A critical evaluation of different methods of urban climate mapping : a case study of Glasgow City

Abstract

The urban climate is a modified urban atmospheric phenomenon shaped by urban morphology and land use pattern. Urban Heat Island (UHI) is an emerging urban climatic concern that increases the heat risk likelihood in urban settings together with the global climate change effect. This dissertation has undertaken an urban climate mapping exercise with available climatic, socio-economic, and terrestrial datasets to visualize the urban heat risk (UHR) analysis in a spatial framework for Glasgow city, largely evaluating the methodological processes for several alternative features. With an abductive approach, simple mixed-method research is designed to integrate both qualitative and quantitative secondary data. This study has used nine base indicators for hazard, exposure, and vulnerability components to synthesize UHR with both map algebra and weighted overlay techniques in ArcGIS. The resultant UHR maps identify the climate-sensitive hotspots in the highly built environments including the city center alongside the river Clyde. Moreover, the thesis demonstrates that both GIS techniques provide a similar overarching results, but map algebra gives heterogeneous spatial UHR distribution at a smaller scale. As for two alternative hazard components (Land Surface Temperature and Air Temperature), this study found that LST-based maps give a detailed and pragmatic reading compared to air temperature as air temperature data is coarse and of poor quality. This study infers that the selection of the number and type of indicators and risk components, and spatial analysis technique affect the UHR outputs spatially. It is concluded that climate-cautious priority intervention can be identified through UCM which is further dependent on the mapping’s methodological choices. Thus, the local government should pay careful attention to the mapping methods to attain desired UCM results. As for implication, based on the Urban Climate Planning Recommendation Map, the study recommends to preserve the green spaces that provide cooling benefits and take immediate actions for climate-sensitive hotspots by incorporating urban green infrastructure at both local and city scales.