Spatiotemporal changes of green cover pattern in urban areas of Batticaloa, Sri Lanka

Abstract

Sri Lanka’s cities are subject to varying green cover patterns due to rapid population growth in urban areas. Over the last two decades, urbanization has driven the rampant development of built-up areas, predominantly residential development. As a developing city in Sri Lanka, Batticaloa involves rapid construction development after the civil war. This trend increases pressure on green cover, making the city population more susceptible to urban challenges. This study investigates the spatial and temporal dynamics of green cover changes in selected urban areas in Batticaloa, Sri Lanka, from 2000 to 2020. Three (3) nearby areas were selected for the study, namely Kallady, Arayamapthy, and Kattankudy. ArcGIS Normalized Difference Vegetation Index (NDVI) analysis was used to identify the green cover pattern and changes using Landsat Images. The changing patterns were detected between 2000 - 2010 and 2010 – 2020. The study reveals that the total loss of green cover was high in the first decade, approximately 44.15%, which has slightly increased about 12.58% in the second decade of the selected years. The Kattankudy zone shows a high built-up density, while the Arayampathy zone is low. This pattern has led to the further loss of green cover in the Kattankudy zone, while the other two (2) zones are significantly mixed with the green cover. A significant proportion of the green cover is occupied by the newly built-up areas, mainly residential areas throughout the period. Thus, the green cover conservation should prioritize the built-up expansion to protect the environment. The residential green cover is essential for humans’ daily lives, and one of the most vital mechanisms in the urban green cover system cannot be ignored. This finding can contribute to the land use planning application and make policies to conserve the green cover in the future.