Flash flood hazard assessments, mitigation measures, and water harvesting efforts in desert environments are often challenged by data scarcity on the basin scale. The present study, using the Wadi Atfeh catchment as a test site, integrates remote sensing datasets with field and geoelectrical measurements to assess flash flood hazards, suggest mitigation measures, and to examine the recharge to the alluvium aquifer. The estimated peak discharge of the 13 March 2020 flood event was 97 m³/h, which exceeded the capacity of the culverts beneath the Eastern Military Highway (64 m³/h), and a new dam was suggested, where 75% of the catchment could be controlled. The monitoring of water infiltration into the alluvium aquifer using time-lapse electrical resistivity measurements along a fixed profile showed a limited connection between the wetted surficial sediments and the water table. Throughflow is probably the main source of recharge to the aquifer rather than vertical infiltration at the basin outlet. The findings suggest further measures to avoid the negative impacts of flash floods at the Wadi Atfeh catchment and similar basins in the Eastern Desert of Egypt. Furthermore, future hydrological studies in desert environments should take into consideration the major role of the throughflow in alluvium aquifer recharge.

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.

The conducted research offers an environmental assessment of municipal waste (MW) using remote sensing (RS), geological, and geophysical datasets. As a test site, the present study aims to characterize one of the largest uncontrolled dumpsites in Egypt. RS data analysis indicates that high temperature values are concentrated at the MW and landfill site allocations as a result of the decomposition process, leading to fire risks. Moreover, the geological and structural data draw attention to the structural-controlled old topography role on MW distributions. Consequently, the dumpsite MW has larger surface quantities near the downthrows of the mapped faults. For MW characterization, geophysical data are acquired to produce2D/3D resistivity models. Because MW has the ability to become soft clay, the municipal organic waste and landfill leachate resistivities are lower than that of municipal solid waste and sandy soils. The geophysical inversion results indicate that the maximum thickness of MW calibrating with the drilled borehole data is 60 m. Furthermore, the estimated MW dumpsite volume is about 42.32 MCM. Accordingly, the MW can be characterized in an accurate qualitative and quantitative manner. Our findings, therefore, help the efforts of uncontrolled dumpsite development and thus contribute to sustainability plans.