Climate change poses a major challenge for Sahelian cities such as Bol, located in the Lac province of Chad, a region classified as one of the world's climate change hotspots. In this city, the vulnerability of the built environment remains insufficiently documented. Against this backdrop, this study analyses the main climate risks, their impact on housing types and local adaptation strategies in the city of Bol. The methodology adopted is based on a mixed approach combining the analysis of long-term climate data (1982–2022), surveys of 385 households, interviews, field observations and statistical analyses (χ²), supported by GIS tools. Three types of housing (traditional, semi-modern and modern) were analysed. The results show strong seasonality in climate risks, with flooding and erosion predominating in the wet season and heat waves, fires, and strong winds in the dry season. All types of housing are vulnerable, although in different ways. Local adaptation strategies are mainly structural, autonomous and reactive. This research makes an original contribution by offering a holistic view of the physical vulnerability of housing, integrating climate, social perceptions and construction types, and providing key elements to guide adaptation policies in Sahelian cities.

The San Clemente Island fox (Urocyon littoralis clementae) is classified as a focal species for conservation management by the US Navy. They are considered vulnerable to a variety of vector-borne diseases due to their relatively high population density and low genetic diversity. During the dry (July–November) and wet (December–February) seasons of 2017–2018 we live-trapped 95 foxes and collected ectoparasites to test for the presence of pathogens. We found a significant difference in ectoparasite abundance on foxes between seasons, but no differences associated with sex or age. We found that foxes carried two species of flea (Echidnophaga gallinacea and Orchopeas howardi) and two tick species (Ixodes pacificus and Ixodes jellisoni). No evidence of Borrelia burgdorferi, Anaplasma phagocytophilum, or Borrelia miyamotoi bacteria were found. This paper is the first account of ectoparasite species identification, quantification, and pathogen testing for the San Clemente Island fox subspecies.

Seasonal acclimatisation is a mechanism enabling individuals to advantageously adjust one or more physiological parameters in response to changing environmental conditions. The ability to adjust metabolic rates and thermal physiology in response to seasonal changes is known to be central to the physiological ecology of some reptiles, but few studies have examined the ability of reptiles to exhibit seasonal flexibility in rates of evaporative water loss (EWL). We measured acclimatisation to seasonal changes for both temperature and water-related traits in six species of geckos in the genus Gehyra from the highly seasonal tropics of northern Australia. Four species from a mesic, more thermally stable site did not have seasonal differences in thermal preference (Tpref), but Tpref was significantly lower during the cooler dry season in three species from a semi-arid, more thermally variable site. EWL was lower (34% to 76% reduction) during the dry season compared to the wet season, a significant reduction for all gecko species. EWL decreased rapidly from wet to early dry season, then either remained low or continued to decrease to a minimum in the late dry season. These results indicate acclimatisation in EWL, resulting in the conservation of water during the dry season. A growing body of evidence suggests that seasonal acclimatisation of EWL broadly occurs in lizards in the wet-dry tropics of Australia, but less is known about seasonal acclimatisation of EWL in other geographic regions.

This study evaluated the effectiveness of wastewater management practices on effluent water quality at the Wupa Sewage Treatment Plant, Abuja, using an integrated descriptive, analytical, and experimental research design. Primary institutional and operational data were obtained through structured questionnaires administered to 173 respondents comprising Wupa treatment plant staff and Abuja Environmental Protection Board (AEPB) officials, alongside systematic field observations and facility inspections of the activated sludge system with extended aeration. Influent and effluent wastewater samples were collected during wet and dry seasons over three consecutive weeks and analysed for physio-chemical and biological parameters using standard laboratory methods, with results assessed against NESREA and WHO guidelines. Findings showed unanimous agreement (100%) among respondents that the plant operates under established regulatory frameworks (FME, NESREA, and WHO) and applies an activated sludge treatment system with extended aeration, discharging only treated effluent into the Wupa River. Laboratory analyses demonstrated substantial reductions in turbidity, BOD, COD, TSS, nutrients, heavy metals, and coliform counts in both seasons, with most effluent parameters complying with regulatory limits; however, mean BOD values during the wet season were marginally above the recommended threshold for surface water discharge. Paired sample t-test results revealed a statistically significant difference between influent and effluent mean values in the wet season (t = 7.785, p < 0.05), confirming the effectiveness of wastewater management practices in improving effluent quality prior to discharge. Overall, the study concludes that the Wupa Sewage Treatment Plant is largely effective in protecting receiving water quality, though targeted improvements are required to achieve full compliance for all parameters under varying seasonal conditions.

Understanding and predicting climate change impacts on the terrestrial water cycle is essential for water resources management and hazard prevention. This study aims to project future runoff of a densely-populated river basin, the Pearl River Basin (PRB), under different Shared Socioeconomic Pahway (SSP) scenarios, by combining the Soil and Water Assessment Tool (SWAT) model and the CMIP6 climate projections. Results show that climate change will significantly increase the runoff of the PRB, with changing rates of 0.21, 0.20, 0.11, and 0.17 mm/month/year for low- to high-emission scenarios SSP126, SSP245, SSP370, and SSP585, respectively. Future runoff exhibits strong seasonal and spatial variability due to complex changes in precipitation and potential evapotranspiration across the basin. The PRB may experience higher flood risks during the wet season under all SSP scenarios, driven by a ~15% increase in runoff during the wettest month during 2061–2100 relative to that of 2021–2060. Conversely, drought risks may escalate in the East River Sub-basin of the PRB during the dry season under the high-emission scenarios (SSP370 and SSP585), with a ~20% reduction in runoff during the driest month during 2061–2100 relative to that of 2021–2060. The highest-emission scenario (SSP585) may lead to the most drastic hydrological changes, including increased risks of flooding and drought across different parts of the PRB. Our findings suggest intensified water cycling and increased hydrological risks in the PRB under a changing climate, highlighting the necessity of future water resource management to consider potential climate change impacts to mitigate the risks of floods and droughts effectively.

The existing cultivars of aromatic rice are not sufficient to satisfy the demand for aromatic rice because of their limited yield potentials and environmental constraints. High yielding aromatic rice is a significant agricultural focus in Bangladesh due to its potential to enhance food security, economic growth, and export revenues. The research was instigated to develop high yielding, premium quality new aromatic rice variety to satisfy the present market demand. Therefore, single crosses were made and after confirmation of F1 s, generations were advanced through the pedigree selection method until the selection of several superior inbred lines. Among the selected lines, the proposed genotype (BU-103-23-5-3) was derived from ACC 34 X ACC 51 with better qualitative and quantitative attributes than the check variety (BRRI dhan70). The proposed genotype has the modern plant architecture, having tall but robust plant with an erect flag leaf, a long panicle with higher filled grain in addition to insects and diseases resistance. On an average, it requires 120-125 days to mature with a yield potential of 5.0 to 5.5 t ha-1, which is earlier and showed nearly 20 % higher yield than the check variety. It is recognized as long-slender, premium quality rice with 21.9 g of 1000-grain weight. Amylose and protein content of the polished rice are 26 and 7.56 %, respectively. The proposed genotype is Zn and Fe biofortified aromatic rice containing 23.6 ppm of Zn and 11 ppm of iron in the 11% polished rice. The newly developed genotype has satisfactorily passed the Proposed Variety Trial (PVT) conducted in ten locations during wet (Aman) season of 2023. Consecutively, the National Seed Board (NSB) approved the proposed genotype (BU-103-23-5-3) as GAU dhan 3 for commercial cultivation in the wet season in Bangladesh because of its significant benefits for food security, economic growth, and export revenues. Ann. Bangladesh Agric. 29(2): 125-140

Abstract. The Lancang-Mekong River (LMR) Basin is highly vulnerable to extreme hydrological events, including Drought-Flood Abrupt Alternation (DFAA). The efficacy of potential mitigation measures, such as reservoir operations, on DFAA under climate change remains poorly understood. This study investigates these dynamics using five Global Climate Models (GCMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6). It employs the Revised Short-cycle Drought-Flood Abrupt Alteration Index (R-SDFAI), along with the Tsinghua Representative Elementary Watershed (THREW) model integrated with the developed reservoir module. The findings reveal that DFAA in the LMR Basin is primarily dominated by DTF (drought to flood), with probabilities of DTF exceeding those of FTD (flood to drought) at mild, moderate, and severe intensity levels. The increase in DTF probability for future periods is also significantly higher than that of FTD. Mild DTF and mild FTD account for 58 % to 90 % and 75 % to 100 % of their total probability in the future, making the mild-intensity events the most frequent DFAA. Reservoirs play a significant role in reducing DTF risks during both dry and wet seasons, though their effectiveness in controlling FTD risks, particularly during the dry season, is relatively weaker. Furthermore, there is a positive correlation between the reservoir's capacity to mitigate total DFAA risk and its total storage. Reservoirs display a stronger ability to regulate high-intensity FTD and high-frequency DTF events, and significantly reduce the monthly duration of DFAA. These insights provide valuable guidance for the effective management of water resources cooperatives across the LMR Basin.

This study investigates the impact of non-sewered sanitation systems (NSS) on groundwater quality in peri-urban areas of Islamabad, Pakistan. Groundwater samples were collected from five locations served with septic tanks and pit latrines during dry and wet seasons. The study revealed significant contamination, particularly during the wet season, with high levels of ammonium-nitrogen (NH4 +–N) (43 mg/L in wet season vs. 19 mg/L in dry season), Chemical Oxygen Demand (COD) (52 mg/L in wet season vs. 29 mg/L in dry season), and E. coli (> 23 CFU/100 ml) in both wet and dry season. The Water Quality Index (WQI) indicated that most groundwater samples were “unfit for drinking” with a notable deterioration during the wet season. During the dry season, 47% of samples were classified as “marginal” (WQI ≤ 100), while 53% were “poor” (WQI 100 − 200). In the wet season, nearly all samples fell into the “poor” (WQI 100 − 200) and “very poor” quality (WQI >200). The Principal Component Analysis and Multi Linear Regression (PCA-MLR) determined that high NH4 +–N and COD in groundwater takes its genesis from anthropogenic sources and increasing distance between NSS and groundwater well improves water quality. Thus, groundwater in the area is unsuitable for drinking, domestic, and agricultural needs. The study highlights the critical importance of proper construction, operation, and maintenance of NSS to prevent groundwater contamination and protect community health.

Assessment of groundwater quality is becoming essential for effective resource management. In this study, we conducted a seasonal assessment of groundwater quality, hydrogeochemical processes, and statistical analyses in the city of Moundou. A total of 62 groundwater samples were taken in the 27 districts of the city, in August 2022 (rainy season) and May 2023 (dry season), respectively. From a geochemical point of view, the results highlighted two dominant geochemical facies in both the dry and wet seasons: the calcium-magnesium bicarbonate facies (Ca-Mg-HCO₃) and the sodium-potassium bicarbonate facies (Na-K-HCO₃). The multivariate analysis showed that the mineralisation of gypsum (CaSO4 · 2H2O), CaCl2 salts, silicates, carbonates and the decomposition of organic matter are the main processes affecting the quality of Moundou’s water. The physico-chemical results show that of the parameters monitored, only pH, iron and ammonium do not comply with the WHO standard, and almost 89% of the sites sampled are considered acceptable according to QWI values. Only the sites in the north-east of the city showed poor water quality during the rainy season. On the whole, this water is of better quality for irrigation.

Introduction: Diarrhoea constitutes a significant cause of morbidity and mortality among children under five, globally. The disease situation among children under five in the Savannah Region has not been studied. This study described diarrhoea morbidity data to determine the distribution of cases among children under five years in the Savannah Region of Ghana. Method: We conducted a descriptive cross-sectional study using diarrhoea data of children under five extracted from the health system database from 2017 to 2021. The data was exported to Microsoft Excel 2019 and STATA 15.1 for analysis. Descriptive statistics were used to express the results as frequencies, percentages, and rates. We plotted the cases month-by-month for each year to determine seasonality. Results: A total of 90,381 cases of diarrhoea were reported, with the highest cases among children aged 12-59 months, 61,745 (68.3%). Most cases were among males, 47,160 (52.2%). Cases declined with the highest incidence in 2017 and lowest in 2020, 244 and 126 per 1000 persons, respectively. Bole district recorded the highest incidence (618 per 1000 persons in 2017). Two major peaks were recorded in January and June, with minor peaks in March and August. Rainfall did not significantly influence diarrhoea pattern (p>0.05). A five-year forecast projected a decrease in cases from approximately 11400 in 2022 to about 4300 cases by 2026. Conclusion: Children within the age category 12-59 months and males accounted for most cases. The study illustrated seasonal variations in diarrhoea diseases, with cases in both the wet and dry seasons. All districts were affected, with the Bole having the highest burden. Cases are projected to decrease over the next five years. Health officials should strengthen surveillance and sustain interventions to reduce the incidence of diarrhoea in the region.

The accumulation of heavy metals (HMs) from coal resource exploitation and coal-related industries poses serious ecological and health risks in the hinterland river sediments of Shenfu coal field in Northern China. Using data from 59 samples, the geo-accumulation index and ecological health risks of HMs were assessed probabilistically using Monte Carlo Simulation. Two coupling models were constructed in this study, integrating both the Positive Matrix Factorization and ecological health risk models to identify the risk levels of pollution sources in the Kuye River. The risk of HMs during the wet season was explored due to the lower concentrations and a broader range of pollution sources compared to the dry season. The Igeo value of Hg was greater than 1 in 69% of the samples, suggesting moderately contaminated sediments. According to the source-oriented coupling models (PMF-RI/HRA), coal-mining sources contributed to the overall ecological risk by 48.79%, primarily due to Hg (98.50%). Industrial sources (51.48%) were the largest contributors to carcinogenic risk, with Ni corresponding to the target HM. This indicated that different HMs originating from distinct pollution sources were responsible for ecological or carcinogenic health risks. The probabilistic health risk evaluation results indicated that children faced higher risks than adults, with over 94.07% of carcinogenic risks exceeding thresholds. Traffic sources followed, contributing 34.41% to ecological and 41.09% to carcinogenic risks. The results highlight the priority sources and target HMs based on specific sources in the mixed 'mining-industrial-traffic' areas, providing valuable insights for environmental protection and the development of risk prevention strategies in a typical energy industry area.

Background and Aim of the Study: The status of naturalised understory herbs serves as a key indicator of habitat change within forest ecosystems on both local and global scales. Petiveria alliacea, a low-growing, naturalised shrub, forms dense community patches, particularly along secondary forest edges and disturbed areas. Its increasing exploitation for multipurpose uses raises significant concerns regarding its conservation, biodiversity, and the health of ecosystems. This study assessed the composition, abundance, and spatial–temporal differences between P. alliacea and other understory plant species within selected secondary forests of the University of Ibadan, Nigeria. Data and Methodology: Floristic surveys were done at the University of Ibadan’s Teaching and Research Farm (TRF), Botanical Garden (BG), and Department of Botany (DB). At each site, systematic sampling was employed during wet and dry seasons over two consecutive years, establishing four transects at 50 m intervals. Each site has eight 25 m² plots with 40 quadrats laid (35 at the Department of Botany). Relative Importance Value (RIV-%) was calculated to determine species dominance, while the Jaccard Similarity Index (SCJ-%) was used to compare species composition across sites and seasons. Results: Species richness was higher in BG (52 species, 28 families) and DB (51 species, 28 families) than in TRF (41 species, 21 families), with greater richness during wet seasons across all sites. Petiveria alliacea exhibited the highest RIV across seasons and years in TRF and BG, and during dry seasons in DB. Peak RIV values occurred in dry seasons, whereas the lowest values were recorded during wet seasons. Species composition similarity was highest between wet seasons within the same sites and lowest between dry and wet seasons across different sites. Conclusion: Petiveria alliacea is a dominant, fast-spreading species with pronounced spatial and temporal variation but poses no serious threat in the short term to the heterogeneity of the landscape, suggesting its ecological compatibility as a pioneer plant within the secondary forest.

The spatiotemporal distribution, partitioning, and prioritization of current use pesticides (CUPs) in aquatic environment of Pearl River Delta.

Spatio-temporal dynamics and flux of microplastics in the lower Ganges-Brahmaputra-Meghna River system and estuary.

Ridge-to-reef linkages in Apra Harbor, Guam describe spatial and temporal variation in water quality and coral reef assemblages.

Bioconversion of heavy metals in river sediments: Seasonal dynamics, driving mechanisms, and BSAF-based assessment in the Liujiang River basin.

Studies of the length-weight relationship (LWR) and condition factor (CF) in fish are abundant but often descriptive; yet, most studies overlook how intrinsic and extrinsic drivers structure these metrics. Here, this study tested whether the growth exponent (b) varies across sex, season, and ecological region, and whether CF is elevated in females and before spawning. Over the course of a complete annual cycle, a total of 1436 individuals were collected from four mudflat sites, measured for total length (TL) and weight (W), and analyzed using log10-linear regressions of LWR and CF, along with appropriate parametric or non-parametric tests under false discovery rate control. The TL strongly predicted W (r 2 = 0.87) with b = 2.46 ± 0.02 SE, (< 3; p < 0.001), indicating negative allometry. Females showed a larger size and higher b value (2.52) than males (2.41). The dry season yielded a higher b value than the wet season, and southern sites showed a non-significant trend towards a higher b value than northern sites. Mean CF was 1.01 ± 0.01 SE, elevated in females (1.09 vs. 0.98) and in the dry season (1.04 vs. 0.99), while monthly fluctuations (0.89-1.08) tracked feeding and reproduction but showed no regional differences. Overall, S. histophorus exhibits consistently negative allometric growth, with systematic variation in b and CF across sex and season. These findings provide hypothesis-driven baselines for monitoring semi-terrestrial gobies and highlight the importance of considering life-history and hydrological context when applying LWR/CF in ecological and evolutionary research and management.

Indoor dust serves as a medium for the deposition of heavy metals, and young children's rapid physical growth and hand-to-mouth behavior expose them to the impacts of heavy metals. This project aimed to measure the concentrations of heavy metals in classroom dust from the selected preschools in southwestern Nigeria. Dust samples were taken via a dust collector and analyzed quantitatively and qualitatively via the Atomic Absorption Spectroscopy (AAS) scheme. The descriptive and inferential statistical method was employed for the data analysis, and standard calibration, recovery analysis, and blank determination were carried out for the quality control measures. It was found that, in the dry season, the total metal concentrations in dust were 1.82 gg-1 Cu to 80.00 gg-1 Zn, whereas, in the wet season, the heavy metal concentrations were 0.83 gg-1 Co to 38.43 gg-1 Zn. Hence, the selected preschool dust was significantly enriched with high levels of Cd and As contamination but unpolluted for Co, Cu, Mn, and Pb across all examined metals. The results indicate elevated concentrations of lead (Pb) and cadmium (Cd) in high-traffic indoor spaces, with levels exceeding recommended safety thresholds. Lead (Pb) exposure is linked to neurodevelopmental disorders and reduced cognitive function, Cadmium (Cd) can cause kidney damage and impair bone development, while arsenic (As) is associated with immunotoxicity and an increased risk of cancer. To mitigate these risks, this study recommends practical measures, including frequent wet cleaning of floors and surfaces to reduce dust accumulation and limiting the use of materials known to contain heavy metals, such as lead-based paints and older plumbing fixtures.

Nonnegligible migration of rubber-derived chemicals from road surface to adjacent greenbelt soil.

Illegal gold mining filters soil bacterial communities and enhances mercury mobility across Brazilian biomes: A multi-season study.