Estimating reclamation-induced carbon loss in coastal wetlands using time series GF-1 WVF data: a case study in the Yangtze Estuary

Abstract

Coastal wetland is a net carbon sink with a high carbon density. However, coastal reclamation directly changes the structure of coastal wetland ecosystem and consequent carbon sink function. The aim of this work was to estimate the reclamation-induced carbon loss in coastal wetlands using time series GF-1 WVF data. For this purpose, GF-1 WVF imageries of 2013 (before reclamation) and 2017 (after reclamation) in the Yangtze Estuary were collected and analyzed combined with field monitoring. Results showed that the converted coastal wetland area occupied up to 61.60% between 2013 and 2017. Carbon estimation indicated that the coastal wetland before reclamation had greater potential contribution to the global warming mitigation than the wetland reclamation to other land cover types. Finally the vulnerability of carbon stores and uncertain analysis with remote sensing technology in coastal wetlands environment were discussed. We emphasized that long-term monitoring of coastal wetlands and its carbon dynamic are urgently needed, because so many uncertain factors exist in short-term monitoring.