Forensic Hydrology: A Complete Reconstruction of an Extreme Flood Event in Data-Scarce Area

On 18 September 2020, the Karditsa prefecture of Thessaly region (Greece) experienced a catastrophic flood as consequence IANOS hurricane. This intense phenomenon was characterized by rainfall records ranging from 220 mm up to 530 mm, in time interval 15 h. Extended public infrastructure damaged and thousands houses commercial properties were flooded, while four casualties recorded. The aim this study provide forensic research on reconstruction event vicinity city. First, we performed statistical analysis rainfall. Then, used two numerical models observed data, either captured satellites or mined social media, order simulate posteriori. Specifically, rainfall–runoff CN-unit hydrograph model combined with hydrodynamic based 2D-shallow water equations model, through coupling hydrological software HEC-HMS HEC-RAS. Regarding limited available gauged led us use wide spectrum remote sensing datasets associated rainfall, such NASA GPM–IMREG, numerous videos posted Facebook, validate extent flood. overall assessment proved that exceedance probability flooding ranged 1:400 years low-lying catchments, 1:1000 upstream mountainous catchments. Moreover, good performance for simulated achieved using comparing their output footage provided SENTINEL images, along georeferenced media.