ABSTRACT
World urbanization has been increasing at a rapid pace over the past few decades, particularly in developing countries. The urban heat island (UHI) effect, which occurs during rapid urbanization, profoundly affects human life and health. The cooling effect (CE) of urban wetlands can effectively mitigate the impact of UHI. The intensity of UHI and the quantitative assessment of the CE of urban wetlands in cities of northeast China were estimated by using split-window algorithm (SWA) to estimate land surface temperatures (LST) from Landsat-8 TIRS. The relationships between characteristics of wetlands and surrounding buildings and two CE indices, normalized cooling capability index (NCCI) and normalized cooling efficiency index (NCEI), were examined. Results have shown that the average NCCI of urban wetlands is 42.3 times higher than that of green spaces. A strong positive relationship exists between the cooling capability of urban wetlands and the area, shape, and hydrologic connectivity of wetlands. Wetlands with more complex shapes have better CE. The average NCCI of wetlands connected to other surface waters is six times higher than that of isolated wetlands.
