Spatial and Temporal Changes of the Greenery of Colombo City

Abstract

Plans for landscaping of the City of Colombo are now in place and it is of timely important tostudy the spatial distribution of the vegetation cover and its pattern of change occurredthrough the past to identify the priority areas for restoring and revitalizing the greenery. Thisstudy was therefore focused on mapping the vegetation cover in 47 Wards of the ColomboCity for the years of 1956, 1982, 2001 and 2010 using aerial photographs and IKONOSsatellite maps. The present work was also involved the evaluation of the percentage extents ofvegetation cover and its rates of change in each Ward.

According to the resultant maps, a gradual decline of green cover percentage was depicted forthe study period. The green cover of the study area was 35.7%, 32.2%, 31.5% and 22.2% in1956, 1982, 2001 and 2010 respectively. In 2010, the highest green cover (49.65%) wasreported from Narahenpita Ward and only three other Wards (Kirulapona, CinnamonGardens, and Thimbirigasyaya) showed the green cover above 30%. Ten Wards(Kochchikade North, Kochchikade South, Grandpass North, Masangasweediya,Panchikawatte, Fort, Gintupitiya, New Bazar, Maligakanda, Aluthkade East) had green coverless than 10% in 2010.

The per capita green cover in 13 Wards did not comply with the World Health OrganizationStandard for urban green spaces. Expansion of built-up areas and road network can beidentified as the major reasons for the gradual reduction of green cover in the City ofColombo.

The study also highlights the necessity of a well-planned strategy for upgrading the greencover in the study area. Planting of trees and grasses in public and private lands, increasingpublic awareness on economic value of green spaces as well as implementation of aparticipatory tree maintenance programme would be mandatory for the sustainability of thecity’s greenery.