NatResPoNΔ

Ensuring resilience of the Po River Delta to rising relative sea levels using nature-based solutions for building land and mitigating subsidence – NatResPoNΔ

River deltas are among the largest depositional features on Earth and are ecologically and economically important. However, continued increases in climate extremes, population growth, and human-induced subsidence pose a serious threat to the sustainability of many of the World's river deltas. It is becoming increasingly clear how hard engineering measures (e.g., dams, dikes, and levees) are unsustainable and likely to reduce deltaic ecosystems' resilience in the long run. Thus, a paradigm change in river-delta management plans is underway, from hard infrastructures to new approaches designed to “work with the river”, leading to a broad interest in “nature-based” solutions to restore deltaic lands. This research project aims to test the feasibility of nature-based solutions to increase the resilience of the Po River Delta - the main deltaic system in Italy and one of the most important worldwide - to relative sea-level rise, ultimately mitigating long-term flood and storm-surge risks and ensuring the sustainability of communities on the delta. Emphasis will be placed on quantifying the inherent ability of the delta system to create new land and contribute to the accretion of existing soils by depositing river-borne sediments, as testified by a newly emerged crevasse-splay system that has recently formed in a previously embanked area that was completely flooded due to soil subsidence. 

This goal will be achieved through a multidisciplinary approach involving sedimentological analyses, remote sensing, and numerical modeling. Through sedimentological and remote sensing analyses, the potential land-building rates will be estimated. The information gained from the field will be used to inform and calibrate an ad hoc hydro-morphodynamic numerical model. Once calibrated, the model will be applied to the entire Po River Delta and used to test the feasibility of reducing its vulnerability by creating controlled sediment diversions and moving channel embankments to promote active sedimentation and counteract coupled soil subsidence and eustatic sea level rise. The results will improve our knowledge of the resilience of natural systems and offer critical insights into future management strategies for the Po River delta and similar coastal areas.

This work is funded by the European Union – NextGenerationEU and by the Italian Ministry of University and Research, PNRR programme.

Start date: 30 November 2023

Duration: 24 months

CNR scientific referee: Dr. Valentina M. Rossi, CNR-IGG (valentinamarzia.rossi@cnr.it)

Project Coordinator: Dr. Alvise Finotello, Università degli Studi di Padova (alvise.finotello@unipd.it)