PurposeRivers in low plains in the subtropical regions of China, where the population is dense and economies are active and well-developed, might be a large terrestrial carbon pool. This present study of the Sanyang wetlands in Wenzhou, southeastern China, aims to quantitatively estimate the volume of sediments in this region’s polluted river systems and their carbon storage.Materials and methodsThe bathymetry of river sections were surveyed using an echo sounder equipped with a differential GPS. An underwater digital elevation model (DEM) was then developed using the anisotropic ordinary Kriging method. Sediment samples were collected and analyzed for carbon content and sediment properties. Carbon storage in sediments was calculated using bathymetric and sediment analysis data.Results and discussionThe studied rivers have been receiving organic pollutants from local residences and industries for decades. Results from a river network of 1.2 km2 revealed a total carbon storage of 46.7 million kg in the sediments which had a volume of 1.4 million m3, with the upper 20 cm depth of sediments contributing about one third of this carbon storage.ConclusionsThe present work demonstrated that GIS technologies can be used to create digital river sediment surfaces and assess sediment amounts as well as determine the spatial distribution of sediments and their components. This could provide further insight into river restoration planning and other options from a carbon-balance perspective. |