Assessing flash flood erosion following storm Daniel in Libya

Area of Science:

• Earth and Environmental Sciences
• Hydrology
• Remote Sensing

Background:

• The eastern Mediterranean basin faces increasing storm activity and coastal flooding.
• Historically less prone coastal areas are now vulnerable to extreme weather events.
• Storm Daniel in Libya caused unprecedented flash floods, leading to significant loss of life and infrastructure damage.

Purpose of the Study:

• To analyze flash flood erosion and sediment dynamics in watersheds using remote sensing.
• To map urban damages in coastal cities affected by Storm Daniel.
• To assess the vulnerability of arid coastal watersheds to hydroclimatic extremes.

Main Methods:

• Utilized Sentinel-1A C-band Synthetic Aperture Radar (SAR) imagery.
• Characterized surface erosion and sediment load dynamics.
• Mapped urban surface damages in Derna and Susah.

Main Results:

• Increased sediment loading intensified turbid stream density.
• 66% of Derna and 48% of Susah urban surfaces suffered moderate-to-high damage.
• Erosion and sediment dynamics exacerbated flash flood impacts in coastal cities.

Conclusions:

• Eastern Mediterranean arid coastal watersheds are increasingly vulnerable to hydroclimatic extremes.
• A transformative coastal management approach is needed.
• Implementation of nature-based solutions and land-use changes is crucial for risk mitigation.