Despite the growing availability of Earth observation data, African countries like Mozambique lack an integrated, long-term approach for the combined assessment of LULC change and its caused vegetation stress. This approach is necessary for supporting sustainable land management practices. This study addresses this gap by incorporating advanced remote sensing techniques to monitor combined trends for land cover and vegetation dynamics in Mozambique from 2024 to 2024. This research involved the use of Landsat 8 OLI/TIRS data processed in GEE for LULC classification using RF classifier, NDVI and FVC to evaluate vegetation health in the area. The results reveal that the urban areas have been expanding by 60% since 2014. Forest, which covers 80% of the country's land cover, initially fluctuated but then recovered after 2016. Agricultural land peaked in 2020 but collapsed after it up to 69% by 2024, indicating potential degradation. Mangroves declined by 55% after 2017, while bare land expanded after 2022. NDVI and FVC trends aligned with the land cover changes, with higher values in the northern densely vegetated areas, and lower values in the urban and bare lands of the country. FVC acted as an early warning system and detected pre-deforestation stress that caused forest loss in 2015. The integration of FVC and NDVI acts as a strong framework for tropical land systems monitoring. The findings provide practical guidance for coastal conservation, agricultural restoration, and sustainable urban planning in Mozambique and contribute to SDGs for zero hunger, sustainable cities, and life on Land.

Non-engineered municipal solid waste landfills pose significant threats to the surrounding environment. Therefore, the purpose of this study was to assess the concentrations of toxic heavy metals in groundwater surrounding the Botshabelo non-engineered landfill site in South Africa. Four groundwater samples were collected randomly during early summer season. The levels of toxic heavy metals in groundwater sources were determined using inductively coupled plasma mass spectrometry and ion chromatography. The concentrations of heavy metals were as Al (0.08), As ( Mn > Al = U > Ba > Mo > B = Fe > Cr = Cu = V > Zn while As, Sb, Cd, Co, Ni, Pb, and Se were below limit of detection. When compared to the national standards (SANS and DWAF) and international standards (WHO), the mean values of toxic heavy metals such as Mn and U were above all drinking water standards (SANS and WHO) and irrigation standards (DWAF) while Mo was above DWAF acceptable standard for irrigation. To lessen water contamination in the surrounding area, better waste management procedures and well-designed landfill sites must be built. It is also recommended that proper segregation of biodegradable, non-biodegradable and recyclable materials such as plastics and metals be implemented. The outcomes of the study may assist local government bodies in determining appropriate treatment techniques and developing waste management policies and strategies.

Groundwater vulnerability to leachate contamination is a significant public health concern, particularly in developing countries where non-engineered landfill sites are common. These sites pose a huge risk of contaminating groundwater resources used for drinking. The study employed a comparative case study research design utilising the GOD and RTt vulnerability assessment methods to evaluate the risk of leachate contamination at the Botshabelo non-engineered landfill site. Field data, including depth to groundwater and nitrate concentration, were collected using a Solinst 101 water level meter, and groundwater samples were analysed at the University of the Free State Institute for Groundwater Studies. Results showed that the GOD method indicated a very low vulnerability with an index of 0.08, while the RTt method suggested a moderate vulnerability with an index of 53. Validation using nitrate concentration yielded a mean of 0.33 mg/ℓ, confirming very low contamination levels which aligned closely with the GOD model. The rise in values observed in RTt was attributed to the shallow depth of groundwater and slope sensitivity, while the relatively flat trend in GOD findings was linked to the dominance of confining lithological layers. The findings highlight the importance of selecting assessment methods that are well-adapted to local conditions such as soil type, lithology, precipitation, and slope. Although the study indicated low contamination risk, ongoing monitoring and additional water quality testing are recommended to ensure the continued safety of groundwater for consumption.

Introduction: This study aimed to assess the environmental health risks of heavy metal pollution in groundwater around non-engineered landfills in Botshabelo, South Africa. Materials and Methods: Inductively coupled plasma mass spectrometry and ion chromatography were used to analyze heavy metals in groundwater collected during the dry and wet seasons. Ecological risk factors and potential ecological risk indices were used to assess ecological risks. A human health risk assessment method was used to assess potential public health risks. Results: The mean concentrations of heavy metals were as F(0.29) > Mn(0.24) > Al(0.08) > Ba(0.06) = U(0.06) > Mo(0.04) > Fe(0.03) = B(0.03) > Cr(0.02) = Cu(0.02) > Zn(0.01) mg/l and F(0.21) > Mn(0.12) > B(0.06) > Fe(0.02) > Al(0.01) mg/l in wet and dry season respectively. Generally, only Mn, Mo, and U were above the acceptable standards for drinking water. It was only Mo that posed a high potential ecological risk during the wet season, whereas in the dry season, all heavy metals showed low ecological risk. The potential ecological risk index revealed a significantly high and low ecological risks during wet and dry season respectively. There was a potential non-carcinogenic risk of Mo, U, and Cr during the wet season for all population groups. The study also revealed that Cr has an acceptable carcinogenic risk and no possibility of carcinogenic risks during the wet season for children and adults. Conclusion: It can be concluded that there is potential heavy metal pollution of groundwater migrating from Botshabelo non-landfill.

Changes in land use over space and time are key drivers of water pollution. However, current studies on landuse-water-quality relationships in small watersheds are insufficient to support regional development. Comparative research across large-scale watersheds can better inform water environmental protection, yet such studies remain limited. This study analyzes data from 100 sampling sites across four major watersheds in Zhejiang Province. Using multivariate statistical methods and redundancy analysis, it investigates the effects of land use patterns on water quality across seasons and spatial scales. Results reveal pronounced spatial and temporal heterogeneity among watersheds. In the Qiantang River Basin, pH remains relatively stable, while other indicators vary considerably. Reduced downstream flow, particularly during the dry season, promotes the accumulation of pollutants. During the wet season, water quality in the Feiyun and Ou River Basins is more strongly influenced by geogenic processes related to land use. The Feiyun River Basin, dominated by forests and grasslands, is susceptible to rainfall-induced erosion. In the Ou River Basin, land reclamation alters hydrodynamics and salinity, and precipitation intensification further intensifies land-use impacts. At the spatial scale, the 2000m buffer exerts the strongest influence on water quality in the Feiyun, Ou, Yong, and Jiao River Basins, likely due to longer runoff pathways integrating multiple pollution sources. In contrast, in the Qiantang River Basin, the 500-m buffer is more influential during the dry season, while larger buffers dominate in the wet season. Overall, this study provides a scientific basis for watershed-specific land-use planning and water-quality protection, emphasizing policies tailored to distinct spatiotemporal dynamics.

Water shortages remain a significant challenge in Mangaung Metropolitan Municipality (MMM), affecting socio-economic development, agriculture, and residents’ well-being. Frequent water interruptions have also contributed to negative perceptions about the quality of water supplied in Bloemfontein. This study aimed to evaluate existing water infrastructure and assess water quality provided by Vaal Central Water and MMM, while also examining community perceptions. A mixed-methods approach was applied in two phases. The first phase used a questionnaire (n= 115) to gather quantitative data on public perceptions, while the second involved laboratory analysis of water samples from both supply sources. Advanced techniques, including spectrophotometry, ICP-MS, ICP-OES, and microbial tests, were employed. Findings revealed a link between perceived and measured water quality, particularly in terms of colour and turbidity. Elevated zinc and microbial levels exceeded SANS 241 standards in some cases. Overall, infrastructure performance is adequate, but maintenance gaps and poor communication contribute to public dissatisfaction.

In arid environments, shallow hypersaline lakes are critical to regional ecological stability. However, accurately monitoring suspended particulate matter (SPM) in these waters remains challenging for conventional optical remote sensing. The primary obstacles include signal saturation during high-turbidity events, interference from bottom reflectance in shallow zones, and insufficient satellite revisit frequency. To address these limitations, we developed a physics-informed machine learning (PIML) framework to isolate the hydrodynamic drivers of SPM in Ebinur Lake. Unlike purely data-driven approaches, we constructed a feature space grounded in wave mechanics, incorporating variables such as bottom shear stress, effective fetch, and temporal memory into a Random Forest regressor. Crucially, we employed physically downscaled ERA5 instantaneous wind gusts to capture the nonlinear threshold behavior of sediment entrainment. The model demonstrated robust performance, achieving a five-fold cross-validated R-2 of 0.91 (RMSE = 81.14 mg/L; RRMSE = 32.3%) while overcoming optical saturation issues. Feature attribution analysis identified instantaneous wind gusts as the dominant factor (>90% importance), significantly outperforming mean wind speed. We further quantified a critical physical threshold of similar to 12.0 m/s, confirming that sediment resuspension is an energy-limited process triggered by extreme wind events. Additionally, the model functioned as a "virtual geostationary sensor," successfully reconstructing hourly SPM dynamics typically missed by polar-orbiting satellites. This study presents a transferable and physically interpretable paradigm for high-frequency water quality monitoring in data-scarce inland lakes.

The coastal counties of Zhejiang Province, China, are important for economic development, marine economy, and nature conservation. This study aimed to support sustainable land-use policies through the planning and management of 35 counties, using official land-use data from 1990 to 2020. Spatial analysis methods included transition matrix, land-use intensity, landscape-pattern indices, centroid shift, and standard deviation ellipses. Results showed a “north-cropland, south-woodland” structure, together over 75% of the area. Construction land expanded steadily to 20%, mainly from cropland, woodland, and grassland (87% of outflows). Inflows mainly involved construction land, woodland, and cropland (91%). The wetland was dominated by the river channel and mudflat. Mudflat and beach made up 94% of outflows; reservoir and pond, 78% of inflows. Land-use intensity increased overall, with Pinghu highest. Grassland centroid shifted 38.74 km. Ellipses showed directional changes. Land-use diversity and spatial complexity increased, reflecting intensified human influence and offering a basis for sustainable planning and ecological restoration.

Pollution from human activities causes water contamination that impacts aquatic ecosystems and threatens public health while endangering environmental sustainability. This highlights the need for water restoration and biodiversity protection using indigenous, low-cost, and sustainable technologies. Adsorbents currently used in wastewater remediation are evolving from traditional materials to more cost-effective options. This study is focused on tracking advancements and the evolution of adsorbents while maintaining ecological sustainability, and to identify gaps requiring further research. The review consolidated the ongoing work on adsorbents collected from Google Scholar and dated 2020-2025 to evaluate emerging trends and developments in low-cost adsorbents. The evolution of these materials demonstrates remarkable adaptability and multi-functionality, enabling low-cost adsorbents to address a wide range of water quality issues efficiently; however, there is a need to maintain minimal environmental impact. Multifunctional adsorbents derived from biomaterials, nanotechnology, and stimuli-responsive materials show promising potential for simultaneous removal of multiple pollutants. These adsorbents also facilitate tailored recycling and secondary applications of exhausted materials, thereby reducing secondary pollution. The integration of biomaterials, nanotechnology, and stimuli-responsiveness marks a significant advancement in creating more versatile and effective wastewater treatment technologies capable of tackling diverse challenges. Their notable features—such as high surface area for adsorption, responsiveness to environmental stimuli, and photocatalytic abilities—enable low-cost adsorbents to effectively eliminate pathogens, as well as organic and inorganic contaminants from wastewater. The study highlights current challenges related to real-world pilot studies, secondary pollution, and scaling up. It concludes that integrating low-cost adsorbents with enabling technologies can be the key to their successful deployment in practical pilot settings that are easy to scale up, ultimately supporting ecosystem health and enhancing ecological resilience.

Urban community gardens are valued for promoting sustainable food production, yet the accumulation of toxic heavy metals in city soils can present both ecological and public health risks. Therefore, this study was aimed at assessing the environmental and health risks of toxic heavy metals in community gardens soil contaminated by an industrial fire hazard in New Brunswick, Canada. Both top and subsoil soil samples were collected at Carleton community garden. The collected samples were examined for toxic heavy metals using inductively coupled plasma optical emission spectrometry and inductively coupled plasma mass spectrometry. Ecological risks were evaluated through the ecological risk factor and the potential ecological risk index, while human health risks were determined using a standard human health risk assessment approach. The mean concentration of Pb, Zn, Cu, and Sn exceeded permissible limits when compared to the Canadian soil quality guidelines and upper continental crust values. Findings from the ecological risk assessment showed that all metals were associated with low risk, except for nickel, which posed a high ecological risk across both soil layers. PERI results revealed a low overall ecological threat. The human health risk analysis indicated that children could face non-carcinogenic and carcinogenic risks from As exposure, while adults were not at risk from any of the studied metals. These findings identify arsenic as the primary contaminant of concern, with children representing the most vulnerable population, emphasizing the necessity for targeted mitigation strategies and protective measures to reduce their exposure. The results of this study can inform interventions aimed at safeguarding both environmental and public health, while also raising awareness about the presence and risks of toxic heavy metals, ultimately contributing to the protection of human health and the broader ecosystem.

Groundwater constitutes a significant source of freshwater in the global water resources, especially in arid and semi-arid regions like the Modder River catchment. However, the Modder River catchment is facing over-abstraction and inefficient management practices. This study presents a predictive expert-based system for assessing groundwater sustainability at the Modder River Catchment. The system integrates hydrological data from the Modder River Catchment including pump rate and storage, to calculate the Aquifer Sustainability Index (ASI) for individual boreholes. Additionally, groundwater depletion was modeled over a period of 50 years and visualized on an interactive spatial map across the catchment using folium Python package. The ASI result shows that 26 of the 51 boreholes are sustainable and visualized on the interactive depletion map. The Groundwater depletion model results show 25 of the 51 boreholes are at risk of depletion after 50 years. The reward system shows that approximately 13 boreholes have less than R10,000. This approach can be implemented for sustainable groundwater management on boreholes with similar challenges.

The sustainability of aquifers, vital sources of freshwater, faces increasing threats due to over-extraction and contamination. This paper proposes a comprehensive approach for aquifer risk management utilizing SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis in Northern Mpumalanga the B60D sub-catchment of the Olifants Water Management Area. By integrating this strategic framework, the study aims to delineate effective strategies for groundwater conservation and demand management. Drawing on interdisciplinary perspectives, the research examines the internal and external factors influencing aquifer sustainability, including hydrogeological characteristics, socio-economic dynamics, and regulatory frameworks. Through SWOT analysis, inherent strengths such as natural recharge mechanisms and weaknesses such as vulnerability to pollution are identified alongside opportunities like technological advancements and threats such as climate change impacts. Based on these insights, a suite of adaptive strategies is formulated, encompassing sustainable abstraction practices, land use planning, community engagement, and policy interventions. Additionally, the paper highlights the importance of stakeholder collaboration and adaptive management approaches in implementing these strategies. Case studies and empirical data are incorporated to illustrate the application and effectiveness of the proposed framework in diverse aquifer contexts. Ultimately, this research contributes to advancing aquifer sustainability by offering a structured methodology for proactive risk assessment and strategic decision-making, thereby fostering resilience in groundwater management practices.

Universally, informal settlements form a major parts of the urban landscape due to urbanisation and upsurge in population. The large population in urban informal settlements leads to a huge accumulation of wastes and the release of chemicals such as heavy metals to the surrounding environment. The aim of the study was to give an overview on the current heavy metal content in soil from Winnie Mandela informal settlement in Gauteng, South Africa and evaluate their possible health implications. Methods: Five soil samples were collected from five different functional areas of the settlement during dry season. A random sampling method was used to collect the samples. A 10 g sample was pulverised to a particle size of less than 200 mesh. To determine the concentration of elements, the samples were analysed by the wavelength dispersive XRF method. The level of pollution was assessed by the use of pollution indices, such as geo-accumulation and enrichment factor. Results: The major elements concentrations decreased as SiO2, Al2O3, Fe2O3, MnO, K2O, TiO2, CaO, MgO, P2O5, and Na2O with SiO2, Fe2O3, P2O5, and TiO2 above their average shale values. The concentration of trace elements was descending as Cr > Ba > Zr > V > Zn > Ni > Cu > Rb > Sr > Co > Pb > As > Y > Sc > Nb > Th > U with V, Cr, Co, Ni, Cu, Zn, As, Zr, Nb, and Pb above their average shale values. Moreover, Cr and V were also above the South African soil screening values. All the pollution indices exhibited the highest value of Cr in soil possibly from anthropogenic activities. A strong correlation was witnessed between pairs of Y–Sr (r = 0.94), Zr–As (r = 0.90), Pb–As (r = 0.92), Pb–Zr (r = 0.95), Ni–Cr (r = 0.89), Sr–Rb (r = 0.85), Nb–Co (r = 0.75), Nb–Rb (r = 0.85), Th–Y (r = 0.87), and U–Zn (r = 0.89). The analysis of variance displayed a significant difference (P < 0.05) of trace elements in soil signifying that the trace elements pollutants in this informal settlement originate from different anthropogenic sources. Possibly, traffic, sewage waste, poor waste management, waste burning, and construction materials may be attributed as the sources of these trace elements. The level of trace elements in soil exhibited a possibility of non-cancer risks to children and adult. For carcinogenic risk, the total cancer risk values in children and adults were also above the acceptable limit signifying a likelihood of cancer risk to the local inhabitants. In this informal settlement, children were at higher risk of both non-cancer and cancer risk than adult. Conclusion: Urban informal settlements impact the environment negatively therefore, there is a need to raise awareness on heavy metal pollution and their possible health effects. The study will serve as a basis for future research on geochemistry and health risk assessment of urban informal settlement’s soil. It will also help to develop guidelines for management of informal settlements environment and protection of inhabitants’ health.

An unlined oxidised sulphide nickel mining tailings storage facility (TSF) at Onverwacht farm, Mpumalanga province, South Africa was constructed within an area underlain by fractured dolerite dykes aquifer. This is known to provide a preferential flow path for migration of toxic pollutants to deeper horizons and the surrounding environment. Subsequently, the possible deterioration of surface and groundwater quality was investigated. From May 2016 until January 2018, 168 water samples collected from supernatant water, boreholes and downstream surface water were analysed for ions and metals of potential concern using ICP-MS, which were then used to determine the impact of the TSF on water quality. Findings from the study indicated that the TSF was a source of pollution, which caused significant deterioration in the quality of groundwater and downstream surface water in the study area. The results revealed concentrations of SO4, Cl, Ca, Mg, Na, CaCO3 and EC in groundwater and downstream surface water exceeded acceptable numerical limits for drinking water in the Water Use Licence, South African National Standards, World Health Organization guidelines for drinking water quality and the background water quality data. Unlike other sulphide TSFs, the Onverwacht facility contained high concentrations of CaCO3 (maximum of 231 mg/L), which was the main distinction between the reduction and neutralisation of heavy metal concentrations, and the absence of acid mine drainage in the area. This study has shown that the geology of an area is a major consideration before siting a mining tailings storage facility in order to reduce possible environmental damages to the surrounding environment.

Assessing the groundwater vulnerability to point source pollution is a very contentious subject amongst researchers. This is because many methods for assessing groundwater vulnerability to pollution have been modified and adapted to suit various contexts of study investigations and conditions. This paper provides an overview of numerous intrinsic groundwater vulnerability methods and how they were modified to improve their specificity, efficiency, and effectiveness from previous studies across different parts of the world. Depending on the context, groundwater vulnerability assessment techniques utilise a range of complex biological, chemical, and physical processes such as in Analogical Relation (AR) and Numerical Model Assessment methods to simple weight-based criterion as in most common parametric methods such as the AVI, DRASTIC, and the GOD method. Each of these vulnerability assessment methods have their strengths and limitations which were reviewed in this paper. Most groundwater vulnerability methods are based on selecting between objective and subjective criterion for assessing the risk of groundwater contamination and their modification to target specific contaminants comes with a huge risk of bias. This paper also highlights the importance of why the validation of groundwater vulnerability assessment methods is critical in affirming the outcomes from groundwater assessment methods.

The accumulation of plastic waste from various sources into marine and inland water is considered a global problem due to its serious impacts on aquatic ecosystems and human health. In the past decade, remote sensing has played an important role in monitoring of plastic pollution in marine and inland water sources and has achieved a series of research results in this field. In this study, a comprehensive review was conducted on the development, opportunities, and challenges of datasets and methods in Marine and Inland Water Plastics Remote Sensing (MIWPRS) monitoring over the past decade, based on the Web of Science (WOS) core database. The results indicated that compared with traditional methods, remote sensing has attracted the attention of scholars due to its advantages. Since 2014, the number of related publications has been increasing year by year, especially in China and the United States, which have achieved tremendous development. The MIWPRS research focus mostly on the use of different satellite remote sensing data and related algorithms to obtain the distribution of plastics in marine and inland water. However, it faces the challenge of lacking subsequent systematic impact assessment models and key pollution prevention measures. In terms of data acquisition, there is a lack of continuous observation models due to the fluidity of marine and inland water. Therefore, MIWPRS has great development opportunities in developing specialized sensors and combining multi-source data with interdisciplinary knowledge such as artificial intelligence (AI) and GIS. It is necessary for us to improve the seasonal migration model of plastics in water and promote the development of MIWPRS towards broader and deeper fields.

The aim of this study was to investigate the causes of building failures in a part of Ilorin. Vertical electrical sounding (VES) was conducted, and 1D inverted resistivity indicates four distinct layers. The first layer is top soil with resistivity values of 16.1 ohm m to 81.1 ohm m and a depth of 0.1 m to 0.3 m. The second layer is clay/silty clay with resistivity values between 12.6 ohm m and 59.6 ohm m and a depth of 1.1 m to 2.8 m. The third geoelectric layer is weathered basement with resistivity values between 5.9 ohm m and 38.4 ohm m and a depth of 1.3 m to 6.2 m, and the fourth layer is fresh basement layer. Four pits were dug to a depth of 1.5 m, and undisturbed soils were collected for geotechnical test. Maximum dry density of the soils falls between 1.73 and 1.84 with an average of 1.90 Mg/m. Dynamic cone penetration test (DCPT) was conducted, and the quantity of blows to achieve 1000 mm (1 m) penetration depth (n) was recorded. DCPT of the soils varies between 89.8 kN/m(2) and 314.3 kN/m(2), with low bearing capacity of 89.8 kN/m(2) to 134.7 kN/m(2) at a depth of 0.1 m to 0.3 m, which is below the recommended minimum value of 150 kN/m(2), and this contributed to the building failures in the study area.

The study monitored the occurrence of emerging contaminants such as acetaminophen, carbamazepine, ibuprofen, triclosan, atrazine, metolachlor, simazine, terbuthylazine, 17-alpha-ethinyl-estadiol, progesterone, testosterone and estradiol in selected wastewater treatment works (influent and effluent) around Bloemfontein during autumn season. Samples collected from influent (n = 3) and effluent (n = 3) were analysed by high performance liquid chromatography. To assess the performance of wastewater treatment works in removing the targeted compounds the removal efficiency (

This study was aimed at monitoring the occurrence and potential sources of emerging contaminants in water sources within the Modder River catchment. Selected water quality indicators were analysed by Hanna multi-parameter meters. Emerging contaminants such as acetaminophen, carbamazepine, ibuprofen, atrazine, simazine, metolachlor, terbuthylazine, 17-alpha-ethinyl-estradiol, estradiol, progesterone, and testosterone were analysed by high performance liquid chromatography mass spectrometry. The sources of emerging contaminants were determined by statistical methods such as Pearson correlation and hierarchical cluster analysis. Results showed that all the sampled water sources have some level of questionable drinking water quality and necessitate some amount of treatment to reduce the contamination before consumption, especially DO, EC, and pH. The 17-alpha-ethinyl-estradiol mean values in rivers (7.79 and 31.55 µg/L), dams (1.83 and 6.90 µg/L), and treated drinking water (0.2 and 0.73 µg/L) were the highest in summer and autumn seasons, respectively. Wastewater effluents, domestic sewage, urban surface runoff, agricultural runoff, and illegal dumping were identified as the possible sources of emerging contaminants pollution. Waste management education, proper application of herbicides, and advance wastewater treatment methods were some of the suggested mitigation strategies. The outcomes may be relevant for environmental protection and water sustainability in the catchment.