Analysis of urban heat island effect based on changes of urban surface parameters

Abstract

With the accelerated development of urbanization and industrialization, the scope of cities continues to expand. However, natural landscape such as vegetation and water in the city has been transformed into artificial impervious water. This has aggravated urban heat island effect and caused serious damage to the urban eco-logical environment. To explore the relevant factors that affect urban heat island effect, this study selects Tianjin, which has a high level of urbanization and a significant heat island effect, as the study area. Land satellite remote sensing images from 2013, 2018, and 2022 were selected for data acquisition. The analysis was conducted from the perspective of urban surface parameters changes. The selected urban surface parameters for this study include vegetation index, water body index, impermeable surface index, and surface temperature index. The heat island area will increase over time. In 2013, 2018, and 2022, the proportion of this area to the total area was 41.92%, 48.73%, and 49.16%, respectively. In 2022, the pro-portion of different regions in total area ranges from 40.21% to 54.22%. At this time, the heat island area of Dongli District is the largest and that of Jinnan District is the smallest. Surface temperature is negatively correlated with vegetation and water bodies, and positively correlated with impermeable water surfaces. Be-tween 2013 and 2022, over 90% of impermeable water surfaces belonged to heat island area, over 80% of vegetation belonged to green island area, and over 97% of water bodies belonged to green island area. In conclusion, the method proposed in the study can well analyze urban heat island effect and urban surface parameters change?s connection. This provides solid scientific data support for alleviating the heat island effect.