Geo-Environmental Insights for Sustainable Development: Assessing the Most Southern Part of the Red Sea Coast, Saudi Arabia

The southern Red Sea coastal zone of Jizan Province in Saudi Arabia is increasingly exposed to seismic hazards, soil erosion, flash flooding, and tectonically shaped landscape instability, raising challenges for sustainable development. This paper integrates high-resolution 12.5 m ALOS PALSAR digital elevation model data, morphometric analyses, geomorphic interpretations, and the Revised Universal Soil Loss Equation (RUSLE) model to assess soil erosion vulnerability and relative tectonic activity along 24 sub-basins. A total of 22 morphometric parameters were investigated, analyzed, and integrated into a weighted compound ranking key for prioritizing erosion-prone sub-basins. Geomorphic interpretation was assessed using the hypsometric integral, valley-floor width-to-height ratio, and basin shape, which were processed in the Relative Tectonic Activity (RTA) model. The results recognize sub-basins 8, 7, 22, 18, 23, 13, 3, and 9 as the highest-priority zones for soil conservation, while hypsometric integral values (0.04–0.48) reveal mature landscapes with geomorphic reactivation. High spatial correlation among morphometric prioritization, RTA interpretation, and the RUSLE model reveals that drainage characteristics, relief, lithology, and tectonic signatures indicate a significant spatial association with the soil erosion framework. The proposed model presents a reliable baseline key for sub-basin prioritization and climate-resilient mega-structure planning in data-poor settings, directly supporting SDG 9 and SDG 13.