Implementation of Nature-Based Solutions for Hydro-Meteorological Risk Reduction in Small Mediterranean Catchments: The Case of Portofino Natural Regional Park, Italy

Abstract

Nature-based solutions (NBS) are usually defined as complementary or alternative solutions to “grey infrastructures” (traditionally made with cement) aimed at conserving and regenerating the functionality of natural and semi-natural ecosystems. The research to date shows a considerable potential of NBS to address the current challenges related to climate change and geo-hydrological risks. Despite significant interest in NBS by researchers and practitioners, knowledge concerning their practical implementation, monitoring, and evaluation is still lacking. This is particularly true for large-scale NBS. The present paper discusses how such solutions can be implemented in the context of hydro-meteorological risk reduction in small Mediterranean catchments with a strong tourist vocation. The work presented here is situated within the RECONECT Project (Regenerating ECOsystems with Nature-based solutions for hydro-meteorological risk rEduCTion), which aims to contribute to a European reference framework on NBS by demonstrating, upscaling, and replicating large-scale NBS in rural and natural areas. The Italian case study of RECONECT is the Portofino Natural Regional Park, which represents a unique natural landscape element with high ecologic, social, and economic (touristic) value, which is threatened by a range of geo-hydrological hazards, such as flash floods, hyper-concentrated floods, shallow landslides, rockfalls, and storm surges. This paper also presents details of NBS interventions in two pilot catchments (San Fruttuoso and Paraggi) visited by thousands of tourists throughout the year. It addresses some of the key aspects related to monitoring meteorological and hydrological processes, as well as remote sensing activities (i.e., LiDAR surveys), which are necessary for the identification of critical-instability areas along waterways and the reconstruction of dry stone walls. Lastly, a discussion of relevant mitigation and adaptation strategies that are potentially replicable at national and international levels is also provided.

GIS-Based Landslide Susceptibility Mapping for Land Use Planning and Risk Assessment

“…The combination of those types of landslides and flash flood often occurs, causing the culverts saturation in urban and peri-urban areas and resulting in large damage. The RECONECT EU funded project is actually adopting risk mitigation strategies for slope stabilization in the studied area and a susceptibility map is a crucial decision support tool for interventions planning [110].…”

A Battery of Soil and Plant Indicators of NBS Environmental Performance in the Context of Global Change

“…If we consider the soil dimension, the proportion of NBS studies that examine soils is also small, almost 15% (search terms "nature based solution*" AND "soil"), and a similar proportion is obtained when only the studies mentioning indicators are included ("nature based solution*" AND "indicator*" AND "soil"). In any case, when analysed in detail, one sees that all these studies are focused on urban environments, except one article [83] on catchment scale NBSs to reduce erosion. Although NBSs have been applied and studied using a wide range of different terms (e.g., green-blue infrastructure, ecological engineering, etc., whose analysis exceed the scope of this paper [84]), using NBSs as the single term in the bibliography search provides an interesting picture on the subject.…”

Can Drones Map Earth Cracks? Landslide Measurements in North Greece Using UAV Photogrammetry for Nature-Based Solutions

“…In addition, the use of grass is preferred against surface soil erosion because grasses can develop a good turf and dense root system [92]. The truth is that in deep-seated landslides, soil bioengineering techniques are not enough, so hybrid solutions (conventional engineering solutions which are combined with NbS) are required to maintain or reduce the hazard [93]. Climate change is another factor that densifies such events so the monitoring of such phenomena is highly compulsory.…”