INFLUENCE OF CLIMATE CHANGE AND URBANIZATION TO FUTURE THERMAL ENVIRONMENT WITHIN A MEGACITY

Recently, temperature in urban areas continue to rise as an effect of climate change and urbanization. Asian megacities are projected to expand rapidly resulting to serious in the future atmospheric environment. Thus, detailed analysis of urban meteorology for Asian megacities is needed to prescribe optimum countermeasure for these warming. A building-resolving large eddy simulation (LES) offline coupled with an energy balance model is conducted for a highly urbanized district in central Jakarta on typical daytime hours. Six cases were considered; two cases which utilized present urban scenario and four cases represent different urban configurations in 2050. The present case was used for validation by comparison with a moving observation of wet bulb temperature (WBGT). Meteorological inputs of the other present case and four future cases were acquired from a downscaling model. The future configurations were based on representative concentration pathways (RCP) and shared socio-economic pathways (SSP). Using the standard new effective temperature (SET*), thermal comfort in urban area in Jakarta was calculated and analyzed. Construction of dense high-rise buildings can reduce SET* (thermal comfort) due to increased shading throughout the district during daytime. Near-surface winds and temperatures were affected by the projected changes in morphology. For example, homogeneous high-rise buildings (case 3 and 4) prevented cooler downdrafts thereby maintaining high potential temperature within the street canyons.