Synergising the thermal behaviour of water bodies within thermal environment of wetland settlements

The thermal characteristics of an area are influenced by the surrounding physical environment including land cover, land use, and urban geometry. The environment of wetland settlements is primarily influenced by the presence of water bodies. This study utilised land cover and urban geometry to characterise the thermal behaviour of the Ogan Permata Indah Jakabaring Palembang wetland settlement area. Data collected hourly during 72 h of field measurements included air temperature, relative humidity, globe temperature, and wind velocity. The cloud cover was qualitatively recorded. The land cover, urban geometry, and solar and wind orientations of the settlement were also investigated. Results showed that compared to the natural environment, the increase of air temperature during the day in built-up areas is about 2.5–7.4 °C which depends on the weather condition. Besides that, the openness of the area facilitated airflow, while roughness increased airflow turbulence, rendering more effective cooling. The role of the water body in delaying heat re-emission into the environment was more effective if the building geometry did not inhibit airflow. In this case, the role of the water body is to increase the surrounding air temperature by 1.2–1.6 °C at night, as stabilization of daily temperature. This study demonstrates that wetland settlement development policies should consider their unique thermal environment. Settlement development policies should be guided by form aspects, considering the role of the wind cooling effect, and by material aspects, considering the role of water thermal mass for delaying the re-emission of heat energy.