Sensitivity analysis of 'Local Climate Zone' based urban morphology parameters for outdoor thermal comfort in the tropics

The Local Climate Zone (LCZ) classification system encompasses climate-critical urban parameters (such as land cover, land use and urban morphology) in its definition. A sensitivity analysis of geometric and surface cover characteristics, could allow an in-depth understanding of which parameters are critical to climate sensitive urban spaces in the warm humid tropics. In this work we examine the sensitivity of these variables to local warming in Colombo, Sri Lanka. Mean Radiant Temperature (MRT) - a key variable in outdoor thermal comfort at street level - is linked to urban indicators in the LCZ classification, together with climate variables generated by the microclimate simulation model ENVI-met. The simulations include a series of LCZ-based morphology options to reduce MRT in the urban outdoors at present and in a future climate change scenario. Statistical analysis of results show stronger relationships with geometric and surface cover variables in the globally warmed background scenario, while the geometric variables are more important to local warming than surface cover variables. The sky view factor (SVF) showed the strongest relationship to MRT. Based on these results the work presents ways in which the utilisation of geometric and surface cover parameters could enhance planning and policy for a climate sensitive city.