Dramatic variations in water discharge and sediment load from Nanliu River (China) to the Beibu Gulf during 1960s-2013

摘要: Abstract River discharge and sediment variation is vital to material transport between river sea, which the focus of research on river–sea interaction. This study takes Nanliu River, a typical independent into sea in Beibu Gulf as an example, analyzing regimen bed morphology variations during 1960s–2013 response climate change human activities based wavelet analysis Man–Kendall test methods. The results indicate that have significant seasonal characters with over 70% 90% occur summer half year. Compared 1960s–1980s, time peaked monthly water Suspended Sediment Concentration (SSC) 1990s–2000s had shifted from June/August July April July, respectively. Meanwhile, both flow SSC present 4–6 years 11 fluctuations. In recent 50 years, annual downward trends decreased by 13.9% 22.28% respectively upstream downstream while 33.72% 49.05% downstream, Rating-curve turns clockwise rotation enveloped area 1965–1989 relatively narrow appearance 1990–2012 upstream, but indicates relatedly mild downstream. Evolution characterized “erosion flood season deposition dry season”. Moreover, entering dominated precipitation controlled middle lower reaches supply. Human activities, including soil erosion, forest conservation hydraulic engineering along river, are responsible for decrease sea.