Advanced remote sensing techniques in flash flood delineation in Tabuk City, Saudi Arabia

Flash floods have been the most frequent, extensive, and dangerous type of worldwide natural crisis. Mountainous, urbanized, and arid land areas like Tabuk region of Saudi Arabia are highly vulnerable to flooding due to heavy and sudden rainstorms that affected the people, infrastructures, and ecological and biophysical environment. Immediately following such a disaster event, advanced techniques are very essential to delineate and assess the damage resulted from successful rescue and relief operations. In this article, the European Space Agency (ESA) freely accessed images were conducted from the earth observation synthetic aperture radar (SAR) sensor, the images were successfully practiced to delineate the deadly flood crisis took place in Tabuk City in January 2019. The Sentinel Application Platform for Sentinel-1 Toolbox (S1TBX) is used to support the display and analysis of the large archive of products from the ESA SAR mission. Level-1 ground range detected with high resolution of 20 m × 22 m image at 2019/01/30 T15:39:44 acquired and processed. A backscatter value of − 22.39 dub is selected to separate water from everything else. Only region of interest mask pixels are considered for the histogram analysis. Accordingly, the maximum threshold error is set to 0.255. RGB map created a binary mask of flooded, and non-flooded pixels show that a significant part of the area was in danger. The findings of the current methodology quantify the flooded surface area by almost 9 km2 covers mainly the agricultural practices and the urban areas of the city of Tabuk. This study recommends that the future master plan of the Tabuk area should consider similar flooding risks. Finally, most arid lands like Tabuk are covered by sand that has similar backscatter as flooded land conditions. Therefore, the influence of this backscatter in flood mapping works should be assessed and exclusion techniques must be included to increase accuracy.