An analysis of Urban Cooling Island (UCI) Effects by Water Spaces Applying UCI Indicies

Abstract

An urban cooling island (UCI) involves an area that has a lower temperature compared with its surroundings. The UCI effect is created from shading effects by urban trees or evapotranspiration effects by green space and water spaces. Water spaces such as stream and lakes in particular play an important role in creating urban cool islands because water spaces have higher evapotranspiration rates than green spaces. The objective of this study is to present planning and management information on water spaces to mitigate urban heat islands (UHI), by analyzing their effects on air temperature due to water space characteristics. To achieve this, the UCI effects of urban water spaces were analyzed by applying UCI indices such as UCI scale, temperature difference, and UCI intensity. Next, considerations for composing and managing water spaces to mitigate urban heat islands were identified through analysis of the relationship between UCI indices and characteristics of water spaces such as area, perimeter, shape, and width. The results show that larger water spaces are more useful in reducing urban heat. In addition, more complex water spaces were found to be more efficient than simple ones. The results of this study can be applied to analyze priority areas for the creation or restoration of new water spaces. It can be also utilized as a planning guideline for designing water spaces.