sediment sedimentation and soil ersion for yangtze river streams with silt runoff academic research and study

The builders of the Three Gorges project are showing new concern about the prospect of a dangerous buildup of silt in the massive reservoir behind the dam, and are still discussing basic aspects of the dam operating regime and likely impacts.
And also they arranged at least 9 soil sedimentation physical model to research the sediment and soil erosion for Yangtze River through several academic research institutes.
In 2003, China lunched a report on Sedimentation and Soil Erosion of Yangtze River with its streams.

Water flux:
Annual average runoff 28400 M3/S, the maximum annual average runoff 43100M3/S in 1954 and minimum annual average runoff 21400M3/s in 1978 (for the period of 1950-1985). And maximum monthly average runoff 48600M3/S in July, minimum monthly average runoff 10400M3/S. And the runoff for 3 months of June, July and Aug accounts for 39%, and from May to October is flood season, runoff accounts for 71.1%.

Silt Sediment sedimentation and soil erosion (history):
Annual average soil & sands content in water as: 0.547kg/M3, and flux as 13.77t/s. The annual maximum as 679000000 M3/a in 1964, the annual minimum as 239000000 M3/s.

In 2004, the annual average sediment content at various hydrological control stations in the mainstream Yangtze River was decreased by 6-35% compared to 2003.

The water and soil preservation project in upper streams of Yangtze River now takes effect, which reduce the soil erosion and sediment sedimentation.

And according to the report, the sediment content are reduced down by 1% annual after 2004.