Browsing by Author "Zawadzka, Joanna Ewa"
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Item Open Access The importance of spatial configuration of urban land cover in governing thermal response of urban form structure at design and masterplan levels.(Cranfield University, 2020-09) Zawadzka, Joanna Ewa; Corstanje, Ronald; Harris, Jim A.Urban areas worldwide are affected by the urban heat island (UHI) effect whereby towns and cities are warmer than their rural backgrounds, having a negative impact on human health and well-being, energy use, and ecology. Appropriately distributed and spatially configured urban greenspaces can be used to mitigate the UHI, however, their efficacy so far has been investigated from either sparse air temperature measurements, micro-scale model simulations or coarse- resolution remotely sensed land surface temperature (LST), resulting in outcomes specific to particular urban fragments or averaged over areas relevant to masterplan and not urban design level. Additionally, the effect of the non- vegetated portion of land cover (LC) on the capacity of urban greenspaces to alleviate excess heat has largely been ignored. In this work, these gaps are addressed by using fine spatial resolution LST and LC data over the entire extents of three British towns to elucidate the relationship between LST and spatial configuration of urban form, taking into account both the spatial properties of greenspaces and their built-up neighbours. Spatial configuration of urban form was defined by aggregation of individual LC patches, size, elevation, and distance to LC patches of other types. Elucidation of the urban form-LST relationships required downscaling of available coarse resolution imagery with the use of high resolution ancillary data, and sub-division of main LC types into classes with distinct spatial aggregation and thermal properties. Random Forest regression allowed for determination of specific spatial configuration conditions leading to the formation of the hottest and coldest LC patches of a given type and highlighted the importance of neighbouring LC in their formation. Subsequently, the requirement for sophisticated spatial analyses for UHI-mitigating urban design was verified through assessment of the heat mitigation index generated by the InVEST 3.8.7 Urban Cooling model, which performed better at scales relevant to masterplans.Item Open Access The relationship between spatial configuration of urban parks and neighbourhood cooling in a humid subtropical city(Springer, 2024-02-14) Verma, Ravi; Zawadzka, Joanna Ewa; Garg, Pradeep Kumar; Corstanje, RonContext Urban parks are essential for maintaining aesthetics within cities and keeping their its energy balance by helping mitigate the Urban Heat Island (UHI) effect through controlling ambient and land surface temperature (LST). Objectives To investigate the impact of cooling in terms of distance by variously configured urban parks of a humid subtropical city, using landscape metrics and open-source data. Methods Land use (LU) was obtained through maximum likelihood classification of 3 m resolution aerial RGB-NIR imagery supported by ground control points and park boundaries collected during field survey. LST at matching resolution was obtained through downscaling of Landsat-8 LST at 30/100m resolution, calculated with the Radiative Transfer Equation (RTE). Landscape metrics for patches of parks were calculated using landscapemetrics R library and related to neighbourhood distances over built-up land use (LU). Results Urban parks with homogenous cores and less complex shape provide distinctly higher cooling of neighbouring built-up LU of circa 2.55 °C over the distance of 18 m from park boundaries. Four metrics: contiguity index (CONTIG), core area index (CAI), fractal dimension index (FRAC) and perimeter-area ratio (PARA) represent significant relationship between spatial configuration of parks and their cooling distance. No cooling capacity of parks regardless of their shape and core was observed beyond the distance of 18 m, which remained constant with small fluctuations in the range of 0.5 °C up to the distance of 600 m. Conclusions The study concludes that cooling distance of urban parks in their neighbourhood extends up to 18 m, which is shorter than suggested by other studies.