ABSTRACT River regulation by dams is considered a major threat to river biodiversity, including that of benthic algae, macroinvertebrates, and fish, due to alterations in river hydrological regimes. However, it remains unclear how annual air temperature and precipitation influence the effects of low‐head dams on the biodiversity of various river biomes. This review conducted a meta‐analysis of studies that quantify the impacts of low‐head dams in relation to annual temperature and precipitation on riverine biodiversity. We extracted estimates of the impacts of dams on the richness and Shannon‐Weiner diversity index of river biomes (i.e., fish, macroinvertebrates, and benthic algae) from 79 case studies. We found a significant increase in Shannon–Wiener diversity downstream of diversion outlets. The annual average temperature significantly increased the effect size of species richness both upstream of the dam and downstream of the outlets, as indicated by positive correlations derived from mixed‐effect models. Furthermore, both annual average temperature and annual precipitation significantly amplified the effect size of the Shannon–Wiener diversity index downstream of the outlet. Our review reveals the significant impacts of dams on riverine biodiversity and highlights the crucial role of climatic factors in understanding the effects of hydropower and dam construction on aquatic ecosystems.

ABSTRACT Accurate estimation of soil erosion at regional scale is essential to preserve fertile soils. Assessing soil erosion is crucial to plan conservation works in a river basin. The Shimsha basin is predominantly an agricultural basin, which faces soil erosion issues. This research evaluates the soil loss in the Shimsha basin, Karnataka, India, using the Revised Universal Soil Loss Equation (RUSLE) together with geographic information system (GIS) methods and remotely sensed (RS) data. RS data are used to obtain the important parameters of the RUSLE model, whereas GIS is used for mapping areas that are susceptible to erosion. Input datasets of rainfall, soil maps, land use land cover (LULC), and digital elevation model (DEM) are employed to calculate the corresponding RUSLE model factors. In the GIS setting, these factors—topography, rainfall erosivity, erodibility of soil, cover management, and conservation practices—are computed and merged to evaluate spatial patterns of soil loss throughout the watersheds. The estimated soil loss in the Shimsha basin varies from 0 to 4669.4 t ha −1 year −1 , and the annual mean total soil loss has been approximated to 2.81 million tonnes per year and an average soil loss of 3.24 t ha −1 year −1 . The findings indicate that soil erosion rates are highest in intensively cultivated areas and mountainous regions that have sparse vegetation and steep slopes. RUSLE and GIS integration approach offers a dependable estimate of soil loss. The results help in identification of priority areas, enabling effective planning along with execution of sustainable soil management activities.

ABSTRACT Groundwater contamination by nitrates (NO 3 − ) poses a major environmental and public health risk worldwide. This study investigates nitrate pollution in the Mitidja aquifer (Algeria) using the Nitrate Pollution Index (NPI) and non‐carcinogenic risk assessment through the hazard quotient ( HQ ) method proposed by the US Environmental Protection Agency (USEPA). Forty‐nine groundwater samples were collected in 2019–2026 during the wet season and 23 during the dry season. Nitrate concentrations were analyzed using the Gaussian mixture model (GMM) for cluster classification, while non‐carcinogenic risks were estimated for adults and children through Monte Carlo simulations (10 000 iterations) to quantify parameter uncertainty. Results reveal that 42.3% of wet season and 43.5% of dry season samples exceed the World Health Organization (WHO) guideline of 50 mg/L. GMM identified two clusters per season, distinguishing moderately and highly contaminated zones. Based on NPI, 50% of wet season samples and 47.5% of dry season samples were classified as “clean to low pollution,” while 38.5% and 43.4%, respectively, indicated “high to very high pollution.” HQ values ranged from 0.06 to 7.18 (children) and from 0.02 to 3.08 (adults) in the wet season and from 0 to 7.81 (children) and from 0 to 3.34 (adults) in the dry season. Probabilistic results showed 25th–95th percentile HQ values of 0–8.95 for children and 0–2.94 for adults in the wet season, and 0–8.34 and 0.027–2.72, respectively, in the dry season. Sensitivity analysis confirmed children's higher vulnerability to nitrate exposure. These results highlight the urgent need for groundwater protection and remediation strategies in the Mitidja region.

ABSTRACT Economic growth is accompanied by roadway infrastructure development and an increase in vehicles. Generally, pollution impacts developed and low‐income countries (LICs) to different extents, and the disease burden due to roadway dust is not uniformly distributed across socioeconomic classes. Previous reviews have reported effects of street sweeping, dust suppressants, washing, and risk assessment of heavy metal exposure to street dust in developed countries, but a detailed review on LICs is still lacking. Hence, this review aims to address this gap through synthesizing literature on the pollutant burden of roadway dust in LICs. Research within the period 1966 to 2024 was retrieved from scholarly databases, and the key findings were: (1) roadway dust is laden with pollutants that carry public health risks, (2) assessment of pollutants in roadway dust is imperative to determine the quality of the urban environment, and (3) although there is evidence of regulatory frameworks in LICs, their implementation remains doubtful. This evidence informs policymaking for the regulation and abatement of the emission of pollutants into roadway dust.

ABSTRACT A detailed (high‐resolution) spatiotemporal analysis of lightning flash clusters and fatalities in Uttar Pradesh, India, was conducted for 2000–2022. Unlike previous national or regional lightning assessments, this study integrates long‐term satellite‐based Lightning Imaging Sensor (LIS) observations with geospatial techniques to generate high‐resolution maps of lightning flash density (LFD) and fatality risk at the state level. A total of 2 146 322 lightning flashes were recorded, showing substantial interannual variability, with a peak in 2007 and a low in 2018. Between 2000 and 2014, annual lightning strikes exceeded 120 000, whereas between 2018 and 2022, they mostly remained above 60 000 per year, indicating noticeable variation and an upward trend after 2018. Annual LFD (defined as flashes per square kilometer per year) revealed higher concentrations in the northeast, east, and parts of central Uttar Pradesh. Month‐to‐month LFD analysis showed peak lightning activity in May and the lowest in November, with sharp seasonality. Peaks coincided with the pre‐monsoon and monsoon periods, particularly in northeastern and eastern districts such as Sonbhadra and Kushinagar. The diurnal distribution peaked at 3:00 a.m. and 7:00 p.m. Indian Standard Time (IST), with greater intensity from late evening to midnight, suggesting favorable conditions for thunderstorms. Analysis of lightning‐related fatalities recorded 5010 deaths, predominantly male, with the highest number in 2016. These findings emphasize the urgent need for public health interventions, safety awareness programs, and modern forecasting techniques to protect vulnerable populations. The study provides critical insights for developing targeted safety measures, public outreach initiatives, and urban planning strategies to mitigate lightning impacts in Uttar Pradesh.

ABSTRACT The rapid advancement of technology underscores the urgency of addressing the challenges posed by population growth and the critical need for increased crop production in the near future. With climate change casting a long shadow over agricultural practices, the path forward is becoming increasingly clear. Strategies based on nanotechnology have shown great promise, offering effective solutions that complement and enhance existing approaches to crop production, ensuring sustainability in the face of environmental challenges. The future of agriculture must be reinforced by well‐characterized technological approaches, and nanotechnology stands out as a key solution with immense potential. Plant genetic engineering, the backbone of agriculture, can benefit tremendously from nanoscale innovations, leading to groundbreaking practical outcomes. Nanotechnology is proving its worth by enhancing tolerance to both abiotic and biotic stresses, delivering target molecules in a controlled manner, improving seed priming, and offering more reliable solutions in pesticide and fertilizer applications. However, the successful implementation of nano‐based strategies comes with its own set of challenges, risks, and gaps that must be continuously addressed to drive further improvements. Recently, concerns about nanotechnology residues and their potential impact on human health and environmental safety have been raised. Therefore, a thorough review of the materials and strategies at play is necessary to strengthen the scientific foundation for nanotechnology's application in agriculture.

ABSTRACT The present study investigates the degradation of ciprofloxacin (CIP), an antibiotic, using UV‐based advanced oxidation processes, that is, UV photolysis, UV/persulfate (UV/PS), and UV/PS/ferrous ions (UV/PS/Fe 2+ ) processes. The degradation efficiencies were measured to be 15.8% and 86.5% at 60 min using sole UV and UV/PS, respectively, employing [CIP] 0 = 10 mg/L, pH = 6.0, and [PS] 0 = 0.5 mM (in the case of UV/PS system). The UV/PS/Fe 2+ system further improved efficiency, eliminating 92.6% of CIP within 45 min under optimal conditions of: [CIP] 0 = 10 mg/L, [PS] 0 = 0.5 mM, [Fe 2+ ] 0 = 0.5 mg/L, and pH = 3.0. The experiments were conducted under varying pH conditions. The UV/PS process was most effective at pH 6.0, as evident by the values of rate constants ( k o b s ), that is, 0.0313, 0.0366, and 0.0278 min −1 at pH 3.0, 6.0, and 11, respectively, at 300 min. However, UV/PS/Fe 2+ showed greater activity at pH 3.0. Furthermore, the removal of TOC was found to be 32.8% and 46.4% for UV/PS and UV/PS/Fe 2+ , respectively. The effects of inorganic anions, such as chloride, nitrate, bicarbonate, and carbonate, were found to inhibit CIP degradation. Gas chromatography–mass spectrometry (GC–MS) was used to identify the degradation products (DPs), and toxicity of CIP and its DPs was evaluated by Ecological Structure Activity Relationship (ECOSAR) program. This work provides a comprehensive understanding of degradation pathways, environmental factors affecting CIP removal by UV/PS and UV/PS/Fe 2+ , and toxicity evaluation, highlighting the novelty of this work.

ABSTRACT Floating marine litter has a severe impact on major coastal ecosystems, including the bay areas of San Fernando City, La Union. Hence, a 3‐day intensive sampling was conducted along the Lingsat Marine Protected Area (LMPA) and Dalumpinas Oeste, a nonmarine protected area, to compare the distribution of floating marine meso‐ and macro‐litter for the first time. The floating litter densities between the two sites were also assessed and compared by developing a modified prototype of the Low‐Tech Aquatic Debris Instrument (LADI) suggested by the Civic Laboratory for Environmental Action and Research (CLEAR). For both sites, plastic was the predominant type of litter. Floating marine litter in LMPA was dominated by macro‐litter. In Dalumpinas Oeste, a total of 277 pieces were found, which is not significantly lower than the 604 pieces found in LMPA ( p = 0.161). Similarly, the floating litter densities between the two sampling sites ( p = 0.412) showed no statistical difference, indicating that, regardless of protection, relatively similar floating marine litter can be taken up in both nearby areas. These results now suggest an urgent need to review the current measures taken by LMPA.

ABSTRACT The increasing global energy demand for clean energy, combined with the depletion of fossil fuels and rising environmental pollution, has driven the search of sustainable energy solutions. Photocatalytic hydrogen (H 2 ) production using solar energy offers a promising pathway for clean fuel generation. Among various photocatalysts, graphitic carbon nitride (g‐C 3 N 4 ) has attracted attention due to its appropriate band structure, chemical stability, and metal‐free composition. However, limitations such as low surface area, rapid charge carrier recombination, and narrow light absorption spectrum limit its efficiency. To address these issues, g‐C 3 N 4 /MXene composites have emerged as advanced photocatalytic materials. MXenes, a family of two‐dimensional (2D) transition metal carbides/nitrides, possess high electrical conductivity, tunable surface functionalities, and excellent interfacial compatibility with g‐C 3 N 4 . This review highlights various synthesis strategies, including polymerization, electrostatic self‐assembly, solution mixing, and calcination for fabricating g‐C 3 N 4 /MXene heterostructures. The improved physiochemical properties such as enhanced charge transport, increased active surface sites, extended visible‐light absorption, and photostability are systematically discussed. Special emphasis is placed on advanced characterization techniques such as X‐ray diffraction (XRD), Scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FT‐IR) which are essential for probing the crystallinity, morphology, chemical states, and functional group of the composite material. Moreover, the photocatalytic performance of g‐C 3 N 4 /MXene composites in H 2 evolution is explored, supported by recent density functional theory (DFT) studies that provide mechanistic insight into charge transfer and active site interactions. The review concludes by outlining current challenges and proposing future research directions, including surface engineering, interface modulation, and computational design, to further optimize g‐C 3 N 4 /MXene photocatalysts for efficient and scalable H 2 production.

ABSTRACT A significant volume of groundwater is extracted from Indian aquifers, approximately 1427 m 3 per capita, which categorizes the country as water‐stressed according to the Falkenmark index. However, India has a substantial amount of surface water that, with minimal processing, can be made available for distribution. Climate change and the growing population in India are leading people to rely more on groundwater. This groundwater is used for drinking, irrigation, and in the beverage industry. The Purba Medinipur shoreline is 90.6‐km long, accounting for 57.52% of the coastline of West Bengal. In this region, the lithological characteristics indicate that the upper brackish aquifer is located at 120 m below ground level (mbgl), with a confined aquifer situated below that level. Surface alluvial soil is also present here. Using GIS methodology, the groundwater potential (GWP) in Purba Medinipur is estimated to be 2.771 and 2.869 billion m 3 in the upper and lower aquifers. This method provides insights into the significance of GWP at a particular location and can also be cross‐verified using the D8 model procedure in GIS. Areas like Panskura, Egra I–II, Potashpur I–II exhibit high GWP, while Kolaghat, parts of Panskura, Moyna, Tamluk, Sahid Matangini, and portions of Potashpur‐I are identified as having very low GWP. Notably, the upper aquifer is also facing saline water intrusion. Consequently, techniques such as fluoride removal, membrane treatment, ion exchange, distillation, bioremediation, magnetic separation, and hybrid technologies can be implemented, as feasible, to mitigate the freshwater crisis along the coasts of Purba Medinipur.