Satellite observation of extreme flooding in the Irkutsk Region in 2019

Abstract

At the end of June 2019, heavy rain showers over the territory of the southwestern regions of the Irkutsk Region led to the occurrence of floods on the rivers Biryusa, Uda, Iya, Oka, originating in the mountains of East Sayan. The rapid rise in water level over several days caused a catastrophic flood in the Irkutsk region, resulting in human casualties and significant economic damage. Siberian Center of State Research Center “Planeta” was monitoring the development of the situation in the areas of the passage of the flood wave. Daily monitoring was carried out using low-resolution satellite data. Medium-resolution and high-resolution satellite images were used for detailed mapping of flooded urban areas. The availability of data from the hydrological posts of the Roshydromet ground-based observation network on water levels, its changes per day and critical elevations in conjunction with satellite imagery made it possible to observe the rapid displacement of the flood wave. The most devastating consequences of the flood were in Tulun, which was due to a sharp rise in water, the features of the relief and location of urban buildings. The 2019 flood in the Irkutsk region on the rivers Uda and Iya became the largest in the entire history of observations.