Comparing the Effects of Green and Blue Bodies and Urban Morphology on Land Surface Temperatures Close to Rivers and Large Lakes

Understanding the complex contributions of several factors to an urban heat island is crucial for assessing the impacts of planning on the thermal conditions within cities. It is relatively well-known how the different factors work separately, but how they work together, especially near water bodies, is still unclear. This paper investigates the effects of blue bodies (rivers or large lakes), the normalized difference vegetation index (NDVI), building coverage (BC), and building height (BH) on the land surface temperature (LST), comparing the situation around lakes and a river. Their inter-relationships are explored in a square grid of 30 x 30 m using Landsat-8 data on LST measurements in Prague, Czech Republic, in summer 2022. Multiple regression models are used for the analysis. The results imply that the NDVI significantly reduces LSTs, followed rivers if within 200 m of one, while the effect of lakes is negligible. The effect of BH is low. BC is a predominant factor in the city, generating a warming effect, which increases with the city's compactness. The main planning implications are to base urban heat island mitigation strategies on compensating for building coverage with live and dense green bodies, promoting vertical development.