Land Cover Change and Flood Risk in a Peri-Urban Environment of the Metropolitan Area of Rome (Italy)

Land cover change (LCC) is the most important factor in causing ecosystems services (ES) loss. In Mediterranean basins, coastal areas historically suffer from great anthropic pressure. These changes influence runoff, and municipal authorities often cannot estimate the impact of complex land cover transitions. In such context, the great urban and industrial development of the towns surrounding the city of Rome (Italy) represents a paradigmatic case study. In this paper, land cover evolution in a watershed located in a peri-urban environment has been studied in terms of LCC and the consequential flood risk. The information concerning land cover transformations was analyzed in following time scenarios: 1954, 1967 and 2018. The identification of occurred rainfall events, and the application of a combined hydrological and hydraulic modelling, allowed the estimation of flooded areas and volumes. The obtained results allowed to quantify the increase in the flood risk, that was more pronounced in the part of the selected area that has been more extensively interested by the soil sealing. The increase in the flood risk was larger in the hypothesis of a rainfall occurring when the soil is dry, like it can happen for the common case of summer precipitations.