The Urban Heat Island (UHI), driven in part by urban green space transformation, and resulting in bioclimatic stress, is one of the major environmental problems facing cities today. A brief reprise ...in UHI severity is hypothesised to have occurred for many cities during COVID-19 lockdown, as a result of the marked reduction in individual and industrial activities. This study explores the UHI the city of Esfahan, one of the major metropolises of Iran, comparing the urban temperature for the period 20 March to 20 April 2020, the first lockdown period in Iran, with a long term mean for this month calculated from 2000 to 2019. During the lockdown period, the UHI effect covered a much smaller land area than in all prior years investigated. The land surface area which experienced heat stress reduced significantly during the lockdown period, and the total energy heating requirement (heat degree days) increased by 23,945.2° day calories compared to the long term average. These results demonstrate the significant changes in UHI and related variables during lockdown. While lockdown regulations are not sustainable in the long run, the improvements recorded demonstrate the potential to mitigate anthropogenic heating.
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•COVID-19 lockdown resulted in reduced pollution and anthropogenic heating globally with the suspension of industrial activities.•This has the potential to reduce the intensity and land surface area of urban heat islands, and alleviate the reliance on cooling energy.•We explore changes in the UHI size, position and intensity, and cooling and heating requirements for Esfahan City.•Statistically significant decreases in temperature for 2020 relative to 2000-2019, increased heating energy requirements.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this study, it has been attempted to quantify model climate change effects of the coming decades on energy demand and carbon dioxide emissions of a dominant building brigade under hot and humid ...climates on the southern coast of Iran, based on three stations of Bushehr, Bandar Abbas and Chabahar. In this research, the Meteonorm and DesignBuilder software have been used for climate and thermal simulation of building. One of the results of this study is the increase in temperature and relative humidity for the coming decades for all three study stations. The findings of this study showed that the average annual temperature for the 2060s compared to the present decade, will increase by 2.82 °C for Bandar Abbas, by 2.79 °C for Bushehr and for Chabahar it will reach 2.14 °C. This increase in temperature has led to an increase in discomfort warmer days and a decrease in discomfort cold days. But given the climatic type of the area, a decrease in the heating energy demand for the coming decades will not have a significant effect on the pattern of energy consumption inside buildings. Because for two stations of Bandar Abbas and Chabahar, more than 95% of the energy demand for the 2060s is for cooling energy demand, which is about 80% of energy for Bushehr. In total, due to the increased demand for cooling energy in the coming decades, this will further increase carbon dioxide emissions, which is higher in Chabahar than in other study stations.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this study, the wet-bulb globe temperature (WBGT) validated biometeorological index is used to monitor and project future human thermal stress in Iran. The meteorological components required to ...calculate this index include dry and wet temperatures, relative humidity and radiation. To monitor and project thermal stress, data for two time periods are used: (i) baseline data for the period 1980–2010 and (ii) Can-ESM2 model outputs from the CMIP5 model series, which projects values for the period 2020–2049. Four physical geographic factors are used for modeling WBGT frequency; these include station height (elevation), distance from nearest large water body, latitude and longitude. To establish the role of these components on WBGT extreme values, a weighted geographical regression method is used. Findings show that by considering these variables in the form of multivariate weighted regressions, WBGT threshold values are reliably modeled. Based on projected global warming scenarios in coming decades, the threshold of thermal stress occurrence for most regions of Iran shows larger values than those for the reference period. Parameters of latitude, longitude and distance from a large water body will have an incremental impact as contributors to the occurrence of future thermal stress, relative to the reference period. Of these, latitude will have the greatest impact on thermal stress (6.3%), while that for longitude and distance from a large water body will be 2.4% and 1.4%, respectively. However, station elevation will have a reduced impact on thermal stress (by 4.1%).
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Thermal stress poses significant direct and indirect risks to human health. Under climate change, both mean temperature and the frequency and intensity of extreme thermal stress events are projected ...to increase. Located within an arid to semi-arid region, Iran is anticipated to experience particularly intense temperature and humidity changes under climate change, potentially heightening the public health challenges associated with thermal stress. To facilitate improved adaptation to these thermal threats, accurate high spatial resolution thermal heat stress risk maps are important. This study combines various climate indices to produce such a thermal stress risk map for the reference period 1980–2010, with RCP4.5 projections for the period 2020–2049. Although the results of the various indices are statistically significantly correlated, each index returned a remarkably different spatial distribution and risk classification. Therefore, a fuzzy approach was followed through a geographical information system (GIS) to combine the results of the five bioclimatic indices and prepare a final thermal stress risk map. Based on the RCP4.5 scenario, the results indicate a notable 24.5% reduction in the areas susceptible to thermal stress at the high-risk and very high–risk levels, compared with the reference period. The lowest projected risk is for the central parts of Iran, while the southern and northern coasts of Iran were the zones of the highest risk, for which adaptation responses are most necessary.
Research on the temporal and spatial changes of the urban heat island effect can help us better understand how urbanization, climate change, and the environment are interconnected. This study uses a ...spatiotemporal analysis method that couples the Emerging Hot Spot Analysis (EHSA) technique with the Mann–Kendall technique. The method is applied to determine the intensity of the heat island effect in humid subtropical climates over time and space. The data used in this research include thermal bands, red band (RED) and near-infrared band (NIR), and Landsat 7 and 8 satellites, which were selected from 2000 to 2022 for the city of Sari, an Iranian city on the Caspian Sea. Pre-processed spectral bands from the ‘Google Earth Engine’ database were used to estimate the land surface temperature. The land surface temperature difference between the urban environment and the outer buffer (1500 m) was modeled and simulated. The results of this paper show the accuracy and novelty of using Emerging Hotspot Analysis to evaluate the effect of vegetation cover on the urban heat island intensity. Based on the Normalized Difference Vegetation Index (NDVI), the city’s land surface temperature increased by approximately 0.30 °C between 2011 and 2022 compared to 2001 to 2010. However, the intensity of the urban heat island decreased during the study period, with r = −0.42, so an average −0.031 °C/decade decrease has been experienced. The methodology can be transferred to other cities to evaluate the role of urban green spaces in reducing heat stress and to estimate the heat budget based on historical observations.
The Alborz Mountains are some of the highest in Iran, and they play an important role in controlling the climate of the country’s northern regions. The land surface temperature (LST) is an important ...variable that affects the ecosystem of this area. This study investigated the spatiotemporal changes and trends of the nighttime LST in the western region of the Central Alborz Mountains at elevations of 1500–4000 m above sea level. MODIS data were extracted for the period of 2000–2021, and the Mann–Kendall nonparametric test was applied to evaluating the changes in the LST. The results indicated a significant increasing trend for the monthly average LST in May–August along the southern aspect. Both the northern and southern aspects showed decreasing trends for the monthly average LST in October, November, and March and an increasing trend in other months. At all elevations, the average decadal change in the monthly average LST was more severe along the southern aspect (0.60°C) than along the northern aspect (0.37°C). The LST difference between the northern and southern aspects decreased in the cold months but increased in the hot months. At the same elevation, the difference in the lapse rate between the northern and southern aspects was greater in the hot months than in the cold months. With increasing elevation, the lapse rate between the northern and southern aspects disappeared. Climate change was concluded to greatly decrease the difference in LST at different elevations for April–July.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Agricultural activities are considered the most important source of income for ~ 23% of the population in Mazandaran Province, Iran. However, farming activities are overwhelmingly exposed to the ...detrimental impacts of drought in this region. The purpose of this paper is to establish differences in farmers’ perceptions on the effects of drought on social, economic, and environmental activities between coastal lowland and inland mountain foreland regions. Our research focuses on rural farming communities residing in the towns of Chalus (coastal plain adjacent to the Caspian Sea) and Kelardasht (Alborz mountain foreland). In 2019, questionnaires were distributed to villagers, and subsequently completed by household heads. Sample size was determined using Cochran, with 384 responses per sub-region. Results obtained by statistical analyses using SPSS indicate that farmers in the coastal region perceived stronger drought impacts on food security, agriculture, economy, education, immigration, and the natural environment than those in the adjoining mountainous region. The study demonstrates how location over relatively small distance, but different in topography, distance from the coast, climate, infrastructural development, and societal factors, has profound impact of people’s perceptions to, and experiences of, drought in northern Iran.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Urban development and its climatic consequences have caused urban decision-makers to establish strategies to mitigate climate change. The implementation of different green spaces is one of the main ...strategies to reduce the environmental and climatic consequences of urbanization. Therefore, the main objective of this research is to reveal the effect of different green space scenarios on micro-bioclimatic conditions of a hospital located in Gorgan city, Golestan province. Therefore, in order to determine the position of the hospital building relative to Gorgan’s urban heat island (UHI), the location and changes in UHI intensity of Gorgan were determined as evidence of urban expansion. Since 27 July was determined as the hottest day in Gorgan city based on historical data analysis, the climatic conditions during 27 July 2021 were measured using an AR847 data logger installed in the hospital environment. Additionally, four different conditions, including actual environmental conditions of the hospital (actual conditions), along with the application of cypress trees (scenario A), plane trees (scenario B), and Buxus shrubs (scenario C), have been used to analyze the impact of different vegetation species on the bioclimatic conditions of 5 Azar Hospital during two time intervals, including observational periods (1970–2020) and the decade of the 2040s. Finally, spatiotemporal patterns of the predicted mean vote (PMV) thermal index were calculated for the observational period and during the 2040s using the ENVI-met micro-scale model. Results showed that the study site is in the UHI, which can affect the micro-bioclimatic conditions and the patient’s thermal perception. For all designed scenarios, results indicate that the average PMV index will increase by the 2040s. However, implementing different green space scenarios showed that the minimum and maximum values of PMV were found in scenario B, of 2.7. The actual PMV conditions of the studied site increased by 3.5. The scenario introduction of green spaces during the 2040s indicates that the average PMV at the hospital site will be decreased by 0.9 compared to the actual conditions. The study proves that appropriate green space strategies can reduce thermal loads occurring due to global climate change and improve the thermal conditions in the study area.
The past two decades of the 20th century and the first of the 21st century have been characterized by global temperature rise and increased frequency of weather-induced extreme events such as heat ...and cold waves. Using mean daily meteorological observations from 1995 to 2014, the Physiological Equivalent Temperature (PET) was used to detect heat and cold waves at 155 climate stations in Iran. Additionally, the acclimatization approach was introduced to evaluate human adaptation to interannual thermal perception. This paper, for the first time, uses PET and includes an analysis of consecutive days, as well as statistical filters to measure thermal adaptation of humans to extreme temperature events in Iran. This study presents a valuable first step for the quantification of cold waves and cold stress as well as heat waves and heat stress. Results showed that based on three thresholds resulting from different methods, no cold wave (CW) is observed in southwestern Iran and stations in the coastal strip of northern Persian Gulf and Oman Sea. Based on three thresholds, most frequent cold wave occurrence is observed for areas and highlands of North West, North East and the Zagros mountain range with different frequencies for different thresholds. Compared with cold wave, heat waves have been detected throughout the country. Although maximum threshold of the occurrence of this climate hazard occurs at Iran's southern coast, the most frequent occurrence was observed in boarder areas of eastern Iran. On the other hand, findings of the present study confirm the fact that the risk of heat waves in Iran is more serious than that of cold waves.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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