Climate-resilient cities: temporal analysis of urban land changes, and percapita: green spaces from 1993 to 2023: case study of Colombo, Sri Lanka

Abstract

There is a dearth of research on how urban expansion and the reduction of green cover affect fast-growing cities in the Global South. This study conducted a time series analysis of changes in urban land use and land cover (LULC) in relation to per capita green space (GS) in Colombo, Sri Lanka, over a 30-year period (1993–2023) using Landsat satellite image analysis. It provides an in-depth exploration of the relationship between urban LULC and per capita GS reduction in a rapidly growing city within a tropical context. The study utilized the support vector machine technique for satellite image analysis and categorized five land use types: water bodies, built-up areas, bare lands, trees and shrubs (dense vegetation), and grasslands and lawns (sparse vegetation). The study found a clear decline in GS and an increase in built-up areas in Colombo; however, it also highlighted some positive changes due to the Colombo city remodelling program. Additionally, the study analysed Colombo’s position compared to international per capita GS standards and proposed necessary actions for future improvement