Urban green to mitigate UHI in the historic center. Case study: Tarija - Bolivia
Natural and Built Heritage, Urban Heat Island and Microclimate, Urban Vegetation and NDVI, ENVI-met Simulation.
Revaluing the urban heart of the city involves multiple actions that affect both the physical infrastructure and the democratic exercise of use and recognition of public open space (OPS). In this context, it is propitious to analyse mitigation strategies of urban heat island (UHI) effects for the city, at a micro-climatic scale. The main objective of this research is to contribute to the study and analysis of the environmental performance of urban greenery in the historic centre of the city of Tarija, Bolivia, specifically in a 15.75 ha (450m*350m) section of the monumental heritage area, based on the relationship between morphology, microclimate and urban vegetation. The methodological process comprises three procedures: 1) identification and analysis of UHI through quantification and temporal comparison over 20 years (2001-2021) in the autumn, winter, spring and summer seasons, by means of geoprocessing and remote sensing of LANDSAT8 satellite images, for the indicator: Land Surface Temperature (LST), and the Normalized Difference Vegetation Index (NDVI), both cases at the scale of large structure. 2) historical and heritage characterisation of the centre and centrality based on an axial map with the Integration indicator (Inthh) and morphological analysis of the square, courtyard and street elements, at a site/building scale, for the cataloguing of the OPS, analysis based on the classification according to the fields of perception, proposed by (ROMERO, 2011), scale of large urban structure, scale of sector/site, of place, and building; 3) comparison of two urban green scenarios: base scenario (current) and deep green scenario (proposed), involving tree planting in the road system, the network of courtyards and green corridors articulating three squares in the centre, as a strategy of Nature Based Solutions (NBS), by means of computational simulation with ENVI-met V5 for the indicators of Air Temperature (Air T), Surface Temperature (T Surface) and Thermal Comfort Indicator (PET), at site/building scale. The results are expected to corroborate the hypothesis that the scalar performance of urban greenery increases if existing central green areas are articulated, a situation that makes visible the benefits of micro-urban design, suggesting its implementation and replication in other neighbourhoods and urban districts as a policy of mitigation to climate change.