5:15 PM - 6:45 PM
[AAS07-P06] Investigating the rainfall and soil moisture during Baybay landslides: A case study of Tropical Cyclone Megi 2022
Keywords:rainfall-induced landslides, soil moisture, GPM IMERG, TC Megi
In the Philippines, Rainfall-Induced Landslides (RILs) are one of the common hazards in communities. The devastating TC Megi "Agaton" of 2022 caused massive landslides in multiple barangays in Baybay City, Leyte (LGU Baybay, 2022). Asio (2022) explained the geomorphological aspect contributing to these landslides. However, the investigation of meteorological factors remains to be determined. This study focused on examining rainfall and soil moisture during TC Megi from April 8- 12, 2022, in three barangays: Bunga, Kantagnos, and Mailhi. Rainfall data were obtained from Global Precipitation Mission’s Integrated Multi-satellitE Retrievals for GPM (GPM IMERG), and soil moisture data from Soil Moisture Active Passive (SMAP) Level 4 datasets were analyzed. The study observed a continuous increase in rainfall levels in the study areas over time, even before the onset of Megi. Additionally, there was also a consistent rise in soil moisture levels between March 25 and April 11. Pearson-Correlation Analysis revealed a strong and statistically significant positive correlation between the parameters. TC Megi rainfall was compared to other identified extreme rainfalls from March 2021 to April 2022 and the global threshold set by Caine (1980). In this analysis, only Megi exceeded the threshold. This highlights the unique characteristics of TC Megi's rainfall (intensity and duration), and the preceding two-week rainfall, setting it apart from other events. In conclusion, rainfall and soil moisture play a significant role in the Baybay landslides. Incorporation of other factors, such as geomorphological and other meteorological parameters is recommended to further understand the underlying causes of the landslide events.