Identifying the impact of urban development on abutting ecology in Chandigarh using remote sensing based ecological index

The city of Chandigarh has been urbanizing and expanding at an aggressive rate. Despite the urban expansion being mostly planned in nature has shown underlying indications of deteriorating ecological health in the city and its abutting natural resources. Changing migration patterns and decreasing vegetation cover are just few of the indicators raising the need to analyse the ecological quality of the region. Ecological quality can be seen as a measure of the health of an environment to sustain life. Remote sensing can be used to monitor the land surface over varied spatiotemporal extents. This study uses the Remote Sensing-based Ecological Index (RSEI) to study the spatiotemporal changes in the environmental quality of the city of Chandigarh over four decades. Four factors i.e., greenness, wetness, dryness, and heat that affect environmental quality are analysed using principal component analysis to calculate RSEI. The contribution of each of the indicators to RSEI and the spatial correlation of results are studied using correlation analysis and Moran’s Index. Landcover maps are developed using Cart classifier to understand the growth patterns and establish relation to changes in ecological index values. The change in RSEI for individual land cover categories shows the degradation of ecological health in natural resources. The RSEI values of vegetation and surface water show a deteriorating trend from 1991 to 2020. Furthermore, the study area shows intense degradation of RSEI values in the city outskirts where a major shift to built-up landcover has taken place. The association of landcover change and its impact on ecological quality can assist planners in adopting suitable strategies to assure that ecological health is integrated when urban expansion is carried out. This study provides insights into the development strategies and their impact on the ecological resources of the city that may otherwise not be identified by overall RSEI value and landcover assessment.