Factors Affecting Flash Flood Disaster in Ghat Town in Libya

Abstract

Objectives: The research aimed to remove the ambiguity about the reasons that led to the occurrence of the flood disaster in Ghat town in June 2019 and to identify the factors that influenced its occurrence.

Methods: The analytical approach was used to analyze satellite imagery from the European satellite (Sentinel 2) to determine the areas where floods spread throughout the town and the area surrounding it as well as the pathways through which they invaded the town. In addition to conducting a field study to evaluate the damage and verify the accuracy of remote sensing data, wadi streams and basins that had an impact on the town were also extracted using digital elevation models (DEMs).

Results: The study showed that using remote sensing techniques in GIS environment was successful in determining the spread of floods and calculating their quantities, as well as extracting wadi streams and calculating the areas of their basins. It also became clear that the most significant wadis affecting the town are those descended from the Tassili-Nazjer series, led by Wadi Innaghen, Wadi Tahramet-Azzezjer, and subsequently Wadi Tinalkum, all of which are tributaries of the Tanezzuft Great Wadi. It became apparent that the floodwaters entered Ghat from three directions: the southern, western, and northern.

Conclusion: It was discovered that the main cause of the disaster was a severe rainstorm that lasted through ten days, as well as the construction of new town neighborhoods in the lowlands, which in fact represent a natural spillway for two large wadis