Flooding is a natural disaster with extensive impacts. Desert regions face altered flooding patterns owing to climate change, water scarcity, regulations, and rising water demands. This study assessed and predicted flash flood hazards by calculating discharge volume, peak flow, flood depth, and velocity using the Hydrologic Engineering Centre-River Analysis System and Hydrologic Modelling System (HEC-HMS and HEC-RAS) software. We employed meteorological and morphological data analyses, incorporating the soil conservation service (SCS) curve number method for precipitation losses and the SCS-Hydrograph for runoff transformation. The model was applied to two drainage basins (An-Nawayah and Al-Rashrash) in southeastern Cairo, Egypt, which recently encountered several destructive floods. The applied model revealed that 25-, 50-, and 100-year storms produced runoff volumes of 2461.8 × 10³, 4299.6 × 10³, and 5204.5 × 10³ m³ for An-Nawayah and 6212 × 10³, 8129.4 × 10³, and 10,330.6 × 10³ m³ for Al-Rashrash, respectively. Flood risk levels, categorised as high (35.6%), extreme (21.9%), and medium (21.12%) were assessed in low- and very-low-hazard areas. The study highlighted that the areas closer to the Nile River mouth faced greater flood impacts from torrential rain. Our findings demonstrate the effectiveness of these methods in assessing and predicting flood risk. As a mitigation measure, this study recommends the construction of five 10 m high dams to create storage lakes. This integrated approach can be applied to flood risk assessment and mitigation in comparable regions.

Climate extreme events such as floods and droughts in any area have a significant impact on human life, infrastructure, agriculture, and the economy. In the last two years, flash floods caused by heavy rainstorms have become frequent and destructive in many catchments in Northern Iraq. The present study aims to examine flash floods in the Erbil region, Northern Iraq using Remote sensing (RS), Geographic Information System (GIS), and Principal Component Analysis (PCA) for geomorphic data. PCA results revealed that 12 geomorphic parameters exhibited a significant correlation with two different statistical components. To facilitate practical application, ranks are assigned based on the calculated parameters for flood susceptibility mapping. Out of the 24 basins in the current study, three basins (16, 3, and 14) have the highest geomorphometric values (36–39), indicating the zone most susceptible to flash floods and making up a maximum area of 38.58% of the studied region. Six basins (4, 8, 9, 10, 12, and 15), which have geomorphometric values between 30 and 35 and cover a land area of 27.86%, are the most moderately vulnerable to floods. The remaining basins, which make up 33.47% of the research, are occasionally subject to floods and have geomorphometric scores below 30. The precision of the flood susceptibility mapping was validated using the bifurcation ratio and drainage density relationship as well as past flood damages, such as economic losses and human casualties. Most of the recorded injuries and fatalities took place in areas that were particularly prone to severe past flooding. Additionally, the investigation revealed that 44.56% of all populated areas are located in extremely vulnerable basins. The findings demonstrate a notable correlation between the identified flood-susceptible areas and the occurrence of past flood damage.

The spatial and vertical distributions of heavy metals were quantitatively determined for organic-rich agricultural soils in the Southwestern Nile Delta. This study aims to undertake an assessment of heavy metals contamination in the soils of Quessna district using the inductively coupled plasma-optical emission spectroscopy, remote sensing, and geographic information system techniques. In this study, 24 soil samples were collected at 12 sites representing the main suburbs in the Quessna district. The concentrations of the studied metals decreased in the order of Zn > Cr > Pb > Cu > Ni > Co. The contamination degree and ecological risk assessment for metals in soil samples were evaluated using the enrichment factor, geoaccumulation index, improved Nemerow's pollution index, Pollution load index, and potential ecological risk index. The spatial and vertical distribution of heavy metals concentrations were affected by soil properties such as clay and organic matter content and scavenger metals (Fe and Mn). The intensive urbanization, industrial activity, and agricultural practices are thought to be the main anthropogenic sources of heavy metals contamination. Further studies especially human health risk assessment are recommended to investigate possible risks for humans from heavy metals in this area.

Marine sediment samples were collected along the Jeddah coast, Red Sea, Saudi Arabia, in order to assess radiation hazards and the exposure to human and marine living organisms. Using collaborative techniques, grain size, mineralogical characteristics, and natural radioactivity were investigated. To examine the influence of sediment characteristics over the distribution of the measured radionuclides, resulting data were statistically processed by using multivariate analyses. ²³⁸U, ²³²Th, and ⁴⁰K levels were specified to be 19.50, 9.38, and 403.31 Bq kg⁻¹, respectively. Radionuclides distributions were affected by sediment mud content, organic matter, and heavy minerals index. The calculated radiation risk parameters are within the safe range and lower than the global average. Natural radiation from these marine sediments is normal and poses no significant radiological risk to the public or marine living organisms. The natural radioactivity of the marine sediment in this Jeddah coastline will have to be monitored on a regular basis to avoid overexposure to the residents.

Due to heightening concern about radiation hazards protection, activity concentrations of ²²⁶Ra, ²³²Th, ⁴⁰K in forty soil samples collected from Shoubra El Kheima in the South Nile Delta were measured using gamma-ray spectrometry. The mean activity concentrations of ²²⁶Ra and ⁴⁰K were higher in 20% of the considered samples than the world average values. A comprehensive comparison with up-to-date data was carried out. Spatial distribution maps of the measured radionuclides and radiological parameters were generated. The distributions of natural radionuclides were influenced by the soil organic matter, clay content, and scavenger metals oxides, as well as differences in the physical and chemical attributes and solubility of these radionuclides. The results revealed that industrial activity and agricultural practices in the study area caused an incremental increase in ²²⁶Ra and ⁴⁰K activity concentrations. It can be deduced that although there are intensive industrial activities in this area, the natural radiation that comes from the soil is normal and does not pose a significant radiological hazard to the public. The natural radioactivity of soil in this area needs to be monitored periodically to prevent unnecessary radiation exposure to inhabitants.

The potential impact of tourism, industrial, and urban activities on Egypt’s Red Sea coastline, which is well-known for its economic and environmental importance, was investigated at fifteen coastal sites. In the present study, the concentration of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) in marine sediments from these sites, was determined using Inductively Coupled Plasma Mass Spectrometers (ICP-MS). In detail, various pollution indices, statistical analyses, and spatial distribution patterns were used to assess the pollution status, impacts of human activities, ecological risks, and sources of potentially toxic elements (PTEs) in surface marine sediment. A detailed comparison with up-to-date data was conducted. These sediments were composed predominantly of fine and very fine sands. Mean grain size distribution typically depends on the source of the sediment from the following two prime sources: terrigenous (autochthonous) and biogenic (allochthonous). The detected PTE mean concentrations were as follows: Fe > Mn > Zn > Cr > Ni > Pb > Co > Cu > Cd. Multivariate statistical analysis results revealed their close distribution and association. Cd and Pb levels in the studied area have been slightly impacted by anthropogenic inputs. According to the calculated pollution indices, although a minimal or moderate contamination degree was detected in the study area, it was determined that there was a low to moderate ecological risk. The slightly high degree of contamination and risk centered in the middle of the study area around phosphate mining and related activities. More attention should be given to the concentrations and sources of Cd, Ni, and Pb as the main pollution factors.