Greening urban spaces: A comparative simulation study of vertical greening in diverse urban contexts in Colombo district.

Abstract

Vertical Green Systems (VGS) play an important role in creating more resilient and sustainable urban settings by efficiently tackling several environmental concerns while also contributing to a vibrant and healthier environment. Numerous researches on vertical gardening systems has shown that they have a favorable influence on urban sustainability and overall quality of life across social, economic, and environmental aspects. The purpose of this research is to evaluate the thermal benefits of VGS in various urban contexts, especially in the Colombo district, during hot, humid end-of-summer sunny conditions in August. The study compared the thermal benefits of several vertical greening configurations, taking into consideration plant percentage and orientations (100% East-West, 50% East-West, and 75% North-South). Selected VGS configurations were strategically employed across four locations using different fractions based on ENVI-met designs. The research includes the introduction of different fractions of ENVI-met designs to the site, using carefully chosen vertical green attributes, to assess the thermal advantages. Furthermore, air temperature at 1.5 m was retrieved from ENVI-met IDT data, and actual and predicted temperatures were compared. Under present conditions, the software validation exhibited great accuracy with a 0.9838 R2 for simulated versus real ground measurements. The research findings revealed that applying various vertical greenery treatments in accordance with their vegetative proportions resulted in a significant decrease in outdoor temperature. Consistent with the research outcomes, the Colombo district observed decreases in temperature ranging from 1 to 2.5 ⁰C after adopting various forms of VGS. Vertical Greenery Applications at full intensity (100%) and in the East-West direction yielded the most temperature decline, whereas 75% North-South configuration generated the least.