Analysis of Landscape Structure and Connectivity at watershed scale

From a holistic perspective, a river ecosystem and its surrounding landscape can be considered as a unique and continuous system where the status of each element strongly conditions the healthiness of the others: e.g. in presence of a landscape with mature vegetation fragmented and low connected and also of a degraded riparian buffer, the river auto-depurating functioning results heavily compromised. The assessment of fluvial functionality jointly with vegetation cover structure and connectivity, therefore, become fundamental in order to point out different levels of watershed vulnerability. For analyzing the vulnerability of a fluvial basin at different hierarchical levels (patch and class), we propose an approach that integrates satellite and field data. It was tested on the upper Sinni River watershed (about 1,600 km(2)) in Southern Italy. The assessment of landscape vegetation cover structure and connectivity was performed on a detailed land-cover map derived from multispectral satellite data and elaborating different landscape metrics. At river ecosystem level, we evaluated the fluvial functionality by performing field surveys based on the assessment of the Riparian Channel Inventory index adapted for Italian environments (IFF). The landscape metrics analysis revealed that the portions of the territory closest to the river show a high level of fragmentation mainly concerning the transitional vegetation. The IFF values underlined a river functionality strongly influenced by both the riparian vegetation status and the watershed land-cover structure. By classifying and integrating in a GIS environment the obtained results, we implemented the watershed vulnerability map suitable for supporting monitoring and management activities at basin scale.