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, be- come fundamental in order to point out different levels of watershed vulnerability. For analyzing the vulnerability of a fluvial basin at dif- ferent 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 km2 ) in Southern Italy. The assessment of landscape vegetation cover struc- ture and connectivity was performed on a detailed land- cover map derived from multispectral satellite data and ela- borating different landscape metrics. At river ecosystem level, we evaluated the fluvial functionality by performing field surveys based on the assessment of the Riparian Chan- nel Inventory index adapted for Italian environments (IFF). The landscape metrics analysis revealed that the por- tions of the territory closest to the river show a high level of fragmentation mainly concerning the transitional vegeta- tion. The IFF values underlined a river functionality strongly influenced by both the riparian vegetation status and the wa- tershed land-cover structure. By classifying and integrat- ing in a GIS environment the obtained results, we imple- mented the watershed vulnerability map suitable for sup- porting monitoring and management activities at basin scale.