The Cooling Effects of Water Body System on Land Surface Temperature in Vicinity Regions: A Case Study in Hue City, Vietnam

Uncontrolled rapid urbanization and global climate change have often leveled and reduced water bodies in urban areas leading to the rise of land surface temperature (LST). The cooling effects of the water body are one of the ecosystem services solutions that can significantly decrease the urban heat island phenomenon in cities. Using integrated geographic information system (GIS) and remote sensing techniques, along with spatial statistics, this chapter aims to analyze the impact of water body surface on the LST to quantify their role in mitigating the urban LST of the Hue City area. Land use/land cover, LST, normalized difference vegetation index (NDVI), landscape metrics, and water body surface maps for the entire Hue City were developed from interpretation of Landsat-8 Operational Land Imager/Thermal Infrared Sensor (OLI/TIRS) acquired on July 16, 2020. GIS proximity analyses were conducted on 50, 10, and 150 m from the water bodies’ surface. The water body system’s average temperature cooling effect in the region is about 0.35 °C. The findings also indicate that the cooling intensity of the water body surface (CIWS) has a nonlinear relationship with the water body’s surface area but in a small range. Besides, the intensity of heat mitigation is inversely correlated with the water body surface shape index (SI). The water body cooling effect is only significant at fewer than 50 m from rivers. Small water surfaces, such as ponds, significantly reduce urban surface temperatures. By conducting multiple stepwise regression analyses, the CORE AREA landscape metric of the water body was found to affect the forming of LST in the urban city. This study might contribute to sustainable development and management policies in urban planning and development in the context of global warming and increasingly complex climate change.