Interaction between Rainfall and Soil Moisture in Korean Peninsula: A Comprehensive Study with SM2RAIN

Understanding the interaction between rainfall and soil moisture (SM) is an essential and globally monitored factor in the hydrological cycle. In recent years, the occurrence of extreme weather events due to accelerated climate change has increased. Therefore, monitoring SM saturation and extreme rainfall is crucial for disaster risk management [3]–[5]. On the Korean peninsula, in-situ measurements are being conducted to build a database of rainfall and SM. However, due to the presence of numerous islands and mountainous, it is challenging to produce spatially representative data using only in-situ measurements. Therefore, remote sensing techniques are being utilized to monitor a wide range of areas for an extended period. Nevertheless, these techniques require accuracy and validation of the data. To address these limitations, this study utilized SM2RAIN [9] to analyze the factors that influence the over- and underestimation period due to SM saturation. The study considers both the accuracy and the spatial representativeness of the factors using in-situ, satellite, and reanalysis data, and distinguishes the degree of SM saturation by SM2RAIN. The results of this study allow us to analyze the interaction between environmental factors and extreme rainfall events that affect the timing of SM saturation by the SM2RAIN on the Korean peninsula. In the future, it may be possible to estimate environmental factors affecting SM saturation in ungauged areas by utilizing various factor and long-term data.