This study addresses the hydrogeochemical assessment of alluvial aquifers in a semi-arid region, where groundwater constitutes a critical resource for drinking supply and irrigated agriculture but is increasingly threatened by salinization and geogenic constraints. It investigates the hydrogeochemical characteristics and practical usability of groundwater from the Quaternary aquifer of the Bousselam Upstream River basin (BUR), northeastern Algeria. Forty-two groundwater samples were collected from fourteen wells during three monitoring campaigns conducted in 2020, 2022, and 2024 to capture spatial variability and short-term temporal evolution. Physicochemical parameters and major ions were analyzed following APHA standard methods, and hydrochemical facies were identified using Piper, Schoeller, Wilcox, and Riverside diagrams. Groundwater is mildly alkaline and moderately mineralized (EC:1154-1632 mu S/cm), reflecting dominant water-rock interactions with limited anthropogenic influence. The prevailing Ca-Mg-SO4-Cl and Ca-HCO3 facies are controlled by carbonate and evaporite dissolution and ion-exchange processes. Total hardness values indicate predominantly hard to very hard water. Water Quality Index values (25-75) range from good to poor, while irrigation assessments classify most samples as S1C3, indicating low sodium hazard but elevated salinity. Beyond academic characterization, the results highlight practical constraints on long-term use and support the need for targeted management strategies to sustain groundwater use for drinking and irrigation.
This study examines the spatial variability of soil particle-size distribution (PSD) along an agricultural hillslope at Mechtat Kef Laatatfa (Ouled Hamla, northeastern Algeria). The vertical and lateral organization of PSDs is investigated in relation to morphological setting, hydroclimatic conditions, and lithological context, which are considered the primary controls on sediment redistribution along the slope. The study aims to assess the added value of combining compositional and multivariate analytical approaches for interpreting particle-size variability in hillslope soils. Soil samples were collected from exposed horizons of three representative soil profiles and analysed using dry-sieving granulometry. Compositional data analysis (CoDA), principal component analysis (PCA), and end-member modelling analysis (EMMA) were jointly applied to disentangle granulometric patterns and transport-related processes. The results show that PSD accumulation is primarily governed by parent material erosion and slope gradient, with subsequent modification by size-selective sorting during downslope transport. A marked reduction in granulometric variability is observed from upslope to downslope positions, reflecting a systematic transition from coarse- to fine-dominated textures along the geomorphological gradient. By integrating compositional and multivariate techniques, this study provides a more robust and process-oriented interpretation of soil textural patterns along agricultural hillslopes, highlighting their relevance for understanding sediment redistribution under cultivated conditions.
A big problem in coastal development is changes in the coastline. This is a global issue because it affects planning in the area. This study looked at how sediment movement affects the shoreline in northern Semarang. The aim was to study sediment at different points using core samples and satellite images from Landsat 5, 7, and 8 (1996-2024) with the Google Earth Engine and Digital Shoreline Analysis System. The results show that this area has a barrier island system with strong sediment movements. The study also found a local change since 2021 due to the closure of an inlet channel. Shoreline changes every four years from 1996 to 2024 showed that erosion is the main process, causing the shoreline to move back. Landsat images from 1996 were used because they had a good resolution. However, at points TRG-01 to TRG-04, local growth was observed, marked by channel closure and sediment buildup. The differences between satellite images and sediment data show variations in time and space, where erosion is a long-term trend and growth is a short-term local change. These findings show that Tugurejo coast is very dynamic, mainly due to erosion, but it also shows growth in certain areas.
The relationship between δ18O values in phosphate (δ18OP) and carbonate (δ18OC) fractions of dental enamel bioapatite is a tool for evaluating the preservation of isotopic signals in fossil teeth. Until now, this relationship has been recognised mainly in ungulates. To expand the database to a statistically representative set of carnivorans, δ18OP and δ18OC values were analysed in 32 samples from modern dogs and foxes collected in Poland. The results obtained for canids are consistent with data reported for other mammals, suggesting a universal model of oxygen isotope fractionation between enamel phosphate and carbonate in mammals, including carnivorans, artiodactyls, and perissodactyls.
Groundwater salinization and nitrate contamination pose serious threats to water resources in many agricultural regions worldwide. This study investigates groundwater quality and evaluates its suitability for drinking and irrigation in the Sidi Smail Plain (northwestern Tunisia) using geochemical, statistical, modelling and GIS-based approaches. A total of 59 groundwater samples and four surface water samples were collected during the autumn transition (October 2021) and dry summer season (August 2022) and analysed for pH, electrical conductivity, total dissolved solids and major ions. Most groundwater samples were brackish to saline, with average TDS values of 2.225 mg/L in autumn and 2.381 mg/L in summer. Increased salinity during summer was attributed to enhanced evaporation and reduced rainfall. Spatial variability was pronounced, with higher mineralization in the southern plain linked to dissolution of Triassic evaporites and lower values in the north due to dilution from rainfall infiltration and karstic formations. Water Quality Index (WQI) values ranged from 45 to 281, classifying groundwater from excellent to very poor quality. The integrated use of geochemical tools, statistical analysis, WQI and GIS mapping provides a robust framework for assessing seasonal and spatial groundwater quality variations in sub-humid to semi-arid agricultural regions and highlights the need for controlled fertilizer use to protect groundwater from nitrate pollution.
