Study region

This study focuses on an arid zone of Saudi Arabia that is experiencing rapid urban growth and escalating water scarcity. The region encompasses major cities such as Mecca, Jeddah, Khulays, and Rabigh, where the demand for sustainable water resource management is becoming increasingly urgent due to the limited availability of natural freshwater sources. The challenge is further intensified by ongoing urbanization and large-scale economic developments, particularly around Mecca, Jeddah, King Abdullah Economic City, and Yanbu Industrial City, which place additional pressure on the region’s fragile water systems.

Study focus

The objective of this research is to assess and map the suitability of rainwater harvesting (RWH) sites using an integrated approach that combines Geographic Information System (GIS), the Analytic Hierarchy Process (AHP), and Multi-Criteria Decision Analysis (MCDA). The analysis incorporates hydrological, geological, and infrastructural criteria, guided by Food and Agriculture Organization (FAO) guidelines. The study also evaluates the performance and contribution of existing RWH infrastructure and identifies optimal locations for future dam construction.

New hydrological insights for the region

The results indicate that approximately 6000 km² (∼26 % of the study area) is highly suitable for RWH, with an estimated surface runoff potential of about 730 million m³ . Existing dams—Khlays, Rabiigh, and Fatima—play a significant role in regional water supply. Four primary locations—Ghoran, Thule, Qahah, and Fatima—were identified as optimal for new dam sites, with estimated water storage capacities calculated. These findings demonstrate the potential of integrated RWH planning to enhance renewable water resources, support long-term water security, and inform policy and infrastructure development in arid regions like Western Saudi Arabia.

Integrating passive and active seismic approaches is essential to yield reliable geotechnical site characterization, particularly in forthcoming industrial and/or urbanized regions. The primary objective of this study is to deliver reliable geotechnical site characterizations and address uncertainty-related repeatability of different techniques to derive S-wave velocity structures (). We employed three comprehensive field survey measurements, including 10 shallow P-wave refraction tomography profiles, 10 multi-channel analyses of surface waves (MASW) profiles, and 20 horizontal-to-vertical spectral ratios of microtremor (MHVSR) measurements. These measurements were carried out on the forthcoming industrial zone in Aswan, Egypt. We newly introduced a straightforward approach based on the allowable bearing capacity () and the local geological information to examine the resulting uncertainty.

Thus, we addressed the repeatability of different techniques to derive the  using MASW and MHVSR. The  based on MHVSR-derived  considered as the safest lower boundary. Consequently, the criticism of MASW and MHVSR inversion uncertainty is addressed for the future-planned low-rise buildings in the forthcoming industrial zone in Aswan, Egypt. The derived seismic vulnerability index () exhibits very high, high, and low categories. The NS and EW directional MHVSRs are transverse to the EW and NS main strikes of the seismogenic active fault system, respectively. There is a remarkable correlation between  and the time-averaged S-wave velocity of the upper 30 m () derived from MHVSR. Finally, we found that high densities, empirically calculated based on P-wave velocity, correlate well with the high-gravity anomalies observed in the southern portion of the study area.

This study presents the first integrated geographic and predictive modeling assessment of Hofmeister ions in groundwater and their potential link to chronic kidney disease of unknown etiology (CKDu) in South Sinai, Egypt. A total of 25 groundwater samples were collected from Wadi Feiran and Wadi El Sheikh and analyzed for major ions, nutrients, and key physicochemical parameters. The results revealed alarmingly high levels of nitrate (mean = 478.1 ppm) and total dissolved solids (TDS, mean = 2093 ppm), far exceeding World Health Organization (WHO) safety standards, and pointing to substantial potential risks to public health in these arid communities. Although the weighted arithmetic Water Quality Index (WQI) classified all samples as “good” to “excellent,” detailed hydrochemical assessment showed that concentrations of Hofmeister ions—particularly calcium and sodium—surpassed safe average daily intake thresholds in many samples (21 and 16, respectively). Such exceedances raise concerns over the potential development of hypercalcemia, hypertension, and the progression of CKDu, particularly among populations with limited access to alternative drinking water sources. Hydrochemical interpretations suggest that rock–water interactions, evaporation, and anthropogenic inputs are likely contributors to the observed ion levels. Predictive modeling using multiple linear regression (MLR) demonstrated excellent performance (R² = 99.71 % for nitrate), highlighting its value in forecasting contamination trends and identifying groundwater vulnerability hotspots in data-scarce arid regions. These findings underscore the urgent need for targeted groundwater quality monitoring, the integration of predictive risk modeling into management frameworks, and the implementation of preventive public health measures. By bridging geochemical data with health risk metrics, this research provides a scientific basis for developing evidence-based policies to safeguard communities and promote the sustainable use of groundwater resources in arid environments.

Morelia City stands in central México, within the Trans-Mexican Volcanic Belt and the Michoacán-Guanajuato volcanic field. With a population of about 850,000, it is the largest and most populated city in the state of Michoacán. In 1991, UNESCO designated its historic center as a World Heritage Site, attracting millions of tourists yearly. However, the city is vulnerable to regional intraplate and inter-plate earthquakes and the municipality’s outdated building regulations. Recently, the strong shaking experienced in the metropolitan area due to the November 19th, 2022 (Mw7.7) subduction earthquake on November 19th, 2022 (Mw 7.7), emphasizes the need to understand the site's effects and to update the municipality’s building regulations. This study presents a comprehensive seismic microzonation of Morelia, using the ambient noise horizontal-to-vertical spectral ratio (HV) technique as an initial step toward mitigating seismic risk. Because of several peaks in the HV, we presented the HV amplification at several frequencies and not only at the dominant frequency, as is usually the case. We identified amplification levels of up to 6.0. We also inverted the HVs, considering the thicknesses identified by geological data, to create a velocity model of the subsurface extending to a depth of 400 m. The results indicate the existence of a local half-graben where the sediment thickness ranges from 50 to 110 m and define the regions with the most significant amplification. Furthermore, we reported the existence of long-period ground vibrations that could affect high-rise buildings, long-span bridges, and historical buildings. Since HV ambient noise amplification maps do not always effectively predict earthquake responses, we also compared these maps with acceleration maps from two recorded earthquakes at similar frequencies. One of these earthquakes was a subduction event, while the other originated from a local source. They exhibited low and high central frequency sources, respectively, as recorded by the accelerograph network of the Universidad Michoacana. The excellent correspondence between all the output results indicates the reliability of the used approach.

Beni Suef Basin has a promising prospect for hydrocarbon
production in the Egyptian Western Desert, so it has been given
priority in exploration plans. Geochemically determined TOC data
are expensive and are usually obtained from limited samples as in the
Beni Suef Basin. Thus, geophysical methods will be used to provide
a cost effective continuum of organic richness and maturation data of
the latest Cenomanian "G" and the Turonian "F" members of the Abu
Roash Formation in the Azhar E-2X well. An attempt was made to
differentiate between total organic carbon (TOC) content of kerogen
in potential source intervals and TOC content in hydrocarbon bearing
reservoir intervals using the Δ log R technique and the gas
chromatography data (Gas wetness ratio: GWR%, Light to heavy
hydrocarbon ratio: LHR%, Oil character qualifier: OCQ). In the
source rock intervals, a good match between the geochemically
determined TOC and log-derived TOC data was found, where the
later TOC data reliably determined the organic richness.
Additionally, the geophysically estimated maturation index (MI)
values were calibrated with the geochemical Tmax data. A
continuum of MI data successfully provided a reliable assessment of
thermal maturation of source rock intervals. Conversely, in gas
bearing reservoir intervals, both the log-derived TOC and MI data
were hampered by the gas effect. Meticulous distinction between
reservoir and source intervals in unconventional source rocks having
intraformational reservoir interbeds is necessary to determine
correctly the organic richness and maturation of these source rocks.

Integration of facies analysis with organic microfossils (mainly dinoflagellate cysts) provides insights into the paleoenvironmental reconstruction of the onshore part of the Douala sub-basin of Cameroon. Nine lithofacies were identified, grouped in three main facies agglomerate/conglomerates, sands/sandstones and clay facies were identified. These facies reflect periodic proximal to distal sediment inputs, under changing water level, most likely controlled by climate and tectonics. The recovered dinoflagellate cysts were essentially composed of Cerodinium granulostriatum, Glaphyrocysta microfenestrata, Lejeunecysta sp. and Senegalinium laevigatum, along with Longapertites marginatus, Spinizonocolpites echinatus and Spini- zonocolpites baculatus as significant terrestrial pollen. The dinoflagellate cysts were indicative of a shallow marine environment, affected by freshwater influx, under fluctuating dysoxic-anoxic, suboxic-anoxic and oxic states. These paleoenvironmental characteristics are consistent with the Upper Cretaceous sedimen- tary cycle of the Douala sub-basin, which terminated during the Maastrichtian, with a rapid and differen- tial marine regression. The recovered organic-walled palynomorphs were a powerful biostratigraphic tool in the correlation of Campanian-Maastrichtian in the area and surroundings.

Palynological organic matter (POM) of the Neogene succession from the Sidi Salim-1 well, located in the onshore Nile Delta, Egypt (Eastern Mediterranean), suggests a wide range of environments, from deltaic to offshore marine. These environments were discriminated by the overall palynofacies composition, including indicative dinoflagellate cysts, mainly Spiniferites and Selenopemphix. Near-shore marine environment was interpreted for the Middle Miocene (Langhian–Serravallian) Sidi Salim Formation. Deltaic to shallow marine environments were suggested for the Qawasim (Miocene) and Kafr El Sheikh (Pliocene) formations, while the distant (offshore) marine setting was established in the Pliocene Abu Madi Formation. This deeper environment, of the Abu Madi Formation, can be used to confirm a previous documentation of an Early Pliocene progressive drowning of an incised valley, related to the Messinian Salinity Crises (MSC) events, by the late Messinian sea level drop in the Mediterranean. Suboxic to anoxic conditions existed during deposition of the investigated well succession. Anoxia was confirmed by the occurrence of imprints of pyrite crystals across much of the well succession. The occurrence of abundant Poaceae pollen may suggest widespread dry grassland vegetation during deposition of the Neogene sedi-ments of the well. In a regional context, the Neogene environments in the Nile Delta area vary according to the relative position of the investigated sediments, due to structural, palaeogeographic and basinal settings. The recovered palynofacies fluctuated between amorphous organic matter (AOM)-dominated and phytoclast-dominated categories, mostly of the kerogen type II, which is capable of producing oil and gas. The visual assessment of the spore coloration index (SCI) of thin-walled trilete spores in the well section, shows values ranging between 5 and 8, confirming a thermallymatureorganicmatterand,consequently,canbepotentialsourcerocks.©2025ElsevierB.V.andNanjingInstituteofGeologyandPalaeontology,CAS.Allrightsarereserved,includingthosefortextanddatamining,
AI training, and similar technologies.

The gas chromatograms of the n-alkanes of the investigated Tineh Formation (Oligocene) show a dominance of short-chain n-alkanes with a slight admixture of medium-chain n-alkane components. They indicate the dominance of algae, microorganisms, Sphagnum moss and aquatic macrophytes. The low wax content (average 0.77), the low TAR value (0.01) and the high Paq value (average 0.91) show that submerged and floating seagrasses predominate over higher woody vascular plants in the studied formation. The redox potential based on the ratios of Pr/Ph (average 0.67) and Ph/n-C18 (average 0.32) of the Tineh samples indicates that an anoxic and dysoxic aquatic marine medium prevailed during the accumulation and preservation of OM. The low value of the ACL proxy (average 26.36) can also be attributed to the dominance of seagrass over woody plants, which took place in a relatively cool paleoclimate. The CPI shows an average value of about one (1.04), with two samples showing a value of less than one (samples C and D), which emphasizes the margin and the entry of the Tineh Formation into the main stage of maturation.