Artificial canals restoration through nature-based solutions: experience in Po Plain with a vegetation and water quality view point

Floodplains provide crucial ecological and social benefits. Their fertile soils and proximity to water have historically attracted human settlement while simultaneously offering ecosystem services to wider catchments. Yet, the expansion of levees, dams, and engineered canals for urban and agricultural development has increasingly threatened these functions. The Po Plain, one of Europe’s largest alluvial plains shaped by the Po River and its tributaries, exemplifies this tension. Over the last century, land reclamation, intensive farming, and urbanization have profoundly altered its natural hydrological dynamics. Artificial canals, though essential for irrigation and drainage, have caused reductions in riparian vegetation diversity and promoted nutrient accumulation in water and sediments. This dissertation investigated the use of nature-based solutions, specifically pond construction and canal bank reshaping, as strategies to restore ecological quality. A five-year monitoring program was carried out in the Emilia-Romagna region (Italy), focusing on water, sediment, and vegetation indicators. Results indicated that neither water nor sediment presented risks for agriculture or surrounding habitats. Nevertheless, the interventions produced negligible short-term improvements in water and sediment quality, an outcome attributed both to the limited spatial extent of the measures and to major floods in 2023, which temporarily degraded conditions. In contrast, vegetation responded more positively: biodiversity increased despite reductions in total cover caused by flooding and the interventions themselves. This highlights the sensitivity of riparian plant communities and the potential for targeted management to restore ecological value. The study concludes that nature-based solutions can contribute to the enhancement of agricultural floodplains, although significant, measurable changes require larger-scale applications and longer monitoring horizons.