Increased urban thermal discomfort in major Cities of the Arabian Peninsula

Lahore is the second major metropolitan city in Pakistan in terms of urban population and built-up area, making the city a more ideal place to form the surface urban heat island (SUHI) effects. In the last two decades, the considerable land-use conversion from a natural surface (vegetation) and permeable (waterbody) surface into an impervious (built-up area) surfacehas lead to an increase in land surface temperature (LST) in Lahore. The human thermal comfort (HTC) of the residents is alsoimpacted by the higher LST. The present study uses multi-temporal Landsat (5&8) satellite imageries to examine the ecological and thermal conditions of Lahore between 2000 and 2020. The ecological and thermal conditions of Lahore are assessed by calculating the urban heat islands and UTFVI (urban thermal field variance index), based on LST data which quantitatively assessed the UHI effect and the quality of human life. The outcomes establish that the urban built-up area has increased by 18%, while urban vegetation, vacant land, and waterbody decreased by 13%, 4%, and 0.04%, respectively. In the last 20 years, the mean LST of the study region has risen by about 3.67 °C. The UHI intensity map shows intensification and a rise in surface temperature variation from 4.5 °C (2000) to 5.9 °C (2020). Furthermore, the finding shows that the ecological and thermal conditions are worse in construction sites, transition zones, and urban areasin comparison to nearby rural areas. The lower UTFVI was observed in dense vegetation cover areas while a hot spot of higher UTFVI was predominantly observed in the areas of transition zones and built-up area expansion. Those areas with higher hot spots are more vulnerable to the urban heat island effect. The main conclusions of this study are essential for educating city officials and urban planners in developing a sustainable urban land development plan to reduce urban heat island effects by investing in open green spaces for urban areas of cities.

Assessment of urban thermal field variance index and defining the relationship between land cover and surface temperature in Chattogram city: A remote sensing and statistical approach

The rapid urbanization of Srinagar city, located in the Himalayan region, has led to significant changes in land use and land cover (LULC), resulting in an increase in the Urban Heat Island (UHI) phenomenon. This study investigates the relationship between Land Surface Temperature (LST) and LULC changes over a decade, from 2010 to 2022, focusing on four key categories: built-up areas, agricultural land, water bodies, and natural vegetation. Using Landsat satellite data, we analysed seasonal variations in LST across these categories and calculated the Urban Thermal Field Variance Index (UTFVI) to assess the ecological impact. The findings reveal a substantial increase in LST, particularly in built-up areas, where maximum temperature increased from 34.6°C in 2010 to 37.19°C in 2022. Additionally, the UTFVI analysis showed a decline in areas with "Excellent" ecological conditions, dropping from 57.91% in December 2010 to 47.24% in December 2022, while areas categorized as "Worst" ecological conditions increased, indicating a worsening UHI effect. These results highlight the growing environmental challenges posed by urbanization in Srinagar city, necessitating urgent sustainable urban planning interventions. Keywords: Land surface temperature (LST), Urban heat island (UHI), Urban thermal field variance index (UTFVI), Land use land cover (LULC), Urbanisation

Assessing and predicting land use/land cover, land surface temperature and urban thermal field variance index using Landsat imagery for Dhaka Metropolitan area

Modelling the impacts of land use/land cover changing pattern on urban thermal characteristics in Kuwait

Evaluating urban heat island to achieve sustainable development goals: A case study of Tiruchirappalli city, India

Assessment of urban thermal field variance index and thermal comfort level of Addis Ababa metropolitan city, Ethiopia

Due to expanding populations and thriving economies, studies into the built environment’s thermal characteristics have increased. This research tracks and predicts how land use and land cover (LULC) changes may affect ground temperatures, urban heat islands, and city thermal fields (UTFVI). The current study examines land surface temperature (LST), urban thermal field variance index (UTFVI), normalized difference built-up index (NDBI), normalized difference vegetation index (NDVI), and land use land cover (LULC) on a kilometer scale. According to the comparative study, the mean LST decreases by 3 °C and the NDVI increases considerably. Correlation analysis showed that LST and NDVI are inversely connected, while LST and NDBI are positively correlated. NDVI and NDBI have a strong negative association, while LST and UTFVI have a positive correlation. Urban planners and environmentalists can study the LST’s effects on land surface parameters in different environmental contexts during the lockout period. The urban heat island (UHI) phenomenon, in which the land surface qualities of an urban region cause a change in the urban thermal environment, forms and intensifies over an urban area. The minimum and maximum LST in grid number 1 in 2009 was 20.30 °C and 29.91 °C, respectively, with a mean LST of 25.1 °C. There was a decline in the minimum and maximum LST in grid number 1 in 2020 with a minimum and maximum LST of 17.31 °C and 25.35 °C, respectively, with a mean LST of 21.33 °C. There was a 3.8 °C drop in the LST of this grid. The minimum and maximum NDVI were also − 0.16 and 0.59, respectively, with an average NDVI value of 0.21. Therefore, it is essential to evaluate and foresee the impact of LULC change on the thermal environment and examines the connection between LULC shifts with subsequent changes in land surface temperature (LST) along with the UHI phenomenon. Maps of the UTFVI reveal positive UHI phenomena, with the highest UTFVI zones occurring over the developed area and none over the adjacent rural territory. During the summer months, the urban area with the strongest UTFVI zone grows noticeably larger than it does during the winter months during the forecasted years. Future policymakers and city planners can mitigate the effects of heat stress and create more sustainable urban environments by evaluating the expected distribution maps of LULC, LST, UHI, and UTFVI.

Analytical study of land surface temperature for evaluation of UHI and UHS in the city of Chandigarh India

Urban physical and biotic heterogeneity phenomena that caused by the decrease of vegetation and the expansion of built-up land can influence the urban climate response. The increase of land surface temperature brings on the Urban Heat Island (UHI) phenomenon. Spectral resolution, temporal resolution, and the synoptic overview capability of remote sensing data are capable in urban study. Remote sensing imagery is able to extract the land surface temperature changes widely and simultaneously. The aims of this research are to identify UHI phenomenon and analyze the ecological condition in Semarang City using Landsat 7 ETM+ in 2002 and Landsat 8 OLI in 2019. Urban Thermal Field Variance Index (UTFVI) transformation is used to measure the intensity of UHI. Remote Sensing Ecological Index (RSEI) that based on principal component analysis transformation is used to analyze the urban ecological quality with the occurrence of UHI phenomenon. The results show that the land surface temperature mean value increase to 3,19°C so that some parts of Semarang occured UHI. The trend is also increased and stronger. It is consistent with the decrease of RSEI. The increase of temperature and UHI phenomenon during 2002-2019 impact on the degradation of urban ecological quality in Semarang City.

Predicting land use dynamics, surface temperature and urban thermal field variance index in mild cold climate urban area of Pakistan

Analysing the day/night seasonal and annual changes and trends in land surface temperature and surface urban heat island intensity (SUHII) for Indian cities

Analysis and prediction of land surface temperature with increasing urbanisation using satellite imagery

Prediction of seasonal urban thermal field variance index using machine learning algorithms in Cumilla, Bangladesh

Urban Heat Island effect and Urban Thermal Field Variance Index phenomenon at the heart of ‘Chicken's Neck Corridor’ of India