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MANGROVE: Mapping and Analyzing the Geomorphological Roles of Mangrove Vegetation and its contribution to erosion control for sustainable coastal development in Baganga, Davao Oriental
No full textCoastal geomorphology in typhoon-prone regions of the Philippines is increasingly threatened by erosion and shoreline retreat, compounded by population growth, anthropogenic pressures, and the degradation of mangrove ecosystems. Mangrove forests, due to their sediment-trapping capacity and wave attenuation function, serve as natural buffers that enhance shoreline stability. This study assesses the geomorphological role of mangroves in mitigating coastal erosion along the shoreline of Baganga, Davao Oriental. Multi-temporal satellite imagery from 2000 to 2025 was analyzed to quantify changes in mangrove distribution and shoreline position. Mangrove coverage was mapped using the Post-Classification Change Detection, which works by carefully comparing each image pixel by pixel to detect changes in land cover types, such as mangroves, across different layers, often requiring the classifications to be resampled to a common resolution and grid to ensure accurate comparisons. Shoreline dynamics were assessed using the Digital Shoreline Analysis System (DSAS), applying Net Shoreline Movement (NSM), End Point Rate (EPR), and Linear Regression Rate (LRR) to evaluate patterns of erosion and accretion
Estimation and modeling of total suspended solids of Davao River: Basis for sustainable resource management
No full textWatersheds play a significant part in ecological and hydrological balance; however, natural phenomena and anthropogenic activities continue to threaten this harmony. The quality of the riverine environments can be measured in terms of the water quality parameters such as Total Suspended Solids (TSS). This study aimed to estimate the TSS impacts of TSS by Land Use and Land Cover (LULC) changes of Davao River from 2016 to 2023 and forecast in 2030 and 2050 utilizing Cellular Automata-Artificial Neural Network through QGIS and identify trend using Mann-Kendall Test. Based on the results, the 2030 and 2050 predictive models produced a Kappa coefficient of 0.94 and 0.89, respectively. The 2016 to 2023 LULC percent change revealed that built-up, cultivated and High TSS areas increased to 5.83, 38.18 and 48.23, respectively while forest and shrublands decreased by 12.05 and 11.43, respectively. The study showed increasing trend for 14 water monitoring stations but no trend for stations 3d, 4a, and 10 from 2013 to 2023. Predictions revealed that all stations are above threshold except stations 7, 9 and 10 in 2030, while stations 7 and 9 in 2050. Recommended mitigation includes leveraging Nature-based Solutions with engineering measures, addressing root causes, and better policy
Jump-preserving estimation and structural break detection in nonparametric regression models with missing covariates
No full textNonparametric regression analysis has broad applications. In some
cases, the regression function with jumps (i.e., the regression
curve is discontinuous) seems to be more appropriate to describe the
related phenomena. A number of methods exist for estimating
discontinuous curve, most of which are based on complete data, which
is unrealistic in many practical situations. In this paper, we
consider estimating discontinuous nonparametric model with covariate
with missing values. Based on inverse selection probability weighted
and jump-preserving techniques, a jump-preserving estimation
procedure is proposed. The proposed method is capable of
automatically accommodating possible jumps in the nonparametric
function, without the requirement of prior knowledge regarding the
number and locations of jump points. The proposed estimator for the
discontinuous regression function is shown to be oracally efficient
in the sense that it is uniformly indistinguishable from that when
the selection probabilities are known. Furthermore, it is proved
that the fitted curve by this procedure is consistent in the entire
design space. Numerical simulation also indicates the finite sample
performance of this method is efficient and reliable
Integration of solar PV in a Norwegian energy system, navigating the trade-offs between land use and solar power production
No full textTo achieve our climate goals, the energy sector is increasingly shifting towards zero-emission sources, mainly renewable energy sources (RES), with solar power playing a pivotal role on the global stage. Nevertheless, many forecasts for future energy systems concentrate mainly on techno-economic aspects, which may not sufficiently capture the complexities associated with the deployment of renewable energy technologies. In particular, the expansion of RES has in recent years sparked tensions related to land use for new energy infrastructure, as well as growing concerns for biodiversity and environmental degradation. This study investigates the land use implications of different renewable energy system configurations in Norway, highlighting key trade-offs between land use requirements, costs, and emissions. The research specifically investigates potential pathways for solar photovoltaic (PV) in the Norwegian energy system, aiming to assess its potential future role within the broader Nordic context. Our findings shows that achieving national climate targets could require land use ranging from 18.43 to 5149 km2, depending on the selected scenario and land use metric. While onshore wind is initially favored due to high availability and a low physical footprint, including considerations such as spacing requirements and access roads significantly increase total land impact. Conversely, solar PV systems demand greater installed capacity, raising the physical footprint. Offshore wind and rooftop PV systems offer minimal direct land use but involve higher costs and technical constraints. The analysis underscores the importance of consistent land use metrics, integrated spatial planning, and the inclusion of socio-economic factors in energy system modeling. As the expansion of RES increases land demand, careful planning is essential to balance ecological preservation, public acceptance, and climate goals
Personal air purifier fans as adaptive cooling in Qatari offices: Insights from a mixed-methods field study
No full textIn hot-climate regions like Qatar, overcooling in centrally air-conditioned offices often leads to occupant discomfort and increased energy use. This study explores the effectiveness of personal air purifier fans (Dyson TP-09) as an adaptive cooling strategy in seven office buildings in Doha across autumn, winter, and spring. Using a mixed-methods longitudinal design, we collected 24,373 environmental data points and 411 occupant survey responses. Fans were used adaptively, with a behavioral threshold around 25°C. Logistic regression confirmed a strong temperature-dependent fan use pattern, while moderate speed settings were preferred due to concerns about noise and draft. Fan usage improved perceived thermal comfort, particularly in counteracting overcooling, though usage was limited (34.6% of observations). Subjective thermal sensation was generally neutral to slightly cool, with many preferring slightly warmer conditions. Air quality remained within healthy limits; VOCs were the most common pollutant, and sensor data from fans closely aligned with independent loggers. Classification tree analysis showed that thermal preference, adaptive behaviors, and air quality perceptions were stronger predictors of overall comfort than fan-specific variables. The findings support the use of personal fans as a low-energy, occupant-centric solution to improve comfort and indoor air quality in hot-climate office environments
Thermal performance evaluation of double-skin façade in mid-rise wooden building based on field measurement
No full textThe thermal performance of a double-skin façade in Japan’s first mid-rise purely wooden fire- resistant building was evaluated through a year-long field survey. In October, the solar heat gain coefficient for the entire window was measured at 0.46 with the blinds open and 0.11 when the blinds were closed. The design featured a wooden frame structure with a large volume and an offset inner skin layer, which helped shade the inner glazing from May to August. The wooden columns and beams exhibited high thermal performance even without thermal insulation, with a thermal transmittance of 0.22 W/(m²·K), accounting for the effects of the double-skin layer. In contrast, the single-skin façade on the 8th floor, made of Low-E double glazing, had a thermal transmittance of 1.85 W/(m²·K). The overall thermal transmittance for the whole window of the double-skin façade on the 4th floor was recorded at 1.66 W/(m²·K)
0-Spatial distributions of indoor radon exposures- from city to regional levels
No full textThis study investigates the spatial and vertical distribution patterns of indoor radon (Rn- 222) in China’s Yangtze River Delta (YRD) region by integrating field measurements, meta- analysis, and spatial modeling. Field monitoring across ten campus buildings revealed a general decline in radon concentration with increasing floor height, from 55.1 Bq/m³ on ground floors to 21.9 Bq/m³ on the ninth floor. However, a distinct bimodal concentration profile was observed between the fourth and eighth floors, suggesting the involvement of non-gravitational transport mechanisms. Meta-analysis of 3,800 georeferenced samples from 41 cities demonstrated a pronounced west-to-east spatial gradient, with concentrations ranging from 90.1 Bq/m³ in Anhui to 14.8 Bq/m³ in Shanghai. This gradient was associated with synergistic influences from geological background, industrial emissions (e.g., +1.2 Bq/m³ per 1000 tons of particulate emissions), and climatic factors (e.g., -32.94 Bq/m³ per °C increase in temperature). A key finding is the establishment of a dual-mechanism model: in cities with low background concentrations, radon levels increased by 1.56 Bq/m³ per meter of building height, implicating construction materials as a major source; conversely, in high-concentration cities, building parameters exhibited negligible effects, with geological background controlling exposure. Low-rise structures (6,000 Bq/m³) exhibited concentrations 40% higher than those in taller buildings. These findings highlight limitations in current radon standards, which largely overlook vertical heterogeneity and regional mechanistic differences. We propose height-differentiated ventilation protocols, geology-informed building codes, and targeted industrial emission controls to mitigate region-specific exposure risks
Gas Phase Air Cleaner Technologies: Abilities and Limitations
No full textAir cleaning technologies like activated carbon (AC) filters and photocatalytic oxidation (PCO) process are commonly used in commercial air purifiers, with some anecdotal evidence supporting their effectiveness. These technologies, when functioning efficiently, can enhance indoor air quality (IAQ), reduce chemical contaminants, and lower energy use by minimizing the need for high outdoor air exchange rates by mechanical ventilation systems. However, TiO2-based PCO filters often show low to moderate activity in degrading common volatile organic compounds (VOCs), such as alkanes, alcohols, ketones, aromatics, and aldehydes, under HVAC-like conditions. Furthermore, limited studies have investigated PCO performance when treating complex VOC mixtures, where interactions between compounds can alter degradation pathways and by-product formation. A significant challenge in PCO systems is catalyst deactivation over time, which leads to a decline in performance, yet this issue remains underexplored. In contrast, AC filters have long been used for VOC removal, and their effectiveness depends on factors such as AC properties, surface functional groups, and the properties of VOCs, as well as operational parameters. This paper presents a review of these two technologies. The abilities and limitations of each technology are discussed. The impact of each influencing factor on the quality of air and energy consumption will be presented
The conditions of office environment and perceived evaluation of workers difference by season: Insights from field surveys in summer and winter in Tokyo
No full textCreating a thermal environment where workers can work comfortably is essential for offices. Considering seasonal variations in office environments and gender differences in comfort is essential for improving worker comfort. This study analysed the relationship between the office environment and worker comfort in multiple seasons. Measurement surveys were conducted in 15 offices in 11 buildings in Tokyo in the summer of 2022 and the winter of 2023, and questionnaire surveys were conducted with 56 workers. The results of the measurement data showed that the average indoor air temperature, relative humidity, and CO2 concentration in all offices were respectively 25.3°C, 60.6%, and 556 ppm in the summer, and 24.6°C, 38.6%, and 852 ppm in the winter. Additionally, the neutral temperature for male workers in summer was found to be 26.5°C. Furthermore, male workers tended to feel less comfortable as the air temperature increased in the summer, while female workers tended to feel less comfortable as the air temperature decreased. In addition, seasonal differences in office workers’ sensitivity to the thermal environment were indicated. The results of this study provide fundamental knowledge about the conditions of the office environment and the perceived evaluation of the office environment by workers in multiple seasons