Explore the vast range of titles available.

Abstract Individuals in the USA are insufficiently active, increasing their chronic disease risk. Extreme temperatures may reduce physical activity due to thermal discomfort. Cooler climate studies have suggested climate change may have a net positive effect on physical activity, yet research gaps remain for warmer climates and within-day physical activity patterns. We determined the association between ambient temperatures (contemporary and projected) and urban trail use in a humid subtropical climate. At a trail in Austin, TX, five electronic counters recorded hourly pedestrian and cyclist counts in 2019. Weather data were acquired from World Weather Online. Generalized additive models estimated the association between temperature and trail counts. We then combined the estimated exposure–response relation with weather projections from climate models for intermediate (RCP4.5) and high (RCP8.5) emissions scenarios by NASA NEX-GDDP. From summer to autumn to spring to winter, hourly trail counts shifted from bimodal (mid-morning and early-evening peaks) to one mid-day peak. Pedestrians were more likely to use the trail between 7 and 27 °C (45–81°F) with peak use at 17 °C (63°F) and cyclists between 15 and 33 °C (59–91°F) with peak use at 27 °C (81°F) than at temperature extremes. A net decrease in trail use was estimated by 2041–2060 (RCP4.5: pedestrians =  − 4.5%, cyclists =  − 1.1%; RCP8.5: pedestrians =  − 6.6%, cyclists =  − 1.6%) and 2081–2100 (RCP4.5: pedestrians =  − 7.5%, cyclists =  − 1.9%; RCP8.5: pedestrians =  − 16%, cyclists =  − 4.5%). Results suggest climate change may reduce trail use. We recommend interventions for thermal comfort at settings for physical activity.

In warm humid climate regions where majority of the population spend most of the time outdoors, an adequate outdoor thermal environment is crucial. A number of studies on outdoor thermal comfort in warm humid climates were carried out in the past decade. However, most of these studies focused on the formal urban fabric and left the informal urban fabric, where typically 30 to 85% of the population in developing countries resides, unattended. Theoretically, the informal urban fabric structure of towns/cities poses many outdoor thermal environmental challenges, such as lack of air movement, high thermal stress and discomfort. This paper reviews previous research on outdoor thermal comfort in warm humid climates, and, particularly, it focuses on the relationship between outdoor thermal comfort and urban fabric as well as human thermal perception. Regarding the formal urban fabric, this review asserts that the thermal comfort range is higher in warm humid climates than in temperate climates and that thermal indices alone cannot predict thermal comfort; behavioural and psychological adaptation have proven to have a big impact on thermal perception. As for the informal urban fabric, only few studies have investigated the influence of the urban geometry and none has studied people’s thermal perception of the outdoor thermal environment. To conclude, the article highlights practical challenges posed by the informal urban fabric in contrast to the formal urban fabric in terms of structure (morphology).

This study aims to evaluate agreement among subjective thermal comfort, thermal sensation, thermal perception, and thermal tolerance indices, according to pedestrians in downtown Santa Maria, southern Brazil, which has a humid subtropical climate (Cfa). Between August 2015 and July 2016 (three periods), 1728 questionnaires were applied. Evaluation of the dependence of statistical variables was based on gender and age, at three periods of time: August 2015 (864 respondents), January 2016 (432 respondents), and July 2016 (432 respondents). Statistical evaluation was based on Pearson’s chi-square test using RStudio software, and a significance level (α) of 5% for thermal comfort, thermal sensation, thermal preference, and thermal tolerance was used. Results indicated that age and gender affect the relationship between the variables. Thermal comfort and thermal tolerance presented the best correlation and coherence, regardless of age or gender. This study contributes to knowledge on the local microclimate and can contribute to urban planning to implement strategies that improve pedestrians’ thermal comfort.

In humid climate regions, a short period of water deficit, especially during the vegetative growth and tuberization stages, has been found to affect potato plant growth, yield and tuber quality. However, there is still a lack of information on the impact of the water deficit duration. In this study, we examined potato plant growth, yield and tuber quality parameters with plants under 0 to 25 days of water deficit initiated at the beginnings of the vegetative growth stage and the tuberization stage, respectively. We found that for both the vegetative growth and tuberization stages, a longer water deficit duration resulted in no significant change in final plant height but significantly delayed flowering and reduced total biomass, yield, tuber dry matter content and share of large tubers. We estimate that per day of prolonged water deficit, there will be a yield loss of 3.1% and 3.4% for the vegetative growth and tuberization stages, respectively. Similarly, for per liter of irrigation water, there will be a yield increase of 16.3 g and 19.1 g for the vegetative growth and tuberization stages, respectively. Further studies are suggested to examine how supplemental irrigation can be used most effectively to mitigate the impact of water deficit on potato production in humid climate regions.

Due to spatial and temporal heterogeneity in moisture conditions, the responses of arid/humid climate regions (AHCR) to climate change are complex. In this study, we delineated the AHCR of China using information about the balance of the atmospheric water supply and demand collected from 581 meteorological stations over the past 50 years. We also analyzed inter-decadal shifts and linear trends in the AHCR and examined the influence of precipitation and reference evapotranspiration. The results indicate that the semi-arid region expanded significantly over the last five decades, mainly in northwest China, northern China, and the Tibetan Plateau and, by the 2000s, had increased by 33.53% relative to its extent in the 1960s; in contrast, the arid region shrank by 20.75%. The semi-arid region grew mainly because of transfers from the arid region in western China and the sub-humid region in eastern China. The decreased reference evapotranspiration and significantly increased precipitation together contributed to the expansion of the semi-arid region in northwest China and the Tibetan Plateau over the last 50 years. In contrast, the expansion of the semi-arid region in Inner Mongolia and northern China reflects the counteractive influence of decreased reference evapotranspiration and decreased precipitation.

Research simultaneously examining building energy consumption and outdoor thermal comfort within urban environments remains limited. Few studies have delved into the sensitivity of design parameters based on building energy consumption and outdoor thermal comfort. The purpose of this study is to investigate the correlations between urban morphological design parameters and performance indicators, focusing on building energy consumption and outdoor thermal comfort (UTCI), across different urban block layouts in hot-humid regions, like Guangzhou. By establishing six fundamental morphological models—three individual unit layouts and three group layouts—the research explores both control and descriptive parameters through extensive simulation studies. Scatter plot visualizations provide insights into the impacts of various design parameters on energy consumption and UTCI, facilitating a comprehensive analysis of trends and quantitative relationships. Additionally, the study conducts sensitivity analyses on design parameters under different layout conditions to highlight their influences on target performance indicators. The findings reveal common trends, such as the significant impacts of plan dimensions and the Floor Area Ratio (FAR) on energy efficiency and outdoor comfort, as well as differential patterns, such as the varying sensitivities of the Shape Factor (S/V) and the Sky View Factor (SVF), across individual and collective layouts. Ultimately, this study offers a nuanced understanding of urban block morphology’s role in creating sustainable, comfortable, and energy-efficient urban environments, providing valuable guidelines for urban form design in hot-humid climates.

Drought is the primary driver of wildfires in humid regions, and the main drought drivers for wildfire occurrence and spread vary across different humid climatic areas. This study explores the suitability of different drought descriptions for wildfires under various humid temperate climates in Japan. Based on wildfire data from 1995 to 2012, statistical and correlation analyses were conducted to examine the performance of effective humidity (EH) and soil moisture (SM) as indicators of atmospheric and soil drought. EH is used for nationwide wildfire and drought warnings in Japan. The results show that EH is significantly influenced by seasonal and regional factors, with its ability to assess drought for wildfire varying accordingly, whereas SM demonstrates a more consistent ability to assess drought across different seasons and regions. Correlation analysis revealed that atmospheric drought better explains the drought conditions for wildfire ignition in 11 prefectures, mainly concentrated in the northern regions along the Sea of Japan. In contrast, the correlation coefficients for SM were higher in 33 prefectures, particularly along the Pacific coast, indicating that soil drought better explains the drought conditions for burned areas in these prefectures.

The increasing global temperatures have led to a higher demand for energy to maintain thermal comfort. In 2018, air conditioning was found to be the largest contributor to energy consumption, accounting for approximately 62% of the total energy used, according to data from the Ministry of Energy and Mineral Resources. Consequently, energy-saving initiatives that focus on cooling systems can play a crucial role in global energy conservation efforts. One such initiative is the implementation of Eco-Coolers. This study aims to compare the effectiveness of Eco-Coolers and windows in reducing room temperature for thermal comfort in hot and humid climates using Ansys simulations. The research adopts a quantitative approach by simulating the Eco-Cooler and window models using the Ansys application, followed by descriptive statistical analysis. The Eco-Cooler simulation involves a model with a diameter of D1 = 50 cm and D2 = 25 cm, which is then compared to a window measuring 45 cm × 100 cm. The results of the Eco-Cooler simulation demonstrate a decrease in temperature in all rooms where the Eco-Cooler is placed, with a maximum temperature of 27.05°C. This represents a decrease of 0.65°C from the initial temperature of 27.7°C. In contrast, the window model exhibits an upward airflow pattern, resulting in a maximum temperature of 27.35°C. This indicates a temperature drop of 0.35°C from the initial temperature of 27.7°C. Previous research on thermal comfort in Gorontalo City has shown that discomfort typically begins at a temperature of 29°C, with the peak of discomfort occurring at a temperature of 33°C. Therefore, based on the simulation results, the temperature range of 26.65°C – 27.05°C achieved by the Eco-Cooler can provide a comfortable or neutral sensation for individuals.

Long-term changes in precipitation and temperature indirectly impact aquifers through groundwater recharge (GWR). Although estimates of future GWR are needed for water resource management, they are uncertain in cold and humid climates due to the wide range in possible future climatic conditions. This work aims to (1) simulate the impacts of climate change on regional GWR for a cold and humid climate and (2) identify precipitation and temperature changes leading to significant long-term changes in GWR. Spatially distributed GWR is simulated in a case study for the southern Province of Quebec (Canada, 36,000 km2) using a water budget model. Climate scenarios from global climate models indicate warming temperatures and wetter conditions (RCP4.5 and RCP8.5; 1951–2100). The results show that annual precipitation increases of >+150 mm/yr or winter precipitation increases of >+25 mm will lead to significantly higher GWR. GWR is expected to decrease if the precipitation changes are lower than these thresholds. Significant GWR changes are produced only when the temperature change exceeds +2 °C. Temperature changes of >+4.5 °C limit the GWR increase to +30 mm/yr. This work provides useful insights into the regional assessment of future GWR in cold and humid climates, thus helping in planning decisions as climate change unfolds. The results are expected to be comparable to those in other regions with similar climates in post-glacial geological environments and future climate change conditions.

This study explores a prediction system for global horizontal irradiance and cloudiness in a humid subtropical terrestrial region. This system consists of regional simulations performed with the Weather Research and Forecasting model using the initial and boundary conditions from the Global Forecast System. The predictions show significant biases for the variable of interest, with notable variations within the daily and annual cycles. This study also finds significant biases in cloud incidence and clarity index predictions, with relevant diurnal and seasonal variations. During austral summer, multiplying the relative humidity of initial and boundary conditions by a fixed factor improves the forecasts of global horizontal irradiance and cloud incidence for the central hours of the day and the afternoon. During austral winter, an empirical correction of the clarity index obtained from the simulation’s outputs also shows the potential to improve the forecasts’ biases. This work proposes a hypothesis about the causes of the forecast biases.