Spatiotemporal analysis of land surface temperature owing to NDVI: A case study of Vadodara District, Gujarat

Abstract

The expeditious extension of LULC in the name of development is the root cause of global warming. Replacement of natural resources due to the expansion of manmade erections is accountable for the increase in LST of Earth’s topography. The impression of change in LULC is reflected in LST. To seize the rising temperature, the lamentation of a new plan of action for urbanization is of utmost requisite. This paper examines the change in LULC and its spatiotemporal impact on LST in Vadodara, which is situated on the bank of river Vishmamitri river. Vadodara an arid region has three main seasons and these are summer, monsoon, and winter. The climate is characterized by hot summer and dryness in the non-rainy seasons. May is the hottest month while January is the coldest month. The annual rainfall of the district is 475.2 mm. Hence, to analyze we used multi-spectral and multi thermal Landsat TM and ETM+ satellite images to monitor the evaluation of LULC and its impact on LST from 2001(pre-monsoon) to 2021(pre- monsoon). The study explores to what extent observed LST can be examined by vegetation cover measured through NDVI from2001 to 2021. To achieve this an analysis of co-relation is performed between LULC and LST and by using spectral indices comprising NDVI with the help of software like ArcGIS 10.2 and Erdas Imagine 2014. It had been observed that a considerable increase in LST in Vadodara was 58.338°C (Max) and 21.9014°C (Min) in 2001(pre-monsoon) to 60.844 °C (Max) and 24.6784 °C (Min) in 2021(pre-monsoon) which is just about 2°C increase in Max and 3 degrees increase in Min for LST in past 20 years. It was also observed that there is an inverse relationship between LST and NDVI. The value of NDVI is observed that change from 0.380711(H) and -0.59322(L) in 2001 to 0.551(H) to -0.351193(L)in 2021. Moreover, SMI places a vital role to investigate and verify the relation between LST and NDVI. Henceforth, to verify SMI was also calculated and it was noticed that places with high LST value and low NDVI value contained less soil moisture and places with less LST value and high NDVI values contained more soil moisture. Thus, it can be concluded that, if urban planners and decision-makers implement suitable land-use strategies then Earth’s topography can be protected from adverse effects of urban heat by planting adequate and appropriate trees in bare soil and beside the impervious areas, thus the expansion of UHI can also be controlled. Moreover, with the help of SMI values, it will also be beneficial for the agricultural sector.