit by combing the hydrological model and the proposed shallow landslide model. Finally, we tested the calculated result in Maguihe watershed, Guangdong province, South China where experienced group-occurring massive shallow landslides on September 21th, 2010. The study result showed that the macropores of vegetation roots have a significant effect on increasing the permeability of granite residual soil. The initial infiltration rate and the stable infiltration rate of coniferous forest land are the highest, followed by shrub forest land, and bare land. The verification result shown that the correct rate of proposed model judgment was 80.65% which can be used for early warning of shallow landslides in South China. We discussed the application condition and parameter calibration of the proposed model in the end, with recommendations for future work suggested.