Thermal properties based on air temperature observations in different local climate zones in Bogotá, Colombia

Abstract

This paper demonstrates an early application of local climate zones (LCZs) in the city of Bogotá, Colombia. The main goal was to assess the thermal properties within the areas of influence (sectors) of 10 meteorological stations in the city, classified into the LCZ scheme. Air temperature observations at 07:00, 13:00 and 19:00 h (T7:00, T13:00 and T19:00) and daily measurements were obtained from the stations, and the maximum (Tmax), minimum (Tmin) and mean (Tmean) values were calculated. Their distribution and variation were analyzed, thermal sensation categories were calculated, and the thermal differences (ΔTLCZX-LCZD) between open-compact LCZ types and LCZD (typical rural type with low plants) were obtained in order to identify patterns between the stations and their assigned LCZs. Furthermore, we compared urban morphology (form) parameters to the ranges proposed in the literature to classify LCZs. The results clearly showed variations and patterns between the stations and their assigned LCZs when using Tmin, T7:00 and T19:00 air temperature data and the indices and categories calculated from these. Values of ΔTLCZX-LCZD > 5°C were found in the densely urbanised LCZ at night, and some negative values at noon suggested the presence of an urban cool island. The results show the usefulness of LCZs in understanding differences and temperature variations between divergent urban sectors. However, when different LCZ types are grouped, the thermal differences between them can be better appreciated and explained. The main conclusion is that the urban surface of Bogotá does not generate high temperatures, but decreases the occurrences of low values in Tmin, Tmean, T19:00 and T7:00.