Effect of urbanization on land surface temperature and NDVI: a case study of Dehradun, India

Abstract

One of the significant environmental consequences of urbanization is reduction in vegetation cover and formation of urban heat island effect. The present research utilized Landsat data from 1998 to 2017 to study the spatiotemporal pattern of NDVI and land surface temperature (LST) in Dehradun - capital of the newly formed state of Uttarakhand, which experienced rapid urbanization since 2000. LST has been calculated from thermal data of Landsat TM/TIRS using emissivity derived from NDVI images. The spatio-temporal pattern of LST indicates that urban/builtup area has increased over two decades and has higher temperature than the surrounding vegetated areas. LST statistics show that there has been a rise of 3.5 degrees in the minimum and 4.9 degrees in the maximum temperature in the 19 years. Urbanization leads to increase in the built-up areas which inturn get heated up as compared to the surrounding areas leading to urban heat island effect. In addition, correlation has been attempted between NDVI and LST. The results show an obvious negative correlation between the two i.e. the NDVI values are low or even negative where LST is high and vice-versa