CARBON SEQUESTRATION AND HABITAT RECONSTRUCTION ON RIVERBANK CONSOLIDATION WORKS BY MEANS OF BIOENGINEERING TECHNIQUES WITH WIRE MESH STRUCTURES.

Carbon sequestration, combined with an increasing attention for environment, as stated in different EU Directives (WFD, Flood Directive, Habitat directive) and EU Policies (Green Infrastructure and Biodiversity), is a leading argument for technicians involved in river management. The study's purpose was the evaluation of carbon sequestration and habitat reconstruction by means of bioengineering techniques on wire mesh hydraulic structures. A set of seven Italian case studies with different geographical and climatological locations and various construction typologies was selected for the estimation. In particular, green reinforced earths, bank protections mattresses and gabion dams and walls were analyzed. A standard field survey was conducted on every location in order to measure dendrometric parameters of arboreal and shrubby vegetation and to calculate an estimate for biomass through empirical correlation formulas; phytosociology of present vegetation was analyzed in order to characterize biodiversity and to obtain habitat reconstruction results. The total CO2 sequestration amount was derived from fresh and dry weight calculated from biomass together with the annual CO2 sequestration rate pro unit area. Values obtained were consistent with the estimates made for natural woodland vegetation. Higher values of the total CO2 stored amount were found among older works, or where the study area already presented previous natural vegetation. Some of the study areas previously described are going to be investigated by the new Environmental Quality Assessment (EQA) methodology developed within the EU-project (FESR South Tyrol) WEQUAL, based on ecological indicators derived from LiDAR data, RGB and multispectral images collected by drone surveys. Biomass, canopy cover, vegetation height/distribution/continuity, river morphology and riparian zone width are examined in order to evaluate habitat sustainability, biodiversity, landscape connectivity and carbon sequestration capacity. The WEQUAL EQA aims to support technicians and administrators in evaluating hydraulics works impacts ex-ante and ex-post, providing an easy and time-cost-effective instrument. [ABSTRACT FROM AUTHOR]