Increasing frequency of severe floods on the middle and lower Changjiang (Yangtze) River during the past
few decades can be attributed to both abnormal monsoon rainfall and landscape changes that include extensive
deforestation affecting river sedimentation, and shrinking lakes and levee construction that reduced the
areas available for floodwater storage. The Three-Gorges Dam (TGD) and the South-to-North Water Transfer
Project (SNWTP) will also affect frequency and intensity of severe floods in the Poyang Lake region of the
middle Changjiang. Process-based National Integrated Catchment-based Eco-hydrology (NICE) model
predicts that the TGD will increase flood risk during the early summer monsoon against the original justifications
for building the dam, relating to complex river–lake–groundwater interactions. Several scenarios
predict that morphological change will increase flood risk around the lake. This indicates the importance of
managing both flood discharge and sediment deposition for the entire basin. Further, the authors assessed
the impact of sand mining in the lake after its prohibition on the Changjiang, and clarified that alternative
scenario of sand mining in lakes currently disconnected from the mainstream would reduce the flood risk
to a greater extent than intensive dredging along junction channel. Because dry biomasses simulated by
the model were linearly related to the Time-Integrated Normalized Difference Vegetation Index (TINDVI)
estimated from satellite images, its decadal gradient during 1982–1999 showed a spatially heterogeneous
distribution and generally decreasing trends beside the lakes, indicating that the increases in lake reclamation
and the resultant decrease in rice productivity are closely related to the hydrologic changes. This
integrated approach could help to minimize flood damage and promote better decisions addressing sustainable
development.