Assessing Degradation in Local Environment due to Recent Urban Sprawl: Case Study of an Indian Satellite Town

Commercialization and infrastructural development has resulted in severe urban sprawl in New Town, a satellite town of Kolkata. This is a part of Rajarhat C.D. Block. Escalating land use practice has lead to a dynamic transformation in the local land cover and associated micro environment of this region. Replacement of vegetation with concrete surfaces has caused problems of natural resource depletion without any attention paid to environmental sustainability. The study aims to identify the negative impacts of urban growth in this region, for the latest decade i.e. from 2009 to 2019. Loss of natural resource, as vegetation was monitored by mapping Fractional Vegetation Cover (FCOVER) index over time. Transforming the natural vegetation with built up surfaces also modifies the local climate of a city region. As an indicative climatic parameter Land Surface Temperature (LST) was considered. Landsat satellite images were processed for identifying the environmental degradation over time. Through areal change detection, nearly 40% vegetation loss was observed. Landscape metric analysis has been carried out for a better understanding of structural characteristics of this vegetation cover parameter. The analysis showed fragmentation and reducing density for vegetation patches over the area. The combined effect of vegetation loss and urbanization resulted in a rising LST patterns. New heat islands have been spotted and are found to grow spatially. This was established by statistically relating FCOVER with LST. The negative correlation between vegetation and temperature was found to be significant at α
0.01
. The critical areas of heat islands have been identified which urgently needs implementation of mitigation. Thus the study helps to build a database for future landscape planning and environment management.