The Impacts of Vegetation on Summer Extreme Temperature of 4 Major Cities in China Based on Scatter Analysis and Linear Trend Analysis

Abstract

In the summer of 2022, the extreme high temperature phenomenon is particularly obvious in China, especially in Chongqing, Zhengzhou, Guangzhou, and Shanghai. Some studies have pointed out that there is a strong correlation between vegetation activity and regional climate change, and some vegetation types can mitigate the rise of extreme temperature. However, few papers can put forward inductive suggestions on what types of vegetation can effectively alleviate the extreme temperature in China. Therefore, in this paper the extreme temperature data of CMIP6 (tasmax) is used to explore the correlation between the vegetation cover rate and the extreme temperature of the four major cities in China through the scatter analysis and linear trend analysis. It is found that the vegetation cover rate has a significant correlation (p<0.05) with the extreme temperature: The high vegetation cover rate has a negative correlation with the extreme temperature (p=0.01), and the low vegetation cover rate has a positive correlation with the extreme temperature (p=5.86 x 10-9). According to the geographical location, 4 cities are divided into two types: inland cities and coastal cities. The results show that: (1) planting high vegetation may be more conducive to the mitigation of extreme temperature; (2) the increase of low vegetation coverage may be more conducive to the reduction of temperature rise rate; (3) inland cities may need to plant more high vegetation than coastal cities to mitigate extreme temperature.