Combined Effects of the Surface Urban Heat Island with Landscape Composition and Configuration Based on Remote Sensing: A Case Study of Shanghai, China

Hongyu Du,Yongli Cai,Hong Jiang,Pudong Liu,Jinquan Ai

doi:10.3390/su11102890

Abstract

Rapid urbanization leads to changes in surface coverage and landscape patterns. This results in urban heat island (UHI) effects and a series of negative ecological consequences. Considering this concern and taking Shanghai as an example, this paper concentrates on the effects of surface coverage and landscape patterns on urban land surface temperature (LST). The research is based on quantitative retrieval of remote sensing data with consideration of methods in multiple disciplines, including landscape ecology, geographic information systems, and statistical analysis. It concludes that, over time, the thermal environment of Shanghai is becoming critical. The average LST ranking of different surface coverage is as follows: Construction land (CL) > bare land (BL) > green land (GL) > agricultural land (AL) > water body (WB). LST varies significantly with the type of surface coverage. CL contributes the most to the UHI, while WB and GL have obvious mitigation effects on the UHI. The large area, low degree of landscape fragmentation, and complex outlines lead to low LST rankings for GL, WB, and AL and a high LST ranking for CL. The conclusions indicate that CL should be broken down by GL and WB into discrete pieces to effectively mitigate UHI effects. The research reveals UHI features and changes in Shanghai over the years and provides practical advice that can be used by urban planning authorities to mitigate UHI.

Highlights

During the process of urbanization, the natural land cover changes to artificial surfaces on a large scale
CBLLhaares tshigenhifiigchaensttlyLhSiTg,hwerhtihleaWn tBhehaasvethraegleowLSeTsto. fGSLh,aAnLg,haani.d water body (WB) are significantly lower, and Construction land (CL) and bare land (BL) are significantly higher than the average land surface temperature (LST) of Shanghai
The results show that the thermal environment of Shanghai has become worse over the years

Summary

Introduction

During the process of urbanization, the natural land cover changes to artificial surfaces on a large scale. The increased artificial surfaces have different thermal capacities, reflection rates, aerodynamics, and levels of evaporation [1,2]. This leads to urban heat island (UHI) effects, which cause a series of ecological consequences, such as the formation of hazy weather, the deterioration of air quality, and extra urban energy consumption [3,4]. Previous studies showed that underlying landscape patterns have an important influence on LST [9,10]. Most research in this field concentrates on the relationship between LST and land cover types or area. In-depth research of the relationship between LST and the landscape patterns of land coverage types still needs to be improved

Results

Discussion

Conclusion