JPSS Satellites Observed Historic Asia Floods and the Potentially Affected Population During the Summer Monsoon Rainy Season

During the Asian summer monsoon rainy season, heavy and continuous rainfall usually causes widespread floods in many Asian countries, including the two most populated countries China and India. Flood mapping datasets from moderate-resolution satellites, such as the JPSS (Joint Polar Satellite System) series including Suomi-NPP (Suomi National Polar-orbiting Partnership) and NOAA-20, can be invaluable for monitoring floods and assessing the affected population. The flood maps derived from the VIIRS (Visible Infrared Imaging Radiometer Suite) imagery can provide a big picture of what’s on the ground over the entire Asia flooding region. The VIIRS 5-day composite flood maps, along with a population density dataset, can be combined to estimate the population potentially exposed (PPE) to flooding. The VIIRS flood maps demonstrate floods in China primarily occurred along the Yangtze River Basin and its tributaries. The VIIRS 5-day composite flood maps, along with a population density dataset, were combined to estimate the population potentially exposed to flooding. Here we use the summer of 2020 as an example, based on the flood extent along with the population density map, approximately over 50 million people in the entire China might have been affected by the floodwaters. In addition to China, several other countries including India, Bangladesh, and Myanmar were also affected. In India, the worst inundation and the affected population were located mainly in the northern states of Bihar, Assam, and West Bengal.