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The availability of gridded, screen-level air temperature data at an effective spatial and temporal resolution is important for many fields such as climatology, ecology, urban planning and design. This study aims at providing such data in a data-scarce, arid city within the greater Cairo region (Egypt), namely the Sixth of October, where, to our knowledge, no such data are available. By using (i) air temperature data, collected from mobile measurements, (ii) multiple spectral indices, (iii) spatial analysis techniques and (iv) random forest regression modelling, we produced air temperature maps (for both daytime and nighttime) at 30-m spatial resolution for the entire city. The proposed method is systematic and relies on low-cost instrumentation and freely-available satellite data and hence it can be replicated in similar data-scarce, arid areas to allow for better spatial and temporal monitoring of air temperature.

Abstract. Over the past decades, climate change has become among the top issues challenging cities worldwide, endangering the urban infrastructures and threatening the health of millions of people. Hence, climate action, both in terms of mitigation and adaptation to climate change, has become a priority for urban planning. This work introduces an example of the promising role that spatial analysis and statistical modelling, employing Geographical Information Systems (GIS) and freely available satellite and land-based data, can provide in supporting urban climate design and policymaking. In particular, this study puts special attention on the Urban Heat Island (UHI) phenomenon. Here, we first introduce a simple, but effective morphological-based approach for mapping potential ventilation corridors across cities of uniform built-up structure, as a common UHI mitigation measure. Then, we propose a methodology for assessing the relative role of these corridors in maximizing the impacts of green solutions upon lowering high temperature. Results show that even under very calm wind conditions, there is still an opportunity for maximizing the benefits of greening measures on the urban climate. Also, it has been demonstrated that green ventilation corridors are more effective during night-time when the UHI effect is peaked. The research findings are very promising, especially for cities where wind is a marginal potentiality.

Urban solar radiation is a primary factor affecting indoor and outdoor thermal and lighting comfort. However, although 3D solar radiation models are achieving remarkable advances in urban climate planning support and decision making, they are time-consuming and cost-intensive. We aim at compensating for such limitations by providing an agile approach to estimate shadows and solar radiation on building facades, using elevation models (2.5D) and image processing techniques. This is achieved by making the best use of the new visibility toolset for raster processing, provided in ArcGIS, and GRASS GIS solar radiation 2D model. Results give a clear and detailed picture of the radiation condition in the study area, which offers promising opportunities for urban solar planning and assessment in complex urban areas.