Wetland health assessment using DPSI framework: a case study in Kolkata Metropolitan Area.

Wetlands are among the most valuable components of the ecosystem, playing an important role in preventing floods, maintaining the hydrological cycle, protecting against natural hazards, and controlling local weather conditions and ecological restoration. The Kolkata Metropolitan Area (KMA) is considered one of the most ecologically valuable regions in terms of wetland ecosystem, but due to haphazard development and human activities, the wetlands of the city are under constant threat of degradation. Therefore, this study aims to assess the factors responsible for wetland health and their dynamics using Driving Force-Pressure-State-Impact (DPSI) framework. To assess wetland health during 2011-2020, seventeen indicators and four sub-indicators were selected to calculate weights using the analytic hierarchy process (AHP). The results showed that most of the municipalities in the healthy category were in the pressure (P) section in 2011, while fluctuations were observed in the impact (I) section in several wards during 2011-20. The condition section (S) showed the overall change in the water, vegetation, and built-up categories from 2011 to 2020, so the most dominant category was "healthy," followed by "unhealthy" and "poor." The highly significant factors worsening wetland health were population density (B1), road density (B3), per capita wastewater generation (B5), per capita solid waste generation (B7), biological oxygen demand (D1a), dissolved oxygen (D1b), pH (D1c), and total coliform (D1d). The results of the study can help develop sustainable conservation and management of the wetland ecosystem in the KMA urban area and at the global level with similar geographical conditions.

Monitoring built-up area expansion led by industrial transformation in Delhi using geospatial techniques.

Historically, industrialization has been a catalyst for built-up expansion generated by economic growth that transforms a landscape. In India, there is a paucity of exploration into how the economic shift transforms the cityscape. Therefore, the objective of current research work was to monitor built-up growth induced by industrialization using Landsat datasets and registered industry data. The k-means clustering technique was applied for assessing land use/land cover, Shannon entropy for sprawl, and Pearson for correlation between industrial growth and built-up expansion. The results manifest exponential trend in industrialization with 102-year registered industry record along with increase in built-up density from 0.30 in 1989 to 0.69 by 2019 and in the entire Delhi; it rose from 0.16 to 0.39. Furthermore, Shannon entropy confirmed the sprawl and the strong positive correlation was found among built-up of industrial areas and built-up of Delhi and registered industries. The striking chorological change in industrial as well as city's landscape was observed co-occurring with the dynamics of economic reforms. The outcome of current research could be utilized for the sustainable planning of industrial landscape in Delhi and cities with alike geographical conditions.