Assessing consequences of land cover changes on sediment deliveries to coastal waters at regional level over the last two decades in the northwestern Mediterranean Sea

Human-induced changes to land cover and associated strong influence such changes have on sediment delivery to coastal waters are a well-recognized threat to nearshore marine habitats worldwide. Land cover has been commonly used as a proxy to document human alterations on sediment discharges. In the present study, changes in sediment delivery to coastal waters along the coastline of the Ligurian Sea (northwestern Mediterranean Sea) were estimated on the basis of land cover data. This area includes benthic habitats-areas that are very sensitive to water turbidity and sedimentation increase -and warrant protection demonstrated by the establishment of five marine Sites of Community Importance and a Marine Protected Area (Portofino MPA). The principal objectives of the study were to identify changes in soil erosion in multiple basins and estimate the strength of the change over a defined period of time in sediment delivery at the outflow. A combination of Revised Universal Soil Loss Equation (RUSLE) model and sediment delivery ratio (SDR) was applied. The strongest changes happened individually in two different basins in the periods 1990–2000 and 2006–2012 meanwhile the period 2000–2006 showed several changes in several basins with less estimated change. This assessment can help to make better coastal-land management decisions for managing or restoring coastal marine ecosystems. •Land cover changes influence sediment delivery to coastal waters.•Changes in sediment delivery may have impact on marine habitats.•Land cover changes as a proxy of potential sediment delivery changes at the outflows.•Regional assessments can help to make better coastal-land management decisions.•Potential sediment delivery to coastal waters largely changed in the last 20 years.