A comparative spatial analysis of environmental changes associated with urban development: Based on the cities of Nuwara Eliya (Sri Lanka) and Kunming (China)

Abstract

This study is an illustration of a comparative spatial analysis of climate-driven environmental changes caused by urbanization in two climatically different cities namely Nuwara Eliya (Sri Lanka) and Kunming (China) between 2013 and 2023. Both cities are examples of rapid urban development, which is known to be one of the main drivers of natural landscapes, ecosystem processes, and local climate regimes globally. Remote sensing and Geographic Information Systems (GIS) techniques were used in the study, and Landsat 5 and 8 satellite images were compared. The methodology quantified and compared the spatiotemporal changes of four environmental measures in three specific time periods, 2013, 2017 and 2023. They were the Normalized Difference Vegetation Index (NDVI), the Normalized DifferenceWater Index (NDWI), the Normalized Difference Building Index (NDBI) and the Land Surface Temperature (LST). The findings confirm an overall inverse relationship between natural resources and urbanization in Nuwara Eliya and Kunming. Nuwara Eliya city showed a significant increase in built-up area, with NDBI values increasing dramatically and this action coincided with a decline in natural resources. On the other hand, in Kunming also it showcases a gradual increment in NDBI values where they kept their NDVI values also in a high range. But the NDVI fell, reflecting the loss of vegetation cover in Nuwara Eliya. Furthermore, in Nuwara Eliya area NDWI values gradually decreased, indicating severe water resource degradation over the study period. As a result, LST values in Nuwara Eliya also increased accordingly. However, Kunming’s urbanization, despite its location, appears to be in trend with the “green development" concept. In addition, the research reiterates the need for Nuwara Eliya to embrace sustainable development measures in the form of appropriate land use planning, environmentally friendly agricultural practices, and well-planned development initiatives to combat the adverse effects of urban sprawl on forest cover as well as the overall environmental condition. Finally, to achieve these goals following of “Green Development” concepts and planning methods that has been used by Kunming area can be used.