Sustainable water resources management in desert environment has yet to be reached due to the limited hydrological datasets under such extreme arid conditions. In the Eastern Sahara, the tectonic activity associated with the opening of the Red Sea adds more complexity to developing sustainable water management by creating multiple aquifers within subsided half-grabens along the Red Sea extension. To overcome these difficulties, a two-fold approach is adopted including integrated remote sensing and geoelectrical methods using Wadi Al-Ambagi watershed in the Eastern Desert of Egypt as a test site. First, the total discharge is estimated as 15.7 × 106 m3 following the application of a uniform storm of 10 mm effective precipitation, which exceeds the storage capacity of existing mitigation measures (5.5 × 106 m3), and thus additional dams are required. Second, the subsurface geometry of alluvium and sedimentary aquifers, within subsided blocks in the Arabian–Nubian shield (ANS), is delineated using 1D direct current and 2D electrical-resistivity tomography (ERT). Findings indicate that significant thicknesses of more than 80 m of permeable sedimentary units occur within the subsided blocks. Therefore, the scarce water resources can be managed by controlling the flash floods and suggesting proper dam sites at the location of thick alluvium and sedimentary rocks, where aquifers can be recharged representing a sustainable source for freshwater. The proposed approach is transferable and can be applied in similar arid rift-related watersheds in Saudi Arabia and worldwide.

This study focuses on the use of radar and optical satellite imagery for flood hazard mapping and monitoring around the archaeological sites of the Wadi Baba area, situated at Sinai (Egypt) and well known for its heritage treasures belonging to diverse historical periods and civilizations from the Pharaonic, Nabateans, Christian, and Islamic eras. Although this area is located in an arid to semi-arid climatic region, it is intermittently flooded due to torrential rainstorms. To assess the amount of rainfall expected and its impacts on heritage sites, satellite Sentinel-1 (C-Band) and Tropical Rainfall Monitoring Mission (TRMM) data were jointly used with measurements from meteorological stations and the Digital Elevation Model (DEM) from Shuttle Radar Topography Mission (SRTM). Envi5.1, ArcGIS 10.4.1, Snap 6.0, and the GEE platform were used to process optical and radar data, which were further analysed using the ArcHydro model. In this study, the TRMM accumulated rainfall data acquired on 17 January 2010, Sentinel-1 radar images between 2017 and 2019, and Sentinel-1 data captured from 1 to 30 March 2020 processed by GEE platform were chosen to assess the effects of flood events on the archaeological sites in the study area. The results indicated that the study area is exposed to flood risk that significantly threatens these heritage sites. Based on that, mitigation strategies were devised and recommended to mitigate the flood hazard impact around the archaeological areas.

No abstract