Land use and damaging hydrological events causing temporal changes in the Sarno River basin: potential for green technologies mitigation by remote sensing analysis

Urban growth will lead cities to adopt best management practices in order to mitigate the relevant effects, such as an amplification of the hydrological cycle. The use of synthetic-aperture radar (SAR) imagery allowed us to demonstrate, over a period of 20 years (1995–2016), a massive urban development with a 70% increase in the built-up area in the Sarno River basin, in southern Italy, the most polluted river in Europe. Contextually, with the collection of an archive of damaging hydrological events that occurred during the same period, it was possible to identify a potential cause–effect relationship between their statistically significant temporal increase and the increase in the impervious area at the catchment scale provided by satellite imagery analysis. In order to restore the pre-urban development hydrological conditions, a scenario analysis was undertaken where the Storm Water Management Model was used to simulate the hydrological effect of a green roof retrofitting landscape design. SAR imagery was furthermore used to explore the potential retrofitting surfaces, leading to the definition of three different conversion scenarios, accounting for 5, 30, and 100% of potential retrofitting surfaces. The study demonstrated that…..