Spatiotemporal Dynamics and Multi-Factor Drivers of Land Surface Temperature in Andhra Pradesh, India (2020-2024): Integrating MODIS-Derived Indices, Urban Heat Islands, Hotspot Analysis and Trend Detection

Abstract

Land Surface Temperature (LST) is recognized as a primary indicator of regional thermal shifts precipitated by rapid urban expansion and land-use modifications. In this research, a comprehensive five-year longitudinal assessment (2020-2024) of LST dynamics across Andhra Pradesh, India, was conducted. The methodology involved the integration of MODIS-derived products with topographic and land-cover datasets, processed via the Google Earth Engine platform. The temporal analysis indicated that the annual mean LST underwent a distinct reduction in 2022, falling by 0.82 °C compared to 2021 levels. Following this decline, a recovery phase was observed, culminating in a marginally significant monotonic increasing trend, as evidenced by the Mann-Kendall test results (S = +10, Z = 2.205, p = 0.051). Statistical evaluation through Pearson correlation for the year 2022 identified the Normalized Difference Built-up Index (NDBI) as the predominant positive driver of temperature (r = +0.794). Conversely, mitigating influences were attributed to the Normalized Difference Vegetation Index (NDVI, r = -0.654) and the Normalized Difference Water Index (NDWI, r = -0.541). Topographic factors also played a role in temperature regulation, with slope (r = -0.504) and elevation (r = -0.201) showing negative correlations with LST. Regarding localised climate phenomena, Urban Heat Island (UHI) intensities were found to be modest yet persistent, ranging between 0.006 °C and 0.010 °C. The application of Getis-Ord Gi* hotspot analysis further validated the existence of statistically significant thermal clustering within primary urban centers. Throughout the study period, built-up land covers consistently recorded the highest thermal values. It was concluded that urban growth exerts a dominant influence on regional warming, often offsetting the cooling contributions of vegetation and terrain. These findings offer a critical empirical basis for regional heat-mitigation and urban planning within the context of rapidly developing Indian states.