Study on land fragmentation in southern province, Sri Lanka ; based on landscape ecology theory

Abstract

As the landscape is where the majority of economic and human activities take place, it is an effective geographical scale for investigating the long-term consequences of anthropogenic activities on the environment. Land use changes in Sothem province, Sri Lanka, have increased significantly during the last three decades due to increasing of human needs. This research aims to better understand the interplay between land use/cover change and landscape fragmentation in Sothern Province by analyzing the dynamics of these processes. The study comprised three key stages as quantify and examine land use/cover change on landscape structure in terms of fragmentation; examine spatial transformation processes in landscape; detect land use land cover (LULC) changes in the landscape from 1988 to 2021. For this purpose, the United States Geological Survey (USGS) uses satellite images taken in 1988, 2005, 2016, and 2021 to categorize land use and land cover. Arc GIS 10.3 and QGIS 3.28 were used to process satellite images and maximum likelihood classification method was employed. FRAGSTAT 4.2 and MS Excel used to analyze class level metrics of fragmentation and spatial transformation. Agricultural land, home gardens, paddy fields, and vegetative cover have all risen in size and number since 1988, leading to a steady rise in patch density (PD). The low large patch index (LSI) and rapid reduction in PD both point to a severely fragmented landscape. Agricultural land, paddy land, vegetation, and dense vegetation cover are all negatively affected by the fragmentation. From 2005 to 2021, there was a greater amount of disaggregation in the LSI of agricultural land, home gardens, and vegetation cover. That was clear evidence of the landscape’s increasing complexity. Further, perforation is the first step in the chain reaction that leads to vegetation fragmentation. Findings further show the agricultural areas have been indicated to have a positive link with the vegetation (correlation value 0.77139), while home gardens have been found to have a negative correlation (correlation value -0.81306). The results of this study provide a foundation for quantifying and analyzing land use change and land fragmentation, which in turn allows environmental planners to assess the current state of affairs, forecast possible future developments, and develop effective spatial planning strategies and land monitoring mechanisms in pursuit of sustainable development.