A study case of urban heat island intensity based on urban geometry

Abstract

Introduction. The paper presents a method to simulate the maximum intensity of urban heat island (UHI) based on urban geometry using H/W parameters, where H — building height and W — width of neighboring street. Urban heat island is determined by the increase in the temperature in the city centers compared to the surrounding rural areas. Materials and methods. The research is based on remote sensing technology to analyze the thermal surface of Hanoi city. It was run in different seasons thereby determining the expansion of the heat island effect over the years. The research method is based on Oke’s model number theory. An area is selected in the city center with high construction density to simulate the intensity of UHI. Results. The study shows that population growth affects the urbanization process. Over the years the urban land area is affected by the expansion of the heat island effect. Based on Oke’s model, calculations of UHI maximum intensity in Nhan Chinh block (Thanh Xuan district of Hanoi) were made. The estimation showed that the higher the building and the greater the distance from the road, the greater the intensity of the heat island. Accordingly, the lower the building and the smaller the distance from the road, the lower the intensity of the heat island. Conclusions. Using the Oke’s model to estimate heat island intensity based on the height-to-distance ratio of a building to a road makes process modeling possible. As a result, the planner can offer solutions to eliminate the negative impact of the urban heat island effect.

Keywords

• micro climate
• urban heat island
• urban wind
• landscape
• urban planning
• thermal comfort