Hydropower reservoirs enhanced the accumulation of heavy metals towards surface sediments and aggravated ecological risks in Jiulong River Basin, China

Suspended Sediments Quality Assessment in a Coastal River: Identification of Potentially Toxic Elements

“…The upper reaches are mainly covered by forest and mountain areas, while the lower reaches are affected by different human activities, such as agriculture and industry. Moreover, several reservoirs/dams are distributed within the JRB, such as the Wananxi Reservoir, which significantly regulates the fluvial discharge [ 24 ].…”

“…As one of the most important coastal rivers in southern Fujian Province (China), Jiulongjiang River basin contributes to the development of various land ecosystems and supports water resources for millions of inhabitant [ 23 , 24 ]. Moreover, Jiulongjiang River is an ideal region for clean hydroelectric production because of the abundant flow and steeply sloping river [ 24 , 25 ], which can strongly support the local economy.…”

“…As one of the most important coastal rivers in southern Fujian Province (China), Jiulongjiang River basin contributes to the development of various land ecosystems and supports water resources for millions of inhabitant [ 23 , 24 ]. Moreover, Jiulongjiang River is an ideal region for clean hydroelectric production because of the abundant flow and steeply sloping river [ 24 , 25 ], which can strongly support the local economy. The development of hydropower dams, together with other anthropogenic activities (e.g., urban emission and agricultural production), have significantly changed hydrodynamic conditions (e.g., hydraulic residence time, HRT) and further impacted the eco-environmental processes and biogeochemical cycling of the coastal river water [ 26 , 27 ].…”

“…To date, PTE-related studies of the coastal Jiulongjiang River basin (JRB) have mainly focused on dissolved and sediment phases in estuarial areas and the mainstream [ 24 , 29 ]. These studies reported that the dissolved PTEs in JRB can be defined as dominant (>100 μg L − 1 ), moderately abundant (10~100 μg L − 1 ), and less abundant (<10 μg L − 1 ) elements according to their concentrations.…”

“…In contrast, the distribution pattern of PTEs’ contents in river sediment highly matched the reservoir/dam distribution along the JRB. The dominant ecological risks of Cd and Pb in sediments were also observed [ 24 ]. However, the status, pollution, risks, and sources of PTEs in suspended sediments (SPM) and their relationship with dissolved PTEs and PTEs in sediments have been rarely reported in the dams distributed along coastal rivers.…”