A simple approach for the development of urban climatic maps based on the urban characteristics in Tainan, Taiwan

Abstract

Motivated by the increasing thermal load in urban environment, this work established Urban Climatic map (UCmap) focusing on thermal environment issues based on urban development factors, e.g., land cover and building characteristics, representing thermal load of human body and ventilation path in the urban structures. In the established process of UCmap in this work, Tainan city, which is a highly developed city in southern Taiwan, is selected as the research area. A 50-m resolution grid is used to capture urban development factors and the climate data based on 1 year of mobile and fix-point measurements, from which the thermal load and the wind environment map are constructed. The results herein reveal that a higher urban development level is associated with a higher thermal load, and similar areas are more likely than others to suffer from an extreme thermal load and low wind pass conditions. Open and sparse low-rise buildings constitute the most appropriate urban characteristics for urban built environment in Tainan. By the simple approach of establishing UCmap, the microclimate condition and development intensity of regions can be easily detected and linked, for example the compact high-rise areas should be limited by floor area ratio in order to prevent the formation of hot spots. The government, urban planners, and architects without a meteorological background can efficiently obtain climate information by way of mapping the certain area, and making regulations to mitigate the growing problem of thermal stress and urban heat island.

Spatial relationship between land development pattern and intra-urban thermal variations in Taipei

“…This finding is partly inconsistent with previous studies, which have indicated an increase in temperature with building density (e.g. Chen, Lin, & Lin, 2017 ; Shi, Lau, Ren, & Ng, 2018 ; Wong & Yu, 2005 ), building height ( Yang et al, 2019 ) and street openness ( Ali-Toudert & Mayer, 2006 ) in hot to warm climates. Previous research has also observed higher temperature at densely developed high-rise buildings owing to lower ventilation efficiency ( Yang et al, 2019 ); or at openly distributed low-rise buildings due to increase of incoming solar radiation heating up street canyons ( Ali-Toudert & Mayer, 2006 ; Shi et al, 2018 ; Thorsson, Lindberg, Björklund, Holmer, & Rayner, 2011 ).…”

Spatiotemporal Characteristics of the Surface Urban Heat Island and Its Driving Factors Based on Local Climate Zones and Population in Beijing, China

“…Urbanization leads to changes in land use and cover [5,6], mainly manifesting as the replacement of large natural surfaces with impermeable surfaces and buildings. In addition, with the constant large number of people moving to urban areas, building density and human activity intensity also increases [7,8]. Rapid urban expansion directly alters local climate and hydrological systems [9] due to a variety of urban environmental problems, among which the intensification of the urban heat island (UHI) has attracted wide attention.…”

Designing Urban Green Spaces for Older Adults in Asian Cities

“…Study sites of Hong Kong ( a ) and Tainan ( b ) in the first survey (for both maps, darker colors in the legend indicate urban areas with higher density. Please refer to [39,40] for further information).…”