Spatial Pattern of Urban Expansion and Green Spaces: A Case Study of Tangalle Area, Sri Lanka

Abstract

: Urbanization responses to urban expansion, and changes in green spaces. Moreover, urban expansion has a significant impact on urban management. Urban forests (Green Spaces) provide benefits of the natural environment to communities. Recognizing the spatial pattern of urban expansion and green spaces within a certain time period is vital for urban planning. This study conducts to examine the expansion in Tangalle town. Built-up expansion occurs in recent years because of the tourism industry in this study area. The remote sensing indices, Normalized Difference Built-up Index (NDBI) and Normalized Difference Vegetation Index (NDVI) have been used to extract built-up and green spaces for identifying the spatial pattern changes from the years 1990 to 2021. According to the results of the urban expansion/sprawl index, and urban areas have been expanded slightly between year 1990, and year 2000, but decreased urban expansion between year 2000, and year 2010. However, between the years 2010, and 2021, the urban area has sharply expanded by up to 13%. The study revealed that the built-up area has increased enormously. NDVI shows that the increase in this built-up area has led to a decrease in significant agricultural lands and open spaces. Thus, in the year 1990, the urban form was an isolated urban pattern and gradually became a cluster-based pattern. According to the urban expansion results, the urbanization is expanding towards the north direction from the city center.