Traffic-related impacts on air quality around student housing in Malang, Indonesia

Urban air pollution from traffic emissions poses a significant risk to students residing in student communal housing (SCH) near major roadways. This study investigates the impact of peak hour traffic on ambient air quality around SCH in Malang City, focusing on carbon dioxide (CO₂), total volatile organic compounds (TVOC), and fine particulate matter (PM2.5). Measurements were taken at 40 SCH locations during both daytime and nighttime peak hours. The study employed Geographic Information Systems (GIS) for spatial modelling to visualise pollutant distribution and used linear regression to develop a distance recommendation model. The results revealed a strong correlation between CO₂ and TVOC concentrations and traffic volume, whereas PM2.5 levels were more influenced by atmospheric conditions. The air quality index (AQI) classification indicated a shift toward "moderate" pollution levels during the night, particularly in dense urban areas. Indicative empirical regression modelling suggested setback distances of approximately 280 m for PM2.5 and 1,500 m for CO₂. In comparison, an anomalous result of 9,000 m for TVOC highlights significant modelling uncertainty, likely caused by confounding non-traffic sources. Despite its limitations and the need for further validation, this study contributes valuable, policy-relevant insights for urban planning, especially concerning SCH or resident zoning. The findings underscore the necessity of considering both emission intensity and microclimatic factors in residential planning near major roads

Assessing the influence of laterite soil mining on land use and land cover change in sub-Saharan Africa: The case of northern Ghana

Laterite soil is essential in the construction industry, especially in road and building construction. The practice of abandoning borrow pits after mining laterite soil in the Northern Region of Ghana has resulted in land degradation, as well as loss of vegetative cover and biodiversity. This study assessed the land cover (LC) changes in Northern Ghana from 2002 to 2022 to highlight how laterite soil mining has altered the Guinea Savannah Landscape. Landsat images for three selected years (2002, 2012, and 2022) were analysed using SEPAL, ArcGIS, and QGIS. The images were classified into eight LC classes: woodland, shrub/grassland, cropland, bare land, built-up, laterite (gravel) pit, floodplain, and water bodies. It was found that borrow pits increased by 16.61 km2 over the two decades. Croplands and Shrub/grasslands were identified as the most affected classes, with direct LC losses of 11.38 km2 and 7.16 km2, respectively. Additional indirect losses were attributed to agricultural expansion due to the reduction in cropland areas. It is concluded that laterite soil mining, driven by urbanisation, has a dire impact on vegetation cover and local livelihoods due to unsustainable mining practices. It is recommended that development control managers utilise the findings of this study to devise strategies for managing laterite soil mining and promoting sustainable mining practices to meet the targets of SGD 15

A GIS-based mapping of land use changes and atmospheric gaseous composition in marble quarries of Kajiado County, SW Kenya

Mining activities in the Kenyan Marble Quarries (KMQ) are a potential source of atmospheric pollution, raising health concerns for the local population. This study aims to examine the extent to which marble mining contributes to atmospheric trace gas concentrations, using remote sensing and GIS-based machine learning techniques to map and analyse gaseous compositions. The investigation covers KMQ and Kajiado town, spanning 342 km2, and examines changes in patterns of land use and land cover (LULC), climate variables, and gaseous pollutants over five years (2019–2024). Sentinel-5P data for SO2, NO2, CO, O3, and CH4 were processed using Google Earth Engine, and LULC changes were detected through Supervised Vector Machine classification. Climate data were obtained from NASA Power. The results indicate that mining and agriculture are the dominant land uses, and that atmospheric gases are relatively uniformly distributed across the area. Strong climatic influences were observed: humidity, wind, precipitation, and solar radiation show varying correlations with trace gas concentrations, which are consistently higher during the dry season. Overall, the findings suggest that marble mining contributes minimally to the levels of the analysed gases, with vegetation clearing and agricultural activities also serving as significant drivers of gaseous variation across the region

Exploring technology acceptance factors for improving waste management: Lessons from Bandung waste bank

Waste management in urban areas of developing countries faces numerous challenges, including high waste generation, inadequate infrastructure, and low public engagement. Community-based initiatives such as waste banks have emerged as a promising solution. However, their effectiveness depends on technology adoption to ensure accurate data and efficient operations. This study aims to explore the factors influencing the adoption of the SMASH application in waste banks in Bandung, Indonesia, using the Technology Acceptance Model (TAM). A qualitative case study approach was applied through focus group discussions and semi-structured interviews with waste bank managers, government officials, and application developers, complemented by document analysis and selected closed-ended questions. The findings indicate that perceived usefulness, perceived ease of use, and intention to use are relatively high. However, actual system usage remains low, with only a small proportion of waste banks actively applying the system. Barriers include limited digital literacy, lack of mandatory regulation, insufficient training, and technical issues such as the need for manual price updates. The study concludes that while TAM is valid in explaining adoption intentions, contextual factors significantly influence actual usage. Strengthening regulation, integrating digital systems, and providing continuous technical support are essential to improving technology adoption in waste banks

Sustainable practices of fabric waste among small-scale garment enterprises in the Kumasi metropolis

In recent years, fabric waste has become an important sustainability issue that raises concerns and attracts attention from stakeholders in the fashion industries and the media. Over the past 15 years, the production and consumption of clothing have increased substantially, driven by the rise of demand for fashionable style and the proliferation of fast fashion. This study explores the fabric waste generated by the garment operators within the Kumasi metropolis. A qualitative research design, guided by a phenomenological approach was employed. Data were collected from six zones using purposive sampling technique to select respondents. Interviews and observations served as the primary data collection methods, and data were analysed thematically using NVIVO software. The findings reveal that the use of single-ply and bulk-ply cutting techniques in garments construction led to the generation of tons of fabric waste, particularly among small-scale garment producers. It is recommended that garment operators adopt effective strategies for reusing and responsibly disposing of fabric waste. Furthermore, the use of biodegradable fabrics is encouraged, as they have a lower environmental impact.

Coagulation process optimization for turbidity removal improvement at the Teluk Buyung WTP using Response Surface Methodology with Box-Behnken Design

. The effective operation of the coagulation process in the water treatment plant (WTP) is essential in determining the overall performance of the subsequent process. The coagulant dose is critical in affecting coagulation performance. Due to the fluctuations in raw water quality and the infrequent use of jar tests, Teluk Buyung WTP improperly implemented the coagulant dose, which prompted this investigation. This study aimed to identify the optimum coagulant type and develop an optimization model based on the selected coagulant. The optimum coagulant type was determined in the pre-liminary study, with Polyaluminium chloride (PAC) selected as the coagulant that achieved turbidity removal up to 99.81% at a dose of 40 mg/L and a cost-effective production cost of 4.6 x 10-5 USD/liter. The optimization process was conducted by developing a coagulation process model using PAC as the selected coagulant, with critical factors affecting the process including pH, turbidity concentration, and coagulant dose. The coagulation process optimization was performed by using response surface methodology (RSM) with a Box-Behnken design (BBD). The optimal conditions of PAC in the desirability test resulted in turbidity removal of 99.94% with a PAC dose of 150 mg/L, pH of 7.14, and a residual of 0.04%. The optimization of the coagulation process yielded a quadratic model with R2 of 0.996, an R2 prediction of 0.983, and a significant lack of fit test (p = 0.28). The findings of this study can be further implemented to improve turbidity removal in the coagulation process at the Teluk Buyung WTP

Comparative analysis of water quality models for the Cibarani Irrigation Channel using WASP and QUAL2Kw

Urban growth poses significant challenges to environmental quality, particularly through water pollution in river systems. This study investigates the water quality of the Cibarani Irrigation Channel, part of the Cikapundung River system in Bandung City, which is polluted by domestic wastewater and runoff. Rapid population growth and subsequent urban expansion have significantly deteriorated the water quality, affecting local communities that rely on the channel for fish farming and washing. Field tests showed that water quality failed to meet Class II standards, particularly for Dissolved Oxygen (DO), Ammonia (NH3), and Total Phosphorus (TP), as specified in Indonesian Government Regulation No. 22 of 2021. These findings emphasize the necessity for tools that can effectively support the development of pollution management strategies. This study compares the effectiveness of two water quality modeling tools, QUAL2Kw and WASP, in simulating water quality dynamics. The QUAL2Kw model demonstrated higher accuracy in predicting DO and NH3 concentrations, making it a more reliable tool for pollution control. Continuous model calibration is necessary to improve water resource management and mitigate pollution risks. The findings advocate for using QUAL2Kw in water pollution control strategies, highlighting its precision and its role in supporting sustainable environmental management policies

Malaria risk mapping in the Sahel Region of Nigeria: A geospatial approach

Malaria remains a major public health challenge in Yobe State, Nigeria, with transmission patterns influenced by climatic, socio-economic and environmental factors. Understanding the spatial and temporal dynamics of malaria prevalence is crucial for effective intervention and policy planning. This study examined the trends, seasonality, and spatial variations in malaria prevalence across different ecological zones in Yobe State, providing insights into the impact of climate variability and other risk factors on malaria transmission. A geospatial approach was employed, utilizing malaria incidence data from Yobe State Government’s Epidemic Data Repository and health facilities across three ecological zones: the Sudan Savanna Zone (SuSZ), the Sahel Savanna Zone (SaSZ), and the Transition Zone (TZ). Temporal trends were analyzed using regression models, while spatial patterns were examined through hotspot analysis to identify high-burden areas. Findings revealed significant spatial and temporal variations in malaria prevalence. While malaria incidence showed no strong temporal trend in SaSZ (R² = 0.06) and TZ (R² = 0.04), Sudan Savanna Zone exhibited a notable increasing trend (R² = 0.77), suggesting a worsening malaria burden. Seasonal peaks in malaria cases aligned with the rainy season, emphasizing the role of climate in transmission. Spatial analysis identified persistent malaria hotspots in urban centers such as Gashua, Damaturu and Fika, where high population density and environmental factors contribute to transmission. These results underscore the need for climate-informed malaria control strategies, including enhanced surveillance, early warning systems, and targeted interventions in high-risk areas. Sustainable malaria control efforts must integrate climate predictions, improved healthcare access, and promote community engagement to prevent periodic resurgence and ensure long-term elimination goals are met

Mobility paradox in compact cities: Rethinking energy equity in tropical informal settlements

Informal settlements in tropical urban areas present a complex paradox in energy performance: although characterized by compact urban form, they often exhibit significant thermal inefficiencies, inadequate daylighting, unsustainable material choices, and constrained spatial walkability. This study examines the multidimensional energy and mobility performance of buildings within the dense kampung area of Notoprajan, Yogyakarta, using an integrated analytical framework encompassing operational energy consumption, embodied energy assessment, spatial daylight autonomy (sDA and cDA) evaluation, and walkability metrics. Drawing on empirical field data and advanced digital simulation methods, this research reveals that high urban density does not inherently guarantee energy efficiency, thereby challenging conventional assumptions about compact urban development. Operational energy consumption in small-scale hospitality establishments was found to be nearly three times higher than that of single-family residential units, while material composition demonstrated profound influence on embodied energy profiles across the settlement. Critically, only 6% of surveyed buildings achieved the minimum sDA₃₀₀,₅₀% standard, and 18% met the cDA₃₀₀,₅₀% threshold, underscoring severe daylighting deficiencies. These findings underscore the imperative for passive design strategies, material substitution approaches, integrated spatial planning interventions, and enhanced pedestrian infrastructure to achieve sustainable retrofitting and promote energy equity in informal tropical urban contexts

Enhancing thermal and visual comfort through sun shading and glazing: A case study of Pusgiwa building, Universitas Indonesia

This study examines the relationship between the building envelope and the indoor environment quality, with a specifical focus on visual and thermal comfort. Factors contributing to visual comfort include illuminance and light distribution, while thermal comfort is primarily influenced by air temperature. The research centers on the north façade of the Educational Building at the University of Indonesia, Pusgiwa, particularly the 4th floor classroom, to evaluate how the sun-shading system and glazing materials influence lighting and temperature conditions. By analyzing the existing design and materials, the study investigates potential interventions to enhance illuminance, daylight availability, and operative temperature within the classroom. The methodology includes calculating solar angles and simulating various sun-shading and glazing material scenarios using Rhinoceros and Grasshopper software. The results indicate that installing horizontal, multi-layered overhang shading with optimal spacing can increase daylight availability and reduce indoor air temperature. Furthermore, the use of materials with a low U-Value and Solar Heat Gain Coefficient (SHGC), such as Low-E double glazing, is recommended to further improve indoor environmental quality. These findings provide valuable insights and recommendations for enhancing visual and thermal comfort in both existing and future buildings at Pusgiwa and similar facilities