جستجوی مقالات مرتبط با کلیدواژه « Thermal islands » در نشریات گروه « جغرافیا »

One of the major global environmental concerns in recent years is the phenomenon of global warming. Understanding the relationships between the phenomena affecting this phenomenon can be a way to reduce and control the surface temperature and prevent the formation of thermal islands.The aim of this study was to determine the relationship between surface temperature intensity with variables So2, CH4, Co, O3, NO2, HCHO, H2O, PM, LST-Day as well as temporal and spatial changes of thermal islands in Tehran province. In this study, 8-day productions of Aqua satellite and Sentinel-5 data along with coding method in JavaScript language in Google Earth engine system, path analysis and statistical clustering method have been used. According to the research findings, the trend and direction of spatial changes in the thermal islands of Tehran province during the years 2022-2000 from Tehran to the surrounding cities and satellite towns have been moving and relocating.Based on the temperature similarity between the 22 urban areas, six clusters were formed by K-mean clustering method. Based on the results of the final table of path analysis using AMOS software, among the studied variables, the highest coefficient of total impact on the increase in night surface temperature was related to the daily surface temperature, water vapor and carbon monoxide, respectively. PM particles also have the highest overall impact factor in reducing the night temperature.

Humans have always sought to use and take advantage of nature for their well-being, but most of these uses have caused the destruction of the natural environment around them. It means an area where the temperature of that area is higher than the surrounding environment, in other words, the air temperature in the city is higher than the air temperature of the surrounding environment, which has a uniform and homogeneous temperature. As the aim of this research, they examine and identify the temperature threshold and heat islands of Kerman city, focusing on the landscape changes.

The current research is based on library studies and field investigations in terms of developmental-applicative goal and in terms of descriptive-analytical methodology. To achieve the objectives of the research, 5 indicators (landscape heterogeneity, ecological continuity and connection, connection of land elements, environmental conditions and functional conditions) with 17 sub-indices were extracted. In the following, during three periods (1365-1385-1400), satellite images were prepared and using Envi software, the state of coverage and the results of the temperature surveys of the surface of the land in Kerman city were determined. The colonial competition algorithm (minimum spanning tree MST) has been used in the Matlab 2016 software environment and for the spatialization of the indicators studied in the city of Kerman by the method (Tracking Analyst Tools) in the process of network analysis (Network Analyst Tools) in the soft environment ArcGIS software is used.

As a result of this research, it should be said that at the level of the proposed scenarios, the scenario (construction) in the construction zone in 2016, out of 100% of the available zone in the city of Kerman, 42.44% is dedicated to the construction spot. In 1385, this number reached 49.27% and in 1400, it reached 59.02%. The results of the area metric show that most of the land surface of the study area is made up of patches. Also, construction spots and open spots have increased in area and the growth of this spot between them is significant. The largest share of spots formation in every 3 years is related to artificial spots. The results of the classification spectrum for the measured islands in the city of Kerman were classified into 6 classes. The results show that in the southwest of the city of Kerman, due to the location of numerous polluting centers and industrial towns, as well as the location of the wind, the pollution center of this city. contract.

The results of the location analysis show that the location is very unhealthy in the center of Kerman due to the traffic and population density. In order to investigate and understand the heat islands of Kerman city, relying on the changes and evolutions of pollution in this city, after the investigations carried out on the amount of pollution and carbon dioxide production in 8 sections, the status of each index was examined in terms of the amount of emission. According to the findings of this research, by combining the 8 maps of the previous stage and taking into account what the analysis of the satellite images shows, the state of the heat island resulting from pollution in Kerman city is presented.

Population growth and urban development have made use of much of the urban land, especially agricultural lands and gardens, for residential, industrial, and transportation uses. This use changes lead to increased pollution and degradation of the environment and above all the earth's surface temperature has increased.

This study investigates the relationship between land use and thermal islands in Meshginshahr over the 1984, 1999 and 2020 time periods.

The research method is applied and research in nature. To achieve the goal of the research, after radiometric and atmospheric processing of the images, land surface temperature (LST) and vegetation index (NDVI) were calculated. Then, using the error matrix method, the accuracy and precision of kappa for production maps were evaluated.

Studied Areas: 

The geographical area of this research is MeshginShahr city.

The findings indicate that Maps of the heat island show that in 1984 the minimum temperature is 22 and the maximum temperature is 43 ° C. While this situation has been increasing in 2020, the minimum temperature is 29 and the maximum temperature is 63 ° C.

The results of the relationship between land surface temperature and land use changes show that the highest land surface temperature is related to urban construction lands and this is a result of reduced vegetation cover and increased impermeable levels. Also, the study of the spatial distribution changes of the surface temperature of the island and the thermal island showed that with the disappearance of vegetation inside and around the city the cool temperature class replaced the warm temperature class.

In this research, land use map was prepared by maximum likelihood method in 8 areas of Ahvaz city and altitude and slope maps were prepared. To evaluate the classification accuracy of the land use map, the error of the classified image was compared with a reference image containing a number of ground control points. The map of urban thermal islands was prepared using a separate window algorithm on the Landsat 8 satellite data set in the ENVI software environment. The results showed that the prepared land use map has an kappa coefficient of 86% and good accuracy and credit. The relationship between land use and thermal islands, the results indicate that the eight cities of Ahvaz with an average temperature of 43.3 and the fourth region with an average temperature of 32.6 had the highest and lowest temperatures, respectively. By comparing the percentage of land use classes in the eight and four districts of Ahvaz, it can be said that industrial land use will increase the average temperature of urban areas and space land use will reduce the average temperature of urban areas. Areas with a slope of zero to 1.5 percent have an average temperature of 34 degrees and areas with a slope of 10 to 37 percent have an average temperature of 41 degrees Celsius. In urban areas with altitudes below sea level and urban areas with an altitude of 64 to 80 meters above sea level, the average temperature is 34 and 41 degrees Celsius, respectively.

In some metropolises of Iran, Thermal Islands is somewhat generalization and observable. Existence of tall buildings, traffic, population density in the hub centers and especially in the central part of the city cause the creation of a Thermal island in the city. In this research, the time-spatial identification of the thermal islands of the cold season during the years 1985 to 2019 and the analysis of the factors influencing their formation were done with an emphasis on changes in land use, texture, high-rise construction, land cover and climatic variables in the Tehran city. The current research, which is based on the extraction of Landsat satellite images, produced maps of the mentioned indices using NDVI, LSE, ISA and LST indices, which became the basis of the analyses. The results of the research show that high LST values are spread in areas of Tehran where the NDVI index is relatively low and the ISA index is high. Although the formation of Thermal islands in winter is a little far from expected, small parts of the north, northwest, south and southwest of the city (zones 1, 5 and 18) are permanently exposed to Thermal islands, which are in step with dense land use and areas free of vegetation. The scattered hot spots in the mentioned areas with a temperature cover above 20 degrees Celsius in the middle of the average temperature of the city, which is lower than 17 degrees Celsius during the cold period of the year, is indicative of this fact.

The expansion of urbanization has significant effects on the planet. One of the effects that people are dealing with today is global warming, which has appeared as urban heat islands. Heat islands are urban areas that are significantly warmer than the surrounding environment. The purpose of the research is to extract the spatial-temporal changes of the thermal islands of Shiraz using satellite images and to determine the relationship between the type of land cover and its surface temperature. In this regard, first the necessary pre-processing was done to prepare a user map on the images and the changes in land cover, water, wind, vegetation and albedo and the sky visibility index of the studied area were also extracted and satellite images were prepared and interpreted in the GIS environment. The results show that point number 9 (Qasr al-Dasht gardens of Shiraz) has the lowest temperature and this shows the inverse relationship between green spaces and thermal islands. The use of remote sensing data plays an important role in the management of urban space and effectively helps city managers in urban space planning. Urban building materials have a significant effect on intensifying heat islands in such a way that the use of standard materials reduces the temperature to a large extent, and vegetation has a reducing effect and built surfaces have intensifying effects on heat islands. The pattern of spatial and temporal distribution of thermal islands is influenced by the pattern of land use distribution.

The thermal island phenomenon is the excess heat on the surface of the earth and the atmosphere of urban areas compared to its suburbs. Thermal island by changing the pattern of local winds, enhancing the growth of clouds and fog, increasing lightning and affecting rainfall, lowers the urban air and causes discomfort and discomfort to city dwellers and by affecting human health, the possibility of asthma and various diseases Increases other respiration. Therefore, this research has been done with the nature of developmental-applied and descriptive-analytical and the purpose of simulation and calculation of the maximum intensity of urban heat islands (UHImax) according to urban geometry conditions in Valiasr and Shanb Ghazan alleys of Tabriz. The present research is descriptive-analytical in terms of method and has a developmental-applied nature. In this study, the required data were obtained through library, documentary and field studies. In this research, Landsat satellite imagery of 8 OLI and TIRS sensors in 163 and row 34 for the years 13/01/2019 and 12/08/2019 has been used. The method of this research is based on Oke numerical-theoretical equation. To do this, first the geometry of the desired areas according to a radius of 20 meters in Valiasr alley and 15 meters in the Ghazan slope from the axis of the passages to separate blocks and then the ratio of width of the passages and height of the building (H / W) in GIS software Finally, based on Oke equation, UHImax was calculated and simulated. In this study, in order to calculate the height-width ratio (H / W), first using ARCGIS10.5 software, the central axis of the passages was determined and then to determine the average height of buildings effective in thermal island changes, a radius of 20 meters left and right of the passages for Valiasr alley and a radius of 15 meters was considered for Shanb Ghazan area (the choice of radii depended on the width of the passages). After selecting the appropriate radius for both areas, the blocks were extracted and separated. According to the number of building floors (1 to 5) for Shanb Ghazan area and (1 to 11) for Valiasr alley and the average height of each block, the amount of homogeneity or heterogeneity of each block was determined. According to the passages, the blocks of the studied areas were divided into 10 different blocks from A to J. After selecting the appropriate radius of the building block in each axis, the height of the buildings was classified into three categories: low, medium and high. Then, using the H / W ratio, the intensity of the thermal island in each block was calculated. Also, in order to estimate the effect of the width of the passages and the height of the building on the changes in the intensity of the thermal island of Tabriz, a multiple regression model was used. Finally, after calculating the intensity of the thermal island in Valiasr and Shanb Ghazan alleys, the intensity of the thermal islands in both regions were compared and compared with the Earth surface temperature (LST) map obtained from the Landsat 8 satellite TIRS sensor. The results showed that the increase in population and construction in Tabriz metropolis has caused an increase in temperature. The results obtained from both areas showed that the physical and geometric conditions of Tabriz have a great impact on increasing the thermal island of the city, so that the taller the buildings and the smaller the width of the passages, the intensity of the thermal island The more and vice versa, the lower the intensity of the thermal island. As the width of the passages decreases, the pattern of local winds changes and they can rarely circulate freely in the passages, directing the heat out of the environment and adjusting the temperature there. Narrow passages absorb heat during the day and keep it in the urban environment for hours after sunset. These narrow passages, like deep and narrow valleys, reduce the long wavelength of radiation from the narrow width of the street and keep the heat at the surface of the passages, which increases the intensity of the thermal island. As the results showed, in Valiasr alley, among 10 blocks, block D with 1.9 degrees and block H with 8.2 degrees Celsius has the lowest and highest values of thermal island intensity. In Shanb Ghazan region, among the blocks, block G with 0.8 degrees has the lowest and block B with 6.8 degrees has the highest heat island intensity. Therefore, it can be acknowledged that according to the width of the passages and the height of the buildings in Valiasr alley and Shanb Ghazan area, blocks D and G have the most standard configuration and blocks H and B have the most standard configuration in these areas. The final results showed that although the height of the building has a significant role in increasing the intensity of the thermal island, but based on the estimation of the multivariate regression model, the effect of the width of the passages in Valiasr alley with 0.91 is much greater than the height of the building with 0.6 and Shanb Ghazan area with 0.92 much more than the height of the building with 0.5 is involved in changes in the intensity of the thermal island. Also, the comparison of the variables of width of passages and height of buildings in the studied areas showed that the width of passages in Valiasr alley had the least effect compared to Shanb Ghazan area and the height of buildings was the opposite. The results of surface temperature in the study areas also showed that Valiasr alley has the highest and lowest temperatures in winter and summer, respectively, while the surface temperature in both winter and summer in Shanb Ghazan region did not differ much. And the surface temperature in this area is low.

Heat waves and urban heat islands are phenomena that affect human life. The purpose of this study is to investigation the relationship between heat waves and urban heat islands in the Ahvaz metropolis from 2003 to 2018. For this purpose days with a temperature higher than +2 standard deviation ) and lasted at least 2 days, were identified as days with heat wave using the Fumiaki index, to investigate the effect of heat waves on the intensification of heat islands , heat islands for daytime and nighttime days with the heat wave and a normal day with the lowest maximum temperature as a day without heat wave, the occurrence of each heat wave was calculated using MODIS-AQUA data. According to the results, most of the heat waves in Ahvaz which occurred in March 2010, were at the end of the cold period. In terms of continuity, it was 7 days and long-term. findings also showed that in heat wave and no heat wave conditions, often formed on the day the cold island and at night the heat island, but in the heat wave conditions during the day the cold island it has been often more severe than normal days, and at night time the heat island is often more intense than normal day. In general, the occurrence of heat waves has an effect on the intensification of the thermal islands of Ahvaz in both hot and cold months. these conditions have been more noticeable in warm months than cold months.

Surface temperature is one of the important indicators in the study of models of energy balance at the surface and interactions between the earth and the atmosphere on a regional and global scale. Today, satellite imagery in thermal infrared and red wavelengths is a good source of information for water and land surface thermal mapping due to its extensive coverage. Today, the phenomenon of thermal islands in cities causes many human and financial losses to citizens. One of the problems in cities is that to study and control this phenomenon, you can use appropriate satellite images and identify and manage the infected parts of the city. Therefore, the purpose of this study is to prepare the changes made in urban constructions and the uncontrolled increase of buildings and their relationship with the ground surface temperature using the data of ETM and OLI sensors of Landsat satellite in 2002 and 2019 for Tehran. In this study, the Gram_Schmidet method, which was developed to combine these images, was used. And data for 2002 and 2019, all captured in winter, were prepared, analyzed and evaluated. Correlation coefficient and kappa coefficient indices have been used to verify the method and classification accuracy. The results show; The VbSWIR_BI and IBI indices have the highest accuracy compared to other indices while the results of VbSWIR_BI index show the temporal and spatial changes of Tehran in an acceptable result. Also, according to the results obtained through the surface temperature, with the increase in construction, the increase in temperature in Tehran has been extended to the northern and central regions of the city.

This study was conducted to investigate the effect of vegetation in the city in the form of green space on Land Surface Temperature (LST) and also to identify the thermal islands of the Kerman city. LST was calculated by inverse method Planck function using Landsat 8 in Google Earth engine. The calculated LST was calculated as the average of two images in the middle months of the four seasons of 2014, 2017 and 2020. Landsat Science Notebook and a split window were used In order to evaluate the efficiency of the method used in calculating the LST. The relationship and the effect of vegetation on the calculated LST for Kerman city have been done using correlation and selection of ring buffer at intervals of 50, 100, 150 and 200 meters. Finally, their seasonal changes were examined using Moran's I autocorrelation index and its position changes were analyzed both as a season-to-season trend and as a general trend. The results showed that the Planck function method and the Landsat Science Notebook method had more accurate results than the Split window method. There is a relationship between the area of the park and its temperature, and the lowest calculated temperatures for green spaces are related to the parks with the largest area. Correlation test analysis showed that in all seasons of the year, LST is inversely related to vegetation density index. Also, the amount and intensity of this negative correlation vary depending on different seasons. The highest negative correlation value of -0.48 was recorded for the summer in 2014. Quantifying the effect of green space on the ambient temperature fluctuation showed that, on average distance 200 meters from vegetated areas, the temperature has increased by 3 degrees resulting from increasing distance from the identified cores as green space; it is clear evidence indicating the effect of green space on the amount of measured temperature. The results of this study showed that the calculation of earth surface temperature provides reliable results in the management of urban space that can be useful in future urban decisions.

Numerous human and natural factors are involved in the creation of thermal islands. Accordingly, the purpose of this article is to analyze the occurrence of heat wave in Abadan city and its impact on thermal islands. Heat waves were identified using the 95th percentile index and its application to daily maximum temperature data during the period 1985-2017. Among the heat waves that occurred two waves with more continuity during the hot and cold seasons of the selected year, their satellite images were received from the MYD11A2 MODIS sensor's product during the day and night. Thermal islands were used in Abadan city. Land use map with 4 land use classes was extracted from MOD12Q1 MODIS sensor product by supervised classification method. The results showed that the average incidence of hot flashes in each month of the year is between 3 and 8 waves. The most persistent heat waves occurred in the period of 6/11/2010 to 6/16/2010 and 19/3/2008 to 27/3/2008 with a duration of 6 and 8 days, respectively. Thermal islands in Abadan have specific spatial and temporal fluctuations and the amount of surface temperature is higher in the warm season. The high temperature in barren lands is due to the increase in fuel consumption of 2 hours per day and in the industrial area due to the burning of fossil fuels and the production of polluting gases, which causes the greenhouse effect, heat intensification and Eventually the high density of the islands is thermal and intensifies the effects of heat waves.

With the beginning of the Industrial Revolution in 1830 and the growing growth of human knowledge, various changes have taken place in human life and human needs for energy and consumption of fossil fuels such as coal, oil and natural gas have led to a sharp increase in materials such as Carbon dioxide has been released into the atmosphere. Increasing its population exacerbates this phenomenon. All of these changes have caused the weather to change. The phenomenon of climate change, which is mainly related to the increase of greenhouse gases in the atmosphere, is a clear example in this field. This phenomenon causes many current problems such as gradual warming of the climate, melting of ice, rising sea levels, torrential rains, increasing drought, acid rain and threats to human health. And wildlife species in different regions of the earth (Atabi et al., 2007: 146). The development of urbanization and migration of rural residents to cities to enjoy the benefits of civilization, especially in the second half of the twentieth century led to the overdevelopment of cities (Alijani et al., 2010: 541). The desirability and quality of urban areas make a difference in the value of land use. Knowledge of how urban temperature patterns are distributed allows planners to manage the construction of urban green space to adjust the temperature. Also, by studying the relationship between user patterns and the distribution of thermal patterns, it is possible to provide programs to change and relocate these uses to improve environmental conditions. Despite the year-on-year changes in the average temperature due to the natural variability of the climate, increasing trends in the average annual temperature are evident in most parts of Iran, including the city of Sari. These increasing trends are mainly due to the increase of greenhouse gases in the atmosphere (due to the burning of fossil fuels and changes in the surface characteristics of urban areas (Alizadeh Chobari et al., 2016: 571 and 572). In this regard, the city Sari is located in a dense area of ​​activity and residential centers and with its various capabilities has been able to enjoy a special position in the province.This city due to its strategic location and suitable climate and location ‌ Tourism and unique agricultural capabilities are facing population growth and increased migration. Considering the challenges such as the increasing growth of the urban population, the uneven expansion of cities, the destruction of the environment, etc., which has reduced the quality of life and created heterogeneous uses in different urban areas; As a result, the climatic parameters of the region are also subject to change. In this regard, the effect of these changes on the city of Sari and solutions to deal with it have been studied.

The present research is applied-developmental for the purpose and is descriptive-analytical according to the method of work. In this study, in order to measure the spatial distribution of population in the eleven districts of Sari, data under the Geographic Information System (GIS) has been used. In order to investigate the spatial distribution of population in each area of ​​Sari, the Shannon relative entropy model has been used and to calculate the maximum thermal island intensity, the Oke numerical-theoretical equation has been used. Sari, the capital of Mazandaran province in northern Iran, is one of the largest and most populous cities in Mazandaran province and the north of the country, which is located at 53 degrees and 37 minutes east longitude and 34 degrees and 36 minutes north latitude. In terms of natural location, this city is located in the south of the Caspian Sea and in the plains of Sari city and only its southern and southwestern parts lead to mountains and low satellite hills. The height of the city from the sea level is 18.5 meters and the difference in its area to the coast of the Caspian Sea is 24 kilometers. The general slope of the city is from south to north and is very gentle (Sari Master Plan Studies, Mazand Tarh Consulting Engineers, 2015).

In the present study, the relationship between the spatial distribution of the population and the creation of thermal islands in the city of Sari has been investigated. After examining the spatial distribution of population and the intensity of changes in thermal islands, it is concluded that there is a relative relationship between the two indicators of spatial distribution of population and the intensity of changes in thermal islands in Sari. In region 2 of region 3 of Sari city, which had the lowest equilibrium in the spatial distribution of population, the intensity of changes in thermal islands was also low, and in areas where the spatial distribution of population was semi-balanced (region one of region one, regions 1 and 2 from region 2, and region 1 from region 3 of Sari city), the intensity of thermal island changes was low. Also, in the areas where the spatial distribution of the population was balanced (areas 2, 3 and 4 of area one, areas 3 and 4 of area 2 and area one of area 4), the intensity of thermal island changes was low and moderate. The results indicate the fact that there is a direct relationship between net residential density and the intensity of changes in thermal islands in the city of Sari. As the net residential density increases, the intensity of changes in thermal islands in Sari city increases, and as the net residential density decreases, the intensity of thermal island changes decreases. Based on the findings of the survey of Sari city areas and analysis of the spatial distribution of population and the maximum intensity of thermal island changes, it is concluded that there is a relative relationship between these two indicators in Sari city areas. In the areas that had the lowest equilibrium in the spatial distribution of the population, more intensity changes were observed in the thermal islands and in the areas where the spatial distribution of the population was semi-balanced and balanced, the intensity of changes was less in the heat islands. On the other hand, according to the results of Spearman correlation coefficient, it can be said that the most important effective factor in the maximum intensity of thermal island changes, which is inversely related to this phenomenon, is the net residential density. Areas in Sari that have the highest intensity of thermal island changes They also had the lowest net residential density. Therefore, it is necessary to apply appropriate policies such as revising and improving management in the way of population loading in various urban development plans and planning for the management and organization of urban structures in relation to the intensity of changes in thermal islands. ‌ Can be effective. It can also provide favorable grounds for guiding the development of population policies in various urban development plans to create a balance with sustainability in the city of Sari.

Heatwaves are one of the most harmful weather hazards to humans and the environment. The purpose of this study was to investigate the effect of heat waves on the heat islands of Tabriz metropolis during the years 2003-2008. For this purpose, maximum temperature data of Tabriz Synoptic Station were obtained from the Meteorological Organization and days with heatwaves were determined using Fumiaki index and MATLAB software. To investigate the effect of heatwaves on the intensification of thermal islands, warm waves in the hot and cold months of the year are selected and thermal islands for those days and a day without heatwaves with the lowest maximum temperature before each heatwave during the day and night at Modis Aqua were calculated. According to the results, the maximum heatwave constant was 4 days and had an increasing trend. Its highest frequency was in 2010 and in April, June, and December. According to the findings, in both hot and cold months, the intensity of the cold island of the day is often weak in both heatwave and no heatwave conditions, and with the occurrence of heatwaves, sometimes even the heat island in the city center has been created. At night time, at the same time as the heat waves, the heat island is often more intense than on normal days. Wind speed and relative humidity were lower than normal conditions in hot months compared to cold months. In the cold months, the cold island is often intensified by the heatwave both during the day and at night, compared to the normal day, but the heat island is weaker.

Awareness of the status of vegetation, land use change and surface temperature in each region, and the timing and location of their changes over time are important for micro and macro planning. In order to make optimal use of land, knowledge of land use changes is necessary, which is usually possible by detecting and predicting land use changes. Measuring the role of researches and researchers has been instrumental in the study of natural resources, especially vegetation, surface temperature and user variations in each location, as well as the availability of information for different times for valuable studies. In this study, ETM and OLI were used to study the process of land use change, vegetation cover, surface temperature, and hazards caused by them in perennial seasons. The results show that the area of use changes over the period 2000-2010 has decreased the area of use of the developed area, agricultural and growing gardens and the area of land and rangelands. Artificial vegetation has risen in aggregate and rangeland lands are showing a decreasing trend. Due to the importance of vegetation and its role in reducing the temperature of the earthchr('39')s surface, the trend has been decreasing in regions with intensive vegetation and high temperature. Also, in the period from 2010 to 2017, the range was further increased and the citychr('39')s growth continued sporadically, causing environmental changes and rising temperatures in the city. The change in the citychr('39')s increased range has increased environmental risks, including the loss of good agricultural land and the increase in the temperature of the city. Due to the fact that most agricultural land is located in the vicinity of the city under cultivation of saffron, which in the warm seasons does not have surface coatings, changes in the type of cultivation can also affect the temperature of the earth.

Today the world is experiencing an unprecedented flow of urban . population growth and urbanization is one of the factors influencing air temperature increase in urban areas , which causes the creation of heat island on these regions compared to the surroundings , and its effects can play a vital role in air quality and consequently public health . in this study , aster data are investigated in a case in shiraz , and the خوارزمیک of 5 bands are used to retrieve earth surface temperature and determine the local effects of heat island . in addition , the correlation between surface temperature and vegetation index , construction , barren land and water difference were obtained to determine the effects of green , bare , blue and residential areas on the heat island . the results showed that the effect of urban heat island in shiraz is mainly located in the industrial and residential areas of the west and south east . also , the negative correlation between the temperature of the ground and vegetation index of normal difference showed that green earth and water - covered areas could have weakened the effect of heat island while positive correlation between ground surface temperature and the normalized difference difference can increase the effect of heat island effect in the study area . nowadays , the most important problem in urban areas is to increase the temperature of the earth surface due to the at the natural levels ,

One of the emerging environmental hazards caused by the expansion of urbanization is the "thermal island" phenomenon, in which urban areas have a distinct climate compared to rural areas, and the city center has higher temperatures than its surrounding areas. This phenomenon occurs when a large percentage of natural surface coverings are destroyed and replaced by buildings, roads and other installations. The thermal island phenomenon has been studied and recorded in various cities around the world for more than 150 years. And it generally appears as the surface of the earth shifts from natural to non-perishable. Surface temperature is considered one of the most important parameters in identifying a city's climate that directly controls the effect of the city's heat island. And more recently, many regional studies, such as global climate change, hydrological and agricultural processes, urban land use and land cover, and soil moisture assessment, have been identified as important factors. Traditionally, urban heat islands have traditionally been studied using meteorological station data, or vehicle surveys, but today to reduce the weakness of these methods and to study them more closely, Satellite and remote sensing data are used more frequently because of more spatial resolution than terrestrial weather data. Remote sensing images, because of their wide coverage, timeliness and ability to obtain information in the thermal range of the electromagnetic spectrum, are a useful source of heat mapping and estimation of Earth's radiant energy.
Split-Window algorithm is one of the most important methods for estimating surface temperature which is better than other methods for calculating surface temperature. An important feature of this algorithm is the elimination of atmospheric effects. Since this algorithm does not require accurate information on atmospheric profiles during satellite acquisition, it is widely used in several sensors to retrieve Earth's surface propagation capability. The sensors used in this algorithm include the Multi Spectral Sensor and the TIRS Thermal Sensor. The following are the cases: Due to the lack of a database to measure the Earth's surface propagation capability with Landsat 8 satellite images, the C coefficients through various numerical simulations It was obtained from atmospheric and surface conditions.In this study, Landsat 8 images with 7/15/2015 Landsat 8 (OLI and TIRS) images and land use maps were used to analyze the thermal islands. After processing the images, a separate window algorithm was used to calculate the surface temperature and the maximum likelihood method was used to classify the images. Discrete Window Algorithm is a mathematical tool that uses ground information, thermal sensor brightness temperature (TIRS), ground emission capability (LSE) and fractional green vegetation factor (FVC) obtained from OLI and temperature multispectral band. Estimates the surface of the earth. Image analysis was performed in ENVI 5.3 and ArcGIS 10.5 software environments.
Surface temperature is one of the main factors in the study of cities. Because only two or three degrees differs from the air temperature of the lower layers of the urban atmosphere, which is the center of the surface energy balance, which determines the climate between buildings and affects the comfort of urban dwellers. In the present study, preliminary processes such as radiometric, atmospheric and geometric corrections were carried out and then high atmospheric radii were converted to surface radiation and then calculated by vegetation index, vegetation fraction index, radiation power and water vapor column, temperature. Ground level in the study area was obtained using a separate window algorithm.
 The results of thermal extraction showed that maximum temperature was related to low density vegetation, residential, industrial, industrial, asphalt-concrete and brick-iron frameworks. Minimum temperatures are also visible in green, brick-wood and clay-wood. The results of this research for planners and experts at the regional level to obtain information on the status of land surface temperature and their relationship with land use can pave the way for management decisions to conserve natural and agricultural resources. It is suggested that due to the moderating role of vegetation, vacant land and the wilderness be changed to uses such as parks and landscapes, and in addressing other uses, the reasons for residential and industrial and workshop areas should be taken into account, and the surface temperatures of buildings most The city has its own surface area and has the highest amount of radiation reflection can be reduced by planting vegetation on the roofs of buildings known as green roofs. High resolution satellite images are also recommended for land use mapping.

In recent years with the development of cities coatings of the Earth's has changed surface.  These changes have caused some urban areas to have a few degrees higher than the surrounding temperature. This phenomenon is known as thermal islands. Mashhad is one of the major metropolises in Iran with the problem of thermal islands. Various parameters affect the formation of thermal islands in this city that should be considered. In this study TM, ETM+ and OLI images were used to obtain surface temperature over the period 1987-2016. The study of temporal variations in surface temperature showed that in the studied period, thermal islands were transferred from outside the city to the city. The model for describing the temperature of the surface of the earth has changed and has diminished from the temperature of the city's moderate and cool temperatures, and in contrast, the amount of high temperatures (thermal islands) has increased significantly. The TOPSIS method was also used to obtain the thermal forming factors. 13 natural and human factors affecting the formation of thermal islands were identified. Each expert opinion factor was used to determine the degree of importance. According to experts, the distance from the sanctuary with a weight of %234 and traffic of %155 is the most important and the height with a weight of %022 is least important in the formation of thermal islands. The final results obtained from this model showed that the factors affecting the formation of thermal islands are well recognized and the temperature decreases with these factors.

Land surface temperature is one of the important parameters in environmental science and urban planning. Human activities, such as land use degradation and urban development, have the effect of increasing the land surface temperature and thus the appearance of thermal islands, and this phenomenon has adverse effects on human health over time. The aim of this study was to investigate the effects of land use change on spatiotemporal patterns of land surface temperature and thermal islands in Saqqez city. In this study, images from the years 1989, 1998, 2008, and 2018 were first categorized using the Maximum Likelihood Algorithm in ENVI software. Then, using a Split window algorithm, land surface temperature was extracted in the GIS software. Also NDVI, UHII, and UHIII indices were used to study the spatiotemporal land surface temperature and thermal islands. Also, land surface temperature of the low, medium and high vegetation classes was extracted during the period. The results of the classification accuracy with Kappa coefficient above 80% show the validity of the results. Also, the results of the evaluation of land use changes indicate the increasing trend of water, residential and bare lands areas and the decreasing trend of vegetation. In other words, 3.68, 38.43 and 514/02 km, respectively, are the area of water, residential and bare lands areas has been added, and a total of 550/06 km2 has been cut from the vegetation area to the 29-year period. Also, the results of maximum temperature of each land use indicate an increasing trend in temperature in residential and bare lands areas and vegetation during the studied period. According to the results of UHII and UHIII indices, the class with low vegetation has the highest temperature compared to the middle and high vegetation classes and also based on the results of these indicators, the thermal islands occurred in the northeastern parts of the city in 2008 and 2018.