Detailed inventory and initial analysis of landslides triggered by extreme rainfall in the northern Huaiji County, Guangdong Province, China, from June 6 to 9, 2020

BackgroundIn recent years, the frequency of extreme rainfall events has increased due to climate change, further raising the probability of landslide disasters. From June 6 to 9, 2020, the northern part of Huaiji County, Guangdong Province, and surrounding areas experienced extreme rainfall. By using high-resolution optical remote sensing images before and after the rainfall and interactive human-machine recognition technology, a detailed list of landslides from this extreme rainfall event was established and preliminarily analyzed.ResultsA total of 5173 landslides were triggered by this rainfall event, covering an area of 13.27 km2, mainly concentrated in the central part of the study area. The maximum point density and area density of the landslide list were 60.71 km-2 and 19.11%, showing a high degree of overlap. The relationship between landslide area and quantity, area and probability density showed a good power-law relationship, confirming the completeness of the landslide list. By combining common landslide abundance indicators, the correlation between landslides and five influencing factors including elevation, slope, aspect, strata, and cumulative rainfall was analyzed.ConclusionThis study supplemented rainfall-induced landslide data in the southeastern coastal region of China, aiding in the analysis of landslide occurrence patterns, landslide risk assessment, and providing a basis for warning and emergency response for local governments and relevant departments.