Outdoor Thermal Comfort Optimization through Vegetation Parameterization: Species and Tree Layout

The optimization of outdoor thermal comfort has become the keystone to guarantee the healthy and comfortable use of outdoor spaces. This study aims to optimize the outdoor thermal comfort through vegetation parameterization in a boulevard located in Guelma city, Algeria during summertime. However, two main parameters were investigated, species and tree layout, through a numerical simulation. We first collected microclimate data of a sunny summer day. Second, we used real microclimate data in different simulations using the Envi-met atmospheric model. The findings reveal that Ficus Nitida is the most significant species to intercept solar radiation and provide shade over the day in Souidani Boudjemaa Boulevard, with a maximum reduction of Ta = 0.3 °C and UTCI = 2.6 °C at 13:00 p.m. Tree layout is a determining parameter in the creation of shaded paths, based on the quality of the shadows cast by the trees, namely, their size. Thereby, planting the washingtonia palm trees along the center of the boulevard is the best option to maximize the shaded area within the boulevard, with maximum reduction of Ta = 1.8 °C and UTCI = 3.5 °C at 16:00 p.m.

Cambios en el paisaje arbolado en Hermosillo: escasez de agua y plantas nativas

Resumen: el objetivo de este artículo es determinar el patrón actual de especies en el paisaje arbóreo de la ciudad de Hermosillo, Sonora, de 1992 a 2014, lapso en el que se identificó una sequía hidrológica prolongada que duró 13 años. Se busca conocer en qué medida la escasez de agua ha logrado promover la adopción de especies que demandan poca agua. El patrón de distribución de especies se obtuvo a través del muestreo por observación directa de las banquetas y jardines frontales de las áreas residenciales y se concluye que se ha modificado. Los yucatecos (Ficus nitida) dejaron de ser los más abundantes, y fueron sustituidos por las benjaminas (Ficus benjamina) y el olivo negro (Bucida buceras). Existen más especies nativas en las áreas de desarrollo reciente de la ciudad, pero también ha aumentado la presencia y distribución de la benjamina y del olivo negro.Palabras clave: reforestación; sequía; xeriscape; árboles; especies nativas.Abstract: the goal of this paper was to assess the pattern of species encompassing the present treescape of the city of Hermosillo. The period studied was 1992-2014, during which time the city experienced a prolonged hydrological drought lasting almost 13 years. This study sought to determine to what extent this water shortage influenced the adoption of drought-tolerant trees, especially native species. Data about the frequency and pattern of tree species was collected by sampling sidewalks and residential front yards. The study found that there were changes in the pattern of species comprising the present treescape. The Indian laurel (Ficus nitida) was a common and abundant tree in Hermosillo, but the study suggested that it was substituted by weeping fig (Ficus benjamina). Another species that became important was the black olive tree (Bucida buceras). Native species were more abundant in recently developed areas of the city, but not as much as black olive and weeping fig trees, which were the more abundant and well-distributed trees.Key words: reforestation; drought; xeriscape; trees; native species.