Wetland ecosystem services and their spatial scales of benefit in an urban environment: A case study of varanasi, India.

Abstract

Wetlands are valuable terrestrial ecosystems because they perform diverse ecosystem functions and provide significant benefits to humanity. These benefits, collectively termed ecosystem services, are essential for human survival, particularly in densely populated urban areas. However, wetlands often face neglect due to a lack of awareness among citizens and governments regarding their significance. We assessed the ecosystem services offered by the wetlands of Varanasi, one of the oldest living cities, and elucidate the spatial scales wherein these services are delivered. Field visits, personal observations, and interviews based on the Rapid Assessment of Wetland Ecosystem Services (RAWES) approach, were used to evaluate 27 ecosystem services across 12 wetlands. The ecosystem services of water regulation and local climate regulation had high positive count value inferring highly beneficial contributions to human well-being, whereas pest regulation and regulation of human disease, had negative count value indicating an adverse impact on human well-being, primarily due to the polluted state of the city's wetlands. Supporting services with an Ecosystem Services Index (ESI) of 0.55 made a substantial positive impact on human well-being, while provisioning services made minimal contributions (ESI = 0.12). The analysis of the spatial scale of ecosystem service benefits indicated that the distribution of ecosystem services is highly Varanasi-centric. To provide a comprehensive representation of both the importance scale and the spatial scale of benefit, the Spatial Ecosystem Services Index (Spatial ESI) was developed. Cultural services scored the highest Spatial ESI of 0.17 while provisioning services have the lowest Spatial ESI (0.03).