We are grateful for Darwish's interest in our paper, Fouad et al. (2025, https://doi.org/10.1029/2024EF004883). In this reply, we show that Fouad et al. (2025, https://doi.org/10.1029/2024EF004883) did not attribute building collapses in Alexandria solely to hydroclimatic factors, as stated in the comment. Instead, we emphasize that hydroclimatic drivers are presented as accelerators, with other anthropogenic influences explicitly stated in the original paper. Moreover, our response proves that Darwish (2026, https://doi.org/10.1029/2025ef006885)'s simplistic statistical approach is physically incorrect and obscures absolute risk by normalizing actual building collapse rates to the total number of buildings within a city. Furthermore, our reply shows that the comment conflates the distinct measurement of soil relaxation using shallow isotope mapping at the city scale, as conducted in Fouad et al. (2025, https://doi.org/10.1029/2024EF004883), with deep structural geotechnical assessments for foundation design of individual buildings. The utility and complementarity of both methods are already discussed in Fouad et al. (2025, https://doi.org/10.1029/2024EF004883). We acknowledge that the statement on the “7,000 at-risk buildings” is only mentioned in the abstract and is inadvertently missed in the main text; however, the calculation leading to this result is detailed in our supplementary data set and methods. Accordingly, Darwish (2026, https://doi.org/10.1029/2025ef006885)'s comment, while appreciated, misinterprets Fouad et al. (2025, https://doi.org/10.1029/2024EF004883) and overlooks the contemporary literature on Alexandria's hydrogeological and coastal dynamic contexts and their implications for infrastructure instability. ... Read more

The low-lying, arid coastal regions of the Southern Mediterranean Basin, extending over 4,600 km, face daunting sea level rise and hydroclimatic changes due to shifting weather patterns. The impact of these factors on coastal urban buildings and infrastructure must be better understood. Alexandria, a historic and densely populated port city in Egypt representative of several coastal towns in the Southern Mediterranean, has experienced over 280 building collapses along its shorelines over the past two decades, and the root causes are still under investigation. We examine the decadal changes in coastal and hydroclimatic drivers along the city's coastline using photogrammetric satellite images from 1974 to 2021. We explore the interconnectivity between shoreline retreat, ground subsidence, and building collapses. Our results suggest that collapses are correlated with severe coastal erosion driven by sediment imbalances resulting from decades of inefficient landscape management and urban expansion along the city's waterfront. This severe erosion, combined with sea level rise, increases seawater intrusion, raising groundwater levels in coastal aquifers. Degrading ground stability and accelerating corrosion in building foundations ultimately culminating in collapses. We identified a coastal area of high vulnerability with over 7,000 buildings at risk, surpassing any other vulnerable zone in the Mediterranean Basin. We propose cost-effective and nature-based techniques for coastal landscape adaptation to alleviate these dangers in Alexandria and other Southern Mediterranean cities facing similar climatic challenges. ... Read more