Analyzing spatial and geometrical patterns of Tiruchirappalli and Tier-urban centers using Spatial Metrics

Understanding spatial and geometrical patterns of urbanization is crucial in tackling associated problems. As urbanization progresses through various stages of development, it reflects different forms, patterns, and interactions based on its physical and functional aspects. Spatial metrics is a well-acclaimed technique for quantifying urban morphological characteristics. The current study was conducted for Tiruchirappalli and six tier-urban centers located within a 40-kilometers radius to comprehend the comparative growth and spatial patterns. The urban centers are divided into eight zones based on direction for more precise quantification. The study employed Landsat 5 and 8 satellite images to classify land use/cover for the periods 1996, 2008, and 2020. FRAGSTAT is the software application used to analyze spatial metrics, at patch, class, and landscape levels. The study generated a significant amount of data about spatial and geometric patterns of growth. Area, edge, and aggregation metrics indicated that zones in Manachanallur, Manapparai, Musiri, Thiruverumbur, and Thuraiyur had protrusive urban growth during the study period. Transport networks have been the instrumental factor for such growth. Diversity metrics revealed Tiruchirappalli and Thiruverumbur have abundant patches of various classes in many of their zones since they retain patches like open, vegetation, and water bodies extensively. Shape metrics across all urban centers during the period 1996-2008 were more irregular in shape; it has become significantly smooth during 2008-2020 due to infill developments on the fringe areas. The period 1996-2008 recorded a huge transition of open areas into built-ups, attributing to infill development, especially inside the urban centers; similarly, during the period 2008-2020, edge expansion has been recorded widely across the urban centers. The current study is a significant contribution to urban research in understanding relative spatial and geometric patterns of urbanization.