Assessing current coastal subsidence at continental scale: insights from Europe using the European Ground Motion Service

Abstract

Land subsidence increases the risk of flooding in low-lying coastal zones by amplifying relative sea-level rise (SLR). In this study, we assess for the first time current coastal land subsidence at the scale of Europe using the new Copernicus European Ground Motion Service (EGMS) that was released in 2022. Our results suggest that nearly half of the low-lying coastal areas in Europe are currently subsiding at a rate faster than 1 mm/yr on average. We find that coastal subsidence is higher on average in areas hosting more people, urban centers and critical infrastructure. This raises concerns that coastal subsidence, and therefore relative SLR, tends to be underestimated in Europe and presumably in many other regions around the world. Our study demonstrates that emerging continental-scale land motion services such as EGMS are useful to better characterize the issue and anticipate coastal risks and adaptation accordingly