ASSESSMENT OF URBAN GREEN SPACE DYNAMICS USING GEOSPATIAL TECHNOLOGY

Abstract

Urban green spaces are designated or naturally occurring urban areas with vegetation, trees, and plants. These spaces offer a range of ecological, social, and environmental benefits to urban residents. The study of urban green areas has made considerable use of geospatial technology, which has yielded numerous insightful applications. The ability of geospatial technology to combine many data types, such as spatial, environmental, and socioeconomic data, is one of its main advantages. This integration makes a more thorough study of the variables affecting the standard and accessibility of urban green spaces possible. Geospatial technology also aids in identifying underserved areas lacking sufficient green spaces, thus informing urban planning and policy decisions. The study was done for Dehradun City, where temporal dynamics of urban green spaces were seen over 33 years from 1990 to 2023 using different vegetation indices derived from Landsat and Sentinel 2 Satellites. The study deployed various vegetation indices (NDVI, SAVI, EVI) and applied segmentation to calculate the vegetation cover change over the period. Different areas to be identified where significant changes occurred using change detection algorithms. However, there are certain limitations associated with using Geospatial technology in analyzing urban green spaces. Factors like cloud cover and multi-source data integration can impact data accuracy. Additionally, Geospatial technology may not fully capture the diverse social and cultural values that individuals attach to urban green spaces. Urban green cover has experienced a dramatic decline, shrinking from 198.31 sq. km (78.69%) in 1990 to just 94.24 sq. km (37.39%) in 2023, representing a 52.48% reduction. This significant loss underscores the impact of rapid urban expansion and infrastructure development. Concurrently, agricultural land decreased from 68.60 sq. km in 2018 to 61.55 sq. km in 2024, with further reductions observed in post-monsoon data. This decline reflects converting fertile agricultural land to built-up areas and other uses. Forest cover, however, shows a more resilient pattern. Despite pressures from urbanization, forest areas have seen a slight increase from 67.93 sq. km in 2018 to 69.96 sq. km in 2024. Post-monsoon figures also indicate an increase from 66.25 sq. km in 2019 to 73.02 sq. km in 2023, suggesting effective reforestation and conservation initiatives. Built-up areas have consistently grown, from 85.78 sq. km in 2018 to 89.32 sq. km in 2024, reflecting ongoing urbanization driven by population growth and economic development.