Contrasting urban greenness across cities with varying trends in above-normal weather events

Abstract

Effective urban management demands global empirical research findings. The work aims to determine whether green areas are more significant in cities where above-normal wet events have plateaued. This work compares the green surface cover characteristics of the entire city and identified zones of 54 cities representing cities worldwide. These cities experience varying amounts of above-normal weather conditions. This article classifies the cities in the data set into two groups: Group 1 – frequency of extreme wet weather events has plateaued, and Group 2 – frequency of extreme weather events are increasing or decreasing at higher rates. Next, the work uses structural features of co-located spatial networks, roads and terrain, to identify zones. Finally, high-resolution satellite imagery quantified urban green spaces in the city and identified zones of the two city groups using geospatial and machine learning methods for 2000 and 2020. The data is compared for two groups to understand the pattern of green spaces in cities. Empirical analysis results recognise a higher greenness index in the zones and the entire city amongst the cities of Group1. The pattern in the temporal change in the greenness index of the zones is helpful to formulate a priority plan for locating inter-linked green spaces in urban areas paving the way for Nature-based Solutions. The findings can guide planners and policy-makers to identify and prioritise locations to incorporate a robust green infrastructure network to build resilient cities by 'nature bringing a solution’, the essential concept of Nature-based Solutions.