In contrast to the ongoing worldwide uncontrolled expansion of urban development resulting in sprawled cities, compact cities have been argued by planners and researchers to be the more sustainable urban form. However, in compact cities, it has been shown that a low proportion of green spaces jeopardizes the sufficient supply of urban ecosystem services. This suggests that there remains a deficiency in clear visions for operationalizing compact and green cities. To remediate this, this paper introduces a systemic conceptual framework for compact and green cities by combining the concepts of smart growth and green infrastructure. The indicator-based, smartcompact-green city framework includes two aspects: 1) smart compact cities (considering the need to limit urban sprawl through smart growth) and 2) smart green cities (reflecting the preservation and (re-)development of urban green infrastructure). The paper suggests that there is the need to balance these two aspects to develop a systemic approach towards smart-compact-green cities. A hierarchical target system grounded on four characters for smart compact and smart green cities is developed. Smart-compact-green cities can be characterized through a 1) smart environment of compact and green cities, 2) smart multifunctionality of compact and green cities (economic, social, environmental), 3) smart government for compact and green cities and 4) smart governance for compact and green cities. The characters comprise twelve factors defined by 39 indicators for smart compact cities and 44 indicators for smart green cities, respectively. The systemic framework can support researchers and practitioners to develop visions of how existing or future cities can approach smart-compact-green cities in mainstreaming the ecology of and for cities by better understanding the complexity of urban systems and providing a basis for a systematic spatial monitoring.

A 1D Canopy Interface Model (CIM) is developed to act as an interface between a meso-scale and a micro-scale atmospheric model and to better resolve the surface turbulent fluxes in the urban canopy layer. A new discretisation is proposed to solve the TKE equation finding solutions that remain fully concordant with the surface layer theories developed for neutral flows over flat surfaces. A correction is added in the buoyancy term of the TKE equation to improve consistency with the Monin-Obukhov surface layer theory. Obstacles of varying heights and dimensions are taken into account by introducing specific terms in the equations and by modifying the mixing length formulation in the canopy layer. The results produced by CIM are then compared with wind and TKE profiles simulated with a LES experiment and results obtained during the BUBBLE meteorological intensive observation campaign. It is shown that the CIM computations are in good agreement with the results simulated by the LES as well as the measurements from BUBBLE. The applicability of the correction term in an urban canopy layer and to further validate CIM in multiple stability conditions and various urban configurations is discussed.

Global climate is changing as a result of anthropogenic warming, leading to higher daily excursions of temperature in cities. Such elevated temperatures have great implications on human thermal comfort and heat stress, which should be closely monitored. Current methods for heat exposure assessments (surveys, microclimate measurements, and laboratory experiments), however, present several limitations: measurements are scattered in time and space and data gathered on outdoor thermal stress and comfort often does not include physiological and behavioral parameters. To address these shortcomings, Project Coolbit aims to introduce a human-centric approach to thermal comfort assessments. In this study, we propose and evaluate the use of wrist-mounted wearable devices to monitor environmental and physiological responses that span a wide range of spatial and temporal distributions. We introduce an integrated wearable weather station that records (a) microclimate parameters (such as air temperature and humidity), (b) physiological parameters (heart rate, skin temperature and humidity), and (c) subjective feedback. The feasibility of this methodology to assess thermal comfort and heat stress is then evaluated using two sets of experiments: controlled-environment physiological data collection, and outdoor environmental data collection. We find that using the data obtained through the wrist-mounted wearables, core temperature can be predicted non-invasively with 95 percent of target attainment within ±0.27 °C. Additionally, a direct connection between the air temperature at the wrist (T a,w ) and the perceived activity level (PAV) of individuals was drawn. We observe that with increased T a,w , the desire for physical activity is significantly reduced, reaching ‘Transition only’ PAV level at 36 °C. These assessments reveal that the wearable methodology provides a comprehensive and accurate representation of human heat exposure, which can be extended in real-time to cover a large spatial distribution in a given city and quantify the impact of heat exposure on human life.