Spatial and temporal variations of urban heat island effect and the effect of percentage impervious surface area and elevation on land surface temperature: Study of Chandigarh city, India

Abstract

Significant surface urban heat island (SUHI) has been observed in the Chandigarh study area from the analysis of five years land surface temperature (LST) data from 2009 to 2013. UHI intensity over the study area varies with seasons. Average annual UHI intensity from 2009 to 2013 varies from 4.98K to 5.43K and overall average UHI intensity has been observed to be 5.2K. The maximum value of UHIindex has been found to be 0.93. Pixels with average value of UHIindex more than 0.90 have been considered as hot spots (HS). The relationship of LST between percent impervious surface area (%ISA) and elevation has been investigated in the present study. Parameter like %ISA which represents the extent of urbanization has been used for the UHI analysis and its relationship with LST has been found to be season independent. Positive relationship has been found between LST and %ISA with a consistent rising trend. In the mean LST and %ISA relationship, it has been observed that the coefficient of correlation of winter season is 0.81 which is slightly higher compared to monsoon and summer seasons. Normally the temperature falls with increase in altitude. But in this study, as the elevation increases, rising trend of LST can be observed. Negative relationship between LST and Elevation scatterplots has been observed in high altitude areas during monsoon season compared to summer and winter seasons. Besides other factors elevation also plays a significant role in LST dynamics and spatial distribution of LST.